Quote:
Originally Posted by Southtown
Hmm... ok, why does gravity affect time?  |
You will have to bear with me. I only learned some more about this yesterday thanks to a post elsewhere by Janus. In other words, I'll try to answer correctly, but may misspeak and my comments should be checked.
We know that acceleration results in time dilation/length contraction.
We know that gravity is indistinguishable from acceleration.
Now, in this example, when time is dilated in one reference frame relative to another, it is because there is greater "gravitational potential."
There ya go.
From the wiki link I shared:
Gravitational time dilation is the effect of time passing at different rates in regions of different gravitational potential; the higher the local distortion of spacetime due to gravity, the slower time passes.
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Gravitational time dilation is manifested in accelerated frames of reference or, by virtue of the equivalence principle, in the gravitational field of massive objects. In more simple terms, clocks which are far from massive bodies (or at higher gravitational potentials) run faster, and clocks close to massive bodies (or at lower gravitational potentials) run slower.
It can also be manifested by any other kind of accelerated reference frame such as an accelerating dragster or space shuttle. Spinning objects such as merry-go-rounds and ferris wheels are subjected to gravitational time dilation as an effect of their angular spin.
This is supported by the general theory of relativity due to the equivalence principle that states that all accelerated reference frames possess a gravitational field. According to general relativity, inertial mass and gravitational mass are the same. Not all gravitational fields are "curved" or "spherical"; some are flat as in the case of an accelerating dragster or space shuttle. Any kind of g-load contributes to gravitational time dilation.
