Why are katana blades curved? They are curved to make them more efficient at cutting. Katana are long, curved swords from Japan. Their name “katana” means one-sided blade. “Kata” means “side” and “na” means blade. Many swords are double-sided because it allows them to be more effective when thrust. They can also be used to […]
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How does a caterpillar become a butterfly? By dissolving itself and regrowing. Caterpillars start life as an egg. Female butterflies lay eggs on leaves. It varies by species, but a Monarch butterfly lays about 300 to 400 eggs over a two to five week period. Not all of these eggs will survive. Many of them
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Who made the first English dictionary? Robert Cawdrey in 1604. There was no need for a dictionary throughout most of the history of the English language. Up until the invention of the printing press, in about 1436, words were spelled in several different ways, and often as they sounded. For example, egg could be spelled
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What makes rain smell? A combination of plant oils, bacterial spores, and ozone. Everything always smells very fresh after a rainfall and there is a word for it. Merriam-Webster defines petrichor as, “a distinctive, earthy, usually pleasant odor that is associated with rainfall especially when following a warm, dry period”. The word was invented by
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Why do we have a coccyx? The coccyx is a series of three, four or five vertebrae at the base of the spine. A coccyx is something we have evolved not to need, but it is a great reminder of our origins. The coccyx is also called the tail bone because that is what it
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Does the Oort cloud exist? Possibly, but there is no way of knowing. It is still just a working theory. The Oort cloud was first theorized by Jan Oort, a Dutch astronomer, in 1950. The idea is that a cloud of icy comets and planetesimals are orbiting the sun at a distance of about 0.03
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How does dry cleaning work? Clothes are soaked in a water-free liquid solvent. Dry cleaning is a way of washing clothes without water. At home, all of us wash our clothes in the washing machine using some kind of detergent and water. Inside the washing machine is something called an agitator. This is a drum
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Why do the leaves on a tree change color in the autumn (fall)? The leaves on trees change color in the autumn because the tree breaks down its own chlorophyll. Not all trees lose their leaves. Evergreen trees keep their leaves throughout the year. Trees that lose their leaves in the winter are called deciduous
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Why does smoke inhalation kill people? It reduces the amount of oxygen that the lungs can take out of the air and people die of asphyxiation. House fires are obviously dangerous, but most people who are caught in a fire don’t die from burns. In 2019, there were 3,704 deaths caused by fire in the
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Why do our stomachs grumble? Because the muscles in the stomach and small intestines are contracting and there is no food in there to muffle the sound. Our stomachs rumble a lot of the time, but we usually cannot hear it because the food in our stomachs and small intestines soak up the sound. The
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