El Enrrabadore-mor wrote:
"Tom Roberts" escreveu na mensagem
t...
El Enrrabadore-mor wrote:
It is said that a speeding clock shows less elapsed time than
the stay-at-home clock, because (if already speeding) it is
running at a slower rate. Or else, because it had run at a
slower rate when it was speeding, assuming now it is
stopped near the stay-at-home clock.
While that may be "said", it is wrong in SR. In SR, the motion of a clock
does not affect its rate. But when one compares identical clocks that have
traveled different paths, their elapsed proper times can differ, due to
their different trajectories, not due to any change in their tick rates.

It looks like you have a new theory here.
Instead of velocity being the cause of time dilatation, now
it is the trajectory the cause of time dilatation.

No. I am discussing standard SR.

It seems your perception of SR is wrong. In particular, motion does NOT
affect the proper tick rate of clocks, but clocks that travel different
trajectories can differ in their elapsed proper times between meetings
of their trajectories. This is very basic SR, discussed in:

Taylor and Wheeler, _Spacetime_Physics_.


Below, you say that circular motion and linear motion
causes exactly the same muons lifetime. Since circular
and linear motions are the extreme limits of possible
trajectories, it looks like that you have contradicted
yourself.

Nope. What this shows is that acceleration does not affect the decay
rate of muons, and by implication, the tick rate of their internal "clock".


[... circular motion]
Bailey et al put muons into a storage ring and measured their lifetime for
their circular path. Within experimental resolutions, they have the same
lifetime as muons traveling in a straight line, so their circular path did
NOT affect the internal "clock" that controls their decay. They were
subject to an acceleration of about 10^18 g (1 g = 9.8 m/s^2), which is
FAR greater than claimed in your example. Note this experiment is a direct
implementation of the circular twin scenario, when combined with
measurements of muon decay at rest.

This one is extraordinary.
You claim that Bailey et al experiment showed that muons
lifetime doesn't depend on the acceleration.
It is said that one single experiment that falsifies GRT is
reason enough to discard a theory.

This does not "falsify GRT" at all!

You seem to be using a "sound bite" approach, and seem fixated on
"clocks running slow" (due to motion, or due to gravity). That's overly
naive.

Bailey et al does not refute GR because when one applies GR to their
physical situation and computes what they should observe, one obtains
agreement. It does show that the acceleration does not affect the muon
decay rate.

One can analyze their experiment (including comparison to muon decay at
rest) in two different ways:
a) use the overall inertial frame of their storage ring
and apply SR.
b) use the equivalence principle of GR, and treat the LOCAL
acceleration of the stored muons as a gravitational field
and compute the gravitational time dilation in LOCAL
coordinates in which the stored muon is at rest.
These obtain the same answer.


Tom Roberts