|MadSci Network: Astronomy|
Dear Ben, Thanks for your question; as you know the best theory of gravity we have is Einstein's general relativity. This describes gravity as the effect matter has on space (actually, spacetime, for in relativity we consider time as just another coordinate but that doesn't matter here). I should say first of all that general relativity has passed (so far) the most important test of a scientific theory; it predicts things which are seen in observation and in experiment. The theory, for example, was only accepted after Eddington had observed the bending of light rays due to the Sun. I can see two major problems with the theory you propose (which would, of course, have to make all the same predictions relativity does). Firstly, the strength of the gravitational attraction is directly dependent on the amount of mass present. I suppose this could be explained by saying that space pushes harder on more mass, but in my opinion this solution is not as elegant. Secondly, if gravity was due to space acting on a mass we'd have to take into account the space between the two objects attracting each other; something we can get by without in our current theory. In short, I can't see any reason why your theory couldn't be made to work, but it would not offer any predictions above and beyond general relativity, at the cost of a much more complicated theory. Hope that helps. Chris Lintott
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