> The whole thing with Mercury was readily visible and had been observed for a long time, but Newton and others never came up with an acceptable explanation for

> The whole thing with Mercury was readily visible and had been observed for a long time, but Newton and others never came up with an acceptable explanation for it while Einstein did. This didn't involve insane precision or high speeds or anything like that. https://en.wikipedia.org/wiki/Tests_of_general_relativity https://en.wikipedia.org/wiki/Tests_of_general_relativity Perihelion of Mercury was observed to advance by 574 seconds per century. That is 0.16 degree per century, or 0.0016 degree per year. Of this 574 seconds, Newtonian physics could accurately explain 532 seconds as gravitational interactions between planets. That still leaves about 42 seconds as unexplained. General relativity predicts an additional 43 seconds, which is a near perfect match. Of course, it's always a matter of opinion whether something is "insane precision"... so feel free to think it is not. (Never mind most people never see Mercury itself in their lifetime: I certainly haven't.)