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All the information of this board has been quoted from http://www.bigsiteofamazingfacts.com/
How many paintings did Pablo Picasso paint and did he paint everything in sight?
Pablo Diego José Francisco de Paula Juan Nepomuceno MarÃa de los Remedios Cipriano de la SantÃsima Trinidad Ruiz y Picasso didn’t “paint everything in sight,†but he was a prolific painter in many senses of the word.
He produced over 15,000 paintings in his lifetime—working on three or more canvases a day—and he also painted on surfaces other than canvas.
The story goes that while renting an apartment in Barcelona in 1900, the newly whitewashed walls were too great a temptation for him. He lavishly decorated them with paintings.
His landlord was unimpressed and told him he must pay to have them repainted. Picasso snippily remarked later, after becoming successful,
“He could have sold the whole wall for a fortune if he had only had the sense to leave it.â€
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What Other Paintings Did James Whistler Paint Besides Whistler’s Mother?
The painting Whistler’s Mother (we have seen a film on it named Mr. Bean) has given people the impression that James Whistler was a sentimental Norman Rockwell sort of fellow, but Whistler’s Mother wasn’t his normal style.
Most of Whistler’s paintings were more abstract.
On this occasion, he painted his reluctant mom in a straight-backed wooden chair only because his scheduled model hadn’t shown up.
Despite this one painting, Whistler loved seeing himself as a shocking rebel against the art establishment and presented himself and his work in ways to keep that image alive.
In one of his public melodramas, he sued English art critic John Ruskin for libel after Ruskin wrote a scathing review of his artwork.
After a long and bombastic trial, the jury agreed that Whistler had been libeled, and awarded him damages of one farthing, about a quarter of a cent.
For his “victory,†Whistler was bankrupted by legal fees and lost his house and furniture.
Ironically, he was also forced into backtracking away from his confrontational style and into more commercial, conventional etchings.
Ruskin, for his part, was so outraged by the verdict against him that he stopped writing reviews, resigned from Oxford University, and became a bitter, antisocial recluse.
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Why Does the Moon Go Around the Earth?
Almost everything in the universe travels in a circular path. The moon goes around the earth, the earth goes around the sun, and even the sun revolves around the center of our galaxy. This is because of two basic laws of science.
First, an object moving in space, where there is no air to slow it down, will continue to move forever once it begins in motion. The moon has been moving through space ever since it was formed billions of years ago.
But the gravity of the earth pulls the moon toward us. This gravity isn’t strong enough to pull the moon into the earth, but it holds the moon at a certain distance from the earth, where the gravity of the earth, the sun, and the planets are balanced.
So the moon keeps moving around the earth at that distance, traveling in a circular path called an orbit. And the earth goes around the sun for the same reason.
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Was the White House In Washington, D.C. Always White and What Color Was It Before?
The White House in Washington, D.C. was not always white.
Back when it was called the “Presidential Palace,†it was made of brownstone.
However, in 1814 the British captured Washington, D.C., and burned many government buildings, including the Palace and the Capitol.
So much of its shell was charred from fire that painting the building became necessary.
White covered the burn marks well and brightened the place up.
It had never looked much like a palace anyway, and even less so with bright white paint, so people stopped calling it the Palace and started calling it “the white house.â€
Teddy Roosevelt made the popular name official when he had “Theodore Roosevelt, The White House†printed on his presidential stationery.
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Why Does the Same Side Of the Moon Always Face the Earth?
It does seem like a pretty strange coincidence that the moon would rotate at exactly the same rate that it revolves around the Earth.
But of course it’s no coincidence at all.
When the moon was much closer to the Earth than it is now, the Earth’s gravity distorted the moon slightly, so that it’s somewhat egg shaped.
As a result, the pull on the moon is now slightly stronger on the pointy end, keeping it always faced toward us.
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When did humans appear on Earth?
This is not an easy question to answer. Debates rage over which fossils can be called truly hominoid (humanlike), or hominid (human).
The development of human characteristics took place over millions of years. The earliest primate (an order of mammals that includes humans, apes, and monkeys), no bigger than a rat, appeared 60 million years ago.
About 10 million years ago, the Ramapithecus showed remarkable hominoid attributes. But there is no further evidence until 6 million years later.
The first generally accepted hominoid is called Australopithecus, and some believe they are actually the most primitive of the human lineage.
Homo habilis, dating back at least 2 million years in modern-day Africa, is undisputedly human. Less than a half-million years later, Homo erectus lived in Africa as well as in Asia and Europe.
A fossil skull fragment discovered in England is the oldest known example of modern-day humans: a 300,000-year-old Homo sapien.
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Did Dinosaurs and Humans Ever Coexist On Earth?
Dinosaurs and humans did not coexist on earth.
Dinosaurs first appeared in the Triassic period, about 220 million years ago, and disappeared at the end of the Cretaceous period, about 65 million years ago.
Modern humans (Homo sapiens) appeared only about 25,000 years ago.
Movies that show humans and dinosaurs existing together are only Hollywood fantasies.
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What stops Earth from crashing into the Sun if the Sun’s gravitational force is so strong?
When Earth formed, it created its own gravitational force, enhanced by spinning, or rotating.
This kept the collected material together. Without the Sun’s gravity, Earth would go spinning off into space, but without Earth’s own gravity in conjunction with the gravitational force from other planets, it would be drawn into the Sun.
So, while the Sun pulls Earth toward it, the cumulative gravity of Earth and the other planets keeps it in its orbit around the Sun. Think of it as a multiple tug-of-war.
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How do we know how dinosaurs lived when all we have are fossils?
It is amazing how much can be deciphered from a fossil.
For instance, scientists can often tell what dinosaurs ate by studying their fossil remains. If a fossil of a dinosaur shows that it had sharp teeth and claws, scientists can figure that it was a meat-eating dinosaur.
Meat-eating dinosaurs were bipedal, which allowed them to run swiftly after prey. If a fossil seems to show that the living creature walked on two legs, that might also indicate that it ate other animals.
Plant-eaters had teeth suitable for grinding vegetation. Many were quadrupeds, meaning they walked on four legs. Fossils with these characteristics are of plant-eating dinosaurs.
The depth of fossilized footprints can be used to calculate the weight of dinosaurs. Some of the most impressive fossils are those of dinosaur tracks. Footprints also confirm that many dinosaurs traveled in groups, with younger dinosaurs in the middle of the herd where they would be protected.
These were herbivorous dinosaurs, their social structure resembling herd animals (such as water buffalo) of today.
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Why Is Africa Called the “Birthplace of the Human Raceâ€
Africa is called the birthplace of the human race because scientists have found fossilized bones of human ancestors in eastern and southern Africa that are the oldest of any in the world.
They believe that humans gradually moved out of Africa to populate the rest of the world.
The earliest Homo sapiens, or modern human, found in Ethiopia can be dated back to about 200,000 years ago.
Most scientists believe that the human species originated from the African continent.
Fossil remains of several species of early apelike humans believed to have evolved into modern man, such as Australopithecus afarensis from about 3 million years B.C. have been discovered.
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Why do Fireflies and Lightning Bugs Glow in the Dark and what causes it?
Fireflies glow in the dark to attract mates. Males fly around flashing the world in a pattern of dots and dashes that is very specific to their species.
Female fireflies wait until a male flying nearby flashes the correct signal for their species, and in return, she flashes him with her own light. They meet and create beautiful luminescence together.
Light production in fireflies or lightning bugs is due to a type of chemical reaction called bioluminescence. This process takes place in specialised light-emitting organs, usually on a firefly’s lower abdomen or belly. Enzymes, in the presence of magnesium ions and oxygen produce light.
The enzyme is also useful in the medical industry.
The females of some firefly species prey on the males of other species. They lure the males by imitating the mating signals of the other species.
A oblivious suitor flying too close gets eaten.
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Is the Weather Warmest When the Earth Is Closest to the Sun?
Surprisingly, the earth’s distance from the sun has nothing to do with weather!
The earth’s path around the sun is not a perfect circle, but an ellipse, or egg shape. The earth is actually nearest the sun around January 2, when it’s “only†91,402,000 miles away. This point is called the perihelion. At the earth’s aphelion, or farthest point from the sun, it’s 94,510,000 miles away. And this point falls around July 5.
Why is our weather coldest when the earth is closest to the sun? Because weather is determined mostly by the tilt of the earth’s axis at various times of the year.
When it’s winter here, the earth is tilted in such a way that much of the sun’s radiation reaches us at an angle, and bounces off our atmosphere. In summer, the sun’s rays reach us more directly, and therefore the weather is warmer. Also, in winter the days are shorter, and much of the sun’s heat is reflected off the earth by snow.
The earth doesn’t travel around the sun at a constant speed, either; the speed varies at different points in the earth’s orbit!
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Why Do Some People Snore?
When you are asleep and relaxed, and breathing through your mouth rather than through your nose, the air coming out causes your soft palate, the tissue at the back and top of your mouth, to flutter back and forth. This fluttering, or vibration, makes a sound called a snore. Often this vibration causes the cheeks, lips, and nostrils to vibrate as well, causing an even louder snore.
Although many ways have been tried to stop snoring from tying a bandage from the chin to the top of the head to keep the mouth closed, to actually removing part of the soft palate, no one has found a sure-fire method. However, some people claim that if you sleep on your side rather than on your back, you are less likely to snore. Nobody knows why, but men snore more than women and children.
The loudest snore recorded has been measured at 69 decibels, or almost as loud as a pneumatic drill!
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How does latitude affect or determine the climate on Earth?
Latitude helps determine the temperature of a locale. Since one of the most important factors of climate is the amount of energy, or radiation, received from the Sun (heat), latitude plays a critical role.
Climatologists (people who study climate) use the word insolation for energy that reaches Earth from the Sun. The word combines syllables from the phrase incoming solar radiation. Sunlight is the obvious sign of insolation, but the Sun’s radiation reaches the earth on a cloudy day too. The angle and duration of insolation, which translates into surface temperature, changes depending on latitude.
Because Earth is spherical, when it orbits the Sun, the Sun’s rays hit Earth’s surface directly at the equator and at angles near the poles. Direct insolation is stronger than slanted contact.
Earth also tilts on its axis, so when the Southern Hemisphere is closer to the Sun, it has more hours of daylight than the Northern Hemisphere, and vice versa. At the equator, the hours of night and day remain 12 hours each. But most of us have experienced the shorter days of winter and the longer days of summer that come from Earth rotating at a tilt.
Latitudes that receive direct insolation for many hours a day tend to have warmer climates, such as at the equator. Latitudes toward the North and South Poles get angled insolation for fewer hours overall, and have colder climates.
The longitudinal angle of New York City is 74° west, making the latitudinal and longitudinal coordinates for New York City 40° north and 74° west.
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Why are summer days longer than winter days?
Summer days longer than winter days the same reason that Earth has seasons: because Earth’s axis is tilted in relation to the Sun.
If the axis were straight up and down, different parts of the world would still have different lengths of daylight and darkness, but they would remain constant throughout the year.
When the Northern Hemisphere, or half, of Earth is tilted toward the Sun, the Sun’s rays hit it more directly.
The more direct—and therefore warmer—sunshine creates summer in the Northern Hemisphere. The tilt of Earth also makes the Northern Hemisphere experience longer days during this time, and the Sun appears to pass higher in the sky.
Six months later, Earth has moved halfway through its orbit, and the Southern Hemisphere is tilted toward the Sun. This means it is summer in the Southern Hemisphere and winter in the Northern Hemisphere.
You can see the change in the angle of the Sun very gradually over the course of several months. In the Northern Hemisphere, the Sun climbs higher in the sky each day as summer approaches, until one day—on or about June 21—it seems to stop getting higher.
After that, it drops lower each day as winter comes closer. Then it stops—on about December 21—and begins to climb higher again. June 21 is called the summer solstice, or “summer sun standing stillâ€; December 21 is the winter solstice, or “winter sun standing still.†In the Southern Hemisphere, summer and winter are reversed.
Earth is divided into two sets of hemispheres. The equator divides the Northern and Southern Hemispheres.
The Eastern and Western Hemispheres are divided by the 0° meridian, or the prime meridian, on one side of the globe and the 180° meridian on the other (both not shown).
The two dotted lines show the tropics of Cancer (north of the equator) and Capricorn (south of the equator). Within these two imaginary lines the Sun’s rays are strongest.
You should never look directly at the Sun. The light is so powerful that it could damage your eyes.
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How Do Fish See in the Dark?
Since sunlight never reaches the deeper parts of the sea, these regions are always totally dark. Yet fish live here and swim about without bumping into each other.
How is this so? . . . Well, fish actually “see†without their eyes; they use other sensory organs.
The next time you catch a fish, look for a line running along its skin, from the gills to the tail. All fish have this marking, called the lateral line. All along the lateral line are openings in the fish’s skin. These openings allow water vibrations to reach sensory organs which are located under the lateral line.
These sensory organs, in turn, are connected to the fish’s nervous system, and are very sensitive to slight vibrations in the water.
By reading the vibrations in the water around it, a fish can tell when another fish is approaching, what direction it’s coming from, and how far away it is. The fish can also tell when a rock or other object is close by, because these objects cause vibrations as water flows around them.
So a fish can navigate through the darkness without striking another fish or a rock, and can “see†even in total darkness!
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Where Did the Word “Personality†Come From and How Did the Word “Persona†Originate?
In the Greek and Roman theatres, actors wore masks to indicate the different characters they were playing.
The Latin word for mask, persona, came to mean a personality other than that of the actor.
Today, persona, or personality, still refers to the mask a person wears to hide his or her true character while playing a role for the outside world.
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How did the Chinese make the Great Wall of China so long during the Ming Dynasty?
Initially, the Great Wall of China was built by thousands of people working for a total of seventeen straight years.
Many parts of the wall cover mass graves of the workers who died while building it. And it didn’t stop with the Qin dynasty.
For hundreds of more years during the Ming Dynasty, peasants, soldiers, prisoners of war, or criminals were pressed into working on the wall. There are terrible stories of hardships endured by the workers, living with extreme weather and under cruel circumstances.
Most knew that if you were picked to work on the wall, there was a good chance you’d never return home. That’s the basis for one of China’s most well-known, historical poems.
It was written in the first or second century by the poet Ch’en Lin, and it’s titled “Song: I Watered My Horse at the Long Wall Caves.â€
Here are some parts of the poem from a translation from The Columbia Book of Chinese Poetry:
I went and spoke to the Long Wall boss:
“We’re soldiers from Taiyuan, will you keep us here forever?â€
“Public works go according to schedule, swing your hammer, pitch your voice in with the rest!†A man’d be better off to die in battle
Than eat his heart out building the Long Wall!
I sent a letter to my wife: “Better remarry than wait any longer, serve your new mother-in-law with care and sometimes remember the husband you once had.â€
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How Does a Copying Machine Work?
When you put a piece of printed paper into a copying machine, a lens focuses the letters onto a drum or plate coated with a metal that is very sensitive to light.
This metal has an electric charge, but the electric charge disappears from the areas of the drum that the printing isn’t focused on, in other words, it disappears from all the “white†spaces on the page.
Next, the machine spreads a powder over the surface of the drum. This powder is electrically charged too, but it has a charge opposite to the charge of the metal on the drum. Since opposite electric charges attract each other, the powder sticks to all parts of the drum that are still charged, that is, to all the parts covered by the printing.
Finally, a piece of paper is pressed against the drum. Then an electric charge under the paper attracts the powder left on the drum. Since the powder had stuck only to the parts of the drum covered by the printing, the paper now contains a duplicate of the original page. Heat fuses the powder to the paper, and a finished copy rolls out of the machine.
Some copying machines are so fast that they can turn out two copies per second!
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How Long Will the Universe Exist?
Scientists have tried to figure out how long the universe will exist, but they haven’t been able to agree with one another yet.
Some scientists believe the universe will go on forever, even after all the stars are burnt out. The universe will then be completely dark and cold for the rest of time.
But other scientists believe that the universe will someday explode and start all over again. Right now, the universe is getting bigger, and all the stars are getting farther apart from one another.
Perhaps at some time in the distant future, the universe will begin to grow smaller, and all the stars will move toward one another. After many millions of years, all the matter in the universe will be crushed together in a small area, and then it will explode again, beginning the universe all over again!
Scientists have no way of knowing if the universe has already expanded, shrunk, and exploded many times!
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How fast are other galaxies moving away from us?
How fast other galaxies are moving away from us all depends on which galaxy, as they’re speeding away at different rates.
On top of that, everything that’s speeding away from the Milky Way is accelerating. Here’s a sampling on either end: One of the slower galaxies is speeding away at about 5,040,000 mph. That’s like going from one side of the United
States to the opposite side in about 2 seconds, give or take a little. One of the farther and faster galaxies is going so fast, it would take it about a second to go all the way around the world. It’s being clocked at about 93,600,000 mph.
The general rule is that the farther the galaxy is from the Milky Way, the faster it’s going.
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Why Do Some People Snore?
When you are asleep and relaxed, and breathing through your mouth rather than through your nose, the air coming out causes your soft palate, the tissue at the back and top of your mouth, to flutter back and forth. This fluttering, or vibration, makes a sound called a snore. Often this vibration causes the cheeks, lips, and nostrils to vibrate as well, causing an even louder snore.
Although many ways have been tried to stop snoring from tying a bandage from the chin to the top of the head to keep the mouth closed, to actually removing part of the soft palate, no one has found a sure-fire method. However, some people claim that if you sleep on your side rather than on your back, you are less likely to snore. Nobody knows why, but men snore more than women and children.
The loudest snore recorded has been measured at 69 decibels, or almost as loud as a pneumatic drill!
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Why Do Fish Jump Out of Their Tanks and What Is the Best Way To Prevent Fish From Jumping Out of the Tank?
Fish jumping out of tanks small or large is quite a common problem for enthusiasts, and is the reason why some owners choose to have a glass cover on the top of their aquarium.
There are several theories as to why fish might jump from a small aquarium.
It has been suggested that one reason fish leap from the water is that in the wild they use this method to attempt to rid themselves of parasites.
Depending on the gender and species mix of the fish in their aquarium, it is possible that their fish could have been leaping to avoid predators or unpleasant interactions with other creatures.
They could even be showing off to fish of the opposite sex, in some previously unknown courtship or territorial ritual.
In the meantime, our sincere condolences go out to all those who have lost a fish to a death by jumping.
To captive fish, the air on the other side of the aquarium glass looks like water.
And even in fish world, the water is always cleaner on the other side.
As mentioned when we first spoke, a cover on top of the tank would stop future jumpers from killing themselves.
Just remember to leave enough room for them to breathe.
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Why Is There No Gravity in Space?
There certainly is gravity in space! If there wasn’t, the moon wouldn’t revolve around the earth, and the planets wouldn’t revolve around the sun.
The strength of the force of gravity between any two objects depends on two factors: the mass of the two objects and the distance between them. The heavier the objects are, the stronger the gravitational force between them. The greater the distance between them, the weaker this gravitational force.
If two objects are very massive, as in the case of the sun and the earth, then the gravitational force between them will be strong, even when they’re far apart. That’s why the earth is held in its orbit by the gravitational pull of the sun, even though the sun is 93 million miles away.
The mass of a spaceship is very small compared to the mass of the earth or the sun. As a spaceship moves away from earth, the gravitational pull of the earth decreases until it is too weak to have an effect on the spaceship. But at every point in the universe, there is some gravitational force working on every object.
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How Did the Planets Get Their Names?
We know there are nine planets. But in ancient times, people knew of only six: the earth and the five planets that can be seen without a telescope.
Venus, the brightest planet in our sky, was named after the Roman goddess of love and beauty.
Mercury, the fastest- moving planet, was named after the fleet-footed messenger of the gods.
Mars was named after the Roman god of war.
Saturn was named after the Roman god of farming.
Jupiter, the largest planet, took its name from the Romans’ chief god.
The planet Uranus wasn’t discovered until 1781, and was originally called Georgium, after King George III, who ruled England at the time. But it was soon decided that since all the other planets took their names from ancient gods, the new planet should also. It was then named after the Greek god of the sky.
Next to be discovered was Neptune, in 1846. It was originally called Leverrier after the man who first sighted it, but was later named after the Roman god of the sea.
And Pluto, discovered in 1930, was named after the Roman god of the dead.
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Who Invented Time and How Did Ancient Civilizations Keep Track of Time?
No one invented time; it was merely discovered.
Early humans were aware of time passing and at some point began marking it.
Archeologists continue to uncover ancient civilizations that devised elaborate methods of keeping track of the movement of the sun and the stars.
Stonehenge is one example.
The earliest clock, a shadow clock similar to a sundial, dates back to 3500 B.C.
The hourglass dates back almost as far.
As cultures advanced, the mechanical clock was invented and then the pendulum clock.
By the 18th century, more and more people had access to clocks and watches and were able to keep time more accurately themselves.
Today we use a 24-hour clock and have the world divided into 24 time zones.
The zones start at zero at the original site of the Greenwich Observatory in Greenwich, England.
We go by what is called the Scientific Standard of Time, based on the second, which is defined by scientists as “the duration of 9,192,631,770 periods of radiation†and in other circles as “one Mississippi.â€
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What Does the Expression “Bumper Crop†Mean and Where Did the Saying Come From?
A “bumper crop†is a result of extraordinary abundance.
You can have a bumper business, bumper crowds, or bumper crops.
This ancient use of bumper comes from a drinking goblet called a “bumper,†which was filled to the brim when used for toasts.
While quaffing a bumper of ale, drinkers touched, or bumped these goblets against one another during a festive or celebratory occasion such as an excellent harvest, business growth, or full houses at theatrical performances.
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What Are the Names of the Jacks and Queens in a Deck of Cards and How Did They Originate?
In a deck of cards the jacks are Hector, prince of Troy; La Hire, comrade-in-arms of Joan of Arc; Ogier, a knight of Charlemagne; and Judas Maccabeus, who led the Jewish rebellion against the Syrians.
The queens are Pallas, a warrior goddess; Rachel, Biblical mother of Joseph; Judith, from the book of Judith; and Argine, which is an anagram for regina, the Latin word for queen.
Parisian card names by suit:
Spades: (queen) Pallas, (jack) Ogier Hearts: (queen) Judith, (jack) La Hire Diamonds: (queen) Rachel, (jack) Hector Clubs: (queen) Argine, (jack) Judas.
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Where Did the Words Right and Left Come From and What Do the Terms Mean?
The word right surfaced in English as riht and meant “straight.â€
To put things right is to straighten them out.
Right took the metaphorical meaning of “good†or “just,†as in the Bill of Rights, because most people were right-handed.
The suggestion that left is incorrect was understood, like in a “left-handed compliment,†which is an insult.
The word right became a synonym for correct, but left was evil and so was left alone.
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How Does Your Tongue Taste Food?
Look in the mirror and stick out your tongue. See the little bumps on the surface of it? Inside each of these little bumps, or papillae, are about a dozen tiny organs called taste buds. There are also taste buds in three places in your throat. Not all tastes are detected by the same taste buds. Each group of taste buds in different areas of your tongue and throat helps you recognize different types of taste sensations: sweet, sour, salty, and bitter.
When you put a piece of food in your mouth, the chemicals in it alert the taste buds to carry “taste messages†through your nerve cells to your brain. It is in your brain that you actually become aware of the taste of something.
Since your food and your tongue must be moist for the taste buds to start working, your body sends out saliva to mix with any dry foods. To understand how this works, you can try an experiment. Wipe your tongue very dry and then put a lump of sugar in your mouth. Do you find that you cannot taste the sugar? That’s because your body hasn’t yet started to produce the saliva to dissolve the sugar for you to taste. However, in a minute or two, when that saliva is produced, you are able to taste it.
You have about 3,000 taste buds on your tongue!
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What Does the Power of Attorney Mean and Where Did the Term Come From?
If you give somebody “power of attorney,†that doesn’t mean they suddenly become a lawyer.
It simply means they can legally sign papers and make decisions for you in the area in which you’ve given them that power.
In many, perhaps most, cases, lawyers are given power of attorney, but it doesn’t have to be that way.
The British have several additional terms for people who practise law.
Lawyer is a general term describing all of them. Solicitors do most of the office work, draft documents, talk to clients, and may only appear as advocates in the lower courts.
Barristers do most of the trial work, especially in the higher courts, where they are the only ones who may act as advocates.
Attorney has pretty much the same meaning in Britain as in America, one who acts on behalf of another.
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Why is a Marathon 26.2 miles instead of exactly 26 miles and how did it originate?
The length of a Marathon is yet another distance forever changed by the British royalty.
The marathon used to be less than 26 miles. For the modern Olympics in 1896, the marathon distance was determined by the distance from Marathon Bridge, where the race began, to the Olympic stadium in Athens, 24.85 miles, or an even 40 kilometers.
In 1908, the distance was lengthened to an even 26 miles as it ran between Windsor Castle and White City stadium.
But another 385 yards were tacked on to the end so that the race could finish right in front of the royal family’s viewing box. For some reason, the 1908 distance stuck.
In 1921 the International Amateur Athletic Foundation (IAAF) officially adopted the 1908 distance of 26 miles, 385 yards (26.2 miles or 42 kilometers) as the marathon distance.
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What Does the Word “Gymnasium†Mean in Greek and How Did the Word “Stadium†Originate?
The word gymnasium is from the Greek word gymnos, which means “nude.â€
Thus, gymnasium literally means “a school for naked exercise.â€
The first Olympic event for the nude male athletes, or gymnasts, was a foot race known as a stade.
It was also a Greek unit of measurement for the distance of the race, which was six hundred feet, and that is why the facility was called a stadium.
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Can You See into the Past?
It may sound impossible, but it’s easy. You look into the past every night when you see the stars!
We measure the distance between stars in light- years. A light-year is the distance that light travels in one year, about six trillion miles!
When you look at a star that is ten light-years away, you’re really seeing light that left the star ten years ago, and has been traveling through space since then. That means that you’re actually looking at the star as it was ten years ago.
Astronomers have found stars that are eight billion light-years away. If you were to look at these distant stars, you would be looking far into the past, long before the earth existed.
In fact, some of the stars you look at tonight may not even exist anymore!
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Why Do Clouds Float In the Air If They Are Made of Water?
Despite looking really weightless, clouds are actually heavy.
