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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For 73 years, the Titanic existed in two places at once: in history, where the details of its final night were argued over in inquiries, newspapers and survivor testimony, and somewhere in t...
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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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Imagine exchanging messages with an unseen stranger. The replies are witty, coherent and sensitive to context. The stranger remembers what you said earlier, catches a joke, explains a diffic...
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You may already have yawned simply because you read the word. If not, there is a reasonable chance that a photograph or video of someone opening their mouth in a long yawn would do the job....
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Somewhere on Earth, while you read this sentence, babies are being born and people are dying. Others are crossing national borders, changing the population of one country without changing th...
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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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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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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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