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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Why are stealth bombers invisible? They are not completely invisible, but they are able to reduce the reflection of radar, infrared, visible light, and radio waves. The first stealth plane was the Lockheed F-117 Nighthawk built in 1981. It was an attack aircraft, not a bomber, but it was the first plane to make use
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How far will the Voyager probes go? As far as they can get before they are eroded to nothing by space dust. Voyager 1 and 2 were both launched in 1977. As of today, December 4th 2022, Voyager 1 is about 23.7 billion kilometers from the sun and Voyager 2 is about 19.8 billion kilometers
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What is the difference between snowflakes and hail? Snowflakes are made up of ice crystals and hail is a frozen raindrop. Hail are frozen raindrops. They are generally between 5 mm and 15 cm in diameter. Hail is not as common as snow and can only form in a thunderstorm. For hail to form there
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How does an air fryer work? A fan circulates hot air at high speed which cooks the food. Firstly, let’s look at how food cooks when it is fried. With deep-frying, food is submerged in oil that is heated to between 177 and 191˚C. That seems pretty hot, but it is far below the boiling
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How do mammals keep warm in the winter? They have several different methods. Here are some of them. Many mammals stay warm by putting on more fat. Sea mammals have to cope with very cold ocean water and it is harder to stay warm in water than it is on land. If you are naked
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