Even small, fluffy clouds are heavy.
The water in small clouds can weigh more than million pounds, which is more than 500 cars.
Clouds are able to float in the air because water vapor in the cloud is less dense than water in a liquid state.
Furthermore, clouds are usually formed in air that is moving upward.
So, as long as the water is in the form of tiny droplets, it floats in the warm up-currents.
It’s only when the air cools that the mist condenses into large drops and the downward pull of gravity trumps the upward push of rising air.
Then rain falls.
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How Is the Correct Time Decided?
Ancient man probably measured time by daylight and darkness, or by the rising and setting of the sun. He also probably noticed that as the earth turned, the sun was directly over his head only once a day, in the middle of the day. This he called midday.
But this midday time was different in different parts of the ancient world since the sun is seen differently, depending on the location from which man was looking at it.
When travel was slow hundreds of years ago and no radios, telephones, or television connected all parts of the world, this was not too much of a problem. But as people all over the world needed to be more and more in contact with each other, a correct reference to time was needed.
In 1884, an international conference was held in Washington, D.C. to set up a time system for the world. Using knowledge man had gained from the ancient Babylonians, who had divided the circle of the earth into 360°, the scientists divided the earth into 24 time zones, each one covering 15° of longitude, and totaling 360°. Each time zone differed from the one next to it by one hour, since the earth rotates 15° in one hour.
The conference also decided that the starting point of noon would be an imaginary longitudinal line running through Greenwich, England. Heading east, the next time zone, one hour later, would be 1 P.M. when it was noon in Greenwich. Heading west, the next time zone would be one hour earlier, 11 A.M., when it was noon in Greenwich.
Since New York is 5 time zones west of Greenwich, or 5 hours earlier, it is 7 A.M. in New York when it is noon in Greenwich. Tokyo, Japan, is 9 time zones east of Greenwich, or 9 hours later, so it is 9 P.M. in Tokyo when it is noon in Greenwich.
The place on the globe where the point 12 hours east of Greenwich meets the point 12 hours west of Greenwich is called the International Date Line. It is exactly us, halfway around the world, 180° from Greenwich, and runs through the Pacific Ocean.
A traveler heading west from the United States towards Japan on Sunday would cross the International Date Line and find that it was then Monday. When he returned from Japan, say on Tuesday, he would cross the International Date Line and find himself back on Monday.
A traveler crossing the International Date Line can actually live through 2 Tuesdays (or 2 of any day) in one week!
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What is the Russian Federation and When Did the Soviet Union Collapse and Form 15 Independent Republics?
The Russian Federation is Russia’s offical name.
The Russian Federation, which occupies about three-fourths of the land that once was the Soviet Union, is made up of 21 autonomous republics, 50 oblasts (or regions), 6 krays (or provinces), 2 federal cities (Moscow and St. Petersburg), 1 autonomous oblast, and 10 autonomous okrugs (or autonomous territories).
Russia is a federal semi-presidential republic, comprising 83 federal subjects.
An unsuccessful military coup directed against Soviet leader Mikhail Gorbachev in August 1991 led to the collapse of the Soviet Union which resulted in the formation of the Russian Federation.
The USSR officially dissolved in December 1991 and Boris Yeltsin was elected the President of Russia.
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Why Are There So Many Different Types of Rain From Heavy To Light and What Causes Different Raindrop Sizes?
Elongated stair rods are an illusion. Large raindrops actually tend to be flattened by air resistance.
When they land they are called in Afrikaans, and I understand, in Welsh, “old women with clubs.†The circular sheet of splashing water suggests a wide skirt and the centrally rebounding droplet a cudgel.
Droplet size is the main factor in creating different kinds of rain.
This depends on conditions at the time of formation, particularly humidity, temperature, and the number of airborne nuclei such as dust particles.
For example, moderate numbers of nuclei in moist updrafts tend to promote drops that grow large, because there is plenty of water for them and they cannot come down before they grow heavy enough to fall faster than they are lifted.
When nuclei are crowded they compete with each other and can only form small droplets that may evaporate before they reach the ground.
In still air, big drops fall fast and hard.
Drops that are about 0.4 inch in diameter reach speeds of around 20 miles per hour, at which point their own slipstream tears them into smaller droplets, unless they are partly frozen. This limits raindrop size.
However, a large number of falling raindrops can create a downdraft, increasing the downward velocity a drop can achieve without splitting, while strong horizontal winds can more than double the speed of impact.
Rainfall intensity depends mainly on the depth of the cloud and the strength of the updrafts.
Rapidly rising air produces fast condensation of water droplets and large amounts of rain, mostly when the cloud extends high enough for ice crystals to form among supercooled water droplets.
Shallow clouds with weak updrafts only give drizzle, which rarely falls faster than 10 feet per second. Large raindrops can reach a terminal velocity of about 32 feet per second.
Their fall speed increases with size until the diameter approaches 0.25 inches, at which point wind resistance flattens the base, increases the drag and prevents further acceleration.
However, if the rain is caught in a “downburst†where an air column is descending at 65 feet per second or more, the rain hits the ground harder. Downbursts are often associated with cumulonimbus clouds that contain almost vertical air currents. The weight of precipitation in the cloud may be enough to trigger a downburst.
Rain from deep flat cloud layers is usually caused by slow diagonal ascent along a sloping frontal surface.
Such rain is persistent but seldom heavy. This can change if prolonged lifting makes the layer unstable. Then massive turrets containing strong updrafts grow vertically out of the layer.
These can produce heavy downpours from a cloud mass which had previously only given moderate rain.
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How long does an earthquake last?
If you count tremors prior to the quake and aftershocks, earthquakes can last for months. But the central event lasts only seconds or minutes.
The great San Francisco earthquake of 1906 began when the ground shuddered for about a minute at 5:11 A.M., April 18. Ten seconds of quiet followed. At 5:12 A.M., the major quake-7.9 on the Richter scale—began.
Three minutes later, it was over, leaving thousands of buildings in pieces, broken gas mains, buckled streets, and raging fires. Ultimately, 75 percent of the city was destroyed.
The disastrous earthquake in Mexico City on the morning of September 19, 1985, also lasted 3 minutes. In that time, 250 buildings were leveled. The next day another quake destroyed another 150 buildings and put a stop to the first earthquake’s relief work.
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How Can You Pass 24 Hours in Less Than 60 Minutes?
The lines that divide the world’s time zones meet at the North and South Poles, so the zones get narrower as they near’ the poles.
An Alaskan airline offers a flight over the Arctic regions that includes a circular flight around the North Pole. If you were to circle the North Pole, you’d pass through all the world’s times zones in less than an hour!
If it were noon when you started to circle the pole, you’d soon pass the line marking the beginning of the next time zone, and it would become one o’clock. A few minutes later, you’d have to move your watch ahead another hour.
As the flight continued, you’d keep moving your watch ahead, past midnight, through the morning, until you returned to your starting point, before clocks there had reached one o’clock.
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What Is the Most Common Symbol on the Flags of the World?
The United States is not the only country with stars on its flag.
In fact, about 50 other countries have at least one star on their flag, making the star the most common symbol on the flags of the world.
The second most popular symbol is the crescent, which appears on nine flags.
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What Is the Most Common Symbol on the Flags of the World?
The United States is not the only country with stars on its flag.
In fact, about 50 other countries have at least one star on their flag, making the star the most common symbol on the flags of the world.
The second most popular symbol is the crescent, which appears on nine flags.
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How Do Birds Know Their Migratory Path and How Do Homing Pigeons Find Their Way Home?
Birds are known to use a combination of things, including landmarks, the angle of the sun, stars, odors, even the magnetic field of the earth, as they migrate.
However, scientists still do not know exactly what they use for a map and compass, let alone exactly how they use them.
A flock of birds, for example, is not just headed to a general geographical area like Central America, but to a very specific location.
How do they know when they get there?
They may have an intimate knowledge of the local area, but how they are able to navigate so precisely, even over the ocean at night, is not known.
What might seem an obvious explanation, that birds who have migrated before might lead the way, is not the answer.
Ornithologists know this because in many cases the parents bail out first before the end of the year, and the young continue to feed until they are developed enough to leave, then migrate unassisted.
It appears that birds know where they are going, though they have never been there before, because it is programmed in the genetic material.
Most of the research has been done on the compass.
For example, even on cloudy days, there is a plane of polarized light that lets birds tell where the sun is, and they derive directional information from that.
But if you are plunked down in the woods from outer space, a compass won’t help you decide where to go, and one hundred years of research on the homing pigeon still has not answered the question of how a bird carried a hundred miles in a covered box immediately orients itself and heads accurately for home.
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What Makes the Sound When You Snap Your Fingers?
When you snap your fingers, the fingertip hits the pad of the thumb in the palm and makes a smacking sound.
If you do it just right, it can be pretty loud.
Count it with me, five six seven eight.
“Snap Your Fingers†is also a song written by Grady Martin and Alex Zanetis, originally recorded by gospel singer Joe Henderson in 1962.
Finger snapping may be used as a substitute for hand clapping, because you can’t clap and hold a beer at the same time.
Snapping is also done at posh speeches and announcements as it is less disruptive than rowdy hand clapping.
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Do Birds Fly At Night When They Are Migrating?
Not all birds fly at night when they migrate. Some birds do most of their flying at night, while others get most of their traveling done in the daytime. Scientists believe that stronger birds prefer the day journey and weaker birds feel safer at night.
Most of the daytime fliers are birds that capture their food in the air or must fly great distances to obtain it.
Day fliers include swifts and swallows, which feed as they fly, and herons, geese, ducks, and hawks, all strong fliers that must travel a long way to find food.
Night fliers are generally smaller birds, such as creepers, wrens, thrashers, warblers, tanangers, and sparrows. These night fliers can find food more easily during the daytime when they eat and rest. The dark also offers more protection from enemies.
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Why do migrating birds fly in a V formation?
Migrating birds fly in a V formation because it gives them the best of both worlds, reducing air resistance while allowing the geese or ducks in the back to see where they’re going.
Think of the V formation as the front of a boat cutting a path through water.
The first fowl in the V formation cuts through the air and blocks some of the air and wind resistance for the two birds behind it, allowing them to glide through the air using less energy.
Those birds do the same for the ones behind them, and so on all the way through the V. In this way, the birds can travel long distances with fewer rest stops during migration.
When the front bird gets tired, it drops back, and another takes its place at the front.
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Which Other Birds Lay Eggs in Another Mother Bird’s Nest Besides Cuckoos and Why?
The South American black-headed duck, the African honeyguides, and the whydas are some examples of parasitic breeder birds.
cowbird
The best known bird to North Americans that lays eggs in other nests is the brown-headed cowbird.
These birds have actually evolved the capability to mimic the size and color of other birds’ eggs. Aiding their survival further, they’re well-known song mimics as well.
Cowbirds have been raised by at least 206 different species of birds.
Sure, we humans can get sick and tired of raising our own kids, especially after hearing another one of those long, grueling explanations of why Dark Charazard can whip Ancient Mew in a Pokemon battle.
But birds, presumably, don’t shirk their parenting responsibilities for emotional reasons.
So why do these birds lay their eggs elsewhere? It’s a matter of simple reproduction, really.
When a bird drops off her young in another bird’s nest, it frees her up to do more egg-laying.
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How Fast Is the Earth Moving Though Space?
How fast earth is moving through space depends on what you’re comparing it to.
The Earth is moving in several different directions at the same time, each at breakneck speed.
Rotating on its axis, the Earth goes 460 meters a second (roughly 1,000 miles per hour) at the equator.
Going around the sun, the Earth moves about 30 kilometers per second (roughly 67,000 miles per hour).
Our solar system whirls around the center of our galaxy at about 220 kilometers per second (about 490,000 miles per hour).
Meanwhile, our entire galaxy is traveling at a speed of about 1,000 kilometers per second (620 miles per hour) toward a region of space called the Great Attractor, which is about 150 million light years away. Hold on tight!
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Does the Sun Move?
In ancient times, as people watched the sun move across the sky each day, they thought that the sun traveled around the earth.
Scientists later found out that the sun remains in one place while the earth and the other planets travel around it. But we know now that the sun moves too!
The sun is just one star in a huge group of stars called a galaxy. Our galaxy, called the Milky Way, is spinning around like a phonograph record. And the sun is traveling around the center of the galaxy at a speed of about 481,000 miles per hour. At that speed, the sun will travel around the center of the Milky Way once in about 225 million years.
The Milky Way itself is moving around the center of a group of galaxies, like a planet moving around the sun. And this group of galaxies may be traveling around the center of the universe. So the sun is really moving in two or three directions at once!
Like the sun, all other stars are traveling through space at high speeds, but they’re so far away that to us, they look like they never move!
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How Does a Radio Work?
At the radio studio, the sound waves of a program go into a microphone that has electrical current running through it. These sound waves create vibrations in the current as they travel through wires to a control room.
There, technicians control their volume and send them out through a transmitter. An antenna on the transmitter sends these electrical waves out through the air as radio waves. Radio waves travel through space in all directions, just as waves of water spread out when a pebble is dropped into it.
Each radio station is assigned a particular channel, or electrical path, by the Federal Communications Commission. This channel, called the station’s frequency, must be followed exactly.
You cannot see, hear, or feel radio waves in the air, but the radio in your home, which has an antenna either on the inside or outside, picks up these waves from many stations at the same time. By turning the tuning dial, you can select the station you want to listen to.
What happens is that the current in your radio tunes in to the same frequency as the radio waves sent out by the station you have chosen. An amplifier in your radio strengthens these radio waves, and the speaker changes them back into the original sound waves that went into the microphone in the studio.
Because radio waves travel at the speed of light, 186,282 miles per second, a listener in New York hears a program broadcast from California a fraction of a second before the audience in the broadcasting studio hears it!
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Why Is Human Blood Blue In the Body and Red When It Comes Out Through a Cut or Wound?
Human blood is always red, even blood in the body that is oxygen-deprived and heading back toward the lungs to refuel.
Veins close to the skin show through as purply blue or greyish blue because that’s their color.
The term blue blood as it’s used regarding royalty comes from the fact that royalty didn’t get outside much. Peasants and regular workers were browned by the sun, so their blue veins were less likely to show.
The white skin of European nobles showed off their blue veins, and people assumed their blood was blue as well.
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Why does Earth seem to stand still while the Sun moves across the sky?
Earth is moving around the Sun at about 1,100 miles (1,800 kilometers) a minute, but there isn’t anything close by to show us how fast we’re moving.
Traveling in a car, you see nearby bushes and buildings rushing by, but mountains in the distance don’t seem to move at all. If we had other satellites (objects orbiting Earth) close by along the route of Earth’s orbit, we’d see how fast we were going. But the stars are like the mountains, too far away to help us judge our speed.
While Earth revolves around the Sun, it also rotates on its own axis, one rotation every 24 hours. We don’t feel either of these movements because we move right along with Earth.
On the average, you take a breath every 6 seconds. With every breath, you—and Earth have gone approximately 100 miles (180 kilometers).
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What is the Russian Federation and When Did the Soviet Union Collapse and Form 15 Independent Republics?
The Russian Federation is Russia’s offical name.
The Russian Federation, which occupies about three-fourths of the land that once was the Soviet Union, is made up of 21 autonomous republics, 50 oblasts (or regions), 6 krays (or provinces), 2 federal cities (Moscow and St. Petersburg), 1 autonomous oblast, and 10 autonomous okrugs (or autonomous territories).
Russia is a federal semi-presidential republic, comprising 83 federal subjects.
An unsuccessful military coup directed against Soviet leader Mikhail Gorbachev in August 1991 led to the collapse of the Soviet Union which resulted in the formation of the Russian Federation.
The USSR officially dissolved in December 1991 and Boris Yeltsin was elected the President of Russia.
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Where Did the Term “Blueblood†For the Aristocrats Come From and What Does the Word Mean?
The name bluebloods refers to the pallor of the Spanish ruling classes after the conquest of the darker skinned Moors.
After the blood in them loses oxygen while flowing back to the heart, the veins of fair or untanned people whose skin is never exposed to the sun appear blue.
The veins of those with darker complexions, however, like the Moors, are less obvious.
Their blue blood distinguished true Spanish aristocracy from the conquering Moors.
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Why Aren’t Sunrises as Colorful as Sunsets?
Well, don’t underestimate the time-of-day factor: for most humans, nearly everything looks better at 8:00 P.M. than at 5:30 A.M.
However, in this case you’re righton most days, sunsets are much more brilliantly colored than sunrises. It doesn’t make sense, since most of the same conditions are in place for eacha sun in a low sky sending rays careening through Earth’s atmosphere. So what gives?
Credit humanity. Or rather, blame us. During the day we generate the bulk of our traffic exhaust and factory smoke, which lingers long enough to give brilliance to our sunsets.
During the night, much of the pollution gets blown away from population centers, so less of the blue light gets scattered, resulting in less intense reds and yellows in sunrises than in sunsets.
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Is It Always Worth It to Fight With Your Employer About How They Are Treating You?
It is accurate to say that at one time or another every employee is unhappy or annoyed with what goes on at work. These problems can come from the owners, managers, supervisors, co-workers, the amount of work to be done, or any irritant. Even the building where the work is done may cause problems. The employee must evaluate the problem. Is it an issue that can be resolved by an attorney? Does an attorney even need to be involved? Is it a health issue? Is it a legal issue? Is it something that can be fixed?
I receive many calls from employees who believe that they have legitimate legal grievances against their employers only to find out that the grievance is not covered by any current laws. This could be due to the employer not having a sufficient number of employees or that the unfair action is not considered to be discrimination by the law. Many times these issues involve departments where one group of employees gossips about another group who are all the same in age, sex, race, etc. Or it can be an issue of certain employees being friends with some people and not with others. These may be issues that not only are not covered by the law but are not even covered by the company rules.
For most employees, once they find out that their complaints cannot go anywhere in the court system, they drop the fight and go on working at the same company. However, there are some people who continue to fight even when there is no legitimate way to resolve their issues in a legal venue. The continuation of fighting may include filing lots of internal grievances, writing memos, spending time concentrating on the problem rather than work, or merely telling anyone who will listen about the issue. Or the continuation of fighting may include meeting with several attorneys until the employee finds one who is willing to sue the employer.
From the employer’s standpoint it is difficult to keep an employee who spends time being disgruntled and spreading his or her negativity to other workers. It is hard on the employer to have an employee who will not let go of a problem, especially when the problem has no real solution. This snowballs into poor reviews, promotions not given, and other lost career benefits, which in turn gives the disgruntled employee additional issues to complain about.
We are living in an economy where employers can outsource thousands of jobs, lay off entire plants, or terminate large numbers of people without any warning and without any employment law consequences. Employees must keep this in mind every day. There is no guarantee that work will ever be a fun place to be, and there is no guarantee that your boss will be fair. Once you have looked at all your options and have been told that there is nothing that can be done about the problem, you need to let it go and get back to work. I will leave you with what an Illinois appellate judge once told me: “In employment law, unfair is not always illegal.â€
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Was Napoleon Bonaparte executed after being exiled as leader of France?
No, Napoleon Bonaparte was not executed after being exiled as leader of France.
He tried unsuccessfully to officially step down and have his son put on the throne.
But when that idea was rejected, he abdicated voluntarily anyway and was exiled to the island of Elba in the Mediterranean. His wife and only child were sent to live with his father-in-law—the emperor of Austria—and he never saw them again.
He did, however, manage to escape Elba. In 1815, he returned to France, rallied the troops, and marched on to Paris. He quickly tried to make peace with his former enemies but was refused.
When pushed to battle, he was defeated by the British at the battle of Waterloo.
Despite his popularity back home, Britain and its allies exiled him once more—this time for good—to the island of St. Helena in the South Atlantic Ocean, where he died of stomach cancer six years later.
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Why are clouds white when water is transparent and air is clear?
Clouds consist of millions of tiny water droplets.
Light waves of all the colors bounce and reflect off and refract through the water droplets evenly, sending all of the various colors off in (more or less) equal measure.
As you may remember from school, the “color†white is technically all of the colors mixed together.
Because all of the colors are being evenly dispersed by the water droplets, clouds appear white. We think this is kinda cool, because if clouds weren’t white, the sky would be blue all day and everyday, forever. And that would be pretty boring.
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What Was Edwin Hubble’s Most Amazing Discovery and How Did Hubble Discover That the Universe Is Expanding?
In the nineteenth century, astronomers discovered that studying the light emitted from a star, a study known as spectrum analysis, revealed what elements stars are made of.
Changes in a star’s spectrum indicate the movement of the star, and analysis could determine the star’s speed and direction.
It was revealed that stars only appear fixed in the sky because of their great distance from Earth. They are actually moving at tremendous speeds.
At the same time that Edwin Hubble was fixing the galaxies’ location, the American astronomer Vesto Melvin Slipher was using spectrum analysis to determine their velocities.
He measured 41 galaxies and found their speed was as staggering as their distance. Their average speed was 375 miles per second, and all of them were moving away from Earth.
Hubble took the experiment one step further. He measured the distance to 24 of the galaxies Slipher had measured and noticed something strange.
The farther away the galaxy, the faster it was moving, and the galaxies were moving away from each other at a rate constant to the distance between them. He saw only one explanation: the universe was expanding.
Over the years, Hubble confirmed his findings by measuring 150 galactic velocities.
The finding became known as Hubble’s law. He also realized that with such distances involved and the time it takes light to travel, observers on Earth are also looking far back in time.
For example, light from the Sun takes about eight minutes to reach Earth, so we see the Sun as it appeared only eight minutes before.
However, light from the farthest visible stars, 12 billion light-years away, has taken 12 billion years to reach Earth.
We see these stars as they appeared 12 billion years ago, or around the time of the birth of the universe.
Many years before Hubble’s findings, the physicist Albert Einstein had theorized that the universe is expanding.
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What Is a Microclimate?
When you notice that the temperature forecast in your local media is consistently warmer or colder than that which occurs in your neighborhood, you have identified a microclimate.
Light, temperature, and moisture may all vary from one area to another within a biome because of changes in altitude, vegetation, or other factors.
San Francisco is an example of a city with microclimates and submicroclimates, and the San Francisco Bay area can have a wide range of extremes in temperature.
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How Much Water Do Clouds Hold and How Does the Size and Color of a Cloud Affect How Much Water It Can Hold?
The amount of water inside a cloud is not different from the amount of water in the clear air around it.
However, while the clear air contains water vapor, inside the cloud the air is saturated with water vapor and it has condensed out to produce the cloud.
The difference between the two states is caused by temperature differences rather than the water content.
The color of a cloud doesn’t make much difference either.
In the higher part of a cloud, the water is in the form of ice crystals. Lower down it is a mixture of ice and liquid water. The color of the cloud depends mainly on this ice/water mixture and the size of the water droplets, and less on the total amount of water.
An estimate of a cloud’s water content can be obtained from the amount of rain the cloud can produce.
If the entire atmosphere were saturated with water and it all fell in a steady stream, this could produce some 1.4 inches of rain, while the thickest actual clouds produce about 0.8 inches.
Cloudbursts can produce 2 inches or more, but this requires additional moisture from the surrounding atmosphere, which means such events are localized.
The heaviest cloudbursts roughly follow the following equation: the rainfall in inches equals 162.5 multiplied by the square root of the time in minutes that it has been raining.
A more typical shower produces a fraction of an inch of rain, at a rate of perhaps 0.04 inches per minute. Normally 1 inch of rain corresponds to 900,000 cubic feet of water weighing 4,000 tons per cubic miles of cloud, though the thickest clouds can contain up to 20 times as much.
You can also estimate the amount of water from the volume of the cloud.
By volume, the fraction of the cloud filled with water is about 1 millionth, or 0.0001 percent. The cross-section area of a cloud can be measured from its shadow. A small cloud 1,000 feet by 1,000 feet and 500 feet high has a volume of 500 million cubic feet, of which roughly 500 cubic feet will be water, weighing 15 tons.
Even if you can’t calculate the precise amount of water in a cloud, these numbers may still impress your friends.
Sadly, just looking at a cloud does not give very precise information about how much water it contains.
The color of a cloud depends entirely on the relative position of the viewer and the physical structure of the cloud. Its apparent size is dependent on the altitude of the cloud, and this is generally very difficult to judge from a single observation point.
But knowing exactly how much water is contained in a cloud is important for producing accurate weather forecasts.
The choice of frequency for a Doppler radar beam is very important.
If the beam interacts too strongly with the water in a cloud, in terms of either reflecting or attenuating the signal, then the radar will have only a limited ability to penetrate cloud structure. If the interaction with water is too weak, then no useful information can be returned at all.
One facility in England can analyze and extract a huge variety of data and has a maximum range of around 100 miles. It is able to provide information on droplet density, size, speed, and whether the droplets are water or ice.
Using this tool, your reader could work out fairly accurately the total water content contained within a cloud and, from the structure of the cloud, how likely it is to start raining, this technique has proved very useful at the Wimbledon tennis championships in past years, which are, of course, notorious for being interrupted by downpours.
Such radars help to produce detailed information on weather, from tracking hurricanes to helping to produce your daily weather forecast and predicting areas of turbulence on aircraft flights.
And remember that kinetic energy rises with the square of the velocity.
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Where Did the Engagement Ring Come From and How Did the Tradition Originate?
The diamond engagement ring was introduced by the Venetians, who discovered the diamond’s value in the sixteenth century.
But betrothal gifts hadn’t included rings until 860 A.D., when Pope Nicholas I decreed that a ring of value must be given as a statement of nuptial intent.
It was also mentioned that if the man called off the wedding, the jilted bride kept the ring.
If the woman ended the engagement, she was to return the ring and be sent to a nunnery.
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How Were Time Zones Invented and When?
It would be very confusing if the clock said midday in one place and the sun was high in the sky, but in another place at midday the sky was pitch-black and full of stars. Thank goodness someone had the bright idea of time zones.
Universal Time. Depending where you are on the planet, it might be the middle of the day or the middle of the night, because the Earth is orbiting the Sun. Of course, before time zones clocks weren’t set at the same time for everyone and no one ate their lunch at 3 a.m. or had breakfast at bedtime.
People used the Sun as their guide and the time was set locally, when the Sun was overhead, it was midday. As new ways to travel and communicate were invented, knowing the exact time in different parts of the world became more and more important, and a standard time was needed.
