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Vanadium 50
Feb1-13, 04:54 AM
Sci Advisor
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Experimental proof that gravity ~ 1/R^2 ?

Planetary orbits also provide a stringent test. For a 1/r^(2+x) force, the semimajor axis of the ellipse does not precess only if x=0. Non-observation of precession allows limits to be set on x. (And indeed, for Mercury this was used to show GR made more accurate predictions than Newton)