This should be a relatively simple question (pun intended): is there a single formula combining the time dilation from both gravity and velocity? Or is there a series of equations to combine them? (And what is it/are they?)

[math]-\frac{\Phi}{c^2}[/math]

 

Phi is the potential: v^2/2 for kinetic (at low speeds), -gh or -GM/r, as appropriate, for gravitational.

The more tricky and interesting question I think is what a "formula for time dilatation" is supposed to be in the first place. The rule for calculating the proper time of a given path through space-time is the same in any case; irrespective of whether the space-time is flat or not.

Edited March 7, 201114 yr by timo

This should be a relatively simple question (pun intended): is there a single formula combining the time dilation from both gravity and velocity? Or is there a series of equations to combine them? (And what is it/are they?)

To lazy to Google? Here you go: -> http://en.wikipedia.org/wiki/Time_dilation#Time_dilation_due_to_gravitation_and_motion_together

To lazy to Google? Here you go: -> http://en.wikipedia.org/wiki/Time_dilation#Time_dilation_due_to_gravitation_and_motion_together

Sorry, I just never check wiki

I figured I would ask here since I can get the formula (reliably) and ask questions about it if I don't get something.