Sir Sandford Fleming first proposed time zones for the whole world in 1876. In 1884 an international conference at the Royal Observatory in Greenwich, London, adopted the time zones we know today. Planet Earth rotates on its axis 15 degrees every hour, so the world is divided into 24 15-degree sections, with the clocks in each section set an hour apart (at least, that’s how it works for most of the world).
The zones are all measured from Greenwich, which the 1884 conference decided was the Prime Meridian. The time at Greenwich is known as Greenwich Mean Time or, more grandly, Universal Time.
The Pacific country of Kiribati used to have two different time zones. The eastern half of the country was a whole day and two hours behind the western half! In 1995 the time zone was changed so that Kiribati clocks all told the same time.
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Why Are the Numbers On a Keyboard Arranged With the Lowest Numbers On the Bottom and Phones Are the Opposite?
Mechanical adding machines, based on rotating wheels, always have the 0 button adjacent to the 1 button.
By convention, most old adding machines had the numbers increasing in value from the bottom and this may be a hangover from when the machines had levers on the wheels rather than buttons.
When the numbers were put on to a pad arranged as a three by three grid with one left over, the order of the numbers, as far as possible, was kept the same.
On a rotary telephone dial the 0 comes adjacent to the 9 because a 0 in the telephone number is signalled by in pulses on the line.
When telephones acquired push buttons in a grid, the ordering of the buttons was carried over from the old telephone dial.
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What Artist Painted With His Tongue?
Huang Erh-nan was a well-known painter who lived in Peking, China, during the 1920s.
Most of his work consisted of ink paintings of butterflies and flowers. But what made Erh-nan’s paintings so amazing was that he painted them not with a brush, but with his tongue!
The Chinese artist filled his mouth with black ink, leaned over a piece of silk cloth, and brushed on his designs using his tongue alone!
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How Do Elephants Communicate With Each Other and Why Do They Make Loud Trumpet Noises?
Elephants make several sounds when communicating, and are famous for their trumpet calls made by blowing through its nostrils.
elephants communicate with low frequency sounds
Trumpeting is often made when an elephant is excited or startled.
Researchers have known for years that elephants use their trunks to interact socially. However, they’ve more recently discovered that elephants use low-frequency verbal communication as well.
These low frequency sounds can be felt by the sensitive skin of an elephant’s feet and trunk, which can sense the resonant vibrations.
To listen attentively, members of the herd will often lay their trunks on the ground, and lift one front leg off the ground.
Researchers at Cornell University took recordings of elephant sounds and raised them to frequencies that can be heard by the human ear.
They discovered that herds of elephants also sing to each other, and although the research is still in its infancy, it is helping to solve many mysteries.
These include how elephants can find distant potential mates, and how social groups are able to coordinate their movements over long distances.
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Has an Hour Always Had 60 Minutes?
Since ancient times, though the day has been divided into 24 hours, each hour has not always had 60 minutes, as we measure them.
The ancient Greeks divided the daytime into 12 hours, but they measured a day from sunrise to sunset. So, the longer a day was, the longer was each hour in it.
In Rome, too, there were no minutes, and each hour varied with the length of the day. On the shortest day of the year, a daytime hour had only about 441/2 minutes, while a night hour had about 751/2 minutes.
And on the longest day of the year, the measurements were reversed, and each daytime hour had 75.5 minutes!
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Where Does the Word Kindergarten Come From and What Does Kindergarten Mean In German?
The word kindergarten is German in origin, and means “garden of children.â€
Educator Friedrich Froebel coined the term, but only after trying to coin another one: Kleinkenderbeschaftigungsanstalt.
Although its meaning was clear, “institution where small children are occupiedâ€, its pronunciation was quite a feat.
Public rejection of the term persuaded Froebel to make the switch to Kindergarten.
In most countries kindergarten is part of early childhood education, and children are taught to develop basic skills and knowledge through creative play and social interaction.
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Why Is Play So Important for Children?
Psychologists have studied children for many decades and have found that early problems in play have a strong negative impact on social relationships. This is the case not only during childhood— there are lasting negative effects on adult relationships.
While play may seem to be simply a source of fun, it is actually a crucial aspect of children’s development. Through play, children develop complex social skills that allow them to interact with others, form friendships, develop empathy, and resolve conflicts, skills they will use throughout their lifetime. By the end of preschool, most children have acquired complex social skills that will serve as a foundation for future relationships.
These early skills are displayed in cooperative play, an advanced form of play that involves sophisticated cognitive, emotional, and social skills where the children must respond to one another’s actions, words, and behavior. Emotions are a large part of cooperative play, and children must understand and respond to their playmate’s feelings as well as regulate their own. They resolve differences and disputes through negation, a key skill in getting along with others.
The solitary and rigid play patterns of Asperger’s Disorder children interfere with the natural course of using play to develop proper social skills.
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Why Is Blood-Typing Important and How Is Mixing Incompatible Blood Types Dangerous?
Mixing incompatible blood quickly creates a sea of red dumplings swimming in yellowish liquid, bringing on instantaneous death.
In 1900 Dr. Karl Landsteiner discovered the A, B, and 0 blood groups and demonstrated that blood could be successfully mixed within the same group.
He named the differences the “Rh factor.â€
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What Flower Can Predict the Weather?
The small scarlet, white, or purple flowers of the plant called the scarlet pimpernel can give you a better weather prediction than the radio or TV weatherman.
If you are in the woods in the morning and you see the flowers on this herb close up, you will know that rain or cloudy weather is coming.
If, however, the petals are opened up, the day will be sunny and fair. Because of its unusual powers, the scarlet pimpernel has been nicknamed “the poor man’s weatherglass.â€
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Where Did the Expression “In a Nutshell†Originate and What Does the Idiom Mean?
“In a nutshell†indicates a drastically reduced summary.
Long before modern electronics, a few scholars made attempts at condensing massive literary works so they could be more easily stored.
It became an obsession to some to see just how small they could write.
For example, a copy of the Qur’an was reduced on a parchment measuring four inches by half an inch.
These copies were so small it was said they could be stored in a nutshell.
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What Is the Difference Between a Mortgage and a Deed of Trust?
In some states, a deed of trust, also called a trust deed, is used in place of a mortgage. A deed of trust accomplishes the same goal as the mortgage, but it is structured differently. The deed of trust is a three-party document. The borrower is called the trustor and the lender is called the beneficiary. The deed of trust is not made directly to the beneficiary, but is instead given to a third party called a trustee. The trustee acts in only two situations.
1. If the deed of trust is satisfied and the loan paid off, the trustee issues a reconveyance to the trustor, releasing the lien.
2. If the terms of the agreement are not met (default), the trustee acts for the beneficiary to sell the property.
A reconveyance is a legal term for returning something, such as the deed for your home to you.
The term mortgage will be used for both mortgages and deeds of trust.
Deed of Trust States
Alaska Arizona California Mississippi
Missouri
Nevada
North Carolina Virginia Washington, DC
Mortgage States
Alabama Arkansas Connecticut Delaware Florida Hawaii Indiana Kansas Kentucky Louisiana Maine
Massachusetts
Michigan
Minnesota
New Hampshire
New Jersey New Mexico New York North Dakota Ohio
Oregon Pennsylvania Rhode Island South Carolina Vermont Wisconsin States That Use Both Deeds of Trust and Mortgages
Colorado Idaho Illinois Iowa Maryland Montana Nebraska
Oklahoma
Oregon Tennessee Texas Utah
Washington West Virginia Wyoming
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What Does the Phrase Buyer’s Market In Real Estate Mean?
When the real estate industry is said to be in a buyer’s market, generally home prices are lower, homes stay on the market longer, the amount of money for mortgages is down, and fewer new homes are being built. A buyer’s market is also referred to as an economic correction period because it follows a period of time when home prices rise much faster than salaries and the real estate market is said to be overheated.
In a buyer’s market, those wanting to purchase a home are not rushed into putting money down to hold the first home they see. Because homes are on the market longer, the buyer has time to really compare what is available and find that perfect home. In a buyer’s market the seller must place an appropriate price on the home or the home will remain on the market for a long period of time. For buyers, there is more negotiation available on home prices and the potential of getting a real financial deal from an anxious seller.
Besides price negotiations, a buyer in this market can put more contingencies on his or her offer to purchase, such as financing, which provides that the seller pay some of the fees. Financing in a buyer’s market can be difficult because during that time there is less money available for mortgages. For a potential buyer the problems in obtaining a mortgage can be lessened by having a clean or improving credit report and a larger down payment.
Because the real estate market is cyclical, following a buyer’s market will be a seller’s market. The fun comes in trying to determine how long each will last.
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When Were Stop Signs Invented and What Was the First City In the World to Use Stop Signs?
Stop signs first showed up in Detroit, Michigan, in 1915.
They were black on white and smaller than modern signs.
Until then traffic-control devices were generally manual, using semaphores, or flags, policemen in traffic towers, and hand-turned stop-and-go signs.
In the 1920s, black-on-yellow signs were introduced, while white on-red signs appeared in 1954.
Mounting height has also evolved.
Early stop signs were about three feet off the ground.
Modern stop signs are more than six feet high, making them easier to see.
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Why Does Black Tea Lighten or Change Color When You Add Lemon Juice and What Causes the Chemical Change?
The simple answer to why black tea changes color is that adding lemon juice alters the acidity of the tea and the color change is an indication of this.
The color change is the same way that litmus paper changes color.
A similar effect can be observed by substituting the tea with some cooked red cabbage juice.
Tea leaves are rich in a group of chemicals known as polyphenols that amazingly account for almost one-third of the weight of the dried leaf.
Both the color of the tea and much of its taste are due to these compounds.
One group of polyphenols, the thearubigins, are the red-brown pigments found in black tea and constitute between 7 percent and 20 percent of the weight of dried black tea.
The color of black tea is also influenced by the concentration of hydrogen ions in the water.
Thearubigins in tea are weakly ionizing acids and the anions, or negatively charged ions, they produce are highly colored. If the water used to brew tea is alkaline, the color of the tea will be deeper due to greater ionization of the thearubigins.
If lemon juice, which is an acid, is added to the tea, the hydrogen ions suppress the ionization of thearubigins, and that makes the tea lighter.
Interestingly, the theaflavins, the yellow-colored poly-phenols in black tea, are not involved in the change in color that is associated with a change in acidity.
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Why Are Traffic Lights Red, Yellow, and Green and What Do the Different Colors Mean for Signaling?
Red, green, and yellow traffic lights developed directly from the trial and error of controlling railways during the nineteenth century.
Trains needed advance warning to prevent fatal accidents and collisions.
The first choice was red for stop, which was logical because red had symbolized danger for thousands of years.
During the 1830s, engineers tried using green for caution and clear for go, but sunlight reflecting off clear lights gave false signals.
So engineers solved the problem by introducing yellow for caution and making green stand for go.
The very first traffic light using this system was introduced in Cleveland, Ohio, in 1914.
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What Airline Is the World’s Largest?
The national airline of the Soviet Union, Aeroflot, which is owned by the Russian government, is now the largest airline in the world. Aeroflot has 1,300 planes and 400,000 workers, and carries about 90 million passengers a year to 65 different countries.
The largest airline in the U.S., and the world’s largest airline not owned by a government, is United Airlines, which has 365 planes carrying about 30 million passengers a year.
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How Does the Earth’s Rotation Around the Sun Cause the Stars to Rise and Set at Different Times Every Night?
You may notice that when you are stargazing in your yard at 10:00 every night, the stars appear slightly to the west of where they were the night before.
Stars rise 4 minutes earlier every night, and set 4 minutes earlier.
Therefore, over the months, the starry night changes.
Over the period of a year, those minutes add up to 24 hours, so that every 12 months, the same stars show up at the same positions in the sky.
The difference in the stars’ rising and setting times results from Earth’s rotation around the Sun.
The celestial sphere remains relatively still, but Earth moves around the Sun.
The stars appear to be in a different place at the same time each night because, in fact, you are in a different place in space every night.
Because it takes 365 days for Earth to rotate around the Sun, you have 365 slightly different night skies to study.
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When Was the Hubble Space Telescope Launched Into Orbit and Who Is the Hubble Telescope Named After?
Two months after the Hubble Space Telescope’s launch in 1990, it was discovered that the primary mirror had not been ground properly, among other problems.
The telescope could not be focused.
While this was a major embarrassment, the dangerous and complex repair mission was a coup.
The space shuttle Endeavor was launched in December 1993.
Its crew captured the Hubble Space Telescope, fixed it, and released it successfully.
The images and data returned since have more than outweighed the early difficulties, promising that the Hubble Space Telescope will be remembered for its scientific achievements rather than its flaws.
Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.
The Hubble Space Telescope is named after the astronomer Edwin Hubble.
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Where Is the Busiest Airport In the World and What Is the Busiest Cargo Airport Terminal On Earth?
O’Hare International Airport in Chicago, Illinois, was the world’s busiest passenger airport before 2005.
It beat out the previous world’s busiest airport, Hartsfield International Airport in Atlanta, Georgia, in 2001.
O’Hare had 911,861 takeoffs and landings in 2001.
O’Hare International Airport serves as the primary and largest hub for United Airlines and as a hub for American Airlines.
In 2010, Hartsfield–Jackson Atlanta International Airport, located seven miles south of the central business district of Atlanta, regained its ranking as the busiest passenger airport in the world.
The Atlanta Airport has served about 88 million passengers per year since 1999, and has 151 domestic and 28 international gates.
The busiest cargo airport in the world is in Memphis, Tennessee, which happens to be the hub for Federal Express.
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How Is the Earth’s Magnetic Field Important to Life On Earth?
The magnetic field of Earth is very important to life on Earth because it helps deflect harmful cosmic rays and solar wind.
If we were fully exposed to these charged particles the effects on us could be devastating.
Communication systems would be disabled and the particles could cause damage to all living things.
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Why Do Stars Always Appear to Rise In the East and Set In the West and What Is a Circumpolar Star?
Many of the stars you will see in the night sky follow a path across the sky from horizon to horizon.
Circumpolar stars, however, appear to circle the northern and southern celestial poles without ever rising or setting.
This is because the celestial sphere appears to rotate on the axis between its poles, in fact, it is Earth that is rotating on its axis.
If you draw a circle around the celestial pole in your hemisphere, the North Star in the Northern Hemisphere, at a distance equal to the number of degrees of your latitude, the stars within that circle remain above your celestial horizon all night.
For example, if you are stargazing at 40° latitude, any stars within a 40° radius of the North Star do not rise or set, but are always visible traveling around the celestial pole.
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What Do the Different Numbers On the Richter Scale Mean and How High Does It Go?
The Richter scale is a logarithmic scale that gauges the magnitude of an earthquake’s force.
Invented by Charles Richter in 1935, it is measured on a seismograph machine, interpreting the data the machine picks up from the Earth’s vibrations.
Each number is 10 times more powerful than the previous number.
For example, a quake that registers 8.0 is 10 times stronger than one that measures 7.0; 100 times more powerful than one that measures 6.0; and 1,000 times more intense than one that measures 5.0.
The scale is from 1 to 9 but is technically open-ended.
Many factors influence what occurs during a quake, but the basic scale is as follows:
1.0 Detectable only by instruments
2.0 Barely detectable, even near epicenter 3.0 Felt indoors
4.0 Felt by most people; slight damage
5.0 Felt by all; damage minor to moderate
6.0 Moderately destructive
7.0 Major damage
8.0 Total and major damage
9.0 Devastating in areas several thousand miles across.
10.0 Never recorded.
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How Does the Richter Scale Work and How Many Different Ways Are There to Measure Earthquakes?
The Richter scale measures the magnitude, or size, of an earthquake by using a seismograph to measure the ground motion an earthquake produces.
The scale is logarithmic. A measurement of 7 means an earthquake that has 10 times the ground motion of an earthquake that measures 6.
We can’t feel an earthquake that has a magnitude of less than 2.
Magnitude 5 earthquakes begin to cause real damage. The scale has no top number.
Another way to measure earthquakes is the modified Mercalli scale, which measures the intensity of an earthquake based on observations of the physical damage done.
It uses Roman numerals I through XII, in which I means no damage, VI means slight damage, and XII means total damage, with no structures left standing and objects thrown into the air.
A third way to measure earthquakes is the moment magnitude scale, which uses a seismogram to measure the movement of the Earth’s surface during the quake.
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How Does NASA Brew Beer In Space, What Does Space Beer Taste Like, and How Do You Drink a Coke In Space?
NASA is indeed interested in the questions raised by brewing beer in a microgravity environment.
Scientists who study the physics of gas-liquid mixtures would like to understand, for example, what happens when there is no buoyancy to bring the bubbles to the surface of a fizzy liquid, and the characteristics of fermentation in microgravity.
Two separate space shuttle experiments tackled these questions.
The first investigated how well yeast performs in orbital free fall, not only to see if brewing space-beer might be possible, but also to provide valuable information to pharmaceutical companies with a keen interest in the biology of orbiting microbes.
The space-beer turned out essentially the same as that brewed on Earth.
Its specific gravity and the yeast’s performance when used to brew subsequent batches of beer was comparable to that of control samples on Earth.
However, the total yeast cell count and the percentage of live cells in the space sample were lower. Despite this, the fermentation was significantly more efficient.
This raises the question of whether we can modify the fermentation process, or the yeast itself, to reproduce this effect on Earth.
The second experiment, flown on the shuttle by the Coca-Cola Company, was to test its system for dispensing Coke in a weightless environment.
The challenge was to dispense a fizzy beverage yet keep the gas in solution until the cola is drunk. Because bubbles don’t rise in free-fall, changes in temperature, pressure, or even physical agitation tend to cause the whole thing to degenerate into a foamy mess.
A computer-controlled device adjusted the temperature of the drink during mixing and dispensing, and minimized agitation by dispensing the drink into a collapsible bag inside a pressurized bottle.
The pressure around the bag was slowly released as it filled with drink, keeping the drink under constant pressure and preventing the gas from coming out of solution too quickly.
The end result was a space version of the world-famous fizzy drink.
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Why Did NASA Put the Hubble Space Telescope In Space and Why Do Space Telescopes Take Sharper Images?
Since telescopes were first used by Galileo in the early seventeenth century, astronomers have dreamed of placing them where Earth’s atmosphere would not get in the way of viewing the universe.
The Hubble Space Telescope (HST) fulfills that dream.
The Hubble Space Telescope, a reflecting telescope, is not the largest telescope made on Earth.
Its amazing clarity comes from its position beyond the distorting interference of Earth’s atmosphere.
Hubble’s earth orbit also allows it to take extremely sharp images with almost no background light.
The HST has a primary mirror that is 7.9 feet (2.4 m) in diameter.
In addition to the telescope unit itself, the Hubble Space Telescope has two cameras, two spectrometers, to break up the components of light, and a photometer, to measure brightness.
Its control system for locating stars uses gyroscopes and special star-tracking and sensor devices.
The Hubble Space Telescope is NASA’s baby, but an international effort went into its construction and outfitting.
In return for the help, other countries get observation time using the HST.
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Can the Hubble Space Telescope See the End of the Universe?
The space telescope Hubble that was put in orbit in 1990 is able to see seven times farther into space than any other telescope.
The space telescope was carried into orbit by the space shuttle. It is 45 feet long and consists of five separate astronomical instruments.
Astronomers expect to be able to zoom in on many things they do not now understand, such as quasars, pulsars, and black holes. Astronomers are wondering whether or not they will actually be able to see the ends of the universe.
The space telescope will provide us with a clearer picture of the heavens for two basic reasons. First, it will be beyond the dust in our atmosphere, so that its pictures will be much clearer. Second, some of the light from outer space is “screened†out by our atmosphere, which means that some information from distant stars and galaxies is not “getting through†to us.
The Hubble telescope is able to see everything much clearer than telescopes on earth.
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Why Do Stars Always Appear to Rise In the East and Set In the West and What Is a Circumpolar Star?
Many of the stars you will see in the night sky follow a path across the sky from horizon to horizon.
Circumpolar stars, however, appear to circle the northern and southern celestial poles without ever rising or setting.
This is because the celestial sphere appears to rotate on the axis between its poles, in fact, it is Earth that is rotating on its axis.
If you draw a circle around the celestial pole in your hemisphere, the North Star in the Northern Hemisphere, at a distance equal to the number of degrees of your latitude, the stars within that circle remain above your celestial horizon all night.
For example, if you are stargazing at 40° latitude, any stars within a 40° radius of the North Star do not rise or set, but are always visible traveling around the celestial pole.
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What Was Wrong With the Hubble Space Telescope When It Was First Put Into Orbit?
An error (1/50th the thickness of a human hair) in the curvature of the main mirror caused major focusing problems for the Hubble Space Telescope.
The 2.4 meter (94.5 inch) diameter mirror, was not able to focus all the light it collected to the correct point in the telescope.
NASA suffered great embarrassment for this multi-million dollar mistake.
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How Many Different Types of Precious Gems Are There On Earth?
Gems are valuable, but some are much more valuable than others.
Such gems as topaz, aquamarine, and garnet are called semi-precious, and cost much less than precious gems.
There are only four minerals that are considered precious gems today: diamond, emerald, and two forms of corundum, ruby and sapphire.
Pearl, which is not a mineral but the product of oysters, is also called a precious gem.
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When Was the Hubble Space Telescope Launched Into Orbit and Who Is the Hubble Telescope Named After?
Fortunately, NASA made plans for repairing the Hubble Space Telescope throughout its projected 15-year orbit.
Two months after the Hubble Space Telescope’s launch in 1990, it was discovered that the primary mirror had not been ground properly, among other problems.
The telescope could not be focused.
While this was a major embarrassment, the dangerous and complex repair mission was a coup.
The space shuttle Endeavor was launched in December 1993.
Its crew captured the Hubble Space Telescope, fixed it, and released it successfully.
The images and data returned since have more than outweighed the early difficulties, promising that the Hubble Space Telescope will be remembered for its scientific achievements rather than its flaws.
Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.
The Hubble Space Telescope is named after the astronomer Edwin Hubble.
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What Does the Word “Clock†Mean In French and Where Did the Word for a Large Timepiece Come From?
Like cloche in French, the word clock literally means bell.
When the large mechanical clock was invented in the fourteenth century it didn’t tell time with a face and hands, but rather by sounding bells on the hour and eventually the quarter and half-hour.
This time device was named a clock because it told time by sounding bells.
O’clock, as in twelve o’clock or five o’clock, is an abbreviation for “of the clock,†or “of the bells.â€
The word clock today is used for a large timepiece.
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Who Invented the Zodiac, What Does Zodiac Mean In Greek, and Where Did the Zodiac Signs Come From?
The zodiacal signs originate in Babylonian astronomy during Neo-Babylonian times around 7th century BC.
The real sky that the zodiac corresponds to is simply those constellations through which the sun appears to move during the course of the year as seen from the earth.
People living anywhere on the surface of the earth would pretty much see the sun take the same path in the sky relative to these stars.
The constellations that make up the zodiac are on a plane that can be seen in both hemispheres.
The orientation is different, but the stars are in the same positions relative to each other.
Ancient thinkers observing the changing positions of the stars that accompanied the changes in seasons developed the idea of the zodiac more than two thousand years ago.
They divided the sky into twelve equal sections, or signs.
Later astrologers came to believe that the position of the stars at the time of birth influences people’s lives.
Dividing the sky according to the zodiac is of little scientific use to astronomers.
The position of the earth in space has changed since ancient times, so the dates for each sign of the zodiac no longer represent the time when the sun is in the related constellation.
The word zodiac comes from the Latin word “zōdiacusâ€, which comes from the Greek word “ζῳδιακὸς κύκλοςâ€, which means circle of animals.
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How Does an Oyster Make a Pearl?
How Does an Oyster Make a Pearl?
The inside shells of oysters and other shell-forming mollusks are covered with a shiny, lustrous substance called nacre, or mother-of-pearl. Only tropical sea pearl oysters have the beautifully colored nacre necessary to make valuable pearls. Other edible clams and oysters also make pearls. But we would not recognize them as pearls, and they have no value.
When a foreign particle such as a piece of sand or a parasite enters the oyster’s shell, these nacre-producing cells set to work, covering the particle with layer upon layer of the nacre substance, until the particle is completely enclosed.
The color of the pearl will be the same as the nacre lining of the shell. That is why there are black (really a dark gray), pink, cream-colored, and white pearls.
It takes a pearl-producing oyster about seven years to make a moderate-sized pearl!
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Do Cats Eyes Really Shine In the Dark?
Have you ever walked into a darkened room and seen a cat staring at you with its eyes blazing?
Scary, but beautiful! There are no lights in a cat’s eyes. What you see is simply a reflection of light.
A cat’s eyes are no different than yours in responding to light. In bright light, you both have pupils which narrow to reduce the glare. And at night, your pupils and a cat’s pupils open wide to let in all the available light, thus permitting you to see in dim light.
But a cat’s eyes shine in the darkness because this light which is let in is reflected by a layer of cells in its inner eye. This layer of cells, the tapetum, is pink, gold, blue, or green. When the outside light changes, the tapetum acts like a mirror and reflects a different color.
This reflecting process gives cats an amazing ability to see in the dark, approximately seven times better than the ability of people.
Most cats have blue, green, yellow or orange irises in their eyes, but some cats have two different-colored eyes!
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Why Do Some People Put Pennies On the Eyes of Dead People and Where Did the Practice Come From?
Putting pennies on dead people’s eyes could have been used by many cultures to keep the eyes of the dead shut until rigor mortis sets in.
Some cultures, including the ancient Egyptians and more modern African Americans, have also used coins on the eyes and hands of the deceased to share with relatives in the spirit world or to pay for admittance into eternity.
In some Old World cultures, coins were used to keep the eyes shut for a specific reason: so that the living couldn’t see their own death in the eyes of the deceased.
Today keeping the eyes of the dead closed is more for aesthetic reasons than any other, especially since “viewing the body†has become commonplace.
Coins are rarely used, however. Nowadays, morticians employ one of two methods.
One is to use a device called an eye cap, which resembles a contact lens and actually fits over the eyeball. On the other side there are tiny “grippers†that keep the lids shut.
The other method is to place a thin line of adhesive on the lids to keep them shut.
