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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What was the Hanseatic League? The Hanseatic League was a powerful trade network in Europe that stretched from eastern England to the heart of Russia. It existed from the 12th century until the 16th century, when it gradually faded away. The word Hanseatic came from the Old German word “hanse”, which meant a band, a
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What is Olbers’ Paradox? Olbers’ Paradox says that if the universe is infinite, eternal, static, and the same in every direction, the night sky should be completely illuminated and very bright, all the time. The Olbers behind Olbers’ Paradox was a German astronomer called Heinrich Olbers. In 1823, he was thinking about the size of
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Who discovered Pompeii? Pompeii was accidentally discovered by an Italian architect called Domenico Fontana at the end of the 16th century. The City of Pompeii was buried from 79 AD until it was accidentally discovered in the late 18th century. It was then left untouched until archaeologists started to recover it in the mid-18th century.
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How can a bicycle freewheel? A bicycle can freewheel because of a ratchet and spring-loaded catches inside the gear hub. When you cycle on a bicycle, you use the pedals to apply energy to the chain, which transfers the energy to the wheels and makes you move forwards. You want that when you are on
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Why do deserts have fossils? Deserts seem to have a lot more fossils because the topsoil is stripped away and because they don’t have dense vegetation. Deserts also formed in places that were good for making fossils. Many places around the world have fossils, but it seems like most of them are found in deserts.
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