Physics News

A new experiment proposed by physicists at the National Institute of Standards and Technology (NIST) may allow researchers to test the effects of gravity with unprecedented precision at very short distances?a scale at which exotic new details of gravity's behavior may be detectable.Of the four fundamental forces that govern interactions in the universe, gravity may be the most familiar, but ironically it is the least understood by physicists. While gravity's influence is well-documented on bodies separated by astronomical or human-scale distances, it has been largely untested at very close scales?on the order of a few millionths of a meter?where electromagnetic forces often dominate. This lack of data has sparked years of scientific debate."There are lots of competing theories about whether gravity behaves differently at such close range," says NIST physicist Andrew Geraci, "But it's quite difficult to bring two objects that close together and still measure their motion relative to each other v