Timeline for Why is clock synchronisation such a big deal in physics?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Jan 21, 2023 at 15:30 | comment | added | Florian F | As the OP said, in SR you can work out the local time, assuming you have chosen an inertial reference frame. You just look at a central watch and subtract the time for the light to reach you. In GR both time and distance become tricky. | |
| Jan 21, 2023 at 14:30 | comment | added | Solomon Slow | @FlorianF, Moving a ruler does not permanently change its length. I perceive it to have a different length while it is in motion, but once I have finished laying down my grid of rulers, I can trust that they all have the same length (even the ones that I placed in the far distance) so long as none of them is moving with respect to me. Clocks are slightly different. Moving a clock does not permanently change the rate at which it ticks, but the temporary slowdown that i perceive while moving it out to a distant location does permanently change its "offset" from my time origin. | |
| Jan 20, 2023 at 12:18 | comment | added | John Rennie | @FlorianF all measurements are being made in my inertial frame. | |
| Jan 20, 2023 at 11:51 | comment | added | Florian F | "The positions of events are easy": No. Distances also change depending on the observer. The same point in space and time translates to a different position and different time depending on the speed of the observer. Also, what is "here" in the future depends on the speed of the observer. | |
| Jan 19, 2023 at 20:12 | comment | added | John Rennie | @NeeladriReddy Special relativity is the theory of flat spacetime so the spacetime is uniform by definition. If we move to GR then the meaning of a coordinate system becomes more complicated. In general we can't synchronise clocks in GR, and even if we did they wouldn't stay synchronised. | |
| Jan 19, 2023 at 19:12 | comment | added | Neeladri Reddy | Thank you. But a new doubt - how do we know space/time is uniform in a given reference frame? I see it mentioned as a requirement, but how can it be verified experimentally and what does it really mean? I am asking because I have a vague sense that synchronizing clocks isn't enough, what if they don't run at the same rate due to them being at different places or something? I myself am not clear what I am asking, if you didn't get an inkling of the meaning of my question, it's because I myself am not clear what the issue is. | |
| Jan 19, 2023 at 19:10 | vote | accept | Neeladri Reddy | ||
| Jan 19, 2023 at 17:45 | history | answered | John Rennie | CC BY-SA 4.0 |