Feel the gravity to tell which way is up

摘要

Moonwalking astronauts often lost their balance, but they weren't clumsy - it was gravity's fault. It turns out that the moon's gravity is not enough to help them distinguish up from down. Laurence Harris of York University in Toronto, Canada, and his colleagues spun volunteers on a giant rotating arm to simulate different strength gravitational fields. As the volunteers spun, they saw images of a landscape or the letter "p", which they read as a "p" or a "d", depending on which way they felt was up.