From Eric Kvaalen
At several points in your special issue on time, you state that time runs more slowly where gravity is stronger (8 October, p 37). This is not correct. What counts is how deep one is in Earth’s gravitational potential well. Time runs more slowly down a mine than on the surface, even though the force of gravity is less. The slowest time near here is at the centre of the Earth, where you would be weightless if you could get there.
Les Essarts-le-Roi, France
