#443 Why are people left-handed or right-handed?

Why are people left-handed or right-handed? Because of genetics and environment. There are four types of handedness. People can be right-handed, left-handed, right-handed for some tasks and left-handed for other tasks, and ambidextrous. The majority of the people in the world are right-handed. The number varies from country to country, but it is generally between […]

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#439 When were pencils invented?

When were pencils invented? The first pencil was invented in 1565. It is easy to think that something as simple as the pencil has been around for eons, but that is not actually true. Graphite was discovered in 1565, and the very first pencil was made very shortly after. Before pencils were invented, people used

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#438 Why are katana blades curved?

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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#435 What makes rain smell?

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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