How big was the asteroid that killed the dinosaurs? It was probably 10 km across, but it could have been anywhere between 10 and 17 km. The asteroid that killed the dinosaurs hit Earth about 66 million years ago. Apparently, according to research, it was 66,043,000 (±11,000 years). The asteroid came down in the Yucatan […]
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Why do ant bites hurt? Ants both bite and sting. They drip formic acid onto your skin and some ants inject venom. Not all ants bite. There are estimated to be 22,000 different species of ant and they are on pretty much every landmass except for Antarctica. It is estimated that ants make up between
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Could nuclear fusion power the Earth? Yes, but not in this half of the 21st century. Nuclear fusion and nuclear fission are the two ways we can get energy out of an atom. Nuclear fission is the easiest of the two for us to perform on Earth. In nuclear fission, a neutron is fired at
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When did people start using punctuation? The Greeks were the first people to use punctuation, but the Bible made it commonplace. Most early languages used a writing system that was based on images. There was no need for punctuation or even spaces because the ideas were contained in the symbols. Modern languages like Japanese and
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Why do we get headaches? There are many theories, but nobody actually knows. There are 200 different types of headaches, but they are divided up into primary and secondary headaches. Primary headaches are headaches that aren’t caused by a disease or damage to the brain. Secondary headaches are caused by a disease or damage to
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How does a rocket engine work? Rocket engines work because of Newton’s third law of motion. Newton’s third law of motion states “to every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.” Or, in other words, for
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What makes us itch? Itching is caused by the release of the chemical histamine. There are different types of itch. Almost all animals have an itch and scratch response. Bears scratch themselves on trees and dolphins scratch themselves on rocks, or at the bottom of their tank if they are in captivity. It is an
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Is irradiated food safe? Irradiating food kills off all of the bacteria, gives the food a fresher taste than other preservation methods, and doesn’t make the food radioactive. Ionizing radiation was discovered in 1895. Wilhelm Röntgen discovered that rays coming off a vacuum tube could penetrate a screen and react with a barium solution. He
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Why does UHT milk last so long? UHT stands for Ultra High Treatment and it is heated at 138℃ for 2 seconds to kill all the bacteria. All milk you buy in the shop has been pasteurized. In most countries it is illegal to sell unpasteurized milk because of the dangers. Unpasteurized milk can contain
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Where did Arabic numerals come from? They evolved from a writing system created in India in the 3rd century BC. The first evidence of prehistoric humans using numbers comes from a bone dated from 43,000 years ago. It is the Lebombo bone and it is a baboon femur with 29 notches carved into it.
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