Re: An Interesting Occurrence in Circular Motion

On Sun, 17 Dec 2006 23:18:58 -0600, Tom Roberts
<tjroberts137@xxxxxxxxxxxxx> wrote:

Mike Fontenot wrote:
sal wrote:
In a rotating frame, you cannot synchronize all clocks (using the usual
meaning of the term "synchronize"), due to the Sagnac effect. You end up
with a "date line" someplace and clocks on either side of the date line
are mismatched.

This seems to contradict my results that say (among other things)
that all passengers agree that all passengers are ageing at the
same rate (at all times, not just on average).

It does not contradict that. Sal's description of synchronization was by
slow clock transport, and that cannot be performed consistently in a
rotating frame.


If that is true,
all clocks can obviously be synchronized.

If the center of the rotating frame is at rest in some inertial frame,
you can "steal" the synchronization of the inertial frame for the
rotating clocks. But this cannot be done via slow clock transport in the
rotating frame.


Perhaps the discrepancy
is in the definition of "synchronized", or, equivalently, of
simultaneity.

Yes, it is.


Tom Roberts
Tom,
In this thread you agree that all clocks rotating in the circle
tick at that same rate. Please continue with the following logic
step. Let there be two rotating clocks opposing each other on the
circle, labeled R1 and R2. We agree that R1 and R2 are running at the
same rate.
Let there be two clocks, F1 and F2, in an inertial frame (F1
and F2 have zero relative velocity). Let this inertial frame have
some velocity V with respect to the center of the circle. Let F1 and
R1 meet at a point on the circle while they are traveling in the same
direction. At that point in time and space F1 and R1 have the same
instantaneous velocity and if they measure the tick rates of each
others clocks both will agree that the tick rates are approximately
the same.
At the opposing side of the circle, when F1 and R1 meet, F2
and R2 also meet. Here, F2 has the identical velocity as F1. So at
the opposing point on the circle where R2 meets F2, R2 and F2 are
traveling in opposite directions. When they compare the tick rates on
their clocks, per Einstein, unlike F1 and R1, they find that their
clocks run at different rates. So you've agreed that R1 and R2
clocks are ticking at the same rate. F1 and F2 are ticking at the
same rate. F1 and R1 are ticking at approximately the same rate. And
per Einstein, F2 and R2 are ticking are not ticking at the same rates.
I don't see how these four situations can all be physically possible.
If you agree that the rotating clocks R1 and R2 tick at the same rate,
and F1 and F2 tick at the same rate, please describe how its
physically possible for R1 and F1 to tick at almost the same rate
while R2 and F1 tick at completely different rates. What logic step
do you employ to come to Einstein's conclusion?
Thanks,
David Seppala
.

Relevant Pages

  • Re: Lorentz transformations - a derivation
    ... Synchronizing 2 clocks means setting them so that exactly ... > one tick on each occurs simultaneously. ... inertial frame in which they are both at rest) ... definition of inertial frame, OTOH, cannot subsume force free motion ...
    (sci.physics)
  • Re: Lorentz transformations - a derivation
    ... Synchronizing 2 clocks means setting them so that exactly ... > one tick on each occurs simultaneously. ... inertial frame in which they are both at rest) ... definition of inertial frame, OTOH, cannot subsume force free motion ...
    (sci.physics.relativity)
  • Re: [PATCH 0/5] clocksource patches
    ... clocksource driver, not only do you complicate the driver, you also are ... The existing tick based ... cycle model it has to do extra work to provide ... I'm not trying to fit tick based clocks into the continuous model. ...
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  • Re: An Interesting Occurrence in Circular Motion
    ... Indeed, using the EM signals I discussed, all 3 passengers will agree that the signals from the two other passengers' clocks arrive with the same rate as their own clock. ... So for THIS SPECIFIC METHOD OF COMPARISON the clocks tick at the same rate. ... F1 and F2 are at rest in an inertial frame F moving ... In all cases, measuring the rate ...
    (sci.physics.relativity)
  • Lullaby for coders!
    ... Clocks on chips tick. ... Clocks on chips tock. ...
    (comp.lang.cobol)
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