Are all snowflakes really different? Theoretically, yes, all snowflakes are different, but it is an issue of probability, and there is obviously no way to know for sure. Snowflakes form when the air is cold enough for water droplets to freeze. It is very difficult for them to freeze on their own; it is much […]
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Who was Jim Crow? Jim Crow was a fictional character played by a white actor in blackface in the 1830s, called Thomas Dartmouth “Daddy” Rice. He portrayed an African American slave called Jim Crow. The name later got taken up and made famous in the Jim Crow laws. The Jim Crow laws are not one
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How does kidney dialysis work? Kidney dialysis works by filtering the blood to remove excess water and toxins in cases where the kidneys have failed. Most people have two kidneys, although we can function perfectly on only one. The second one is basically an evolutionary backup in case one of them fails. This is called
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How does projection mapping work? Projection mapping works by using very powerful projectors and software that can map the shapes and angles of the object to be projected upon. You may need two things to do projection mapping. The first is an incredibly powerful projector, or several very powerful projectors for larger venues. The power
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Why does old paper turn yellow? Old paper turns yellow because lignin and cellulose break down. Most things in our world fade with time. The most common culprit is ultraviolet light. If you have a photo on your desk or a nice painting on your wall, over time, it will lose its vibrant color. And
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How would an invisibility cloak work? There are basically three ways you could make something invisible. You could use camouflage to hide it. You could use cameras to project the view behind the object in front of it. Or you could manipulate light so that it bends around the object being hidden. We have all
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How do owls fly silently? Owls have specialized feathers that allow them to fly silently. If you live outside of a city, you may have heard owls hooting at night. You may even have heard them if you live in a city, because these days there are a lot of urban owls. It is not
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When did people start using surnames? People started using surnames at different times in different countries. In Europe, surnames started in the 11th century. I am from the UK, so I am going to begin by looking at the origin of surnames in Europe and then look at other parts of the world. The word
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What is compost? Compost is a mix of materials that can fertilize plants and improve the condition of soil. It is also an excellent form of waste management. It is difficult to get accurate figures on how much food is wasted every year because there is no true way of measuring it. I live in
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What are fiber lasers? Fiber lasers are lasers in which the light is generated and amplified inside an optical fiber whose core has been doped with tiny amounts of rare-earth ions (such as ytterbium or erbium). The laser beam then comes out of the end of the fiber, which makes the system compact, efficient, and
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