Videos

Scientific American Logo
The SciencesNovember 25, 2013

Who Owns Outer Space?

A 1967 United Nations treaty states that outer space isn't up for grabs.This hasn't stopped at least one entrepreneur from selling land on our closest celestial neighbors. SA editor Clara Moskowitz explains.

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Scientific American Logo
BiologyNovember 1, 2013

Why Do We Sleep?

We spend nearly a third of our lives asleep, but scientists don't agree on sleep's purpose. Scientific American contributor Joss Fong explains what we know, and don't know, about our nightly slumber.

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NeuroscienceOctober 11, 2013

Why Is Yawning Contagious?

Contagious yawning can be annoying, but it might also be a sign of good social skills. It is a type of emotional contagion, a phenomenon in which we tend to share the feelings of people around us. SA MIND editor Sandra Upson explains.