How does a self-cleaning surface work? There are two basic ways to make something self-cleaning. You can make it superhydrophobic or superhydrophilic. Both of these methods will use water to clean the object. Self-cleaning surfaces are very useful for places that are difficult to get to and manually clean, such as the windows on the […]
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Does the placebo effect work? The placebo effect works for things that are directly affected by the brain, but not for actual illnesses. Nobody understands exactly the mechanism behind the placebo effect, but there are some pretty good theories. The word “placebo” comes from Latin, and its origins give a clue to what it does.
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Why does an oxyacetylene torch get so hot? An oxyacetylene torch gets so hot because the particles in acetylene hold an enormous amount of energy that they release when they are exposed to oxygen. Most of us will never have used an oxyacetylene torch. They are used by metal workers to weld or to cut
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How can we 3D print organs? Organs can be 3D printed using an ink made of the patient’s own cells that are laid on a scaffold. One of the problems we have as humans is that our organs sometimes fail. There are many reasons for this, from disease to accidents. Some organs we can live
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Why do rechargeable batteries lose power as they age? Because the process of recharging a battery is not 100% efficient and because of chemical degradation. These days, the majority of us use rechargeable batteries every day. While writing this, I have four devices currently recharging. I am sure you have something similar while you are
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Why does soap produce foam? All foaming soaps contain chemicals that are called foaming agents. As their name implies, their job is to make a foam when you add water and air to the soap. The main chemicals that you find in soap are ammonium lauryl sulfate and sodium dodecyl sulfate. Both of these are
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What is the difference between volts, amps, ohms, and watts? Volts measure the difference in electrical force between two points. Amps measure the flow of electricity. Ohms measure the resistance of the material. Watts measure electrical power. The volt is named after Alessandro Volta, who built the first electric battery. Volta lived from 1745 to
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What causes acid rain? Acid rain happens when water molecules in the atmosphere encounter sulfur dioxide or nitrogen oxide. Acid rain was a big problem in the USA and European countries during the 1980s and 1990s, but we don’t hear so much about it anymore. Has the problem been solved, or has it just shifted
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How does carbon dating work? Carbon dating allows scientists to estimate the age of something by counting the number of carbon-14 atoms that are left. Carbon-14 is created in our atmosphere and is absorbed by all living organisms. It is created when cosmic rays impact nitrogen atoms in our atmosphere. A cosmic ray is a
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How quickly does your blood regenerate after you donate it? The blood volume will be back in 48 hours, but it will take four to eight weeks for the red blood cells to regrow. When people donate blood, they usually give about 450 ml, which is about a pint. Depending on your size, that is
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