What does paint primer do? It helps paint stick to the surface, it helps the paint last longer, and it protects the material you are painting. Humans have been using paint for tens of thousands of years. The earliest cave paintings were found in caves in Spain and they have been dated to 64,000 years […]
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Why do we have a leap year? We have a leap year because the calendar year doesn’t exactly match the solar year. Earth orbits the sun at an average distance of 149,600,000 km. We travel around the sun in a clockwise direction and we travel about 940 million km with every orbit. One orbit of
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Why does a golf ball have dimples? They make the ball go further. Golf balls didn’t always have dimples. The game was invented in Scotland in the 15th century, but it could be connected to a game called paganica that was played in Rome. It could also be connected to a Chinese game called chui.
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What happened to Detroit? Detroit declared bankruptcy in 2013, with debts of $18 billion. Detroit was the fourth largest city in the United States at one point and so large that nobody could ever have imagined that it would fail. Indigenous people have lived in the area for thousands of years and the first Europeans
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Where does cork come from? Cork comes from the bark of the cork oak tree. The primary use of cork is to stop up wine bottles. About 20 billion bottles of wine are produced a year and about 80% of those bottles have cork stoppers in them. That is a huge amount of cork and
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Henrietta Lacks developed cervical cancer and the cells taken from a tumor biopsy have formed the HeLa cell line, named after her. Ms. Lacks didn’t know that her cells had been taken and she died in October 1951, before the significance of her cells was known. She was only 31 years old. She did not
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Why does dry ice fog sink? The gas from dry ice is more dense than air and therefore it sinks. Dry ice is solid carbon dioxide. It is called dry ice because when it melts it turns into a gas rather than a liquid. Regular ice would be wet ice because when it melts it
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How do animals find water? They have many methods. Some animals can smell or sense water. Some animals get their water through eating plants. Some animals have evolved to need less water or to store water. Some animals can drink water that we couldn’t. Many animals instinctively know what signs to look for to find
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Why does a pulley make weights easier to lift? They increase mechanical advantage. The pulley is an invaluable invention that has helped humankind immeasurably. Without it, many of the things we take for granted, such as elevators, wouldn’t work. The pulley was possibly invented in Ancient Egypt in roughly 2600 BC. A pulley has been
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Can you live without a spleen? The spleen serves many functions, but you can live without it. Having it removed will affect your life, though. Your spleen is just inside your left rib cage, above your stomach. It is about 12 cm long and weighs approximately 70 g, about the size of an avocado. So,
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