Re: Clock synch


"Tom Roberts" <tjroberts137@xxxxxxxxxxxxx> wrote in message
news:j_PDg.6702$1f6.2244@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Nicolaas Vroom wrote:
"Tom Roberts" <tjroberts137@xxxxxxxxxxxxx> schreef in bericht
"Tom Roberts" <tjroberts137@xxxxxxxxxxxxx> schreef in bericht
There is no "time dilation", in the sense of a clock physically
ticking slower, or in the sense of "time moving slower". There
is
no "shortening/elongating", in the sense of a given object
physically getting shorter or longer.
Accordingly to the book "Introducing Einstein's relativity" by
Ray d'Inverno at page 33 "Thus moving clocks go slow by a factor
SQR(1- v*v/c*c). This phenomenon is called time dilation."
Yes. That is NOT what you described. <shrug>

And accordingly to you what Rat described is not a physical effect ?

The phrase "physical effect" is HIGHLY ambiguous, which is why I said
precisely what I meant. d'Inverno is NOT describing a clock whose
intrinsic tick rate has physically changed, he is describing a
measurement of a clock's rate by an observer in another frame, as I
described earlier in this thread.


Suppose there are two Observers A and B at the same position P1
which both have identical clocks and which initially show the same
value.
How would you call the effect, that, if Observer A stays at home
and Observer B moves from P1 to P2 and back to P1,
that when they meet,
they realize that the two clocks show a different value ?

Those two observers follow different paths through spacetime, and their
path lengths are different. For a timelike observer, elapsed proper time
corresponds to the path length, so it is no surprise that their clocks
display different values when they rejoin, because clocks simply
indicate their elapsed proper times. <shrug>

This is nonsense.....they show different proper time because they were
running at different proper rates when they were apart.


What is wrong by calling that a physical effect ?

It depends on what you mean by the phrase. If you mean "their clocks
ticked at different rates" then it is wrong; if you mean "their clocks
experienced different elapsed proper time" then it is correct.

Call it what you want. But it is not wrong to say that "their clocks tick at
different rates"

Ken Seto



.

Relevant Pages

  • Re: Clock synch
    ... There is no "shortening/elongating", in the sense of a given object physically getting shorter or longer. ... d'Inverno is NOT describing a clock whose intrinsic tick rate has physically changed, he is describing a measurement of a clock's rate by an observer in another frame, as I described earlier in this thread. ... which both have identical clocks and which initially show the same value. ... For a timelike observer, elapsed proper time corresponds to the path length, so it is no surprise that their clocks display different values when they rejoin, because clocks simply indicate their elapsed proper times. ...
    (sci.physics.relativity)
  • Re: Why TWLS=OWLS=c in any ONE Frame.
    ... let them go for a journey along separate routes, ... You claim that if the clocks don't read the same, ... of them must have changed its intrinsic rate. ... If two clocks side by side are acculmulating elapsed proper time ...
    (sci.physics.relativity)
  • Re: Clock synch
    ... For a timelike observer, elapsed proper time ... so it is no surprise that their clocks ... When any observer in an inertial frame observes the tick rate of a moving clock, it is observed to tick more slowly than the observer's own clocks. ...
    (sci.physics.relativity)
  • Re: Clock synch
    ... This should have been Ray ... which both have identical clocks and which initially show the same value. ... How would you call the effect, that, if Observer A stays at home ... experienced different elapsed proper time" then it is correct. ...
    (sci.physics.relativity)
  • Re: IRT: A New Theory of Relativity
    ... >>in motion relative to himself to shrink, and measures clocks in motion ... you are saying that Einstein assumed the observer using the Lorentz ... same speed in all directions in his own frame. ... plugging numbers into the Lorentz transformation, ...
    (sci.physics)
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