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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Look closely at the tip of your finger and you are looking at a landscape that began forming months before you were born. Ridges curve, split, stop and rejoin in patterns so detailed that th...
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Seal a cat inside a box with a radioactive atom, a radiation detector and a mechanism capable of releasing poison. Arrange the experiment so that, after an hour, the atom has a 50 percent ch...
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Nelson Mandela did not die in a South African prison in the 1980s. He was released in 1990, became South Africa’s first Black president in 1994 and died in 2013 at the age of 95. Yet some pe...
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Look up on a clear night and the most obvious feature of the universe is not the stars. It is the darkness between them. That darkness seems perfectly ordinary, yet for centuries it posed a...
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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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In the Chihuahuan Desert of northern Mexico, where Durango, Chihuahua and Coahuila approach one another across an immense dry basin, a patch of landscape has acquired one of the strangest re...
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For generations, chemistry books could place bismuth near the end of the periodic table's stable territory. Its naturally occurring isotope, bismuth-209, showed no detectable radioactive dec...
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In 1929, while scholars were cataloguing manuscripts in Istanbul's Topkapı Palace, they encountered a fragment of an extraordinary world map. Painted in vivid colors on parchment traditional...
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