I Time dilation vs the Equivalence principle

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The discussion centers on the differences between time dilation due to gravity and acceleration, specifically using muons as a measurement tool. It argues that while gravitational time dilation on Earth slightly slows muon decay, the spaceship, experiencing proper acceleration without significant speed, should not exhibit time dilation effects. Participants emphasize that both scenarios, when operationalized, show time dilation that affects muons similarly, challenging the initial assertion of distinguishable decay times. The conversation highlights the nuances of the Equivalence Principle, noting that while gravity and acceleration can appear similar locally, they manifest differently when considering varying gravitational fields. Ultimately, the conclusion is that time dilation cannot be used to differentiate between gravity and acceleration in the manner described without violating the principles of relativity.
  • #31
Prometeus said:
Good point. Experiments with muons showed only velocity dependent time dilation and absence of time dilation in acceleration. Time dilation effect in gravity of the Earth would be negligible and it was only my conjecture that there should be also time dilation effect.
Nevertheless, we can analyze what SR/GR would predict. It predicts that they would be equal.

Prometeus said:
Yes, I am writing specifically about zero height difference and pure acceleration effect and everybody seems like repeating the only mantra they know - the difference in height in the rocket. Seems like common obsession of all who had studied physics. It surely has some hidden Freudian meaning :)
It means that experts naturally assume that if you are asking about gravitational time dilation then you would want to discuss a scenario where there would be measurable gravitational time dilation. Your proposed experiment is not sensitive to the acceleration/gravity.
 
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  • #32
Prometeus said:
Yes, I am writing specifically about zero height difference and pure acceleration effect and everybody seems like repeating the only mantra they know - the difference in height in the rocket. Seems like common obsession of all who had studied physics. It surely has some hidden Freudian meaning :)
Zero height difference in the rocket is the equivalent of zero height distance on the Earth. Zero height difference in a gravitational field produces zero time dilation. Neither gravity or acceleration produce time dilation in of themselves. Time dilation in both cases is only caused by a difference in potential. Either different altitudes in the Earth's gravity or different positions in the accelerating frame of the rocket.
When someone says that the time dilation at the Earth's surface has some value, they mean they mean compared to a point that is at a maximum gravitational potential relative to the Earth. (By convention we set this maximum as being zero, with all potentials closer to the Earth having negative values. Thus the specific gravitational potential at the Earth surface is ~ -62511759 j/kg
 
  • #33
Prometeus said:
Im writing specifically about zero height difference and pure acceleration effect

And we're telling you, repeatedly, that there is no such thing. So your question is answered. And there is no point in continuing to go around in circles about it.

Thread closed.
 

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