Perseverance Is Paying Off for a Test of Relativity in Space

For 46 years, Francis Everitt, a Stanford University physicist, has promoted the often perilous fortunes of Gravity Probe B, perhaps the most exotic, “Star Trek”-ish experiment ever undertaken in space. Finally, with emergency financial help from a pair of unusual sources, success is at hand. Conceived in the late 1950s, financed by $750 million from NASA and launched into orbit in 2004, the Gravity Probe B spacecraft has sought to prove two tenets of Einstein’s theory of general relativity. The first, called the geodetic effect, holds that a large celestial body like Earth will warp time the way a rubber sheet stretches when a bowling ball is placed on it. The second, known as frame-dragging, occurs when the rotation of a large body “twists” nearby space and time; turn the resting bowling ball, and the rubber sheet twists.