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What Are the Advantages of the Hubble Space Telescope?
The Hubble doesn’t have a mirror as large as the new Earth-based telescopes, but being in space it is not limited by the distortions caused by variations in the refractive index of air above the telescope.
In addition, a space telescope can detect the infrared and ultraviolet rays blocked by Earth’s atmosphere.
Other space-based telescopes are designed to detect X rays and gamma rays from extremely energetic stars and galaxies.
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Where Did the Idiom “the Eleventh Hour†Come From and What Does the Phrase for the Last Minute Mean?
The reference is to the eleventh hour on the original clock devised by the Babylonians for use with their sundial.
The period from dawn to sundown, when a sundial was usable, was divided into twelve hours, so the eleventh hour came just before sunset.
In other words, if you did something at the eleventh hour, it was just before you ran out of daylight.
You’ll find this notion used metaphorically in Matthew 20:1-16.
From it we learn that even a sinner can find salvation at the last minute, even someone who procrastinates and doesn’t do what he has to do until, well, the eleventh hour.
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How Do Stars Move Across the Universe and Why Do Stars Move Across the Sky at Night?
Traditionally, people have thought of the stars as immovable and permanent, but they do move.
We know the stars move because we know that the universe is expanding.
But Earth is also moving in the expanding universe, so the movement of the stars is imperceptible, you can’t see it.
“Wait a minute,†you might say. “I can see the stars move across the sky every night. They rise in the east and set in the west, just like the Sun.â€
Just like the Sun, however, the stars only seem to move because Earth is rotating on its axis.
We are the ones who are moving relative to the stars.
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What Is a Reverse Mortgage?
So far, you have read about how important good credit and your income-to-debt ratios are to obtain a favorable mortgage. Now you can forget it. For a reverse mortgage, none of that matters.
What is important is that you are 62 years old or older and that your home is free and clear of any other loans and mortgages, or at least has a lot of equity. A reverse mortgage is a completely different type of loan. If properly used, it can be the best thing to happen to many seniors since Social Security.
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What Is a Reverse Mortgage?
So far, you have read about how important good credit and your income-to-debt ratios are to obtain a favorable mortgage. Now you can forget it. For a reverse mortgage, none of that matters.
What is important is that you are 62 years old or older and that your home is free and clear of any other loans and mortgages, or at least has a lot of equity. A reverse mortgage is a completely different type of loan. If properly used, it can be the best thing to happen to many seniors since Social Security.
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Are Cats Color Blind Like Dogs and Do They Only See Black and White?
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cats are color blind
Humans actually have better vision than cats, except in dim light. But we digress.
Domestic cats have rather poor color vision and can only see two colors: blue and green, and are less able to distinguish between red and green, although they can do so in some conditions.
Animals and humans have rods and cones in their eyes. Rods are sensitive to dim light, and for daylight, you need cells called cones.
These cones in the eyes enable animals to see color. Humans have three kinds of cones that allow them to see blue, red and green which means full color vision.
Cats as well as dogs have only two kinds of cones sensitive to blue and green light, which means they can see some colors, but not all.
Cats see well enough to perceive a movement that’s within their pouncing range and beat us handily in their hearing and sense of smell, both of which are especially useful in hunting.
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How Did Astronomy Begin and Why Did Claudius Ptolemy Believe That the Earth Was the Center of the Universe?
Before the invention of the telescope in the early seventeenth century, astronomy was based on observations made by the naked eye.
First, people mapped the positions of stars and planets in the sky.
Most cultures had their own systems for mapping the sky, but astronomy as we know it today has its roots in classical Greek theories.
In A.D. 150, the Greek astronomer and mathematician Claudius Ptolemy wrote an important treatise on astronomy.
In it, he listed forty-eight groups of stars called constellations, with names, such as Orion and Perseus, taken mostly from mythology. In the same way that we can imagine shapes of familiar objects when we look at clouds, so Ptolemy saw traditional figures in groupings of stars.
Ptolemy also noted that the stars seemed to move across the sky. He said that all celestial bodies revolved around Earth, which stood still in the center of the universe.
This was the accepted scientific theory for centuries.
Ptolemy’s view of the universe is called a geocentric model, because Earth (geo refers to Earth) stands at its center (centric means center).
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What Should I Do When My Child Argues With Her Friends?
“Katie, let’s play house. I’m the mommy; you’re the baby.†“No, I’m the mommy, or I won’t be your friend.â€
“Then I’m not playing with you.â€
This exchange is typical of what preschoolers say when they argue. They may play well together and then suddenly tell each other, “I’m not your friend.†Young children, whose emotions are close to the surface, concentrate on their immediate wishes and needs. And because they’re egocentric, they don’t consider each other’s feelings, but let their anger come out in harsh words or actions. Some children give in when spoken to in this way, while others fight back or persist until they get their way, or try to find an adult to help.
You may wonder what to do when you see this kind of behavior. You should begin by setting limits on your child, who is egocentric and needs your guidance; on her own, she doesn’t think about others when she’s mad. However, if you restrict her expressions of anger too much, she may end up believing that anger is bad and inappropriate.
Your child needs a chance to let her anger out, and even if you don’t like to hear her say, “I’m not playing with you,†or “You’re not my friend anymore,†you should realize that young children are not very good at expressing their exact thoughts. Harsh words are sometimes a young child’s way of letting her strongest negative feelings be known. One five-year-old told her aunt, “You say ‘nanny nanny boo boo’ when someone takes your toy, and you get it back.†She insisted, “You have to say that!â€
When it seems appropriate, you can let arguing children try to work out their differences themselves, as long as no one is getting physically injured or having his or her feelings terribly hurt. Children are sometimes surprisingly good at settling their arguments and can gradually learn to work problems out with one another. A child who seldom has a chance to settle her own arguments may become dependent on her parents for help even with minor difficulties.
Parents should also step in and give suggestions and guidance. “Why don’t you both pretend you’re mommies and let your dolls be the babies?†If one child shouts something mean to another, parents should avoid saying, “That’s not nice!†and instead say, “You’re really mad because Tanya doesn’t want you to play. Why don’t you tell her that?†Even if angry children ignore parents’ suggestions, the very presence of adults will have a restraining effect. Children tend to be less aggressive with each other when parents are nearby.
Young children also respond well when parents are clear. “You have to include her in your play.†“He doesn’t want you to yell at him, so you’ll have to stop.†“Tell her nicely what you want to do.†“I know you’re angry, but I won’t let you be mean to her.†And they benefit from their parent’s support: “Let’s go ask Sam if you can build the tower with him.â€
You can lessen your child’s involvement in arguments by avoiding situations that usually lead to problems. For instance, your child may play well with one child at a time, but not when a third joins in. Three can be a difficult number, two friends sometimes pair up and exclude the third. If you can’t avoid this situation, give all the children frequent reminders about getting along and including each other in play.
If your child consistently argues with one particular playmate, limit their time together or tell them, “You have to find a way to get along with each other.†Allow your child’s emotions to be heard, but when necessary, help her control her anger by changing the situation or setting firm limits.
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What Are Constellations, How Did Constellations Get Their Names, and How Many Constellations Are There?
Constellations are simply groups of stars that people have named for the sake of convenience.
People have been mapping constellations for thousands of years, usually naming them after mythological characters or common items that the group of stars resembles.
For instance, the constellation Leo looks like a seated lion.
If you were to connect the dots, or stars, you would draw a rough outline of a lion.
There are eighty-eight constellations officially recognized by the International Astronomical Union.
The most familiar may be the Big and Little Dippers, or the Great and Little Bear, respectively, and Orion the Hunter.
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What Is the Difference Between Dissecting Microscopes and Compound Microscopes?
Compared to compound microscopes, dissecting microscopes, also called stereoscopic microscopes-provide a much larger working distance between the lens and stage in order to dissect and manipulate specimens.
The light source on a dissecting microscope is above the specimen since the specimen is often too thick to allow light to be transmitted from a light source below the specimen.
Dissecting microscopes are always binocular, which provides a three dimensional image.
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Is It Normal for My Child to Speak Rudely to Me When He Is Angry?
“Be quiet, Dad. You never let me do anything!†“I don’t like you.†“You’re not fair! Leave me alone!â€
When a child is allowed to spontaneously express his anger, he may say rude, hurtful things, because he’s too young to consider his parents’ feelings. In the heat of the moment, he says what he’s thinking, and he doesn’t understand adult reasoning.
Anger at parents is a normal part of growing up. Learning how to express negative feelings in socially acceptable ways takes time. It also takes patience on the part of parents. Yet many parents react harshly. “Don’t you dare talk to me that way!†“I don’t want to hear that tone of voice.†If parents overreact toward their child for his disrespectful words, he may learn that feeling angry is bad and that angry thoughts shouldn’t be spoken.
While some parents overreact, others feel helpless when faced with outbursts. “Should we allow this behavior?†“Why does he talk this way?†“Am I setting enough limits?†Many parents grew up with strong restrictions on their speech. “Don’t ever say that again. It’s not nice.†They may be reluctant to impose similar restrictions on their child’s expressions of anger, yet they feel uncomfortable listening to him say things they would never have said as children.
Your child needs a chance to speak his angry thoughts, but you also need to put limits on how he expresses himself. If certain words or attitudes are unacceptable to you, tell him. “It’s all right for you to be mad at me, but you’ll have to change your tone of voice.†“When you stop name-calling, I’ll be happy to listen to you.†“I don’t like it when you talk to me that way.†“You’ll have to find another way to tell me about being angry.†Not only do such statements guide him toward better ways of expressing anger, but they demonstrate a respectful way of communicating that you’d eventually like him to adopt.
As you help him control the way he speaks to you, consider his age; a young child lacks communication skills. Also, remember that your child is greatly influenced by your behavior. If you expect him to speak respectfully, offer examples. Don’t say, “Get over here this minute!†“Stop acting like a baby.†“You better listen to me!†Instead, talk to him and treat him as you would like him to treat others.
With patience, limits, and guidance, he’ll gradually learn to express most of his feelings appropriately. However, if you become concerned that he can’t control his anger, consider seeking outside help, such as a parenting class. The way you treat this issue now will set the tone for communication with your child later.
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Can Cats See In the Dark and Do Cats Have Night Vision In Complete Darkness?
Cats have excellent night vision and can see at only a fraction of the light level required for human vision.
But even with their powerful night vision, cats cannot see in complete darkness.
No animal can see in the dark without at least a little light, however, cats have a distinct advantage on us in the dark.
For one thing, their pupils can expand three times wider than ours can.
Also, they have a layer of crystalline material behind their retinas that reflects light back out, giving their eyes a second chance to pick up images.
This layer, called the tapetum lucidum, is also the reason that cats’ eyes shine eerily at night when they catch a glint of light.
Unfortunately, what cats gain in night vision they lose in daytime sharpness.
While their eyes are perfectly suited to picking up movement, their overall vision is blurry, so much so that if something stops moving, the cat is likely to lose track of it.
Which is why you sometimes see cats watching television, but almost never catch them reading a book.
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How Should I React When My Child Says “I Hate You Mommy�
When your young child gets angry with you, she may shout, “I hate you. You’re dumb!†This outburst might come after you’ve said she can’t go outdoors or have a friend over or do something else she wants to do.
A preschooler has a hard time putting her exact feelings into words. She doesn’t know how to say, “Daddy, I think you should let me stay up later tonight because…†or “I’m angry with you because you said…†She’s too young for such articulation and too young to show that kind of respect. Instead she expresses her feelings and anger by saying, “I hate you.â€
Some parents accept and understand these words as the beginning of their child’s expression of angry, negative feelings. But all parents can feel betrayed when their child, after receiving love and attention, turns on them over a minor disappointment. It can be frustrating when adult reasoning, logic, and caring fail to keep a child from yelling, “You mean Mom!â€
Parents may be tolerant of a three-year-old yelling, “You dumb Mom!†but it’s harder to be understanding when a four-or five-year old says, “I hate you.†A child’s words can feel threatening to parents who don’t like their children to be angry with them. And parents worry that a bad habit could develop.
It is common for parents who hear “I hate you†to say to their child, “That’s not nice! Don’t let me hear those words again.†But a child needs to release her angry feelings somehow, and if she isn’t allowed to express them verbally, she’ll find other, perhaps more destructive ways. She might turn to aggressive behavior such as hitting, or she might take out her anger by becoming deliberately slow, acting excessively silly, or pretending she doesn’t hear her parents. However, if her angry feelings are acknowledged and allowed to be expressed, she’ll eventually learn to state her feelings more appropriately.
If your child says, “I hate you,†offer her other ways to tell you how she feels. Suggest she say, “I’m mad at you,†or “I’m angry,†or “I don’t like what you did.†Acknowledge her feelings, but say, “I want you to tell me in different words.â€
And remember, children are natural mimics. Your child uses the word “hate†because she hears it so often. Adults say, “I hate this dress,†“I hate when it rains,†or “I hate it when people do that.†It’s natural for your child to use the word to express her dislike of something or someone, or to point out when you’ve said the word: “Aw, you said hate.†You can take advantage of the fact that she’s a mimic, stop using the word hate, and gradually teach your child to express her anger in acceptable ways.
When your child says, “I hate you,†rather than make an issue of the words, simply restate her words and feelings. Say back to her, “You’re really angry at me, aren’t you? You don’t like it when I say it’s time to come in.†If she hears you express her anger and disappointments in this way, she’ll gradually begin to use similar statements herself.
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What Is the Most Common Vegetable In the World?
The vegetables that are grown in the largest quantities around the world are the tomato and the potato. But the most widely used vegetable is the onion!
The onion appears in more dishes and in more countries than any other vegetable. In some places, the onion is used to flavor dishes, while in other countries it’s eaten by itself as a vegetable.
The ancient Egyptians ate onions both ways, for the onion was the most common vegetable in Egypt 5,000 years ago. During the Middle Ages, the onion and a relative of the onion, the leek, were the only common vegetables in Europe.
Today, more than 20 billion pounds of onions are produced around the world each year!
Emperor Nero of Rome ate leeks because he thought they would improve his singing voice!
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What Is the Most Common Vegetable In the World?
The vegetables that are grown in the largest quantities around the world are the tomato and the potato. But the most widely used vegetable is the onion!
The onion appears in more dishes and in more countries than any other vegetable. In some places, the onion is used to flavor dishes, while in other countries it’s eaten by itself as a vegetable.
The ancient Egyptians ate onions both ways, for the onion was the most common vegetable in Egypt 5,000 years ago. During the Middle Ages, the onion and a relative of the onion, the leek, were the only common vegetables in Europe.
Today, more than 20 billion pounds of onions are produced around the world each year!
Emperor Nero of Rome ate leeks because he thought they would improve his singing voice!
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Why Is the Sky Blue On a Clear Day and How Does Rayleigh Scattering Cause the Red Colors at Sunset?
The sky is blue on a clear day because of a process called Rayleigh scattering.
Light arriving from the sun hits the molecules in the air and is scattered in all directions. The amount of scattering depends dramatically on the frequency, that is, the color of the light.
Blue light, which has a high frequency, is scattered ten times more than red light, which has a lower frequency. So the background scattered light we see in the sky is blue.
This same process also explains the beautiful red colors at sunset.
When the sun is low on the horizon, its light has to pass through a large amount of atmosphere on its way to us. During the trip, blue light is scattered away, but red light, which is less susceptible to scattering, can continue on its direct path to our eyes.
According to classical physics, an accelerated charge emits electromagnetic radiation.
Conversely, electromagnetic radiation may interact with charged particles causing them to oscillate. An oscillating charge is continually being accelerated and hence will re-emit radiation. We say that it becomes a secondary source of radiation.
This effect is known as the scattering of the incident radiation.
The atmosphere is, of course, composed of various gases that together form air. We may treat each air molecule as an electron oscillator. The electron charge distribution of each molecule presents a scattering cross-section to the incident radiation.
This is essentially an area upon which the incident radiation must fall for scattering to occur. The amount of scattered radiation will depend upon the magnitude of this cross-section.
In Rayleigh scattering the cross-section is proportional to the fourth power of the frequency of the incident radiation. Sunlight is composed of various visible frequencies ranging from low frequency (red) to higher frequency (blue) light.
Because it is of a higher frequency than other visible components, the blue part of the sun’s spectrum will be scattered more strongly. It is this scattered light that we see and so the sky appears to be blue.
Incidentally we are also able to explain why sunsets are red. When the sun is close to the horizon its light must travel through more atmosphere.
The blue light will be scattered strongly whereas red light, because it is of lower frequency is less prone to scattering and so is able to travel straight to the observer.
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How Did Copernicus Change the Ptolemaic System?
The system introduced by Nicolaus Copernicus (1473–1543) was that Earth and all of the planets revolved around the sun in concentric circles. Copernicus was further able to reduce the number of postulated epicycles to 34, still saving the appearances, or not contradicting what was observed. This shifted the fundamental frame of astronomical reference from Earth to the fixed stars. As he wrote:
First and above all lies the sphere of the fixed stars, containing itself and all things, for that reason immovable; in truth the frame of the Universe, to which the motion and position of all other stars are referred. Though some men think it to move in some way, we assign another reason why it appears to do so in our theory of the movement of the Earth.
Of the moving bodies first comes Saturn, who completes his circuit in xxx years. After him, Jupiter, moving in a twelve year revolution. Then Mars, who revolves biennially. Fourth in order an annual cycle takes place, in which we have said is continued the Earth, with the lunar orbit as an epicycle. In the fifth place Venus is carried round in nine months. Then Mercury holds the sixth place, circulating in the space of 80 days.
Copernicus’ conclusions were based mainly on mathematics, drawing on the perennial value of simplicity and the doctrine that nature always behaves in the most “commodious†(simple) way. To the objection that objects would fly off a moving earth, he responded that a moving sky, because it was larger, would move even faster and do more damage.
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How Much Newspaper Must Be Recycled to Save One Tree?
One 35 to 40 ft (10.6 to 12 m) tree produces a stack of newspapers 4 ft (1.2 m) thick; this much newspaper must be recycled to save a tree.
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What Great City “Disappeared�
Late in the 16th century, an architect building an underground water main in southern Italy came upon the buried ruins of an old city under 30 to 50 feet of ashes, stones, and mud as hard as concrete.
The city was Pompeii, a flourishing town during the days of the ancient Romans that had “disappeared†and had been forgotten through the Middle Ages. In 1748, workers began to dig out the ruins of the old town, and today Pompeii can be visited by anyone who wants to see what life was like in ancient Italy.
Pompeii “disappeared†after an eruption of the volcano Mt. Vesuvius on August 24, 79 A.D. An estimated 20,000 to 30,000 people perished, as volcanic dust and ash settled on Pompeii and the nearby town of Herculaneum, covering them to a depth of up to 20 feet.
When the city was dug out, many of the homes looked just as they had in 79 A.D., at the moment of the eruption. Some kitchens still contained food that had been buried by the volcano and remained untouched for almost 1,700 years!
Vesuvius erupted during an election campaign in Pompeii, and some houses still have election slogans on their walls!
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How Many Volcanoes On Earth Erupt Every Year?
About 60 volcanoes in the world erupt somewhere on land every year.
Many others erupt on the ocean floor.
United States is third in the world in volcanic activity, behind Indonesia and Japan.
Volcanoes are usually found near tectonic plates that are diverging or converging.
The Pacific Ring of Fire is a good example an area with volcanoes caused by convergent tectonic plates coming together.
The Ring of Fire has about 452 of the world’s active and dormant volcanoes.
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How Did the Greeks Figure Out the Size of the Earth?
The Greek Eratosthenes, who lived around 250 B.C., was the first man we know of to figure out the size of the earth. Yet he never traveled around the earth, nor did he have any of today’s measuring equipment. How, then, did he do it?
Eratosthenes used Euclid’s principles of geometry to solve the problem. First he learned that at noon on the longest day of the year, the sun shone straight down to the bottom of a well in the Egyptian city of Syene.
At the same time, in the city of Alexandria, the sun caused an upright post to cast on the ground a shadow shaped like a right triangle, a triangle with one 90° angle. Eratosthenes then measured the other angles and found that one angle was equal to 1/50 of an entire circle.
He then determined that if the lines formed by the post at Syene and the well at Alexandria were extended downward, they would form two sides of another right triangle at the center of the earth. Again using geometry, Eratosthenes proved that one angle of the second triangle was equal to one angle of the first triangle or 1/50 of an entire circle.
Since the earth’s circumference between Syene and Alexandria formed an arc, that arc was also equal to 1/50 of the earth’s circumference. Eratosthenes knew that the distance between Syene and Alexandria was 5,000 stadia (a Greek measure), so he then multiplied it by 50, and found that the distance around the earth was 250,000 stadia, or 24,670 miles.
How close was Eratosthenes back in 250 B.C.? The circumference of the earth is now known to be 24,900 miles! Quite a feat for a time so long ago!
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How Did Birthdays Come to Be?
Birthdays are one of our very oldest customs. We can suppose that prehistoric mothers and fathers noticed that their children grew up in stages. One day, the baby could only gurgle; then the next, he might repeat a word he heard his parents say.
One day, a baby could only crawl; then the next, he stood up and walked. All of these changes probably seemed mysterious and frightening to prehistoric parents. And they feared anything that was new or different.
To be certain that their children continued growing safely, these parents held ceremonies to scare off evil spirits who could harm their offspring. They offered gifts to the spirits so their children would be protected.
They also gave gifts to their children to encourage them to grow. At these ceremonies, the children played games and held contests to show how strong and skillful they were becoming with each new year.
The custom of testing a child’s strength at his birthday celebration continues today. The big breath needed to blow out the candles on a birthday cake is really a test of strength, a way for modern people to carry on an old custom!
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What Is the Most Read Newspaper In the World?
Right now, there are more than 7,000 newspapers published around the world, and about a quarter of them are American papers. Each day, Americans buy some 61 million copies of their favorite papers!
The largest-selling paper in the United States is the New York Daily News, which sells about two million copies each day. The Wall Street Journal is second, with about 1.5 million copies sold daily. The Los Angeles Times is third, and the New York Times is fourth.
But of all the newspapers in the world, a Russian paper called Pravda has the largest circulation. About ten million copies of this newspaper are printed each day!
Sixty years ago there were more papers in America than there are today, 2,461 compared to 1,759 today!
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Can Cats See In the Dark and Do Cats Have Night Vision In Complete Darkness?
But even with their powerful night vision, cats cannot see in complete darkness.
No animal can see in the dark without at least a little light, however, cats have a distinct advantage on us in the dark.
For one thing, their pupils can expand three times wider than ours can.
Also, they have a layer of crystalline material behind their retinas that reflects light back out, giving their eyes a second chance to pick up images.
This layer, called the tapetum lucidum, is also the reason that cats’ eyes shine eerily at night when they catch a glint of light.
Unfortunately, what cats gain in night vision they lose in daytime sharpness.
While their eyes are perfectly suited to picking up movement, their overall vision is blurry, so much so that if something stops moving, the cat is likely to lose track of it.
Which is why you sometimes see cats watching television, but almost never catch them reading a book.
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Thanks Mr. Ansary for your productive post. There are many things that we are not yet aware in this world. However, we should have knowledge on these interesting things.
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Why Is a Newspaper Called a “Gazetteâ€, What Does It Mean, and Where Did the Word Come From?
In 59 B.C. Julius Caesar introduced the first handwritten daily newspapers, which were posted in prominent locations around Rome.
However, it wasn’t until long after Gutenberg’s printing press was invented that news became an industry.
During the mid-sixteenth century, citizens of Venice paid to hear public readings of the news.
The price for these readings was a small copper Italian coin called a gazetta, which gave us the word gazette for a newspaper.
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Why Does Salt Melt Snow and Ice?
When you put salt on ice or snow, it begins to melt. This is because the salt lowers the freezing point of water. The more salt added, the more it melts.
As the salt dissolves, it creates heat, melting more water and dissolving more salt. That’s why towns plow roads to clear them of snow and then put salt on them to melt the remaining ice and keep it from freezing up again.
Fresh, unsalted water starts to freeze at 32 degrees F., but water with even a small amount of salt in it won’t begin to freeze until the temperature drops to 28 degrees F.
Unfortunately, salted sidewalks and streets can be harmful to your pet’s feet. If you walk them in an area that has been salted, be sure to wash their feet afterward.
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How Does a Chameleon Change Colors?
Chameleons are lizards known for their ability to change colors. But contrary to popular belief, the chameleon does not change its color to match its background. It changes as a result of its mood, the temperature, or light conditions.
Most chameleons have brown or green as their main color, but they can turn to an off-white, yellow, or light green. When they are cold, their color is lighter than when they are warm.
The chameleon’s skin has several layers, with different color pigment cells in each layer. The inner layer has black pigment cells. The chameleon’s nerves control the expansion and contraction of the color cells. When the black cells either move closer to or farther from the skin surface, they blend with, blot out, or intensify other cells. This causes the chameleon’s color to change.
The chameleon’s tongue, which always hits its prey, can be extended more than twice the length of the chameleon’s body!
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What Are X-Rays and When Were X-Rays Discovered?
X-rays are electromagnetic radiation with short wavelengths, 10-3 nanometers, and a great amount of energy.
They were discovered in 1898 by William Conrad Roentgen (1845-1923).
X-rays are frequently used in medicine because they are able to pass through opaque, dense structures such as bone and form an image on a photographic plate.
X-rays are therefore commonly used to take images of the inside of objects in diagnostic radiography and crystallography.
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What Is the Moon’s Landscape Like and What Other Features Does the Surface of the Moon Have Besides Craters?
The Moon’s surface has highlands and lowlands just like earth.
The main feature on the Moon’s surface are the hundreds of thousands of craters, or the remnants of craters, found in both regions, some with crater rays of ejected lunar material emanating out from their edges.
Besides craters, there are mountains, mares, rills, and domes.
The South Pole-Aitken basin is the largest, deepest and oldest basin recognized on the Moon.
At about 2,240 km in diameter, it is also the largest known crater in the Solar System.
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Is Snow Frozen Rain?
Hail or sleet is frozen rain, but snow is never formed as a frozen raindrop.
Snow forms from ice crystals high above the earth. These particles turn into snow without first becoming rain.
At the height that snow usually forms, the temperature is from 20 to 60 degrees below zero, far too cold for water to exist as a liquid.
