Screaming Penguin - Source Does Matter

A new NASA probe will launch containing 4 ping pong sized balls made of quartz, "the most perfect spheres ever made" ,inside a vaccum, chilled to almost absolute zero, in order to test the effects of the Earths gravity. All of Einsteins theory has never been empirically tested. Science has observed and tested light being bent by the Sun during an eclipse, and other such "warping effects", evidence that gravity is "warping space time" but apparently the spinning effect or "frame dragging" has never been detected directly. The quartz balls aim to do much more empirical testing of relativity by measuring minute changes in their rotation, theorized as the effects of gravity. See the linked BBC article for more.   Satellite to test Einstein theory: BBC