Whether caused by a tumor, a stroke, a blow to the head, or they were just born that way, people with achromatopsia have a limited or no ability to see color. Each of the possible physical causes of the condition, such as a growing tumor or a brain hemorrhage, damage either the thalamus (a relay station in the brain for […]
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Lindsey asks: How fast do electrons flow inside electrical cables? You may be surprised to learn that electrons flow through a typical copper wire much slower than a turtle walks. Each wire that conducts a flow of electrons, producing usable electric current, is composed of billions of atoms. To move along it, the electrons have to traverse these atoms, randomly […]
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When I was a kid, my parents had a collection of historic old, yellowed newspapers. For example, I distinctly remember an old Washington Post newspaper sitting on a bookshelf from July 21, 1969 with the headline “The Eagle Has Landed – Two Men Walk on the Moon.” Or a fading, brownish-yellow one from August 8, 1974 with the big headline, “Nixon […]
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Brian S. asks: How did they get the space ships on the moon off when there is no oxygen there? Whether it’s two-strokes or four, one cylinder or eight, most of the engines we use today are powered by the internal combustion of fuel and air; however, mixing gasoline and oxygen isn’t the only way to generate the energy needed […]
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Immobile and silent, those who suffer from the severest forms of akinetic mutism either lack the ability or the will to move or to speak. Caused by any of a number of conditions, diseases and injuries, under certain circumstances the disorder can be treated. One of the most remarkable stories of recovery from this devastating condition happened in 1941, when […]
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Julie H. asks: Why did lead used to be added to paint? The use of lead in everyday objects dates back to the ancient Romans. They used lead in makeup, as an additive in food and wine, in pewter dinnerware, and many other items, including paint. The inexpensive metal was even used in the pipes that transported water throughout the […]
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Matt T. asks: I was in southern California a while back and managed to pick up an AM radio station from Washington, but only at night. I’ve experienced the same thing at night in Washington picking up an L.A. radio station. In the day, it doesn’t work. So my question to you is why do radio signals seem to travel […]
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Scott S. asks: When you look at pictures of individual snowflakes, the snowflakes are clear. I was just wondering why is snow white and not clear then? First, it’s important to understand what’s going on when we see certain colors. Visible light from the Sun or other light source comes in a variety of wavelengths that human eyes interpret as […]
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Matthew S. asks: Why doesn’t your tongue quickly stick to plastic or wood in freezing temperatures but does to metal? In that famous scene in the movie Christmas Story, a kid “triple dog dares” another kid in the schoolyard to put his tongue on a metal flag pole to see if it will stick. Lo and behold, it sticks. The […]
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B. Halpern asks: 0 degrees Celsius is the freezing point of water. So what is 0 degrees Fahrenheit? Who came up with Celsius and Fahrenheit? Firmly entrenched in American society, the seemingly capricious nature of the Fahrenheit temperature scale could lead one to think that its Dutch inventor, Daniel Fahrenheit, pulled the number for the freezing point (32°F) of water out […]
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Mark U. asks: Why doesn’t sugar ever seem to go bad? Two foods are left out on the counter – fresh tomatoes and a bowl of sugar. Within a week or so, one will develop black spots and the other remains pristine, albeit perhaps a little clumpy depending on the humidity of the air. The reason? Osmosis. While microorganisms love […]
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Ryan C. asks: How do they make tattoos permanent? In other words, how do they get tattoos to remain even as your skin is constantly regenerating? Depending on the source you consult, anywhere from 14 to 23 percent of American adults and about 24% of British adults have at least one tattoo, a figure that one would think is set […]
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Linda P. asks: Why do we always use “x” for everything in math? For hundreds of years, x has been the go-to symbol for the unknown quantity in mathematical equations. So who started this practice? Algebra was born in the Middle East, during the Golden Age of medieval Islamic civilization (750 to 1258 AD), and its early form can be […]
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Karla U. asks: I heard your podcast on how teflon was invented. You said it’s the third most slippery substance known to man. This makes me wonder how they get teflon to stick to pans? Saving us from soaking, scraping and scrubbing, Teflon has been a lifesaver (or at least a hand-saver) for home cooks for the last 50 years. […]
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Lori asks: When you ask someone a question where they have to remember something, everyone seems to look up and off to the side. Why do we do this? Down and to the left, straight-head but unfocused, and, of course, up and to the right, when asked a tough question or to recall a long-buried memory, most of us shift […]
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Kelly asks: Is it true that men snore more than women? If it is true, why and if not where did this stereotype come from? Thanks! When humans sleep, the muscles around our throats relax and cause the airways to narrow. Snoring occurs when certain soft tissues—such as the soft palate (or roof of the mouth), the uvula (the dangling […]
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Mark R. asks: Why does wet hay that is bailed catch on fire? Plant reactions and bacterial growth combine to raise temperatures in even the driest hay bales, although most never catch fire on their own. However, when hay is packed tightly, and enough moisture gets in, the conditions may be right for spontaneous hay combustion. How does this work? […]
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Jane R. asks: In photos of starving children and babies, their stomachs often seem to be swelled up. What causes this? Of all the tragic, indelible images that come from places of famine, none is more troubling than the iconic photograph of a painfully thin child with an enormous, distended belly. The result of several factors relating to malnutrition, that […]
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