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How Does Soap Get You Clean?
Have you often felt what a bother it was to use soap when a quick swish of your hands under plain water would do just as well? Most kids prefer it that way. But while water alone may remove some of the dirt from the surface of your skin, soap added to the water does get you cleaner.
If you looked at a cross-section of your skin under a microscope, you would see that it has many hollow areas, or valleys, where particles of grease and dirt can become embedded. Water alone may get under the dirt and push some of it out, but when that water hits grease, it will simply sit on top of it in a bubble or just roll off.
But add soap to that very same water and you have a completely different action. The action of mixing soap into water pumps air into the water and forces it to spread out as it creates bubbles. A bubble is actually a balloon of air with a thin outer covering of soap and water.
While bubbles seem to be very delicate and weak things, they actually work like dozens of strong magnets. Just as magnets pull tacks towards them, soap bubbles-pick up dirt and pull it away from the skin. Then the dirty bubbles are carried away in the rinse water, leaving your skin clean.
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Why Are There More Female Babies Born Than Males?
In fact, each year more males are born than females. The normal slight excess of male births is usually attributed to the slightly greater motility of sperm carrying the male, or Y, chromosome.
It was recently discovered that in the average ejaculation, there are slightly more sperm carrying the X chromosome, necessary for conception of a female, than there are sperm with the Y chromosome. But emerging studies of embryos that have been conceived through in vitro fertilization indicate that more males are actually conceived.
Scientists suggest that the Y-bearing sperm are so much better at fertilizing eggs than the X-bearing ones that even though there are fewer of them to begin with, they end up penetrating more than half of all eggs.
What happens to the sex ratio after conception is another story. For example, in societies where women are not valued as much as men, they may be purposely aborted, neglected, or actually killed. In others, where men are subjected to greater stress or risk (from wars, for example), more women survive longer.
The ratio of males to females can vary from time to time and from population to population, whether it is animals or people, and there are numerous suggested reasons.
For example, it has been reported that women in lower socioeconomic groups, presumably under greater stress, bear slightly more girls than boys.
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What Is a Balloon Mortgage?
The balloon mortgage offers very low interest rates in the beginning and then after a certain period of time the balance either must be refinanced or paid in full.
In a variety of the balloon mortgages, after the specific time period, the loan is recalculated with the interest based on a specific index or margin, which makes the total payment significantly increase.
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What Makes the Stars Twinkle?
Not only does the light from the stars appear to twinkle or jump about, it also appears to change color.
When the light from the stars is traveling through space, there is no twinkling or changing of color. It is the earth’s atmosphere that makes the stars twinkle and change color.
This is brought about by the winds in the earth’s atmosphere, which make tiny dust particles move at different speeds. Light passing through these jumbled layers is refracted and appears to change color and jump about.
Some nights the stars appear to jump about more than usual. That’s because on that night there are greater differences in the speeds of the winds in the atmosphere.
Did you know that when you look at the stars with a big telescope, all the twinkling is exaggerated? Sometimes the stars jump about so much astronomers just give up and turn off their big telescopes.
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What Are the Most Common Surnames In the United States?
The most common surnames in the United States in order, are Smith, Johnson, Williams, Jones, and Brown.
A surname is a name added to a given name and in many cases, a surname is a family name.
In Western countries, a surname is also known as a “last nameâ€, but in many countries in Asia, the family name, or surname, comes before the person’s first name.
In Iceland, however, most people do not use family names. Instead, a person’s surname indicates the first name of the person’s father.
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What Do You Do If a Deer Runs Out In Front of Your Car While You’re Driving?
If a deer runs out in front of your car, stay calm, and try not to further endanger yourself, your passengers, other traffic, or the deer as you would in any other collision situation.
But there are several preventative steps you can take to avoid running into deer in the first place.
The first is being aware of the season. Deer are most prevalent in June, when young fawns are on the move, and from October through December (mating season).
A good thing to remember during these times, and always, is to lower your speed in heavily deer-populated areas; if you see deer signs, heed them.
And keep your eye especially keen during the dawn and dusk hours, when deer are most active.
Most car-deer collisions happen during these low-light times of day. If you do hit a deer, some states allow you to keep the carcass.
Whether you want venison for dinner or not, contact the authorities and alert them about the hit immediately.
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What Battle Was Fought After the War Was Over?
One of the most famous battles of the War of 1812 was the Battle of New Orleans, in which General Andrew Jackson and his troops defeated a larger British army.
The battle was fought on January 8, 1815, 15 days after a peace treaty between the United States and England had been signed in Europe. But the news, which came across the Atlantic Ocean on a ship, didn’t reach Jackson or the British troops before the battle.
Although the Americans were outnumbered more than two-to-one at New Orleans, they lost only 71 men while the British lost 2,000!
At the time of the battle, even President James Madison in Washington, D.C., didn’t know about the treaty or the battle!
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How Far Is It to the Center of the Earth and How Hot Is the Inner Core of the Earth?
It’s about 3,700 miles (5,957 km) to the center of the earth.
The inner core of the Earth is believed to consist of an iron-nickel alloy, and may have a temperature similar to the Sun’s surface.
The existence of an inner core that is distinct from the liquid outer core was discovered in 1936 by seismologist Inge Lehmann using observations of earthquake-generated seismic waves that can be detected by sensitive seismographs on the surface of the earth.
The temperature of the inner core is estimated by using the melting temperature of impure iron at the pressure of the inner core boundary, which leads us to a figure of 5,700 K (5,430 °C; 9,800 °F).
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Do Continents Move?
We’ve all looked at the globe and studied the shape and position of the land masses called continents. But the size and the shape of the continents have not been the same during all of the earth’s history.
Parts of the continents were once covered with water, while parts of the sea were once dry land. And scientists are now sure that the continents themselves are moving.
The idea that continents move is called the theory of continental drift. According to this idea, the earth’s mantle, the layer between the outer crust and the core, moves either continually or in fits and starts. The movement of the earth’s mantle probably began more than 200 million years ago, and continues at a rate of about an inch a year.
Scientists who believe in the continental drift theory think that the Western and Eastern Hemispheres were once joined, and have gradually moved away from each other over the last 200 million years.
Therefore, the Atlantic Ocean has been getting bigger as the Western Hemisphere moves away from the Eastern. If this movement continues, the Western Hemisphere would move across the Pacific Ocean toward Asia, and the Pacific Ocean would someday disappear!
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What Happened In Athens After Both Plato and Aristotle Were Gone?
Athens remained the center of philosophy until the Romans sacked it in 87 B.C.E.
Much of our knowledge of Hellenistic philosophical activity comes from the first century B.C.E. Roman writers Lucretius (99–55 B.C.E.) and Cicero (106–43 B.C.E.), and secondary medieval sources. Plato’s Academy became the New Academy, which was devoted to critical work on the thought of other schools.
This was the beginning of the skeptics. Aristotle’s Lyceum, or the Peripatos, was first led by Theophrastus in 322 B.C.E., but after 287 B.C.E., it fell into decline until the middle of the first century B.C.E.
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What Is the Most Popular First Name for a President In the United States?
What Is the Most Popular First Name for a President In the United States?
James is the most popular presidential first name in the United States.
Six of the presidents have been Jims.
Tied for second most popular, with four presidents each, are John and William.
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What Is Sense Knowledge?
Sense knowledge is information gathered through our senses, such as sight, touch, hearing, and so forth.
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Why Is the President of the United States Called “Mr. President†And How Did the Nickname Originate?
The president of the United States was not always called “Mr. Presidentâ€.
Washington wanted citizens to call him “His Mightiness, the President,†but to many people, that sounded too much like addressing the king they’d fought so hard to shed.
The next president, John Adams, thought he should be called “His Highness, the President of the United States and Protector of their Liberties,†but even fewer people went along with that.
Finally, Thomas Jefferson began shedding the trappings of imperialism that earlier presidents had insisted on.
After his inaugural, he walked back to his boarding house instead of riding in a coach.
He was also the first president to actually shake hands with ordinary people, previous presidents had greeted people only with a slight, dignified bow.
People began calling him “Mr. President,†a good mix of respect and equality.
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What Is the Oldest City On Earth?
Man’s earliest surviving written records date from around 3500 B.C.
By scientifically testing objects found on the site of ruins, historians have found that the oldest city on earth is probably Jericho, which is near the Dead Sea in present-day Israel.
As many as 3,000 people may have lived there around the year 7800 B.C., thousands of years before man even learned how to write!
But another, smaller village in Mesopotamia may be even older than Jericho. The city, called Zawi Chemi Shanidar, was probably founded around the year 9000 B.C.!
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Who Invented Calculus and What Does the Word Mean?
The Pythagoreans-ancient Greek followers of the mathematician Pythagoras-were a brilliant lot.
They came up with the mathematical truism, The square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.
They also mathematically figured out the correct shape of Earth. In working out mathematical equations, the Pythagoreans practiced simplicity, using little rocks to represent numbers.
Thus, the word calculus means “pebbles†in Latin.
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Who Was the Smartest President In the United States and Why?
It’s hard to say for sure who the smartest president in the United States was, but James Garfield must be up there in the top percentile.
He was a college professor in ancient languages and literature and once published a mathematical proof of the Pythagorean theorem.
An ambidextrous man, Garfield also had a nifty trick that is probably the best example of presidential multitasking: He could simultaneously write Latin with one hand and Greek with the other.
Another candidate for most erudite president is Herbert Hoover, who translated ancient texts from Latin.
When he and his wife wanted to speak privately when other people were present, they conversed in Mandarin Chinese.
What’s interesting, though, is that neither of these men were considered great presidents, so it may be true that intelligence is not necessarily a requirement of the job.
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How Was Radar Invented and When?
Radar is now essential safety equipment for ships and planes, but it was planned as a deadly weapon.
Bouncing Waves. Radar uses radio waves to detect objects and can plot their position, course and speed. Various inventors helped develop it. German physicist Heinrich Hertz discovered radio waves in 1888 and found that they could bounce off other objects.
In 1904 Christian Hulsmeyer invented a way of detecting ships using radio waves, although his `telimobiloscope’ couldn’t measure distance.
Rudolf Kuhnold demonstrated the first practical radio detection equipment in Germany in 1934.
In 1935 the British government asked physicist Robert Watson-Watt to research radio waves and their use in destroying enemy planes. Watson-Watt quickly concluded that radio waves couldn’t be used as death-ray weapons but discovered that by bouncing radio waves off planes and measuring the delay in the echo, the direction and distance of the plane could be calculated. Only a few weeks after he’d begun his research, Watson-Watt demonstrated radar by plotting the course of an aircraft.
Radar was developed independently in Germany and the USA and was used extensively in the Second World War to plot enemy ships and planes. A US Navy Commander came up with the name, RAdio Detection And Ranging.
Magnetrons: The radio waves used in radar are generated by magnetrons, invented by John Randall and Henry Boot. Wartime radar operators discovered that magnetrons could be used as water heaters for their tea. Today they are used in microwave ovens.
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How Do Astronomers Study Galaxies and Figure Out What Happened Billions of Years Ago?
By studying galactic light that originates 300 million light-years away, astronomers can look at galaxies that are 300 million years younger than the Milky Way.
The light we see today started traveling 300 million years ago, so it represents the source galaxy as it was 300 million years ago.
Galaxies at different distances portray different stages of galactic evolution.
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Why Can Fossils Be Misleading In the Study of Evolution?
The fossil record is biased toward organisms who were very common, who may have had hard shells or bony structures, and whose species lasted a long time.
Therefore, it does not give us a full picture of what species may have been active in the evolutionary past.
Fossils are also unlikely to record soft structure changes such as an increase in muscle mass or the development of new organ systems.
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Who Were Some Important Women Philosophers From Antiquity?
Although they probably are but the tip of an iceberg, Themostocles, Theano of Crotona, Diotima of Mantinea, Aspasia of Miletus, Aesara of Lucania, Phintis of Sparta, Perictione I, Theano II, Hypatia of Alexandria, Ascepigenia of Athens, and Arete of Cyrene deserve specific mention.
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What Are the Most Common Surnames In the United States?
The most common surnames in the United States in order, are Smith, Johnson, Williams, Jones, and Brown.
A surname is a name added to a given name and in many cases, a surname is a family name.
In Western countries, a surname is also known as a “last nameâ€, but in many countries in Asia, the family name, or surname, comes before the person’s first name.
In Iceland, however, most people do not use family names. Instead, a person’s surname indicates the first name of the person’s father.
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What Is the Skin That Forms On the Surface of Milk When It Is Heated?
The skin that forms on the surface of milk when it is heated is a complex of casein, or milk protein, and calcium, and results from evaporation of water at the surface of the heated liquid and the concentration and coagulation of protein there.
Skimming the skin off removes significant amounts of nutrients.
Skin formation can be minimized by covering the pan or whipping up a little foam; either slows down evaporation.
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What Is Thunder?
When electricity is given off through lightning, it heats the air in its path. This heating makes the air expand quickly and often violently.
The molecules of heated air fly around in all directions and collide with cooler, distant air. This collision sets up a “wave†of noisy, rumbling air called thunder.
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How Are Fossils Dated and What Are the Two Methods of Dating Fossils?
The first is known as relative dating.
By determining the age of the surrounding rock, scientists can give an approximate age to the fossils therein.
Rocks are dated by their distance from the surface, with older rocks generally deeper from the surface.
Using the data from other fossils found in the same rock stratum can also be used to give an approximate date to a new sample.
The second method is known as absolute dating.
Absolute dating relies on the known rates of radioactive decay within rocks.
By measuring the ratio between the radioactive forms of an element like uranium-238 to its nonradioactive, “decayed†form, scientists can determine when the rock formed, because that would be when the radioactive isotope was acquired.
Amino acids also convert gradually from one form (the lefthanded) to another (right-handed) after an organism dies and so may be used as a method of dating some fossils.
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Does Canada Have a President and a Congress Like the United States?
Canada does not have a president and a congress like the United States.
The Canadians are led by a prime minister, who is the leader of the political party that wins the most seats in its parliament.
The parliament of Canada consists of the Senate and the House of Commons.
The 104 senators are appointed by the 10 provincial governments, and they may serve until they are 75 years old.
The 301 members of the House of Commons are elected by the people and serve up to 5 years.
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Why Did Indians In Old Movies Put Their Ears to the Ground to Find Out If the Cavalry Was Coming?
Depending on variables like the size of the troop and the type of terrain, the Indians may have been able to hear the troops from quite a distance.
There are many factors involved in the seismology of such a phenomenon, and only individual experiments would determine how much energy would be coupled into the ground and how far the sound would be transmitted.
For example, what is the strength of the source? Are all the forces pushing on the earth together at the same time, or is it random noise?
If the approaching army is on horses, it is probably random noise, while soldiers marching in step would present a different set of factors.
Another important variable is the kind of terrain.
Hard rock would not carry the sound very far, because a running horse does not move the ground much, so not much seismic energy is coupled into the ground.
On the other hand, if there is a river basin with consolidated sediment, and the cavalry is on the road upriver, with the Indians around the corner on the same sedimentary formation, the soil would be a good conduit, and they could hear for quite a way.
If the soil is wet, however, the energy of the horses’ hooves might go into deforming the ground, rather than vibrating it.
A listener along a railroad track might have an advantage.
Seismic energy travels along a linear body, and a train is much heavier than a horse, visibly bending the track when it passes over it.
Therefore, the track would carry sound well, almost like a vibrating wire.
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Who Invented Money and Why?
Money is defined as anything that can be accepted as payment for goods or services. It is also used as payment of debt.
money us 20 dollar bill
Early uses of money began with the bartering of goods almost 100,000 years ago. Goods were exchanged for other goods and this developed the commodity money system. Commodity money is money whose value comes from the object itself. In other words, objects that have value in themselves as well as for use as money.
One of the first forms of currency is The shekel. It was was originally both a unit of currency and a unit of weight and originated from Mesopotamia around 3000 BC. Many cultures in Asia and Africa used shell money which was usually the rare cowry shell.
Eventually, commodity money was replaced by Representative money. Representative money is what most of us are familiar with and are token that represents a fixed monetary value. Examples of Representative money are coins, bank notes or bills, cheques and bank drafts.
The word “money†comes from from a temple of Hera, which sits on on Capitoline, one of Rome’s seven hills. Money was invented to serve three functions, as a medium of exchange, unit of account, and store of value.
Today, the exchange of money and commodity drives the world economy, and as they say on TV, makes the world go round.
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What Is the Stupidest Animal That Ever Lived?
It’s hard to say how smart or stupid an animal is, because animals may show their intelligence in ways that we don’t recognize.
But if the size of an animal’s brain in relation to the size of its body is any sign of intelligence, then the stupidest animal that ever lived was probably the dinosaur called stegosaurus. This huge reptile weighed some 13,000 pounds, yet had a brain that weighed only about 21/2 ounces!
A sperm whale 50 feet long would have a brain weighing about 20 pounds, while an adult elephant’s brain weighs about 10 pounds. A gorilla’s brain weighs about 20 ounces, and an adult person’s brain usually weighs around 3 pounds.
Your brain probably weighs more than 15 times as much as the brain of the huge stegosaurus.
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How Do Fossils Form and Where Do Fossils Come From?
Fossils form rarely, since an organism is usually consumed totally or scattered by scavengers after death.
If the structures remain intact, fossils can be preserved in amber (hardened tree sap), Siberian permafrost, dry caves, or rock.
Rock fossils are the most common.
In order to form a rock fossil, three things must happen:
the organism must be buried in sediment
the hard structures must mineralize
the sediment surrounding the fossil must harden and become rock.
Many rock fossils either erode before they can be discovered, or they remain in places inaccessible to scientists.
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Who Was the Youngest American President In U.S. History?
Okay, pay attention, because this is confusing if you don’t.
Kennedy at 43 was the youngest person elected president, but he wasn’t the youngest president.
Roosevelt was vice president when McKinley was assassinated, elevating Teddy to the presidency when he was a mere 42.
That makes Teddy Roosevelt the youngest American President in U.S. history. Make sense?
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Why Does My Computer Get Dusty Faster Than My Bookshelves?
It’s not just an illusion, most electronic equipment does indeed get dusty faster than other household furnishings.
Dust gets drawn to electric and magnetic fields given off by TVs, stereos, and computers. In fact, it’s one of the reasons so many computers are beige.
Apple Computers ran tests when designing the first Macintosh in 1977 and determined that beige was the best color for hiding dust, and other computer makers followed suit.
These days, many electronics and computers come in black. Black is a classic color but it shows dust really really well. Clean freaks might be wishing for the days of silver electronics to come back.
Silver came back in vogue for a while a little after the year 2000 but most companies have gone back to black. Our guess is the next big color will be purple.
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Why Are Mass Extinctions a Part of Evolution?
A mass extinction is named for a time period in which at least 60 percent of the living species present become extinct over a period of one million years.
Mass extinctions are considered biological catastrophes because of the relative speed and range of their effects.
The loss of so many species allows surviving populations to exploit their adaptations in new ways.
They can adapt to new parts of the environment without facing competition from other species.
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What Is the Temperature of the Ocean?
The temperature of the ocean can vary between below freezing, 32° Fahrenheit (0° Celsius), and just below vaporization, the point where liquid water becomes water vapor.
Sunlight, atmospheric temperature, and condensation of water vapor all heat the surface of the water. The warmer surface generally remains separate from lower, colder water, unless winds or currents stir it up.
The surface is defined by how deep sunlight can penetrate. Sunlight reaches between about 300 and 1,600 feet (91 and 488 meters) into the water. Beneath the surface lies the thermocline, a region where temperatures drop sharply. In the thermocline, temperatures steadily decrease all the way down to the ocean floor.
Surface ocean water can remain liquid below 32° Fahrenheit (0° Celsius) because the salt content doesn’t allow it to freeze. Subzero water near the ocean floor does not freeze because of the immense amount of pressure on it.
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How Hot Is the Earth’s Core and What Factors Determine Its Temperature?
Two factors determine the heat at the center of Earth: pressure and radioactive energy (the energy released by changes in atomic levels).
These amount to an impressive temperature, at least 5,000° Fahrenheit (2,760° Celsius).
Some estimates place the temperature as high as 7,000° (3,870° Celsius).
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Do Other Animals Have Wisdom Teeth?
Other mammals do have what we call wisdom teeth, the molars that lie farthest back in the mouth.
Often in humans, the jawbone is too small to accommodate these teeth, so they can’t break through the gums and become painfully wedged against the jaw and the other molars.
In other mammals, however, their jawbones are still large enough to house them. They’re referred to as “third†molars, and look no different than the other molars in their mouths.
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How Cold Are Clouds?
Water droplets remain liquid in clouds down to —27° Fahrenheit (-32° Celsius), far below freezing.
They remain in a liquid state because of the high pressure in the atmosphere.
The temperature must fall below —80° Fahrenheit (-70° Celsius) before the droplets crystallize into ice.
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What Would Happen If Ocean Water Didn’t Circulate?
Convection currents circulate the enormous amount of heat stored in the ocean and churn up nutrients—such as nitrate, oxygen, and phosphate.
If the cold water from the poles did not displace the warm equatorial water, the heat within Earth would raise the temperature of the ocean floor. Sooner or later, it would be hotter than the surface temperature.
The upwelling of water from the bottom would release devastating quantities of carbon dioxide, destroying both marine and coastal life.
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Where Did the Term “Better Half†Come From and Why Is It Used to Refer to a Man’s Wife?
Most men call their wives their “better half’ because they believe it, but the expression comes from an ancient Middle Eastern legend.
When a Bedouin man had been sentenced to death, his wife pleaded with the tribal leader that because they were married, she and her husband had become one, and that to punish one-half of the union would also punish the half who was innocent.
The court agreed and the man’s life was saved by his “better half.â€
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How Is Temperature Measured In Space and Who Invented the Kelvin Scale for Temperature?
Astronomers can measure temperature in space by studying various electromagnetic radiation waves.
In the United States, the Fahrenheit (F) scale is usually used to measure temperature. Most of the rest of the world uses the Celsius (C) scale.
Scientists, however, use the Kelvin (K) scale, also known as absolute temperature.
In 1848, Lord Kelvin, also known as William Thomson, proposed the need for a scale whereby “infinite coldâ€, or absolute zero, was the scale’s null point.
On the Kelvin scale, 0°K = —273°C or —460°F. Water freezes at 32°F, 0°C, and 273°K.
A normal live human body temperature is 98.6°F, 37°C, and 310°K. Water boils at 212°F, 100°C, and 373°K. The surface of the sun measures 10,000°F, 6,000°C, and 5,800°K.
To translate °K into °F, multiply the number of °K by 1.8 and subtract 460 from the answer. To translate °F into °C, subtract 32 from the number of °F and divide by 1.8.
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What Is the Difference Between Homology and Analogy?
Scientists can determine whether a trait is homologous or analogous by comparing it in species thought to be of common origin and contrasting it to traits of unrelated species in similar habitats.
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How Many Different Kinds of Clouds Exist and What Are They Called?
There are probably infinite shapes which clouds can form, given all the variables in the atmosphere, but three basic shapes are used to classify clouds.
Cumulus clouds are the flat-bottomed, tall clouds that look like whipped cream or cauliflower.
Thick layers of clouds, like blankets in the sky, are called stratus clouds.
Cirrus clouds tend to be high in the air, small, thin, and wispy.
Clouds can exhibit characteristics of more than one type, and more than one kind of cloud can be in the sky at any time. When clouds have combined traits, their names are generally made up by joining the names of the different clouds.
For instance, cirrostratus clouds have the height of cirrus clouds and something of the shape of stratus clouds.
Clouds likely to precipitate are called nimbus, as in cumulonimbus (cumulus rain-snow clouds) or stratonimbus (stratus rain-snow clouds). Cirrus clouds are frequently too thin to accumulate enough condensation to cause precipitation.
The three main types of clouds are cirrus, cumulus, and stratus. Clouds can be combinations or variations on these three types. Nimbus or Nimbo signals likely precipitation. Alto means high.
Clouds below —100° Fahrenheit (-73° Celsius) are completely ice.
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Why Is English Money Called a Pound?
During the Middle Ages, most people in Europe used silver coins. The English used silver pennies; each weighed 1/240 of a pound, and was called a sterling.
The basic unit of money in England became the pound of silver, which was equal to 240 sterlings. So this unit was and still is called the pound sterling.
The word lira that is used for the basic unit of money in Italy also means “pound.â€
The word franc became the name of the money unit in France, because during the 14th century, coins issued there bore the Latin words Francorum Rex, “King of the French.â€
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What Are “Wisdom†Teeth and Why Do We Remove Them?
They’re called wisdom teeth because they’re the latest to arrivewhen a person’s (presumably) older and wiser.
The funny thing about our molars is that none of them form beneath any of the baby teeth. They develop only after our jaws grow big enough to make space for them. The problem arises when your jaw doesn’t quite grow big enough for all the molars that want to come in.
Wisdom teeth are fascinating things if you forget the pain and complications they cause, that is. The complications the fact that so many people no longer have room for their wisdom teethallow you to see evolution in action.
Early humans needed these extra molars to help them chew the tough fibers in meat and vegetation. Being closer to the jaw gave the teeth better leverage. People’s jaws were larger and protruding, in order to make room for all of the teeth necessary for masticating a good meal way back in 10,000 B.C.
But ever since humans discovered how to tame that blazing red fire, we have no longer needed those teeth to survive. We’ve learned how to cook tough foods well enough so that they can be eaten without much effort.
The size and shape of our faces and jaws have changed to deal with these lifestyle advancements. Unfortunately for many, our teeth haven’t completely taken the hint.
We still try to grow these extra molars in the back, despite the fact that we no longer need them and often don’t have space for them.
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Who Invented Pyjamas, How Did It Get Its Name, and What Does the Word Pyjamas Mean?
In the sixteenth century, the first nightgowns appeared as loose-fitting, full-length unisex garments for warmth in bed.
In the eighteenth century the negligee became a lounging garment for women while, the nightshirt with loose-fitting pants called pyjamas replaced the long gown for men.
Pyjamas were modeled after harem pants and were imported from Iran, using the Persian words “pae†for leg garment and “jama†for clothing.
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How Are Your Teeth Like Four Different Tools?
