A key prediction of Albert Einstein’s general theory of relativity has been confirmed by an experiment showing that the Earth’s rotation drags the surrounding fabric of space-time along with it.
The phenomenon, known as frame-dragging, was one of the last untested predictions of general relativity. A NASA satellite, Gravity Probe B, was launched earlier this year to test the same effect.
“Frame-dragging is like what happens if a bowling ball spins in a thick fluid, such as molasses,” said Errico C. Pavlis, of the Joint Center for Earth System Technology, one of the leaders of the international team of researchers that measured the effect. “As the ball spins, it pulls the mo-lasses around itself. … Similarly, as the Earth rotates it pulls space-time in its vicinity around itself.”