Orbit precessions - General Relativity vs Newton

[eltodesukane]

Basically, he major cause of orbit precession is that gravity travels at the speed of light, so that Mercury is not attracted to where the sun is, but to where the sun was.

 

[A.T.]

Basically, he major cause of orbit precession is that gravity travels at the speed of light, so that Mercury is not attracted to where the sun is, but to where the sun was.

This is wrong. Discussed many times here.

 

[PAllen]

Basically, he major cause of orbit precession is that gravity travels at the speed of light, so that Mercury is not attracted to where the sun is, but to where the sun was.

That is false. If that were the way gravity worked, orbits would be wildly unstable, and this was known even by Newton (he was reluctant to propose instant action at a distance but did so when he analyzed that a propagation delay would fail to explain stable orbits).

Here is a reference to the whole issue of apparent instant action at a distance in GR:

http://arxiv.org/abs/gr-qc/9909087

 

[eltodesukane]

Basically, he major cause of orbit precession is that gravity travels at the speed of light, so that Mercury is not attracted to where the sun is, but to where the sun was.

Seems I was wrong, situation not so simple.
Thanks for the reference.
Steven Carlip, Aberration and the Speed of Gravity (arXiv:gr-qc/9909087v2)
http://arxiv.org/abs/gr-qc/9909087