If you know the functions of tools such as scissors, forks, nutcrackers, and grinders, you will understand how marvelously specialized your teeth are.
Although your 20 primary, or baby, teeth first appeared when you were about six months old, your permanent teeth (32) started to grow out when you were about six or seven years old. The rest will appear when you are between 17 and 21.
Your permanent teeth are divided into four different types, of different sizes and shapes. But each type has a special use, like the special use each tool has in the home or workshop. These four types are incisors; canines, or cuspids; bicuspids, or premolars; and molars.
The incisors are your eight front teeth. Four are in your upper jaw and four in your lower jaw. Incisors work like a knife or scissors. As you close your jaws, they bite off large pieces of food.
The canines, or cuspids, are the four strong, pointed teeth, one each to the right and left of the incisors. You use your canines much like you use a fork, to tear larger pieces of food into smaller pieces.
The eight bicuspids, or premolars, are next to the canines, two behind each canine. Bicuspids work like a nutcracker, crushing food into smaller and smaller pieces.
The twelve molars are at the rear of your mouth, three next to each set of bicuspids. Because molars have strong, flat surfaces, they work like a grinder, mashing food into thin, pulpy masses.
Although most people grow only two sets of teeth in a lifetime, there have been actual cases of people growing a third set late in life!
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What’s the Most Important Strait In the World?
The Strait of Hormuz lies between Iran and the Arabian Peninsula, connecting the Persian Gulf with an arm of the Arabian Sea. This strait isn’t the longest or widest strait on earth, but it is probably the most important.
The oil-producing nations of Saudi Arabia, Iran, Iraq, Kuwait, and other countries on the Persian Gulf must export most of their oil through the Strait of Hormuz.
It’s been estimated that as much as 60 percent of all the world’s oil exports pass through this strait.
On the average, an oil tanker sails through the Strait of Hormuz every 21 minutes!
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Do People Sweat When They Swim and Why Does the Body Perspire When the Temperature Is In the 90s?
The body may sweat during swimming, with the moisture dissipating unnoticed in the water.
You do not necessarily sweat when you swim, but if you swim long enough and hard enough so that the exercise raises the internal body temperature, then you will sweat.
This can be proven by measuring body weights before and after exercise.
As to the question of discomfort when temperatures are in the nineties, the body’s metabolism is continually producing heat, some of which is ordinarily lost to cooler surrounding air.
But when the ambient temperature equals the body’s core temperature, it is well above the skin temperature, so the body is gaining heat from the environment, instead of radiating it, as would normally happen.
So at high temperatures, the heat builds up and we feel hot.
Then the only way to dissipate the heat is by evaporating water from the surface of the skin as perspiration.
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What Are the Two Most Common Media to Grow Bacteria?
Beef extract and peptanes, or hydrolyzed protein, are the basic ingredients of nutrient broth.
These materials supply a variety of carbon sources, nitrogen compounds in the form of amino acids, and a mixture of cofactors such as vitamins.
The addition of agar, a complex carbohydrate extracted from seaweed, results in a solid medium.
Agar is an ideal solidifying agent for microbiological media because of its melting properties and because it has no nutritive value for the vast majority of bacteria.
Solid agar melts at 194-212°F (90-100°C); liquid agar solidifies at about 103°F (42°C).
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When Will You Stop Growing?
Girls reach their full height when they are about 18 years old, but boys keep growing taller for a few more years.
There are two periods in your life when you grow very rapidly. The first period began right after you were born and lasted until you were about six months old. The second period occurs when you reach your early teens. Girls grow faster than boys until they become teen-agers, then boys catch up and grow faster and stronger.
Your head stops growing earlier than the rest of you. When you were a newborn baby, you looked as if you were almost all head. By the time you were 10, your head was nearly full size.
The bones of your arms and legs were short when you were a baby. When you reached the age of 9, your bones started to grow rapidly and will keep growing until you reach your full height.
Besides growing taller, your body changes in other ways. When a boy is about 13 years old, his voice begins to get deeper and he may begin to grow a beard. About the age of 13, a girl’s body begins to look and function like a woman’s. Inside the bodies of both teen-age girls and boys, important changes are taking place, changes that make it possible for boys and girls, when they are older, to become fathers and mothers.
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What Causes One Person to Feel Hot While Another Feels Cold at the Same Room Temperature?
It is a complex question, made even more complex by factors like the prior activity of each individual and how long each has been in the room.
Assuming that both people have become acclimatized to the room and that neither is running a fever, there are two important factors.
One is the percentage of body fat, with the higher percentage retaining more heat.
The other is the surface-to-mass ratio for each body, with the larger skin area radiating more heat.
If the room temperature is below the thermoneutral zone, so that the bodies are losing heat to the environment, the person with the larger surface-to-mass ratio feels cooler.
If it were possible to obtain a population of women with exactly the same percentage of body fat as a population of men, the women would feel colder, because they have a larger surface-to-mass ratio.
If a person is running a fever, the phase of the fever determines whether he feels hot or cold.
In the rising phase of a fever, for example, the person feels cold, and the peripheral blood vessels are constricted in an attempt to retain heat and raise the body temperature.
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What Is Credit and Why Is Credit So Important for Most People?
Credit refers to your ability to borrow money and then pay it back over a period of time.
It also refers to how trustworthy a person is considered to be in terms of whether he or she will be eligible for loans and be able to pay off loans.
Credit is important because most people cannot afford to pay cash for large purchases, such as houses and cars. You need good credit in order to receive financing in order to obtain a loan to make large purchases.
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What Is a Bridge Loan?
A common type of hard money mortgage loan is the bridge or gap loan. As the names imply, it is used to connect transactions (bridge) or fill a void (gap) between transactions. The following are examples of the use of these loans.
• Your home is in foreclosure. You can sell it and come out with some money, but you need time to do this. You already have a buyer and have opened escrow. You get a temporary loan to reinstate your mortgage until your sale is finalized.
• You want to buy property, but have to act immediately. You can either sell other property or arrange financing to cover the purchase, but you do not have time for either. You get a hard money loan until you can either sell or arrange suitable financing.
• You have a small business. You have an opportunity to buy inventory at a once-in-a-lifetime price. You know that you can make a large profit, but you need cash to take advantage of the deal. You get a hard money loan until you can sell off enough of the product to pay it off.
All of these loans involve the borrower mortgaging property, usually his or her home, for a short period of time. Most of these loans are for one year or less. They depend on equity for security, and the borrower’s credit or income-to-debt ratios are of secondary importance. The loans fund quickly, some as fast as one week.
The up-front cost of these loans is usually one or two points, plus miscellaneous fees. The higher cost comes when the loan is repaid. This can be as high as 10% of the balance.
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What Is Dew Point and How Is It Measured?
Dew point is the temperature at which water vapor liquefies.
It signifies that the air is filled to capacity with moisture. Like a cloud, the water vapor becomes too heavy to stay suspended in air. It needs a surface on which to condense.
Since the vapor is hovering at ground level, there is a great supply of surfaces, or condensation nuclei, including grass, stones, plants, and animals.
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Are Women Are More Sensitive to Temperature Changes Than Men?
Sensitivity to temperature is much more complicated than a simple gender split, physiologists say.
The reaction depends on many factors, such as exercise, previous conditioning, diseases, and any other tinkering with the complex system of signals to and from the hypothalamus that sets the body’s temperature controls.
Some doctors suspect psychological factors make a difference, but it is difficult to separate psychological reactions based on a strong aversion to heat or cold from physiological responses. It is also possible that women do not dress as warmly.
But some male-female physiological differences may be significant in this area. Women tend to have more subcutaneous body fat than men, making them more likely to have a hard time dissipating body heat when temperatures rise. But women may do better than men as a room cools, because fat holds heat.
Larger animals have a smaller surface area relative to their volume than smaller animals, so they can stand colder temperatures with less heat loss. Men as a group are larger than women, although the size difference may not be enough to cause different reactions to temperature changes.
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What Can Disqualify a Person From Sitting for a Bar Exam?
If there are serious red flags raised during the application process or from evaluations from the student’s law school, there could be problems.
Serious criminal law issues could present a problem, as could allegations of sexual harassment or other bad behavior. If the bar examiners in a state believe that a lawyer has been untruthful or lacked candor in the application process, then there could be problems for that candidate.
If a person had an issue with plagiarism or other form of academic dishonesty, that could be cause for concern. It is hard to generalize because these issues vary from state to state.
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Why Does a Whale Spout?
Though it lives in the sea, the whale is a warm-blooded mammal. It must breathe oxygen from the air to live. When surfacing, the whale takes in oxygen through the blowhole on top of its head. Then, filling its large elastic lungs which are connected to the blowhole, the whale dives to feed.
While underwater, the whale’s body heats up that air. When the whale surfaces, it forces the air that was held in its lungs out the blowhole. This action is called spouting, or blowing. When the warm air comes into contact with the cool outside air, it condenses and turns into a steamy spray. A similar thing happens when our own breath hits the air in cold weather.
Different types of whales spout in particular ways, and experts can tell the species of the whale from the spout!
The whale’s spout can shoot 20 feet in the air and be seen from a mile away!
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Did Plato Change His Philosophy as He Grew Older?
Plato became more conservative in his outlook and more attentive to existing social values and traditions as he aged. The city of the Republic would have required a revolution to set up. In the later Laws, Plato becomes less revolutionary and describes a “second-best†city in which there are traditional families and rulers are elected, rather than specially bred.
In the Parmenides Plato offers a series of criticisms to his earlier theory of forms, which he is apparently unable to answer and which are later taken up by Aristotle. The most famous of these is the “third man argument.†Suppose we discover a form that accounts for what makes similar things similar.
For example, every cat is different, but all cats share the same catness because they participate in the cat form. Now, if we compare this form with any one thing that participates in it, in this case, compare your cat with the cat form, the form and the participating thing will have similarities that make it necessary to posit a second form.
If we then make comparisons of the cat to the second form, a third form will need to be posited, and on and on and on to an infinite regress. That is, Plato was aware of the theoretical problems with his theory of forms.
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How Old Is the Moon?
Before the first man landed on the moon, scientists had come up with three possible ways that the moon might have been formed.
First, it could have formed out of the same gas cloud that formed the earth. Or it could have broken off from the earth many millions of years ago.
Or perhaps the moon formed somewhere outside the solar system and was captured by the earth’s gravity as the two bodies passed close to each other.
But when the astronauts landed on the moon and brought back some moon rocks, scientists discovered that the moon is not made out of the same elements as the earth. This means that the moon probably did not form from the same gas cloud that formed the earth, and that it most likely didn’t break off from the earth.
Scientists were surprised to find that most of the moon rocks were more than 3.5 billion years old. The oldest rocks yet found on earth are about that same age.
But some moon rocks were 4.5 billion years old, older than any earth rocks, and the moon’s soil was also of that age. These rocks and soil may not even be the oldest on the moon.
So now scientists still aren’t sure how the moon was formed, or how old it really is, but it could be older than the earth!
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Why Do People Have Different Colored Eyes?
The pupil, the black spot in the middle of your eye, is actually a hole that allows light to enter the eye. Around this hole is the colored part of the eye, the iris, which regulates the size of the pupil and how much light is allowed into the eye.
The iris has pigment in it to protect it against light. Everyone has pigment at the rear part of the iris, but not everyone has it at the front. When a person lacks pigment at the front, this part of the iris is transparent, and absorbs red and yellow light waves. The remaining light, the blue waves, then bounces off the pigment at the rear of the eye, and gives the eye a blue color.
When the front part of the iris has pigment, it absorbs different kinds of light rays, and the light bouncing off the rear of the iris appears brown or gray.
Often a person has blue eyes when young, and brown eyes later in life, because it takes the eyes time to produce pigment at the front of the iris. Until this pigment appears, the eyes are blue.
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How Can You Use a Cat to Tell What the Temperature Is?
How accurate a read are you looking for? A cat can be used to give a very, very general idea of temperature.
The colder the temperature, the more a cat curls around itself to sleep. If your cat’s lollin’ around, stretched out on her side or back, you can bet it’s warm.
If said cat is tightly curled, with face buried and tail wrapped as tightly around her body as possible, she’s cold. A sweater might help, but cats don’t like them very much. And they look silly in human clothes.
In other words, get yourself a sweatshirt.
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What Does the Expression “Turned a Blind Eye†Mean and Where Did the Phrase Come From?
In 1801, while second in command of a British fleet near Copenhagen, Horatio Nelson was told that his commander had sent up flags ordering a retreat.
Nelson lifted his spyglass to his previously blinded eye and said he couldn’t see the order, and then he ordered and led a successful attack.
Nelson’s insubordination became legend and gave us the expression “turn a blind eye.â€
When someone ignores the rules we say he “turned a blind eyeâ€.
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Where Did the Moon Come From, How Did Earth Get Its Only Satellite, and How Long Ago Was the Moon Created?
There are many theories about how the Moon formed.
The current favorite says that a huge asteroid, maybe the same one that is thought to have tilted Earth’s axis, hit Earth, throwing off a mass of debris into a broken ring around the planet.
Over time, the debris coalesced, creating the Moon.
At first the Moon was much closer to Earth, but it gradually settled in the orbit it has today.
The Moon is the only natural satellite the earth has and is also the fifth largest satellite in the Solar System.
It is currently believed that the moon formed some 4.5 billion years ago, around the same time the Earth was created.
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Why Are There So Many Craters On the Moon and What Caused the Craters On the Moon Shortly After It Was Formed?
There are hundred of thousands of craters visible on the Moon, measuring from a few feet across (craterlets) to about 150 miles across (basins or walled plains).
The craters seem to be the result of both meteorites and volcanic activity.
Most scientists agree that the Moon came under a meteorite bombardment some 4.5 billion years ago, shortly after it was formed.
Within 1 billion years, the meteorites abruptly stopped.
The Moon’s interior rapidly increased in temperature, causing massive volcanic eruptions.
While the volcanoes distorted many of the meteoric craters, they created craters of their own.
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What Do I Do When a Client Refuses to Follow Its Part of the Agreement Such as Paying My Bills After the Work Has Been Completed?
Because you are not an employee, most of the employment laws discussed in this book will not apply to you. If your client will not adhere to a written contract that he or she has signed, you may ultimately need to sue the client in a local civil court on the issue of breach of contract.
Before you start a court fight, you should find out if the client has a problem with the services that you performed. If the issue is merely that the client feels something is still in error on your project, it may be cheaper for you to fix the problem in order to get your money. If the issue is that the client did not provide you with the proper equipment, perhaps the manufacturer is the problem or there is just a misunderstanding.
If the problem is not something that you can fix, you may want to send a certified letter to the client reminding him or her of the obligations under the contract that he or she signed, and giving a deadline to either follow the terms of the contract or deal with your attorney. You might then want to find a local attorney who handles contract breach litigation in your local court.
Many independent contractors who use contracts with clients make the mistake of not putting provisions into the contract for client problems, such as nonpayment. In order to protect yourself, these items must be addressed in accordance with your local laws.
The following are some examples of issues that should be addressed in an independent contractor’s agreement with their client.
• Each contract should be specifically tailored to detail what both the client and what the independent contractor are required to supply and the date these items will be available. There should also be some direction as to what will happen and who will be financially liable if these items are not ready on time.
• Each contract should list exactly what the independent contractor is to do in detail. This should include the goals of the project according to the client, how the client will measure or determine that the project is complete, and how the client intends to determine if the project is a success.
• Each contract should specify who will sign off on the project for the client and what steps will be taken if the client refuses to sign off. An independent contractor does not want to spend the rest of his or her career working for one very picky client who refuses to pay the independent contractor, so this must be very detailed. Some contracts may contain a clause that requires professional arbitration for disagreements that cannot be resolved in a short period of time.
• Each contract should detail the hours the independent contractor will work, location, and what happens when the contractor needs time off.
• Each contract should specify the amount of payment and how it is calculated. There should be provisions for late payments and nonpayment. Late payments may include a grace period and an interest percentage (to be exercised at the option of the independent contractor), which is added to the owed amount. For issues of nonpayment, there should be an indication that the independent contractor has the option to take the matter to court and go after the money owed, interest on that money, and the contractor’s attorney fees.
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How Old Is the Earth?
To figure out the age of the earth, it is important to know how old the rocks on it are. Scientists can date rocks by measuring the amount it of radioactivity, or rays of energy, they give off.
All rocks contain some uranium, which causes radioactivity, and that uranium give off invisible rays of energy which slowly change the uranium into lead. Scientists know how long it takes for uranium to change into lead, so by comparing how much uranium and how much lead are in the rocks, they can determine the age of the rocks.
By this method, scientists have determined that some granite gneiss rocks found in Tanzania, East Africa, are about 3.5 billion years old!
But bits of meteors that have fallen to earth are even older. They are parts of other planets in our solar system, and seem to be 4.5 billion years old! Most scientists believe that our whole solar system started off at the same time. We can therefore figure the planet earth to be about 4.5 billion years old.
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How Was Braille for the Blind Invented and When?
Louis Braille is a hero to millions of blind people all over the world, but not many people know that we also have Napoleon Bonaparte to thank for the invention of Braille.
Braille is a system of raised dots that can be read using touch alone. Before it was invented, there were a few books produced to teach blind people to read using embossed letters, but they were difficult and expensive to produce.
Louis Braille, who’d been blind since he was three, read some of these books when he was sent to the Royal Institute for Blind Youth in Paris. While he was there an army officer, Charles Barbier, visited the Institute and demonstrated an invention that he called ‘night writing’.
French general Napoleon Bonaparte had had the idea of a code that could be read at night and challenged his army to invent one. So Barbier had come up with a system that allowed soldiers to communicate silently and in total darkness using a system of raised dots to represent the alphabet. Unfortunately, Barbier’s night writing was so complicated that none of the soldiers had been able to learn it.
Although Louis Braille was just 11 years old at the time, he saw the potential of Barbier’s dot system straight away. He spent the next six years simplifying it and in 1821 came up with an alphabet of raised dots arranged in rectangles that could be read quickly and easily.
After you’ve read Braille with your eyes, try to read it with your finger Familiarise yourself with the feeling of Braille and take it slowly, because if you miss one bump then a word could take on a whole new meaning or make no sense at all!
Now go and find some signs in Braille and attempt to read them.
Visually-impaired geniuses: These include Horatio Nelson (British admiral), David Blunkett (UK politician), Eduard Degas and Claude Monet (French painters), Stevie Wonder and Ray Charles (US singer/songwriters), and Cupid/Eros (Roman/Greek god of love).
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How Is Temperature Measured In Space and Who Invented the Kelvin Scale for Temperature?
Astronomers can measure temperature in space by studying various electromagnetic radiation waves.
In the United States, the Fahrenheit (F) scale is usually used to measure temperature. Most of the rest of the world uses the Celsius (C) scale.
Scientists, however, use the Kelvin (K) scale, also known as absolute temperature.
In 1848, Lord Kelvin, also known as William Thomson, proposed the need for a scale whereby “infinite coldâ€, or absolute zero, was the scale’s null point.
On the Kelvin scale, 0°K = —273°C or —460°F. Water freezes at 32°F, 0°C, and 273°K.
A normal live human body temperature is 98.6°F, 37°C, and 310°K. Water boils at 212°F, 100°C, and 373°K. The surface of the sun measures 10,000°F, 6,000°C, and 5,800°K.
To translate °K into °F, multiply the number of °K by 1.8 and subtract 460 from the answer. To translate °F into °C, subtract 32 from the number of °F and divide by 1.8.
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What Causes One Person to Feel Hot While Another Feels Cold at the Same Room Temperature?
It is a complex question, made even more complex by factors like the prior activity of each individual and how long each has been in the room.
Assuming that both people have become acclimatized to the room and that neither is running a fever, there are two important factors.
One is the percentage of body fat, with the higher percentage retaining more heat.
The other is the surface-to-mass ratio for each body, with the larger skin area radiating more heat.
If the room temperature is below the thermoneutral zone, so that the bodies are losing heat to the environment, the person with the larger surface-to-mass ratio feels cooler.
If it were possible to obtain a population of women with exactly the same percentage of body fat as a population of men, the women would feel colder, because they have a larger surface-to-mass ratio.
If a person is running a fever, the phase of the fever determines whether he feels hot or cold.
In the rising phase of a fever, for example, the person feels cold, and the peripheral blood vessels are constricted in an attempt to retain heat and raise the body temperature.
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How Were Nuclear Weapons Invented and When?
When the first atomic bomb was dropped in 1945 it changed the world for ever. Many people wish it had never been invented at all.
Splitting the Atom. The idea for a weapon made from atomic energy had been around since Albert Einstein came up with his equation E = MC2 (which means there’s an awful lot of energy in absolutely everything, inside atoms). During the Second World War, when many countries were carrying out bombing campaigns on one another, the race was on to find a bomb that used the power of atoms.
Getting at the energy inside atoms isn’t easy: for that you have to split them (this is called nuclear fission). Atoms are the tiny units of matter everything is made of and they are a million times smaller than the width of one of the hairs on your head. So you can imagine how tricky it is to split one.
The top secret Manhattan Project in America gathered together some of the brainiest scientists in the world to try and manage it. Eventually, they succeeded. In 1945 two fission (or atomic) bombs were dropped on the Japanese cities of Nagasaki and Hiroshima, killing more than 200,000 people. Some people argue that the bombs saved lives because they ended the Second World War.
Nuclear fusion was developed soon after. This new way of releasing atomic power produces weapons hundreds of times more powerful than atomic bombs. They’ve never been used in warfare. Let’s hope they never will be.
Which year saw the first ever use of a nuclear weapon in military action?
How many people are estimated to have died from the nuclear bomb dropped on Hiroshima and its after-effects?
How does a nuclear fusion explosion work?
How many nuclear weapons have been used in military action?
How does a nuclear fission explosion work?
What does A-bomb stand for?
What type of climate is predicted if there were to be a nuclear war?
Apart from in nuclear weapons, where else can you find radiation?
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What Do Real Estate Lawyers Actually Do?
For most of the country the actual sales contract or offer is a formdocument approved by the National Association of REALTORS® that contains all required legal language, so attorneys are not consulted until after the document is signed. In most states there are laws that allow an attorney a short period of time (an average of three to five days) to review the sales contract or offer made by the buyer and accepted by the seller. A real estate attorney begins looking out for the well-being of his or her client with the first review of this document. At that stage, the attorney makes sure the contract reflects the intentions of his or her client.
The next step for the attorney may be to order the home inspection that the buyer has made contingent in the sales contract. Once the inspection report is complete, the attorney will review the report and alert the buyer to any potential issues with the structure of the house. The attorney may then assist the buyer in negotiating a reduction in price, a cash settlement, or a cancellation of the deal due to the inspection results.
The attorney will advise his or her client as to options for holding the title to the property. Depending on local custom, the attorney will order a title search from a title insurance company and a professional survey. The title search verifies that the sellers have a clear title to the home. The attorney reviews this search and alerts both buyer and seller of any potential problems. For example, the problem may be a lien on the home by a former contractor that was not paid. Knowledge of this issue at an early date allows the seller to resolve the debt before closing. The title insurance company also issues an insurance policy on the title guaranteeing that the buyer has a clear title or the insurance company pays. In many parts of the country the title insurance company also provides a closing agent and an office where the closing can take place. The survey is a certified drawing of the land, how the house and other structures sit on the land, including actual measurements.
As the closing gets closer, the real estate attorney will monitor the progress and review documents. The attorney will assist the closing agent in drafting the list of closing costs and, once that draft is completed, review the calculations. When it comes time for the closing, the real estate attorney stands with the buyer. The attorney reviews each document and lets the buyer know what he or she is signing. If problems come up in the closing, the real estate attorney may be able to resolve the problems on the spot. An experienced real estate attorney advocates for the client and protects the client from being taken advantage of in this deal.
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Why Is Uranium Used In Atomic Bombs?
Uranium is used in atomic weapons and in nuclear power plants because it is a radioactive element. The atoms of a radioactive element break down over a period of time, losing particles from their nucleus and releasing energy.
Normally, this breakdown happens in only a few uranium atoms at a time. But in an atomic bomb, the atoms break down very quickly, releasing great amounts of energy all at once.
Uranium atoms break down inside an atomic bomb because they’re hit with nuclear particles called neutrons. When a neutron strikes the nucleus of an uranium atom, it causes the nucleus to split apart.
This releases energy and sends particles from the uranium atom crashing into other atoms, which then split, sending out more energy and particles, and so on. This process is called a
chain reaction.
Once the chain reaction inside the atomic bomb’s uranium begins, it keeps going until most of the atoms have been split. This happens in a fraction of a second, so that all the uranium’s energy is released at once.
The breakdown of the atoms in just one pound of uranium can produce energy equal to the burning of almost three million pounds of coal!
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How Cold Is Absolute Zero and What Is the Highest Temperature Possible In the Universe?
There is no maximum temperature, because there is no limit to the amount of energy you can put into anything.
Absolute zero, minus 273.15 degrees Centigrade, minus 459.67 on the Fahrenheit scale, is theoretically the temperature at which all molecular activity ceases.
It represents an absence of energy.
There is the concept of a lowest temperature because any given body has a lowest energy state, when all possible energy has been extracted.
You can also talk about a maximum temperature for any given body, because at some point it will be hot enough to break up, melt or disassociate, so that at that point it would not be the same body.
However, since there will always be some object or substance that will still exist, the concept of temperature does not have an upper limit, because more and more energy could still be added.
A cosmologist might say that this question is like asking “What is the shortest time?â€
Things have been cooling since the big bang, so a millionth of a second later, approximately as far back as our physics will take us now, would theoretically be the hottest known temperature, but a billionth of a second after the big bang would be still hotter.
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What Is Temperature?
emperature is a quantitative measure of hotness.
In many substances, temperature is proportional to the thermal energy in the object, but the relationship between temperature and energy depends on many factors.
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How Did the Minute Originate and Why Are There Sixty Seconds In a Minute and Sixty Minutes In an Hour?
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Around 2400 BC, the ancient Sumerians, who used six as their mathematical base, divided a circle into 360 degrees, with each degree subdivided into another 60 parts, and so on.
The Romans called these units minute prima, or first small part, and secunda minuta, or second small part.
This system was perfect for round clock faces, and that’s why we use minutes and seconds as divisions of time.
