Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on May 4, 2011
NASA's Gravity Probe B (GP-B) spacecraft has confirmed two key predictions derived from Albert Einstein's general theory of relativity. Launched in 2004, GP-B was designed to test Einstein using four ultra-precise gyroscopes to measure the hypothesized geodetic effect, which is the warping of space and time around a gravitational body, and frame-dragging, which is the amount a spinning object pulls space and time with it as it rotates. (News briefing held May 4, 2011 at NASA Headquarters in Washington.)