Was Einstein wrong? Gravity Probe-B will tell.
Among the many odd ideas born of Einstein's theories of relativity, the one about twisted space-time certainly ranks high: A massive body like Earth creates geometrical dimples in space and, through its rotation, also pulls nearby space along with it. Astronomers verified the dimple effect back in 1919, but proof of the second, called frame dragging, has remained elusive. This month, some 87 years after Einstein cooked up his theory, NASA and Stanford University will launch an incredibly precise, $650 million experiment to put it to the test.