Sharpen Your General Knowledge

[Shamim Ansary]

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).

[Shamim Ansary]

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. President”.

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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.

[Shamim Ansary]

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 name”, 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.

[Shamim Ansary]

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.