In ancient astronomy, a minute can also mean a unit of time equal to 1/60th of a day, or 24 minutes.
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How Many People Have Died From Volcanoes In the Past 500 Years and How Do Volcanoes Affect Life On Earth?
At least 300,000 people worldwide have died as result of volcanic activity since 1500, and many more lost their homes.
Scientists estimate that volcanoes pose a risk to about 500 million people today.
It has been suggested that volcanic activity contributed to the Permian-Triassic and Late Devonian mass extinctions, among others.
One of the largest known volcanic events of the last 500 million years of Earth’s geological history which formed the Siberian Traps, continued for a million years and is considered to be the cause of the “Great Dying†about 250 million years ago.
The Permian–Triassic extinction event is estimated to have killed 90% of species existing on earth at the time.
Gas emissions from volcanoes are a natural contributor to acid rain.
Volcanic eruptions also throw ash into the atmosphere which pose a hazard to flying aircraft, especially jet aircraft that have turbine blades which are easily damaged by ash particles.
The 2010 eruptions of Eyjafjallajökull caused major disruptions to air travel in Europe.
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What Causes the Different Shapes of Volcanoes?
A volcano’s shape is determined by the type of eruption, the environment (other rock formations in the area and their chemical makeup), and the makeup of the volcanic materials.
Explosive eruptions may blow off the tops of volcanoes in a flash, while gentle flows of lava build sloping cones over long periods of time.
Volcanoes vary in shape and in how they erupt. Eruptions can be slow, as in volcanoes in Hawaii, or they can happen very suddenly, like a Pelean eruption.
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What Is the Slowest Growing Plant In the World and Where Does the Saguaro Cactus Come From?
In general, cactus plants are the slowest growing plants on earth.
One kind of cactus, the saguaro, grows just one inch in the first ten years of its life.
The saguaro cactus doesn’t grow a branch until it’s 16 years old, and after that, it grows just an inch a year.
But some pine trees that live very far north in the cold Arctic or very high up on a mountain can grow even slower than a cactus.
One tree, a Sitka spruce, growing in the Arctic, grew only 11 inches in 98 years.
The saguaro doesn’t begin to flower until it’s about 60 years old.
The saguaro cactus can be found in the Sonoran Desert in Arizona, in Baja California, and the Mexican state of Sonora.
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How Did the Universe Begin and How Does the Big Bang Theory Explain How the Universe Was Created?
The most popular theory about the universe’s creation is called the big bang theory.
It is based on the ideas of many scientists, especially Edwin Hubble, a famous twentieth-century astronomer.
The big bang theory claims that the universe was created by a massive surge of energy and matter 10 to 20 billion years ago.
The big bang formed celestial gases and particles, and everything that exists.
The theory also states that the universe continues to expand, that all the celestial bodies, galaxies, stars, and planets, to name a few, are constantly moving away from each other.
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Is There a Highest Temperature That Can Be Achieved?
Although there is an absolute zero temperature, there is no highest temperature.
The highest temperatures achieved to date have been from nuclear explosions, where the temperature can reach as high as one hundred million kelvins.
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How Can You Pass 24 Hours In Less Than 60 Minutes?
The lines that divide the world’s time zones meet at the North and South Poles, so the zones get narrower as they near’ the poles.
An Alaskan airline offers a flight over the Arctic regions that includes a circular flight around the North Pole. If you were to circle the North Pole, you’d pass through all the world’s times zones in less than an hour!
If it were noon when you started to circle the pole, you’d soon pass the line marking the beginning of the next time zone, and it would become one o’clock. A few minutes later, you’d have to move your watch ahead another hour.
As the flight continued, you’d keep moving your watch ahead, past midnight, through the morning, until you returned to your starting point, before clocks there had reached one o’clock.
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How Were the Hawaiian Islands Formed From Volcanoes?
The Hawaiian volcanoes could be said to be more creative than destructive.
Volcanic activity built this chain of islands, and the only known deadly eruptions killed a division of the Hawaiian army—in 1790—and one other person—in 1924. The 1969 eruption took no lives.
Four shield volcanoes make up the island of Hawaii. Mauna Kea first grew to 13,825 feet (4,200 meters) above water. The smaller volcanoes, Kilauea and Haulalai, then sprouted from its sides.
Further internal volcanic activity then created Mauna Loa, 13,678 feet (4,169 meters) in the air. The mild nature of these volcanoes allowed the United States to open them, and Haleakala on nearby Maui, as the Hawaii Volcanoes National Park.
Since 1911, the Hawaiian Volcano Observatory on Hawaii has gathered an immense amount of data and information on volcanology, the study of volcanoes.
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Where Are Volcanoes Located On Earth and Which Areas Do Not Have Volcanoes?
Some places on Earth are especially likely to have volcanic activity. Most of these sites mirror where Earth’s tectonic plates come together and move apart.
The Pacific region hosts the largest concentration of volcanoes, called the “ring of fire.†There are also volcanoes in the Mediterranean Sea, Africa, and the Atlantic Ocean.
Throughout the world there are places called hotspots. Scientists have determined that these areas, while not necessarily residing over the edges of tectonic plates, show accelerated magma movement and heat.
They are also likely places for volcanoes to erupt.
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What Sea Creatures Plant Their Own Gardens?
The spider crab not only plants its own seaweed garden, but it plants the garden right on its own body! This crab snatches pieces of seaweed, cuts them into smaller pieces, and attaches the cuttings to the hairs on its legs and shell.
The seaweed cuttings take root on the crab, and eventually grow to completely cover it. By the time the spider crab is finished with its garden, it looks just like a mass of seaweed, and is perfectly hidden from its enemies.
Another kind of crab, the coral-gall crab, collects small sea creatures called corals and places them all around its body. As a coral grows, it surrounds itself with a shell, and when it dies, the shell remains.
So the coral-gall crab soon finds itself surrounded by a coral shell, with small holes in the shell where the corals once lived. These holes permit water and food particles to reach the imprisoned crab.
So while the coral shell protects the crab from its enemies, the crab can never escape from its shell. It spends the rest of its life locked inside the coral, and may even give birth to young crabs inside the shell!
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What Plant Is Really Two Plants In One?
You may have seen the small, moss-like plants called lichens covering rocks or the branches of old trees. Though you’d never guess it from looking at these plants, lichens are really two plants in one: a fungus and an alga.
The fungus and alga in a lichen live so closely together that you’d need a microscope to tell them apart. The relationship of this fungus and alga in a lichen is called symbiotic, which means that both the fungus and alga help each other survive.
The lichen’s fungi send branchlike pieces into rocks or pieces of wood from which they absorb moisture and minerals. The algae make food by photosynthesis, the process that all green plants use to make food from sunlight, minerals, and water.
So, the fungus “waters†the alga, and the alga “feeds†the fungus.
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How Much Oxygen Do Plants Consume at Night and How Is Sleeping With a Live Plant Dangerous?
There is just a grain of truth in the idea, as green plants do absorb some oxygen for use in respiration, the mirror image of photosynthesis.
Photosynthesis can occur only when there is light, so at night plants are absorbers of oxygen, on balance.
However, true danger would result only from an extremely large body of plants in a very tightly closed sleeping chamber with a very limited supply of oxygen.
Another person in a room would be a far heavier oxygen consumer than one plant.
These principles of gas exchange in photosynthesis and respiration were explored in the late eighteenth century by Jan Ingenhousz, a Dutch botanist.
Once Joseph Priestley had discovered oxygen and plants’ role in producing it from carbon dioxide, there was a great vogue for putting flowers in sickrooms to “purify†the air.
Ingenhousz was skeptical about the benefits.
His experiments showed that only the green parts of plants add oxygen, and then only if placed in strong light; flowers and other non-green parts, as well as green leaves left in darkness, used up oxygen just as animals did, he found.
In aerobic respiration, plants use free oxygen, usually from the air, for chemical reactions that release energy from organic substances; sugar and oxygen react to produce carbon dioxide, water and chemical energy.
In photosynthesis, carbon dioxide and water react in the presence of light energy to produce sugar and oxygen.
During the day, both processes occur, but photosynthesis proceeds more rapidly than respiration, and the carbon dioxide produced is immediately used in photosynthesis.
Excess oxygen from the photosynthesis escapes into the air.
At night, however, photosynthesis ceases and respiration continues, so that green plants are absorbing oxygen and producing carbon dioxide.
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How Do Coal and Oil Produce Energy?
Millions of years ago, when much of the earth was a swampy forest, billions of plants and animals died and fell into the shallow water.
The oxygen, hydrogen, nitrogen, and carbon in these living things were acted upon by bacteria and pressure over thousands of years, freeing gases from the decayed matter and leaving behind only the carbon.
Coal and oil are made up mainly of carbon. The difference is that coal was under more pressure as it formed, and the carbon atoms arranged themselves in solid form.
When coal or oil burns, it combines with oxygen in the air, producing carbon monoxide and other gases. This chemical change produces a great deal of heat energy.
So when we burn coal or oil to heat or light our homes, or to heat water at electricity plants, we’re really burning the remains of plants and animals that lived ages ago!
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Where Do Astronauts Get Oxygen for Extended Space Missions On the International Space Station?
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However, when the space station built, plans were announced to have it carry equipment to recover oxygen indirectly from the carbon dioxide crew members exhale. astronauts
NASA’s Johnson Space Center tested means to recycle air and water used by volunteers sealed in an airtight chamber with a limited amount to breathe and to drink.
Mechanical and chemical means were being used to recycle all the air and water, including urine.
Past tests involved using wheat plants to recycle breathing air, and by 1997, sixty and ninety day tests using plants and/or physiochemical recycling were planned.
In a life-support system for the space station designed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, carbon dioxide is reclaimed from the exhaled air by a concentrator.
The 95-percent-pure carbon dioxide is burned with hydrogen in a carbon dioxide reduction device, yielding water and some waste products, either carbon or methane.
This water is used as drinking water on the space station.
Some water from the hygiene system, dirtier water, is put in an oxygen generator, an electrolyzer that breaks it down into its two components, hydrogen and oxygen, by electrolysis.
The oxygen is to be fed back into the cabin, closing the cycle.
The hydrogen is used in the propulsion system to keep the space station at the proper attitude and to reboost it into the proper orbit as the orbit decays.
Oxygen requirements are about 1.8 pounds per day per person. On past space flights, carbon dioxide was recaptured but not reused.
Initially, the Soviet Union used a multi-step chemical recovery system to obtain oxygen for its extended space flights.
But they switched to an electrolyzer-type process, with the supply vehicle, Progress, bringing up water that is then electrolyzed.
U.S. missions have also supplied breathable air.
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How Can the Sun Burn Without Oxygen?
Nothing can burn on earth without the presence of oxygen.
As what we call “fire†or “burning†is a chemical reaction in which atoms of oxygen combine with atoms of carbon from the fuel, the substance being burned, to produce carbon dioxide, light, and heat.
Since fire needs oxygen, and there is almost no oxygen in space, then how can the sun burn constantly? Well, the sun isn’t “burning†in the same sense that a fire burns on earth. The sun produces energy the same way that a hydrogen bomb produces energy.
In this process, hydrogen is changed into helium, but some hydrogen is instead converted into energy. So the sun continues to “burn†and produce light and heat without oxygen.
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What Is a Tectonic Plate and How Many Tectonic Plates Are There On Earth?
The Earth is not a solid shell, but rather slabs of rock that scientists call Tectonic Plates.
These plates, seven large plates and several smaller ones, have been moving for millions of years.
They hold the ocean floors and the continents. Their movements cause new seafloor to form and earthquakes and volcanoes to occur.
Mountain ranges are formed when two plates collide, causing rock to fold and rise.
Scientists aren’t quite sure what causes the tectonic plates to move, but they believe the intense heat of the Earth’s core is a factor.
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Are All Stars Burning Out and Are New Ones Forming?
Stars are being born as well as dying, but the rate varies greatly from galaxy to galaxy.
Stars form from huge clouds of dust and gas. If a cloud begins to contract because of its own gravity, its interior heats up as gravitational energy is converted to heat energy, reaching millions of degrees, and nuclear reactions begin that change one element into another, releasing energy.
The pressure tends to expand the cloud back out, but eventually equilibrium is reached. That is essentially what a star is, a mass of gas at equilibrium between inward pressure from gravity and outward pressure from nuclear reactions.
A star has a finite lifetime because it is burning fuel. For 90 percent of its life, it burns hydrogen into helium. When the hydrogen is used up, the pressure decreases, but gravity never disappears, so the star contracts until the temperature climbs again, this time reaching hundreds of millions of degrees, while reactions convert helium to carbon and oxygen.
The star can then remain stable for a briefer time. Eventually the star dies, when the reactions no longer produce energy, but only consume it.
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What Does a Third Degree Burn Mean and What Is the Difference Between a First Degree Burn and a Second Degree Burn?
The seriousness of a burn is assessed in degrees depending on the number of layers of skin involved.
A sunburn, or a red mark on a finger touched to an iron, is a first-degree burn.
A second-degree burn blisters.
Third-degree burns mean that all skin is destroyed right down to the layer of tissue under the skin.
Burns on faces, hands, and feet can be more serious than a wound on the thigh, for example, because of the importance of these body parts.
Burns to the genital area are also more dangerous because they are vulnerable to infection.
Second and third degree burns always require immediate medical attention, the first thirty seconds are crucial, to remove the cause of the burn, cool the skin, and protect against infection.
The chance of having a stroke is 1 in 6.
The chance of dying from heart disease is 1 in 3.
The chance of getting arthritis is 1 in 7.
The chance of getting the flu in the course of a year is 1 in 10.
The chance of contracting the human version of mad cow disease is 1 in 40,000,000.
The chance of dying from any kind of fall is 1 in 20,666.
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Where Did the Expression “the Third Degree†Come From and What Does It Mean?
The third degree is a very difficult and sometimes brutal questioning, especially by police.
In fact, without its sinister connotation, the expression comes from the Masonic Lodge and its three degrees of membership, each requiring an increasingly difficult examination.
The first is Entered Apprentice, the second is Fellowcraft, and the third degree, the one most difficult to pass, is Master Mason.
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Why Do Toes and Fingers Wrinkle In the Bathtub and After a Swim?
Actually, toes and fingers don’t wrinkle in the bathtub at all.
They are puckering from swelling. The thick outside layer of skin called the stratum corneum takes on excess water when soaked, sort of like dried beans when soaked in water.
The underlying skin and connective tissue don’t absorb water and don’t swell along with it.
This anchoring of the skin-tissue layers makes the swelled area appear puckered.
It’s not just the fingers and toes that do this, though they are easier to see because the stratum corneum in those areas is thickest.
When you see your fingers and toes wrinkling, take it as a sign that your entire body is on guard to prevent water, soap, dirt, and germs from invading through your skin.
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How Was Soap Invented and When?
The world would be a far less fragrant place without soap, and what would we buy Grandma for her birthday?
Come Clean. It’s anybody’s guess how people washed in the distant past. Maybe they didn’t bother and just picked off the crusty bits. Soap is an unlikely combination of fat and any alkaline substance, so it’s amazing that anyone invented it at all.
The ancient Mesopotamians somehow worked out that mixing animal fat with wood ash makes a substance that can clean clothes and people. They made soap in clay cylinders as far back as 2800 BC.
The ancient Egyptians were using soap made from fats and alkaline salts by about 1500 BC. Maybe they found out about it from their neighbors, the Mesopotamians.
The ancient Romans were very fond of bathing and built public baths all over their empire, but they didn’t use soap. There’s some evidence to suggest that Roman women used a soap-like substance on their hair starting from around AD 50.
People were making soap in Europe by the 600s, but they weren’t using it nearly enough. The Middle Ages saw personal hygiene at its lowest point. Soap was a luxury item until the middle of the 19th century, so be very glad you weren’t around in those days.
Getting into scrapes: Instead of using soap the ancient Romans cleaned themselves by oiling their bodies, then scraping off the oil using a special scraper called a ‘strigil’. Really posh Romans would have a slave do the scraping for them.
If you’re fed up of smelling of roses, make your own soap and you can smell however you like!
EQUIPMENT NEEDED
a neutral glycerin soap bar (available from health or craft shops), a knife, a wooden spoon, a microwaveable bowl, a microwave, various food colourings, essential oils. moulds (you can improvise with washed-out food or drink containers – or buy proper soap moulds from a craft shop)
BASIC SOAP
Cut the soap into small chunks or grate into thin shavings. Be careful not to cut yourself!
Put the soap into a microwaveable bowl and heat in a microwave until it has melted (about 50 seconds) or you can melt it in a saucepan on a cooker.
If you’d like to add colour, add it now drop by drop, stirring with a wooden spoon, until your soap is the colour you want. You can also add a scent at this point. mixing a few drops of the essential oil of your choice.
Pour the liquid soap into your mould. The soap will take about 45 minutes to harden, depending on the size of it.
STRIPY SOAP
To create stripes of colour in your soap, follow basic steps, but then rather than pouring all the colour into one mould, divide it into four moulds. You will end up with a shallow layer of colour at the bottom of each. Now you need to repeat this process using a different colour each time until you have built up four stripy soaps.
Try to add each new layer of coloured soap while the previous layer is still a bit soft. When all your layers are in place, leave it to harden fully.
SWIRLY SOAP
To create swirls of colour in your soap, follow basic steps 1-4 but don’t add any colouring to the soap until it is poured into the mould.
When the soap is in its mould, add a few drops of one colour at one end, and a different colour at the other end (add other colours too, if you want). When you’ve added your drops of colour, take a toothpick or spoon and use it to stir the colours into the soap and create swirls. Leave to harden.
CHUNKY SOAP
To create chunks of colour in your soap, you need first of all to cut up a colored soap (home-made or bought) into little chunks and put these chunks into the bottom of your mould.
Then make a different colored soap, following basic steps 1-4, pouring the liquid soap into the mould over the chunks. Leave to harden. (You can insert other things into the soap bar, such as a plastic spider to scare your mom!)
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What Part of the Body Has the Thickest Skin?
The part of the body that has the thickest skin is pretty much as you’d suspect.
The soles of the feet and palms of the hands have the thickest layer of skin. After that, the back and nape of the neck are the thickest.
The thinnest layer of skin is around the eyes, particularly the eyelids.
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Why Do We Wrinkle as We Age and How Can We Prevent It?
Skin changes that cause wrinkles do accompany aging, as the deeper layer of skin, the dermis, gets thinner.
But it happens more quickly in sun-exposed areas and in people who smoke. The breakdown of two kinds of molecules, collagen and elastin, is at fault.
Collagen type 1 is the molecule that makes up the bulk of the skin. Loss of this type of collagen, the same type found in bones, affects the elderly, and smoking can make it worse.
At least five studies have found that smoking is associated with “smoker’s face,†one that is prematurely aged by fine wrinkles that can accentuate the coarser wrinkles that occur along the lines of expression.
As for elastin, the stretchy molecules that help support the skin, ultraviolet rays cause direct damage, breaking the molecules down.
To help avoid wrinkles as you age, avoid smoking, stay out of the sun, routinely use hats and sunscreens, and use a good moisturizer, which holds water in the dermis and plumps it up.
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Is the Weather Warmest When the Earth Is Closet to the Sun?
Surprisingly, the earth’s distance from the sun has nothing to do with weather!
The earth’s path around the sun is not a perfect circle, but an ellipse, or egg shape. The earth is actually nearest the sun around January 2, when it’s “only†91,402,000 miles away. This point is called the perihelion. At the earth’s aphelion, or farthest point from the sun, it’s 94,510,000 miles away. And this point falls around July 5.
Why is our weather coldest when the earth is closest to the sun? Because weather is determined mostly by the tilt of the earth’s axis at various times of the year.
When it’s winter here, the earth is tilted in such a way that much of the sun’s radiation reaches us at an angle, and bounces off our atmosphere. In summer, the sun’s rays reach us more directly, and therefore the weather is warmer. Also, in winter the days are shorter, and much of the sun’s heat is reflected off the earth by snow.
The earth doesn’t travel around the sun at a constant speed, either; the speed varies at different points in the earth’s orbit!
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How Hot Is Lava and How Viscous Is It?
Exit temperatures—the temperature of lava as it comes from the mouth, or crater, of volcanoes—indicate that lava’s heat varies.
The temperature ranges from 700 to 1,200° Celsius (1,300 to 2,200° Fahrenheit). At its hottest, lava is about 10 times the temperature of boiling water.
It also ranges in viscosity, or how thick or runny it is. Lava can be very thin and fluid, or it can be so thick that it almost doesn’t flow.
The estimated daily lava production of Mauna Loa plus Kiluaea, 2 large volcanoes in Hawaii, would fill 65,000 cement trucks.
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How Does Ultraviolet Radiation Cause Skin Cancer?
The prevailing theory involves damage to the DNA of skin cells.
It is the shorter UVB rays, which penetrate only the top layers of the skin, that are suspect, while the longer and more deeply penetrating UVA rays cause wrinkles and aging.
In tissue cultures, UV damages the DNA of cells, but humans have an enzyme that repairs it. Due to a genetic defect, some people lack the repair enzyme.
The hypothesis is that in the body such DNA damage occurs all the time and is constantly repaired, but some cells do not get repaired, or get repaired improperly, and this is how skin cancer begins.
Researchers found a specific kind of DNA damage in a gene called CQ that occurs in this way. In the error, two DNA units of the type designated as thymine are side by side, instead of two units of the cytosine type.
The error is called a thymine dimer. It is presumed that the brakes on cell multiplication come off because of it, leading to uncontrolled proliferation of cells into a tumor.
Ultraviolet radiation is implicated in the vast majority of nonmelanoma skin cancers, like basal cell carcinoma and squamous cell carcinoma. It is also linked to melanoma, though less clearly.
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What Is Ozone and How Does It Protect the Earth From Ultraviolet Radiation?
Ozone is a unique form of oxygen, and it lies several miles (kilometers) above Earth in the atmosphere.
It serves as a filter against the Sun’s powerful and dangerous ultraviolet rays.
Without this layer of atmospheric protection, ultraviolet radiation would cause many health problems, from skin irritation to cancer in humans, not to mention the harmful effects on other living creatures.
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What Are the Different Kinds of Lava and What Are They Called?
The two most prevalent types of lava worldwide, pahoehoe (pronounced pa-hoy-hoy) and aa (pronounced ah-ah), take their names from the native Hawaiian language.
The state of Hawaii is actually a chain of volcanic islands, where pahoehoe and aa are both found in abundance.
Pahoehoe has the shape of thick cords of rope or puffy billows. It can look something like black whipped cream. When highly fluid lava flows, the outer surface area congeals to form a thin, flexible exterior.
The lava inside continues to run, molding the outside layer into ropelike forms. These shapes remain when the entire mass solidifies.
Aa results from oozing semisolid lava. As aa flows, it carries rough, jagged shards of rock along its path. Aa hardens into sharp, splintery, knifelike edges.
You can walk comfortably on cold pahoehoe barefoot, but aa will slice the soles of your shoes.
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How Do Rivers and Lakes Exist Underground?
Rivers run underground for the same reasons, and as a result of the same causes, as rivers on the surface.
Earth’s crust soaks up precipitation until it can hold no more. Some areas of the crust are so absorbent that water gathers deep underground.
If the crust’s material is more easily eroded underground, the water will begin to flow under the surface. It may emerge onto the surface at a later point in its course if the terrain changes. In the same way, a surface river can disappear underground if the rock material is more easily eroded there.
Similarly, underground lakes have the same characteristics as surface lakes. Whether water gathers above ground or underground depends on the ability of the surrounding environment to absorb water.
Precipitation falling on saturated ground might erode the softer earth underground until it reaches a resilient layer instead of pooling on the surface.
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Why Do We Have Fingerprints and What Beneficial Purpose Have Human Fingerprints Evolved to Serve?
Fingerprints help us in gripping and handling objects in a variety of conditions.
They work on the same principle as the tires of a car.
While smooth surfaces are fine for gripping in a dry environment, they are useless in a wet one.
So we have evolved a system of troughs and ridges, to help channel the water away from the fingertips, leaving a dry surface which allows a better grip.
The unique pattern is merely a useful phenomenon that is used by the police to identify individuals.
Fingerprints are the visible parts of rete ridges, where the epidermis of the skin dips down into the dermis, forming an interlocking structure, similar to interlaced fingers.
These protect against shearing, or sideways stress, which would otherwise separate the two layers of skin and allow fluid to accumulate in the space, and form a blister.
They appear on skin surfaces which are subject to constant shearing stress, such as fingers, palms, toes and heels.
The unique patterns are simply due to the semi-random way in which the ridges and the structures in the dermis grow.
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Why Do We Have Fingerprints and What Beneficial Purpose Have Human Fingerprints Evolved to Serve?
Fingerprints help us in gripping and handling objects in a variety of conditions.
They work on the same principle as the tires of a car.
While smooth surfaces are fine for gripping in a dry environment, they are useless in a wet one.
So we have evolved a system of troughs and ridges, to help channel the water away from the fingertips, leaving a dry surface which allows a better grip.
The unique pattern is merely a useful phenomenon that is used by the police to identify individuals.
Fingerprints are the visible parts of rete ridges, where the epidermis of the skin dips down into the dermis, forming an interlocking structure, similar to interlaced fingers.
These protect against shearing, or sideways stress, which would otherwise separate the two layers of skin and allow fluid to accumulate in the space, and form a blister.
They appear on skin surfaces which are subject to constant shearing stress, such as fingers, palms, toes and heels.
The unique patterns are simply due to the semi-random way in which the ridges and the structures in the dermis grow.
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Why Do We Have Fingerprints and What Beneficial Purpose Have Human Fingerprints Evolved to Serve?
Fingerprints help us in gripping and handling objects in a variety of conditions.
They work on the same principle as the tires of a car.
While smooth surfaces are fine for gripping in a dry environment, they are useless in a wet one.
So we have evolved a system of troughs and ridges, to help channel the water away from the fingertips, leaving a dry surface which allows a better grip.
The unique pattern is merely a useful phenomenon that is used by the police to identify individuals.
Fingerprints are the visible parts of rete ridges, where the epidermis of the skin dips down into the dermis, forming an interlocking structure, similar to interlaced fingers.
These protect against shearing, or sideways stress, which would otherwise separate the two layers of skin and allow fluid to accumulate in the space, and form a blister.
