Timeline for Is this a way to distinguish between a gravitational field and an accelerated rocket?
Current License: CC BY-SA 4.0
8 events
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| Mar 15, 2020 at 6:26 | comment | added | kpv | @Dale: May be you are right, but it is hard for me to understand what would make the time speed different in two clocks in a rocket at two different heights, both are subjected to same acceleration (direction and magnitude), meaning identical curvature of space. You are again referring to equivalence principle, which in theory, makes it cyclic reason as I said earlier..What was actually tested to one part in 10^15, can you please point me to that experiment/test? This is something that needs to be tested in far space with constant acceleration for a prolonged period. Is that what was done? | |
| Mar 14, 2020 at 19:47 | comment | added | Dale | “That should not be true unless you assume equivalence principle means that. Is there a proof?”. Yes, a very easy proof. The weak equivalence principle (tested to one part in 10^15) says: “The local effects of motion in a curved spacetime are indistinguishable from those of an accelerated observer in flat spacetime, without exception.” If, as you say, “clock speed at different heights in a gravitational field will be different, but in a rocket, it will be same” then that would be distinguishable while the weak equivalence principle says it is indistinguishable, including the amount of dilation | |
| Mar 14, 2020 at 16:00 | comment | added | kpv | @Dale: 12KM/second | |
| Mar 14, 2020 at 15:53 | comment | added | kpv | @Dale: That should not be true unless you assume equivalence principle means that. Is there a proof? But we are discussing the practical ways to investigate the principle itself, so yours becomes a cyclic reasoning. Equivalence principle is not absolute. For example, assuming all other equivalence, how do you explain escape velocity? You shoot upward a marble from a 1g rocket at 12kmh , and it should never fall back to earth, but in case of a rocket, it will! there is no escape velocity in the direction of acceleration for a rocket. however in horizontal direction , any speed will do. | |
| Mar 14, 2020 at 0:30 | comment | added | Dale | “if you put two clocks at different heights in the rocket, will they run at different speeds as they do in a gravitational field” Yes, and by the same amount as in the gravitational field, provided tidal effects are negligible | |
| Mar 13, 2020 at 4:22 | comment | added | kpv | @Dale: Yes, there will be time dilation in rocket, but if you put two clocks at different heights in the rocket, will they run at different speeds as they do in a gravitational field? On earth for example, a clock at a meter height and a clock at 2 meter height will run at different speeds. Will that be case in rocket too? | |
| Mar 13, 2020 at 2:59 | comment | added | Dale | Clocks at different heights in an accelerating rocket will have time dilation, just like in gravity. In fact, you can use the SR rocket time dilation to derive the gravitational time dilation per the equivalence principle | |
| Mar 13, 2020 at 2:49 | history | answered | kpv | CC BY-SA 4.0 |