Sharpen Your General Knowledge

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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?

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.