Taste a drop of seawater and the answer seems obvious: the ocean contains salt. The more interesting question is how it got there. There are no gigantic salt deposits steadily dissolving into every sea, and most rivers taste fresh even thou...
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Step out of a dark cinema into brilliant afternoon sunlight and, for some people, the reaction is immediate. The eyes narrow, the nose begins to tingle and within seconds comes an involuntar...
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It is one of those questions that sounds almost too simple to deserve a scientific explanation. Look up on a clear afternoon and the sky is blue. Yet that familiar color is the visible resul...
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Near the heart of the Milky Way lies a cloud with a reputation that sounds invented for a science-fiction cocktail menu. Sagittarius B2 contains alcohol. It also contains ethyl formate, an o...
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Imagine putting the entire Solar System on a cosmic scale: the eight planets, every known moon, the asteroids, comets, dwarf planets, dust and the enormous Sun. The result would be absurdly...
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At this moment, Earth is moving in several different ways at once. It spins on its axis, circles the Sun at roughly 30 kilometers per second, and accompanies the entire Solar System on a vas...
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Space is a vacuum, so an astronaut cannot simply lift a visor and take a sniff. Yet crews returning from spacewalks have repeatedly described something remarkably close to a smell of space:...
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On October 30, 1961, a Soviet Tu-95 bomber crossed the frozen landscape of Novaya Zemlya carrying an object so large that the aircraft had been specially modified to accommodate it. The bomb...
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Suppose engineers invent a computer chip that performs the same calculation using half as much electricity. The obvious conclusion is that electricity consumption should fall. Now suppose th...
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Astronomy has a reputation for expensive telescopes, complicated star charts and distant objects visible only through professional instruments. Yet some of the sky's most memorable events re...
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