How did we work out the age of the Earth? The age of the Earth has been calculated by looking at the oldest minerals here on Earth, rocks on the moon, and meteorite rocks. The Earth formed roughly 4.54 billion years ago. However, that is a date people have only known with certainty since 1953, […]
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What are the differences between a brown, red, orange, yellow, blue, white, and black dwarf? The main difference between them is their state of stage of life. Red, orange, and yellow dwarf stars are living stars. Brown dwarfs are failed stars. White and black dwarfs are dead stars. Blue and black dwarfs are theoretical because
Why is the alphabet in that order? There is no logical reason why the alphabet is in the order it is in. It is mostly an accident of history and of the languages that used it. Before we begin, let’s be clear that I am talking about the Latin alphabet that has 26 letters and
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How did it take so long to invent zero? Zero took thousands of years to invent because there was no need for it. There is evidence that people have been counting for 50,000 years. Ancient people counted using tally marks. Cave walls, bones, wood, and stones have been found with tally marks scratched into them.
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Is Troy a real place? Almost certainly, Troy was a real place. It was located in present day Turkey. However, a Trojan war is only a possibility, and the two poems in which the city is mentioned are probably a mixture of history and legend. The location of the city of Troy was identified by
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What is the Local Bubble? The Local Bubble is an enormous cavity 1,000 light years across that our solar system is currently traveling through. We might think that space between the stars and planets is completely empty, but it isn’t. Depending on where it is, most of interstellar space has about 0.3 to 0.5 atoms
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Could anyone become a knight? In theory, it was possible for anyone to become a knight, but the vast majority of knights came from the nobility. The word “knight” comes from the Old English “cniht”, which meant boy or servant. That came from the Old German “Knecht”, which meant servant, bondsman, or vassal. And that
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How did we discover blood types? Blood types were discovered by Karl Landsteiner in 1900. Humans have four blood types. We have A, B, AB, and O. They are further divided into positive and negative, giving 8 different blood types. The positive and negative refer to the Rh antigen. If you have it, you are
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What was Operation Mincemeat? Operation Mincemeat was a deception by British military intelligence during World War Two to convince the Germans that Britain was going to invade Greece and Sardinia, rather than Sicily, the intended target. They planted false documents on a body that the Germans believed was a Royal Marine Major. The ruse was
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Who discovered prime numbers? The name of the first person to discover prime numbers is lost to history, but the first people to study them formally were Euclid and Eratosthenes, Greek mathematicians. A prime number is any whole number greater than 1 that can only be divided exactly by 1 and itself. For example, five
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