Research Fellow in Mathematics.

Globe-trotter.

LGBTI rights activist.

Did you know that planets don't move on perfect ellipses? Their perihelion, the closest point to the Sun, is in fact not a fixed point in space: after every orbit it moves a little. Newton computed such displacement but the numerical value did not match the actual observed one. This was particularly evident in Mercury's case: the difference between the theoretical value and the observed one was 43 arcseconds/century. Not until Einstein came up with the General Relativity Theory (1915), was such discrepancy solved. The new gravitation theory predicted a new effect which accounted for the mysterious difference in the *precession of the perihelion* which Newton already came across with. This was the first test proving the correctness of General Relativity.