User:JModest/Sandbox
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Gravitational time dilation is an effect of relativity theory whereby the flow of time differs between two points in a gravitational field or an accelerated reference frame. From an observer's location in the field their own clock will always appear to run normally while identical clocks with less potential in stronger areas of the field will run slower and clocks with more potential in weaker areas of the field will run faster. A clock on the top of a building will have greater gravitational potential and thus run a small fraction slower than a clock at the base of the building. This is more than a mere consequence of observation. Upon uniting the clocks, a difference in time displayed makes evident the base clock experienced less time than the elevated clock. Neither is gravitational time dilation an effect of clocks, but rather any measure of time is dilated including the frequency of light, the rate of radioactive decay, and the time experienced by a person.
- For velocity (special relativity) time dilation see: Time Dilation
With Einstein's development of general relativity it became possible to accurately predict time dilation due to gravitational fields. The accuracy of modern atomic clocks and missions like Gravity Probe A makes possible the verification of time dilation of general relativity accurate to 70 parts per million.[1]
Gravitational time dilation is distinguished from velocity time dilation by the involvement of non-inertial or accelerated reference frames. This is true both as a consequence of gravity in a curved gravitational field or a consequence of acceleration which can give corresponding effects in flat spacetime outside any gravitational field. This is so closely related via the equivalence principle it is convention to refer to all time dilation in accelerated frames as gravitational time dilation.