When was the first air conditioning invented? It was invented on July 17th, 1902. The first electrical air conditioning, the predecessor of what we use today, was invented in 1902, but people have been using forms of air conditioning for thousands of years. The first methods to cool buildings relied on architecture. Ancient buildings have […]
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Why are clouds white? Because the water particles in the clouds scatter light equally. When light comes out of the sun, it is white. That is to say, it emits all of the colors of the color spectrum. The sun emits light as radiation and it emits radiation across almost all of the electromagnetic spectrum,
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What is the difference between a wigwam and a teepee? They have a different shape, are made of a different material, are constructed differently and are used in different regions. The only real similarity is that they are both used by Native Americans as a place to live in. A teepee is a conical tent
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Where do modern military ranks come from? There is not one single point where they started. Many countries have different systems and they have all evolved over time. Most of the ones we use in the West came from Italian and French. You don’t need ranks unless you have an organized army. In the beginning
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How is salt mined? In the same way that any other mineral is mined. There are three ways of producing salt. It can be mined out of the ground, it can be mined as a solution, or it can be left after the water is evaporated away. Salt on Earth is usually found underneath the
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How does a missile shield work? Attacking missiles can be brought down in the boost phase, the midcourse phase, and the terminal phase. Each phase of the missile’s path requires a different method to bring it down. A missile defense shield was first thought about in the Second World War. Germany had invented the V-2
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Why does a cracked whip make a sound? One portion of the whip moves faster than the speed of sound, creating a sonic boom. A sonic boom is created by anything that goes faster than the speed of sound, which is 343 m/s in air. Air behaves in the same way as a fluid, so
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Why is there a plastic island in the Pacific Ocean? Because of the amount of plastic waste we throw into the sea and because of the point where ocean currents converge. There are plastic islands in all of the oceans on Earth, not just the Pacific. The Great Pacific Garbage Patch just happens to be
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How many people do you need for a revolution? You need 3.5% of a population to start a revolution. There have been countless revolutions throughout human history. The ones that probably stick in our minds (depending on where we are from) are the French Revolution from 1789, the American Revolution from 1765, the Chinese Revolution
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Do the three laws of robotics need updating? The three laws of robotics were an invention by Isaac Asimov and they were meant for a story, not to be a literal way of controlling the robots and AI in our lives today. We will need some kind of laws that robots have to follow at
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