http://science.slashdot.org/story/14/01/06/236245/experiments-reveal-that-de... Posted by <http://unknownlamer.org/>Unknown Lamer on Monday January 06, 2014 @06:59PM from the deformed-example dept. KentuckyFC writes "<http://en.wikipedia.org/wiki/General_relativity>General relativity is mathematically challenging and yet widely appreciated by the public. This state of affairs is almost entirely the result of one the most famous analogies in science: that the warping of spacetime to produce gravity is like the deformation of a rubber sheet by a central mass. Now physicists have tested this idea theoretically and experimentally and say it doesn't hold water. It turns out that a marble rolling on deformed rubber sheet does not follow the same trajectory as a planet orbiting a star and that <https://medium.com/the-physics-arxiv-blog/b8566ba5a110>the marble's equations of motion lead to a strangely twisted version of Kepler's third law of planetary motion. And experiments with a real marble rolling on a spandex sheet show that the mass of the sheet itself creates a distortion that further complicates matters. Indeed, <http://arxiv.org/abs/1312.3893>the physicists say that a rubber sheet deformed by a central mass can never produce the same motion of planet orbiting a star in spacetime. So the analogy is fundamentally flawed. Shame!" --- co-chair http://ocjug.org/