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We know time slows down as gravity increases, so is the speed of light in high gravity different from its speed in low gravity?
Eric Kvaalen
Les Essarts-le-Roi, France
Time doesn’t necessarily slow down as gravity increases. What matters is how deep a point is in a gravitational well, which depends on how much energy it would take to get a 1-kilogram object very far away from the object producing the gravity.
Clocks run slower at the centre of Earth than they do at its surface, even though the gravitational field there is zero. If you stand in a…
