What are stalagmites and stalactites? They are deposits of minerals that form in caves. Stalactites hang down from the top of the cave and stalagmites rise up from the ground. To help you remember, stalactites have a “c” for ceiling and stalagmites have a “g” for ground. If you want another way to remember which […]
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When did sailing ships die out? There are still ships that use sails today and a new type of large cargo ship that uses wings has been introduced, but the age of sail finished on October 20th, 1827. The first ships were probably powered with oars. However, a boat with oars cannot go very far
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What is CRISPR? It is a way of editing genes and it stands for Clustered Regularly Interspaced Short Palindromic Repeats. It works by separating the genes inside the DNA and inserting a mutation. To begin with, let’s look at what DNA and genes are. DNA is inside all of our cells and it holds the
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Why does time go forward not backward? Because of entropy. Entropy is the measure of how random and dispersed the energy and mass in a system are distributed. It is described by the Second Law of Thermodynamics, which says that the entropy of a closed system increases over time. The system has to be closed
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Who was the first king? This could be a question that is impossible to answer because most of the records of early rulers have disappeared or there is no way to separate myth from truth. It also depends on what the definition of king is. At what point does somebody go from being a tribal
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How have sea levels changed over time? Over the last 542 million years they have varied from 130 m lower than their level today to a theoretical 300 m higher than they are today. It is theoretical because the continents move around a lot, and it is difficult to find evidence for where the seas
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How does an octopus’s suction cup work? It reduces the pressure inside the sucker to create an extremely strong seal. Incidentally, I’m going with octopuses as the plural of octopus. Octopi is equally valid, but octopuses is apparently the more common term amongst the scientific community. Octopus comes from a Latin word and when Latin
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Why do shells form in different shapes? The environment and the biology of each living organism has caused their evolution to go in a slightly different direction. Most of the creatures that live in the sea and make shells are mollusks. They are soft-bodied creatures and use their shells as an exoskeleton. It gives them
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Is there any historical evidence for Jesus? Yes. There are a few mentions of him in other documents, but they all come from after he died. If you can ignore the biases in the Bible, then that is evidence as well. The vast majority of scholars believe that Jesus was a real, historical person. Yet,
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How much height does a parachute need? It completely depends on the type of parachute. We need to think about how long it takes a packed parachute to be released and inflate. Parachutes are packed into the backpack they are carried in and they are usually made of nylon these days. They used to be
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