The discussion revolves around the possibility of having all clocks in a given inertial reference frame read zero time simultaneously. Participants explore synchronization methods, particularly in the context of special relativity, and the implications of different approaches to achieving this synchronization.
Participants express differing views on the methods and assumptions involved in synchronizing clocks to read zero time. While some agree on the feasibility of synchronization, others contest the methods proposed and the underlying assumptions, indicating that the discussion remains unresolved.
The discussion highlights limitations related to the assumptions made about clock positions and the timing of light signals, as well as the dependence on definitions of synchronization in the context of special relativity.
Why not? There shouldn't be any problem at all, if you synchronize them with a spherical light pulse starting from a fixed point.bernhard.rothenstein said:Is it possible to realize a situation in which all the synchronized and ticking clocks of a given inertial reference frame read a zero time?
Thanks
Thanks. At which time should I emit the synchronizing light signal?lightarrow said:Why not? There shouldn't be any problem at all, if you synchronize them with a spherical light pulse starting from a fixed point.
-00. (So you have to wait a lot of time to record all "0" times!)bernhard.rothenstein said:Thanks. At which time should I emit the synchronizing light signal?
Yes it is, for a finite number of clocks. Having established from a given clock by pairwise signalling, the round trip light signal time to every other clock, a series of synchronising signals is sent to each specific clock at zero minus [half the round trip time for that clock], upon receipt of which each clock is zeroed. Thus all the clocks in the inertial system are [Einstein] synchronised at zero.bernhard.rothenstein said:Is it possible to realize a situation in which all the synchronized and ticking clocks of a given inertial reference frame read a zero time?
Thanks
Thank you for your help. Please let me know what do you mean by "pairwise signaling" (outgoing and reflected light signals?) .Boustrophedon said:Yes it is, for a finite number of clocks. Having established from a given clock by pairwise signalling, the round trip light signal time to every other clock, a series of synchronising signals is sent to each specific clock at zero minus [half the round trip time for that clock], upon receipt of which each clock is zeroed. Thus all the clocks in the inertial system are [Einstein] synchronised at zero.
Of course the assumption that the clock be synchronised at half the to-and-fro time is the crucial assumption of Einstein synchronisation that puts the "relativity" into special relativity. The clocks will be "synchronised" only for observers actually in the inertial system concerned.
Yes.bernhard.rothenstein said:Thank you for your help. Please let me know what do you mean by "pairwise signaling" (outgoing and reflected light signals?) .
Er, no. I think you mean to say C(x) is stopped at +x/c, otherwise the clocks would not synchronise.bernhard.rothenstein said:clock C(x) is stopped and fixed to read -x/c. A light signal emitted from O at t=0 arriving at C(x) starts it and so all the C(x) clocks read the same running time.
In order to obtain the situation when all the clocks C(x) read a zero time,each of them is stoped, read t=0 being synchronized by different light signals emitted at -x/c respectivelly.
Could you tell me which is the geometric locus of the simultaneous events which read t'=0 in I' when detected from I?Boustrophedon said:Yes.
Er, no. I think you mean to say C(x) is stopped at +x/c, otherwise the clocks would not synchronise.
In any case your method requires that x be already known for each clock, and the only practicable way of establishing this is with a to-and-fro light signal between already synchronised clocks !
So one comes back anyway to the method I described, which is not merely "in the spirit of" SR but is the very method on which SR is based.
Regards.