Full Idea
Newtonian celestial mechanics does not explain the advance of the perihelion of Mercury, while Einstein's general theory of relativity does.
Clarification
the 'perihelion' is the nearest point of a planet to the sun
Gist of Idea
Unlike Newton, Einstein's general theory explains the perihelion of Mercury
Source
J.J.C. Smart (Explanation - Opening Address [1990], p.03)
Book Reference
'Explanation and Its Limits', ed/tr. Knowles,Dudley [CUP 1990], p.3
A Reaction
A perfect example of why explanation is the central concept in science, and probably in all epistemological activity. The desire to know is the desire for an explanation. Once the explanation is obvious, we know.