Sharpen Your General Knowledge

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.”

The word clock today is used for a large timepiece.

[Shamim Ansary]

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 “zōdiacus”, which comes from the Greek word “ζῳδιακὸς κύκλος”, which means circle of animals.

[Shamim Ansary]

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!

[Shamim Ansary]

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!

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.”

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

Are Cats Color Blind Like Dogs and Do They Only See Black and White?

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.

[Shamim Ansary]

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).

[Shamim Ansary]

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.”

“Then I’m not playing with you.”

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!”

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.”

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.