Einstein Theory Proved

April 18, 2007 04:43 PM
by findingDulcinea Staff
NASA's Gravity Probe B confirms one of the central predictions of the general relativity theory: gravity bends space and time.

30 Second Summary

Gravity Probe B has provided the first experimental evidence of the geodetic effect, one of two key propositions of Einstein’s general relativity theory.

In the most commonly used analogy for general relativity, space is compared to a rubber mat stretched flat. The surface of the mat bends if a heavy object is placed on it. In a similar way, the Earth bends what Einstein called “space-time.”

The NASA probe contains four ultra-precise gyroscopes to measure that curvature. The orbit of the satellite is actually a very slow fall to Earth. Because that fall is over curved space-time, the axes of the gyroscopes move differently to how they would were the surface of space-time flat. Like a ship going prow-first into a whirlpool, the axes are tipped on the approach to earth.

Over the next eight months, the probe will return data to test the second key prediction of general relativity: frame-dragging. Does the Earth’s spinning drag space-time, making it spin like the whirlpool in the above analogy?


Key Players

Related Links

Reference Material


Most Recent Beyond The Headlines