Photo by Pixabay: https://www.pexels.com/photo/assorted-color-laser-lights-417458/ How does a laser work? By focusing light into a narrow beam. LASER is actually an acronym, and it stands for Light Amplification by Stimulated Emission of Radiation. They have been around since the 1960s when the first laser was built by Theodore H Maiman, although the theory behind them goes […]
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Why are rubies red, emeralds green, and sapphires blue? Rubies and sapphires are varieties of the mineral corundum. Emeralds are a variety of the mineral beryl. They all have impurities that give them their color. Rubies are obviously red. Their name comes from the Latin ruber, which means red. They come in many different shades
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How does a Geiger counter work? By using radiation to create an electrical signal. There are four types of radiation and they all have different mass and energy. The types are alpha, beta, neutrons, and electromagnetic waves. Alpha particles are the heaviest. They have two protons and two neutrons. They are made by many of
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Why don’t cats knock things over? It turns out that cats have whiskers on their legs as well as their faces. When I’m making a line of dominos with my daughter, it is inevitable that either she or I will knock them all over. We both seem to have no sensory perception. And yet, my
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How do sparklers work? They burn a combination of metal particles that combust in different colors. Sparklers are coated in a mixture of metal powders and a type of sugar called dextrin. They also contain nitrates and sulfur or charcoal. Each of these ingredients has a different purpose. You must have held a sparkler at
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Why is the Dead Sea so salty? Because the sea evaporates very quickly and there is only one source of freshwater coming in. The Dead Sea is not actually a sea. A sea is defined as “a body of water that is partly surrounded by land”. There are about fifty seas in the world, but
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How do scales work? There are four different types of scales and they work in different ways. They are balances, steelyard balances, spring scales, and digital scales. Balance scales are the easiest to explain and they were the first scales used to measure the weights of objects. The first balance scales were used in the
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How does the heating element in a toaster work? It is made of a metal that has a high electrical resistance so it heats up very quickly. The heating element in a toaster is made of nichrome. Nichrome is an alloy made from (usually) 80% nickel and 20% chromium. Hence its name: nickel+ chrom(e)ium. There are four
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What is the tallest a mountain can be? It depends on the strength of the surface gravity, the amount of volcanic activity, the movement of tectonic plates, and the weather. The highest mountain on Earth is Mount Everest at 8,848 meters high. Technically Mauna Kea in Hawaii is the tallest mountain if you measure from
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How long does a 747’s runway need to be? A Boeing 747 airplane needs a runway that is at least 2,300 m long to land and over 3000 m to take off. However, this is a difficult question because there are many variables that come into play when determining the necessary length of runway for
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