# Anomalous precession of the orbit of Mercury

Can the anomalous precession of the orbit of Mercury be explained just with relativistic length contraction?

• No. If it could we wouldn't need general relativity to explain it. – John Rennie May 2 at 16:21
• @JohnRennie That sounds like a good answer. – G. Smith May 2 at 16:25
• @G.Smith possibly a bit brief for an answer :-) – John Rennie May 2 at 16:30

• @Avantgarde I said “observed”. We haven’t observed gravity’s UV regime, and a cosmological constant (but not an explanation of it) is part of GR. $\Lambda$ is in some sense more basic than $G$ because it simply is the coefficient of the zero-order-of-curvature term in the gravitational action. – G. Smith May 3 at 16:39
• @G.Smith Yes, but $\Lambda$ is just one way. There are other infrared modifications of gravity too, like ghost condensation, non-local gravity, etc. – Avantgarde May 3 at 19:02