Timeline for Time dilation derivation of special relativity
Current License: CC BY-SA 3.0
9 events
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| Dec 26, 2014 at 5:44 | comment | added | M. Zeng | @Danu I figured this out. Even if we use tennis balls, the time measured by the two observers will still be different. I should have used the velocity composition rule to do the calculation, which will give me the desired result. | |
| Dec 26, 2014 at 1:37 | comment | added | M. Zeng | @Danu yes, my doubt is, why the time dilation doesn't seem to apply in the tennis ball example I gave above, which does not involve traveling light. I ask this because time dilation is supposed to be a quite general result when we have a frame moving relative to the other and one observer in each of the frames trying to measure the time elapse for some event happening in one of the frames. | |
| Dec 25, 2014 at 9:14 | comment | added | Danu | @Timo Sorry, I'm not sure what you're getting at. Do you have a question? | |
| Dec 25, 2014 at 4:47 | comment | added | M. Zeng | The constancy of speed of light in all reference frames does play a crucial role in the derivation of time dilation. But how can this result (time dilation) be directly carried over to any of the other events that does not involve light but is happening in one frame moving to an observer. A very simple example would be to replace the light bulb in a moving train by a machine that shoots tennis balls in all directions and measure the time it takes for one of the balls to hit the point on the train floor directly below. The time will be the same for both observers. | |
| Jul 2, 2014 at 17:51 | history | edited | Danu | CC BY-SA 3.0 |
added 227 characters in body
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| Jul 2, 2014 at 17:48 | comment | added | Danu | @Iota Note that it is not possible to derive the second postulate from the first without additional assumptions (e.g. isotropy). This, too, is pointed out on the wikipedia page linked by James Clough. Any other derivation relying on e.g. Maxwell's equations or electrodynamics is ruled out on the basis of being allowed to use only Einstein's postulates, as per your question. I therefore do not understand your downvote (I assume it's yours), and think you should reconsider, for I believe my answer is correct | |
| Jul 2, 2014 at 17:40 | comment | added | Isomorphic | Also ultimately postulate 2 is implied by postulate 1. Now so there must be some derivation of the Lorentz factor, that doesn't use light beam experiments and implies only from postulate 1. | |
| Jul 2, 2014 at 15:55 | comment | added | John Rennie | I'm with Danu on this. If you start from the invariance of the proper time then the equation for time dilation drops out really easily. Doing it any other way is just making unnecessary work. | |
| Jul 2, 2014 at 15:28 | history | answered | Danu | CC BY-SA 3.0 |