Discussion:
the absolute speed of the SR frame is transferred to the Esynchro, SRist ignore it
beda pietanza
2021-06-07 22:16:17 UTC
if an ruler is traveling at .5c (vs the local space or vs the local speed of light)
and we construct a SR frame associated to it, we are bound to synchro the clock in that frame.
limiting our analysis to the single ruler posit along the x axis in the direction of the movement, we synchronize the two clock at ends of our ruler:

a pulse of light is send from the origin 0,0 towards the far end of the ruler, in the direction of the movement: the travel time is sqrt(1-v^2)/(1-v)=
= sqrt(1-v^2)/(1-v) = sqrt(1-.5^2)/(1-.5) = .866../.5 = 1.73..local time = 1.5
now, the SR procedure impose that the far end clock must be set to 1,
so the far end clock is retarded of the exact value of the speed of the SR frame.(all the other clocks are set accordingly, depending also on their orientation angle, of course in the opposite direction of movement the clock along the x axis are anticipating of .5 unit of time )
we can have any SR frame at any speed the Esynchro will always retard the clocks along the x axis of the exact value of the absolute speed of the SR frame, for each x axis unit of length.
conclusion: the absolute speed of the SR frame, not only makes the Esynchro, (along with the speed of light), but the SR frame is carrying along, the value of its absolute speed "stamped" in its clocks Esynchronization "asynchrony"

cheers
beda
rotchm
2021-06-07 23:23:46 UTC
Post by beda pietanza
if an ruler is traveling at .5c (vs the local space or vs the local speed of light)
Assuming LET here, OK...
Post by beda pietanza
and we construct a SR frame associated to it, we are bound to synchro the clock in that frame.
As per the definition of (E)synch.
Post by beda pietanza
limiting our analysis to the single ruler posit along the x axis in the direction of the movement,
a pulse of light is send from the origin 0,0 towards the far end of the ruler, in the
direction of the movement: the travel time is sqrt(1-v^2)/(1-v) ...
Yes, all well know stuff. Why repeat what was known/written about for the past 100+ yrs?
You are just parroting and bringing nothing new.
Post by beda pietanza
now, the SR procedure impose that the far end clock must be set to 1,
so the far end clock is retarded of the exact value of the speed of the SR frame....
conclusion: the absolute speed of the SR frame, not only makes the Esynchro, (along with
Again, parroting 100 yrs of history/LET. Nothing new.
Post by beda pietanza
the speed of light), but the SR frame is carrying along, the value of its absolute speed "stamped"
in its clocks Esynchronization "asynchrony"
Yes, parroting 100 yrs of history/LET. Nothing new.
And this "stamped absolute speed" can't be determined, hence is uselessness for computations. Overkill & not necessary.
Post by beda pietanza
No disagreement since all well versed relativists know all this.
Cliff Hallston
2021-06-08 01:23:49 UTC
Post by beda pietanza
if an ruler is traveling at .5c (vs the local space or vs the local speed of light)
You fall at the first hurdle. You cannot operationally define a velocity "versus space", nor "versus the local speed of light". If you claim that those statements have some operational meaning, you need to state it. On the other hand, if you mean "relative to the inertial coordinates in which the CMBR frequency is maximally isotropic", then you need to say that. And if you just mean "relative to some hypothetical undetectable ether with no operational meaning, as in LET", then you need to say that.

In the latter case, all you are describing is the old Lorentzian interpretation of special relativity. If any of the others, you are describing a relationally-defined system. You are far too self-indulgent, allowing yourself to repeat verbiage that has no meaning.
Post by beda pietanza
and we construct a SR frame associated to it, we are bound to synchro the clock in that frame.
Right, you use inertial synchronization, which you call "peculiar trickery" when it is used in some frames, and "absolutely true" when used in others. Again, far too self-indulgent.
Trivially, we shoot identical bullets from identical guns at rest at the midpoint of a ruler. Likewise we could have a light bulb at the midpoint. When the bullets or the light reach the ends, we set the clocks equal.
Post by beda pietanza
A pulse of light is sent from the origin 0,0 towards the far end of the ruler, in the
direction of the movement: the travel time is...
This procedure can be analyzed in terms of any system of inertial coordinates, not just the magic one you stipulated (or rather, failed to stipulate). To make it simple, consider first the situation in terms of the rest frame of the rod, and then you can convert the description to any other system of coordinates you like. Understand?
Post by beda pietanza
Conclusion, the absolute speed...
Nope, your conclusion is completely senseless. You have not identified anything that singles out an absolute frame. Precisely the same analysis applies to any system of inertial coordinates. The fact that it works in one particular system does not imply that it doesn't work in terms of all the other systems. You need to get past that mental block.