They appear on skin surfaces which are subject to constant shearing stress, such as fingers, palms, toes and heels.
The unique patterns are simply due to the semi-random way in which the ridges and the structures in the dermis grow.
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How Does a Camera Lens Create an Image On the Sensor?
The diagram below shows what would happen if there were three pinholes, each creating an inverted reproduction of the object.
Now, if a converging lens is placed just behind the pinholes it will bend the rays going through it. If the focal length of the lens and the distance between the lens and screen are chosen correctly, then the three reproductions from the pinholes will all be at the same location.
Light rays from the top of the object will converge on the appropriate point on the image. Note that the image is inverted and the same size as the reproductions. What would happen if you had a multitude of pinholes at the location of the lens? The reproductions from all the pinholes would be at the same location, and many more rays from the object would end up at the same place on the image.
The image would be much brighter. So, you can model the formation of an image by a lens as a collection of reproductions of pinholes. The larger the lens, the brighter the image.
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What Is Soil Made of and How Is It Formed?
Soil is generally made up of many different minerals, elements, and organic matter.
The dirt of different areas has specific components—such as aluminum, iron, quartz, sand, acid, or salt—which is why some plants grow better in some places than in others.
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What Makes You Totally Different From Anyone Else In the World?
If you look down at the tips of your fingers and toes, you will see patterns of circles and swirls on the ridges of your skin. No other person in the world, living or dead, has exactly the same pattern as you, nor will anyone yet to be born. Even though your body grows and changes in many different ways, the exact patterns of circles and swirls of your fingers and toes, your fingerprints and footprints, will remain the same all your life.
You can get a clearer picture of what your prints look like by pressing your finger tips or your feet on an inked pad and then on white paper. Your prints will be reproduced in exact detail. You will see one or more of three main patterns: an arch, or small hill; a loop, or hairpin turn; or a whorl, or circular pattern. You may have all whorls or all arches, or a combination of loops and whorls or arches and loops. Not only are these prints different from anyone else’s in the world, but each of your fingers is different from the next.
Fingerprints and footprints provide foolproof identification of newborn infants by hospitals and of missing persons, amnesia victims, and criminals by police.
The FBI in Washington, D.C., has the largest collection of fingerprints on file in the world, nearly 2,000,000!
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Where Does Sand Come From?
Grains of sand are really very tiny particles of rock. It takes time and certain kinds of weather to turn rock into sand. Rain, frost, and wind can do the job. At beaches, the tide hitting against the rocks forms sand. Salt water, too, forms sand by dissolving minerals in the rocks.
Since rocks are made up of minerals and since sand comes from rocks, you would expect to find lots of minerals in sand. There are, in fact, large quantities of quartz and also some lime, gypsum, feldspar, and even iron ore in sand.
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What Are Minerals and How Are They Formed?
A mineral is a unique composition of elements. For instance, silicon and dioxide interact chemically to form quartz.
The most common mineral, feldspar, which makes up about half of Earth’s crust, is aluminum plus sodium, calcium, or potassium.
Minerals will separate from cooling magma and make their way through veins into surrounding rock, called ore.
Miners search for these veins to find the minerals they contain. Some veins contain single-element minerals such as copper.
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What Plant Has the Biggest Leaves?
Can you imagine a tree as tall as a seven-story building? Sure, some trees in your neighborhood may be that tall. But can you imagine a single leaf that big?
The raffia palm is a tree that grows in the tropics of South America and Indian Ocean islands.
While the average size of most palm leaves ranges from 4 to 20 feet long and 1 to 4 feet wide, a single leaf of the raffia palm can be more than 70 feet long and 19 feet wide!
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Which Plant Has the Biggest Seed In the World and Where Does the Seed Come From?
A tall palm tree called Lodoicea maldivicia, which grows only in the Seychelles in the Indian Ocean, produces the largest single seed in the world known in the plant kingdom.
The two-lobed seed can be twenty inches long.
It grows in huge fruits that look something like two coconuts joined together in an almost heart-shaped arrangement.
To the European sailors who first saw the seeds floating in the ocean, the shape was suggestive of female buttocks.
To the tourists who eventually followed, they looked like wonderful souvenirs, and the trees are threatened in the wild because local residents collect the seeds to sell.
The seeds are also much sought after by amateur palm growers, but they are not easy to cultivate. They have a very slow germination time of several years.
Eventually a shoot grows out of the seed and then goes underground.
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Where Can You Find Giant Plants?
If you’re looking for giant plants, there’s no better place on earth to find them than Brazil.
A palm tree that grows in Brazil, the Amazonian bamboo palm, has the largest leaves of any plant on earth. The fronds, or leaves, of this palm can be close to 70 feet long and 19 feet wide!
You’ve seen lily pads, floating leaves that sometimes offer a resting place for frogs. Imagine a lily pad so large it could support a man! The Victorian water lily, or Victoria Regia, found in the Amazon region of Brazil, can measure 6 feet in diameter.
The explorers who first discovered this plant claimed that some of the pads were large enough to support three men!
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What Is Epistemological Rationalism?
Epistemological rationalism is the position that human beings have important ideas or principles present in their minds from birth, and that the most important truths about the world can be derived from thought, without the need for experience.
These a priori truths are also held to be logically certain, which is to say that it would entail a logical contradiction to deny them, and that they are absolutely certain, or, in current terminology, “true in all possible worlds.â€
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Can Any Plants Move From Place to Place?
One of the major differences between an animal and a plant is that an animal can move from place to place, while a plant is rooted to the spot where it grows. But there are some plants that can actually move from place to place in search of water!
The resurrection plant, a desert plant found in parts of the American West and the Near East, grows just like any other plant when there’s enough water around, sending roots into the ground and sporting green, fernlike leaves.
But when water is scarce, the resurrection plant pulls up its roots and dries up, becoming a ball of brown twigs that appear to be quite dead. This ball of twigs is carried along the ground by the wind, and may roam the desert for many years.
But when the plant finds water, it sinks roots into the wet ground, turns green, and begins to grow again! It’s called the resurrection plant because it appears to come back from the dead.
If the moisture in the soil dries up, the resurrection plant will pull up its roots and wander over and over again in search of water!
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How Is Soil Formed?
There are four basic “ingredients†that go into the “recipe†for making soil: tiny pieces of rock, decayed plants and animals, water, and air.
When small pieces of rock break off larger ones, they form the basis of all soil. This breaking can occur in several ways: through the action of glaciers pushing rocks along the ground and grinding them against other rocks; through the action of chemicals in water eating away at rocks; through changes in temperature causing water to freeze in rocks and crack them open; through the force of wind throwing sand and pebbles against rocks; and through the movement of plant roots splitting rocks apart. This rocky, ground-up material is called the parent material of the soil.
When a plant or animal dies, its remains are attacked by bacteria which decompose, or break them down. This decaying matter combines with the parent material and provides the soil with many nutrients to help new plants grow.
Water and air fill in the spaces between the ground-up rock and decaying matter to provide places for tiny insects to live and for plant roots to grow.
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How Are Rocks Formed?
Our earth is composed of three main types of rocks, each having been formed in its own special way.
The first type, igneus rock, was formed when hot (2,000°F.), melted rock material, magma, deep inside the earth rose to the surface during earthquakes, volcanic eruptions, or other movements of the earth’s crust. This magma cooled and hardened. Granite is an example of igneus rock.
The second type, sedimentary rock, was formed millions of years ago mostly on the bottoms of lakes and oceans, when parts of plants, animals, and other, older rocks piled loosely upon each other in layers. Over millions of years, these layers squeezed together to form solid rock. Sandstone and limestone are examples of sedimentary rock.
The third type of rock, metamorphic rock, was formed when great heat or pressure, or chemical actions of liquids and gases changed either the igneus or sedimentary rock in appearance and composition. Marble is an example of metamorphic rock, since it was originally limestone, a sedimentary rock formed from hardened shells and coral upon which chemicals acted.
Smaller rocks of all three types are formed when water seeps into rocks, freezes, then expands. This expansion causes huge rocks to break apart. The movement of glaciers has also ground larger rocks into smaller, more rounded forms.
There is actually a rare kind of thin sandstone, itacolumite, found in North Carolina, which can be bent out of shape by hand!
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Are Mountains Still Growing or Do They Shrink Eventually?
For ages, people believed that Earth would always be the same. Now we realize that it is constantly changing.
The mighty Himalaya Mountains in South Asia, with their record-breaking heights, are still growing. The great Alps in Europe may grow taller still.
On the other hand, the Rocky Mountains in the United States are continuing to wear away, just as the eastern Appalachians have diminished over time.
These changes, however, generally take place at the rate of a pebble, a rock, or a boulder at a time.
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What Was the Reaction to Gregor Mendel’s Discovery In Genetics When His Paper Was Published In 1866?
Gregor Mendel knew he had made a great scientific discovery.
He wrote a paper on his findings in plant genetics and presented it to the Brunn Natural History Society.
They either didn’t know what he was talking about or didn’t understand the significance of it.
The paper, Experiments with Plant Hybrids, was also published in the society’s small scientific magazine, but again there was no reaction.
Mendel sent the paper to scientists throughout Europe, but they were not interested in the work of an amateur and a monk.
Mendel was appointed abbot of the monastery soon after that and spent the remaining 15 years of his life running the establishment. His new responsibilities and the disappointing reaction to his work meant there would be no more research.
When he died, his laws of heredity were still unknown.
It was not until 1900 that three scientists working on heredity discovered Mendel’s paper and revealed his findings to the world.
In the early 1900s, Swedish scientist Nilsson Ehle used Mendel’s findings to create a strain of wheat that would easily grow in Sweden’s cold climate.
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Why Don’t All Months Have the Same Number of Days?
Our calendar comes from the ancient Romans, and is based on the sun. But before the Romans began to use their solar calendar, they used a lunar calendar, based on the moon.
A real month is the time it takes the moon to go around the earth, about 29.5 days. So the Romans gave their months 29 or 30 days. But their 12 months added up to only 354 days, so they had to add a short month of 11 days to the year from time to time.
During Julius Caesar’s reign, the Romans began to use a solar calendar instead of a lunar calendar. The Romans took the extra 11 days in the solar year and divided them up among the other months, making the first, third, fifth, seventh, ninth, and eleventh months each 31 days long. Then they took a day away from February, so that the 12 months contained exactly 365 days.
Some historians think that Augustus Caesar took a day from September and added it to August, the month named after Augustus, and also moved a day from November to December.
That’s why August and December now have 31 days, and September and November have 30. But there’s no proof that this is the way it really happened.
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When Did the World Lose Ten Days?
In 46 B.C., Roman ruler Julius Caesar put a new calendar into effect, which came to be known as the Julian Calendar. The Romans thought that the year was 365.5 days long, so they made an ordinary year 365 days and added an extra day every fourth year, or leap year.
But by the year 730 A.D., it was known that the year was actually 11 minutes shorter than the Romans of Julius Caesar’s time thought it was. This mistake made the calendar wrong by 11 minutes each year, or one day wrong in every 128 years. By 1582, the calendar was ten days out of line with the seasons.
So in that year, Pope Gregory XIII ordered a new calendar placed into effect, which we now call the Gregorian Calendar. To keep the calendar in line with the seasons, it was decided that the first year of each century would be a leap year only when that year could be divided by 400. Therefore, 1200 and 1600 were leap years, but 1800 and 1900 were not. This change eliminated the 11-minute-per-year error in the calendar.
To bring the calendar immediately back into line with the seasons, Gregory ordered that ten days be dropped from the year 1582. People who went to bed on the night of Oct. 5 of that year woke up on Oct.15!
Some branches of the Eastern or Orthodox churches still figure their holidays according to the Julian Calendar, which is now 13 days different from ours!
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How Does the Dimension of an Antenna Play a Significant Role In the Reception of an Electromagnetic Wave?
The length of an antenna determines the frequency that it best receives. The most efficient antennas have a length equal to half the wavelength of the wave it is receiving. This allows the induced electrical current in the receiving antenna to resonate at that particular frequency. If the antenna is a simple rod it is most sensitive when its length is one quarter the wavelength.
A loop or coil antenna are used for the low-frequency, long-wavelength signals in the AM band. A half-wavelength straight wire antenna would be over one hundred of meters long. Shorter wires or rods can be used and are more efficient if coils of wire are used to “load†the antenna.
Home FM radio and television antennas are designed to receive a broad range of frequencies, but with less sensitivity. Antennas for the ultra-high frequencies used in digital high definition televisions are very short and can be easily mounted outside on rooftops or on top of television sets.
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What Is the Electromagnetic Spectrum?
The electromagnetic spectrum is the wide range of electromagnetic (EM) waves from low to high frequency.
The spectrum ranges from low-frequency radio waves, all the way to gamma rays, which have a very high frequency. In the middle of the spectrum is a small region containing the frequencies of light.
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What Is Light Made of, Where Does Light Come From, and Why Is Light a Type of Electromagnetic Radiation?
Light is a familiar everyday phenomena that we take for granted.
When the Sun or other stars shine, we see light. When we turn on a lamp, we see light.
Technically, light is an energy disturbance in the air. Oscillating electric and magnetic fields radiate energy in waves.
The wavelengths and frequency fall in the middle of the electromagnetic spectrum, between ultraviolet and infrared rays. It so happens that our eyes detect radiation at those wavelengths and frequencies in the form of light.
Different elements, and the combinations of elements that make up molecules, emit radiation in different ranges of the electromagnetic spectrum.
Nitrogen-based ammonia, for example, tends to emit microwaves. We cannot see ammonia in space with an optical telescope, but it can be found using a special microwave telescope.
Neon radiation, however, is detected as light. Think of all the neon signs in all the store and restaurant windows you’ve seen.
Technology now allows astronomers to study radiation across the whole electromagnetic spectrum.
Research into all the different kinds of radiation provides far more information, and raises many more questions, about the universe than studying light alone.
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How Dangerous Is Radiation and Are All Types of Radiation Dangerous or Hazardous to Our Health?
There are several types of electromagnetic radiation such as, radio waves, infrared light, visible light, ultraviolet light, and X-rays.
Some radiation from elements can be deadly.
The bombs that the United States dropped on Hiroshima and Nagasaki, Japan, at the end of World War H, were hydrogen and plutonium bombs, respectively.
The radiation from other elements is harmless.
Seventy-eight percent of the air we breathe is nitrogen, whose radiation obviously is not dangerous.
Most types of radiation are harmless at low levels of exposure, but even infrared radiation can be harmful if it is of a high intensity.
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When Did Humans Appear On Earth?
This is not an easy question to answer. Debates rage over which fossils can be called truly hominoid (humanlike), or hominid (human).
The development of human characteristics took place over millions of years. The earliest primate (an order of mammals that includes humans, apes, and monkeys), no bigger than a rat, appeared 60 million years ago.
About 10 million years ago, the Ramapithecus showed remarkable hominoid attributes. But there is no further evidence until 6 million years later.
The first generally accepted hominoid is called Australopithecus, and some believe they are actually the most primitive of the human lineage.
Homo habilis, dating back at least 2 million years in modern-day Africa, is undisputedly human. Less than a half-million years later, Homo erectus lived in Africa as well as in Asia and Europe.
A fossil skull fragment discovered in England is the oldest known example of modern-day humans: a 300,000-year-old Homo sapien.
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Why Is Africa Called the “Birthplace of the Human Race†And When Was Cattle Domesticated In Africa?
Africa is called the birthplace of the human race because scientists have found fossilized bones of human ancestors in eastern and southern Africa that are the oldest of any in the world.
They believe that humans gradually moved out of Africa to populate the rest of the world.
The earliest Homo sapiens, or modern human, found in Ethiopia can be dated back to about 200,000 years ago.
Most scientists believe that the human species originated from the African continent.
Fossil remains of several species of early apelike humans believed to have evolved into modern man, such as Australopithecus afarensis from about 3 million years B.C. have been discovered.
It is believed that cattle was domesticated in North Africa by about 6000 B.C., before agriculture had become widespread.
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Did Dinosaurs and Humans Ever Coexist On Earth?
Dinosaurs and humans did not coexist on earth.
Dinosaurs first appeared in the Triassic period, about 220 million years ago, and disappeared at the end of the Cretaceous period, about 65 million years ago.
Modern humans (Homo sapiens) appeared only about 25,000 years ago.
Movies that show humans and dinosaurs existing together arc only Hollywood fantasies.
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What Is Radiation, Which Objects Emit Radiation, and How Is the Wavelength of Radiation Measured?
Radiation is energy emitted by a source such as a planet, star, or your own body.
We measure radiation in wavelengths. Radiation travels in rising and falling motions called waves, like waves in the ocean.
Wavelengths are measured from the tip of one wave to the tip of the next.
Our eyes can register light waves, which are relatively short, but wavelengths of other kinds of radiation are too short or too long for us to be able to see them.
Radiation waves can also be measured by frequency, or how many waves pass a point within a certain amount of time.
Imagine you are standing in the ocean with a stopwatch.
You time the waves, counting how many pass you within one minute. If three waves go by, the wave frequency is 3 cycles per minute.
Radiation is usually counted in cycles per second (cps): 1 kilohertz (kHz) = 1,000 cps, and 1 megahertz (mHz) = 1 million cps.
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Why Do Trees and Leaves Change Color In Autumn and What Causes the Color Change In Fall?
The leaf color changes of autumn result from a complex interplay of factors of temperature, sunlight and moisture, all dependent on timing.
Not all the processes are predictable, but it is known that sunny days and cool nights in late summer and early autumn make for a particularly bright display of reds.
The yellow display operates separately from the red display, though both result from a shutdown of photosynthesis.
Shorter days signal the development of a layer of cells at the base of the leaf, called the abscission layer, that cuts off the water supply and later severs the leaf.
This stops production of chlorophyll, the green chemical at work in photosynthesis.
The chlorophyll breaks down, unmasking pigments already present in a leaf that will “turn†yellow: the xanthophylls, or yellows, and carotenes, the same orangey-yellow chemicals found in vegetables like carrots.
Still another class of pigment, the anthocyanins, is manufactured more quickly as summer ends.
As the leaf is cut off from its circulation, its sugar is trapped in the leaf and turns into anthocyanins, which depending on the species can be red, purple or maroon.
Cool nights in autumn inhibit the loss of sugar from the leaves, but brilliant sunshine promotes the maximum sugar synthesis and its transformation into anthocyanins.
A mild to moderate drought also stimulates anthocyanin production.
Drought or stresses like insects early in the season have comparatively little effect on the eventual nature of the color display, but can cause premature browning and leaf loss.
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Why Does Black Tea Lighten or Change Color When You Add Lemon Juice and What Causes the Chemical Change?
The simple answer to why black tea changes color is that adding lemon juice alters the acidity of the tea and the color change is an indication of this.
The color change is the same way that litmus paper changes color.
A similar effect can be observed by substituting the tea with some cooked red cabbage juice.
Tea leaves are rich in a group of chemicals known as polyphenols that amazingly account for almost one-third of the weight of the dried leaf.
Both the color of the tea and much of its taste are due to these compounds.
One group of polyphenols, the thearubigins, are the red-brown pigments found in black tea and constitute between 7 percent and 20 percent of the weight of dried black tea.
The color of black tea is also influenced by the concentration of hydrogen ions in the water.
Thearubigins in tea are weakly ionizing acids and the anions, or negatively charged ions, they produce are highly colored. If the water used to brew tea is alkaline, the color of the tea will be deeper due to greater ionization of the thearubigins.
If lemon juice, which is an acid, is added to the tea, the hydrogen ions suppress the ionization of thearubigins, and that makes the tea lighter.
Interestingly, the theaflavins, the yellow-colored poly-phenols in black tea, are not involved in the change in color that is associated with a change in acidity.
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Why Are Bread, Potatoes, Rice, Sugar, and Diamonds Not Black In Color If They’re Made of Carbon?
The best way to explain is with an example.
Sodium reacts violently on contact with water, while chlorine is a highly toxic greenish-yellow gas.
However, sodium chloride, the compound which contains these two elements, is harmless common salt, showing the properties of an element are very different from the properties of that element’s compounds.
The black powder used to produce a photocopy is finely ground carbon in its elemental form.
The particles are extremely small and arranged at random. Any light which falls on them is absorbed and not re-emitted, so the powder looks black. The sandwich certainly contains carbon but not in its elemental form.
Here, it is combined with oxygen and hydrogen as carbohydrates.
These compounds have their own properties which are nothing like the properties of their constituent elements. The slices of bread emit light of many wavelengths reasonably well, so when we look at bread in daylight, it appears white.
Carbon is normally found as an amorphous solid, which means it lacks a definite crystalline structure. Because of this, and because of the position of certain electrons in the outer orbits of the carbon atom, light is absorbed and not re-emitted.
This means the carbon atoms in graphite, soot and carbon black appear black.
Diamond, which is also carbon, is normally clear, because its crystalline structure alters the electrons and their positions to create a colorless crystal. Diamonds can be colored if other atoms, usually metals, are present and alter the electron bonds to create blue, yellow, pink and green versions.
Carbon, as present in foodstuffs such as bread and potatoes, is in hydrated form, the carbon has been chemically bonded with water and so does not appear black.
To get the black carbon back you need to remove the water, usually by heating.
This is why burnt toast is black.
Sugar is also carbon and water. But add concentrated sulphuric acid and you’ll see black carbon appear as the acid efficiently sucks out the water.
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Why Does an Octopus Change Color?
Even though octopuses belong to a group of shellfish called mollusks, they have no outside shell. A tough skin, called a mantle, covers the octopus’ body. This mantle contains small bags of pigment, or coloring matter, which are connected to the animal’s nervous system.
Any outside stimulus that excites the octopus makes its skin change color. It can change to blue, purple, brown, red, gray, white, and sometimes even striped.
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What Is the Carbon Cycle and What Percentage of Organisms Are Made of Carbon?
To survive, every organism must have access to carbon atoms.
Carbon makes up about 49 percent of the dry weight of organisms.
The carbon cycle includes movement of carbon from the gaseous phase (carbon dioxide in the atmosphere) to solid phase (carbon-containing compounds in living organisms) and then back to the atmosphere via decomposers.
The atmosphere is the largest reservoir of carbon, containing 32 percent CO2.
Biological processes on land shuttle carbon between atmospheric and terrestrial compartments, with photosynthesis removing CO2 from the atmosphere and cell respiration returning CO2 to the atmosphere.
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What Causes Grey Hair and How Does the Lack of Melanin Make My Hair Look White?
As people age, their bodies stop producing melanin, the pigment that colors hair.
Without melanin, hair becomes transparent, so you can see through to the air inside the hollow hair shafts.
The diffusion of the light through the air bubbles makes hair look white.
Hair dye works to hide the white because it stains the outside of the hair shaft.
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Why Does Hair Turn Gray When We Get Old and How Long Does It Take for Our Hair to Turn Gray as We Age?
Gray, or white, is merely the base color of our hair.
Pigment cells located at the base of each hair follicle produce the natural dominant color of our youth.
However, as a person grows older and reaches middle age, more and more of these pigment cells die and color is lost from individual hairs.
The result is that a person’s hair gradually begins to show more and more gray.
The whole process may take between 10 and 20 years, rarely does a person’s entire collection of individual hairs, which, depending on hair loss, can number in the hundreds of thousands, go gray overnight.
Interestingly, the color-enhancing cells often speed up pigment production as we age, so hair sometimes darkens temporarily before the pigment cells die.
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Why Do Some People Have Straight Hair and Others Have Curly Hair?
Every hair on your head or on your body is made up of a root, the soft, bulb-shaped section under your skin, and the shaft, the longer strand that sticks out of your skin.
If you were to cut a shaft of your hair from near the root and look at a cross-section of it under a microscope, it would have either of two shapes: round or flat. If it appears round, that means your hair will grow out straight; if that cross-section appears flat, that means your hair will grow at different rates in different places, making it curl or wave. The flatter the shaft, the curlier it will be. The shape of your hair shafts is determined by the shape of your parents’ hair shafts, for this is one of the characteristics you inherited from them.
Some people with curly hair are unhappy with it and have their hair straightened, while others with straight hair take “permanent waves†to make their hair curly. But both of these changes are only temporary, lasting only a short time, for the shape of the shaft cannot be changed, and as that person’s hair grows out, it will look the same as before the change.
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Why Do Evergreen Trees Not Lose Their Leaves In the Fall?
Evergreen trees do not keep their leaves indefinitely, but rather may grow new ones before the old ones fall, or keep some and drop others over a period of time.
As any southern gardener can tell you, some broadleaf evergreens, like Magnolia grandiflora, drop their heavy leaves in a staggered cycle over the course of the year.
Some, like the live oak, may show a heavy leaf loss in early spring, but retain a few old leaves while the new ones develop.
There is also seasonal needle loss with evergreen species of conifers, like pine, spruce, and fir trees. The leaf drop is a normal process, not a disease. The older,
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Can Your Hair Change Color Overnight?
Your hair can and will change color when you are old, but this does not happen overnight.
Different hair colors, from blonde to black, are determined by the melanin, the coloring matter, in your hair cells. This melanin becomes part of your hair cells as they form in the roots. Gray hair starts to appear in older people when less melanin is deposited in the new hair cells as they form. Without this coloring matter, the hair becomes gray and then white.
Certain diseases can cause the body to stop or slow down the production of melanin. So might worry, shock, or deep sorrow.
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Why Are Black Eyes Black and Why Does a Bruise Change Color When It Heals?
Blood released from capillaries and trapped under the skin and breakdown products of hemoglobin in the blood are chiefly responsible for the coloration of black eyes and other bruises.
In the case of black eyes, old blood is never really black, but dark purple and green.
The color of the pooled blood is magnified by the loose and transparent skin around the eyes, making a bruise there darker than it is on other parts of the body.
The chemicals mainly responsible for the changing colors of bruises are a series of products of the breakdown of hemoglobin, the oxygen-carrying compound in red blood cells.
An important one is biliverdin, which is green. There may also be bilirubin, which is yellow-brown.
The timing of the breakdown and the mixing of colors are not fully predictable, but at first bruises are usually dark blue, purple or crimson.
The color gradually changes to violet, green, dark yellow and pale yellow and finally disappears.
In one study pathologists found that they could conclude only that a yellow bruise was more than eighteen hours old.