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# Physics/Regarding perihelion of Mercury

Question
Hi Steve,

I read that the advancement of the perihelion of Mercury can be fully explained by Newtonian physics and there is no need for relativity. Please see the below link. Is this true?

http://www.alternativephysics.org/book/GRexperiments.htm#mercury
http://www.alternativephysics.org/gerber/Perihelion.htm

Regards

Sure, when he assumes this: "Gerber proposed that the speed of gravity was the same as light and this might account for the missing precession."  At the time (before special Relativity in 1905) the speed of light was not generally known to be a constant and the same for all inertial reference frames.  So his supposition at the time was premature.  A fascinating one, but if taken to its fullest conclusion (doesn't change the math shown at all) basically re-creates General Relativity.  So in essence, this little blurb proves relativity by recreating Einstein's result before relativity was known.  It's not inconsistent, Einstein's field equations involve the speed of light and predict that gravitation propagates at that speed.  If Newtonian mechanics, which assume that gravity moves at infinite speed, was completely true then we'd still have this 43 arc second problem.  Since relativity assumes the speed of light, what you pointed to above is consistent with it and not inconsistent.

Relativity is right.  GPS works fantastically well and would be many kilometers off if it was wrong.  The reference you pointed to is consistent with relativity and not inconsistent.  It's actually a proof that relativity is right, which was just waiting for relativity to come along as the proper theoretical framework to put it under.

Physics

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#### Dr. Stephen O. Nelson

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