Published in Nature, 23 Sep 2010
Albert Einstein’s theories of relativity, which predict that relative speed and gravity affect the passing of time, have never been easy to bring home to the general public. In the early 1970s, scientists demonstrated relativity by putting synchronized atomic clocks on jumbo jets that flew eastwards and westwards around Earth. The westbound plane — the one flying against Earth’s rotation — gained time compared with a fixed reference clock on the ground. But this wasn’t exactly an everyday scenario.
Chin-wen Chou and his colleagues at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, have now demonstrated Einstein’s theories on more mundane scales. In tests of the special and general theories of relativity, the NIST researchers show that time speeds up if you climb just one rung up a ladder, and slows down if you travel at just 36 kilometres per hour. Their results are reported in Science this week. […]
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