Re: What's the beef with Einstein?

From: Dirk Van de moortel (dirkvandemoortel_at_ThankS-NO-SperM.hotmail.com)
Date: 08/20/04 

Date: Fri, 20 Aug 2004 10:16:27 +0200

"Carlos L" <carlosla@lix.intercom.es> wrote in message news:ac68ac75.0408192337.29a3b534@posting.google.com...
> "Dirk Van de moortel" <dirkvandemoortel@ThankS-NO-SperM.hotmail.com> wrote in message news:<41247261@usenet01.boi.hp.com>...
> > "Carlos L" <carlosla@lix.intercom.es> wrote in message news:ac68ac75.0408181614.27106b75@posting.google.com...
> > > "Dirk Van de moortel" <dirkvandemoortel@ThankS-NO-SperM.hotmail.com> wrote in message
> > news:<KOsUc.217054$yj6.10829885@phobos.telenet-ops.be>...
> > > > "Carlos L" <carlosla@lix.intercom.es> wrote in message news:ac68ac75.0408171009.2bca9f77@posting.google.com...
> > > >
> > > > [snip]
> > > >
> > > > >
> > > > > SR predicts that any clock that moves relative to the reference frame
> > > > > S of the observer runs slower compared to the clocks at rest in such
> > > > > reference frame. But since for SR all inertial reference frames are
> > > > > equivalent, it asserts that for an observer S' associated to the
> > > > > earlier moving clock, it is now the earlier rest clocks that slow down
> > > > > because they are now the moving clocks. I.e. SR's new logic accepts
> > > > > that both assertions "A > B" and "B < A" are true all the time.
> > > >
> > > > I guess you wanted to write
> > > > "A > B" and "B > A" are true all the time.
> > > > ?
>
> [...]
>
> > > > If SR would claim that, it would be utterly stupid.
> > > > In the scenario you are describing the following assertions
> > > > can be said to be true:
> > > > A > B and B' > A'
> > > > where A and B are times between two events as measured in
> > > > one frame, and A' and B' are times measured in another frame,
> > > > but between the same two events.
> > > > You can't just give these times the same variables. That is the
> > > > whole idea.
> > > > SR specifically and explicitly talks about measurements of times
> > > > in different frames.
>
> [...]
>
> > > Let me try again:
> > > Suppose that 2 very, very long trains (A and B) are located parallel
> > > to each other initially both at rest in the station. Each train is
> > > full of people. During a long while they exchange information between
> > > them and all the radio communications agree that everybody is at all
> > > times seeing that both their neighbours in the same train and the
> > > people of the other train that they can see through their windows have
> > > the same age than themselves. Suppose that at a given epoch both
> > > trains start to accelerate (with the same acceleration) but in
> > > opposite directions. After a while both trains have a high relative
> > > speed that they maintain until the end of the experiment. Then please
> > > answer these questions:
> > >
> > > (1) After some time, when the people of train A look through their
> > > windows at the people of train B (passing by them) do they appear
> > > younger or older than themselves ?.
> > > (2) The reciprocal question for the people of train B.
> >
> > Each A-person will notice on his own clock
> > the same elapsed time as on the particular
> > B-person's clock who just crosses his path
> > at the event of coincidence.
>
> From your answer I then conclude that neither the A observers nor
> the B observers would measure the time dilation phenomena that have
> been experimentally detected (transversal Doppler effect, particle
> lifetimes, etc, ...).

You conclude totally wrongly.

I repeat:
Each A-person will notice on his own clock
the same elapsed time as on the particular
B-person's clock who just crosses his path
at the event of coincidence.

And loosely speaking, both A and B will
notice that the other one's clock is "running
at slower rate than his own clock".

When you translate both statements in terms
of events and measured times and time intervals,
you will notice that there is no contradiction.

> But the reference frames A and B are now just 2
> normal inertial reference frames moving relative to each other. (Their
> past history is unimportant). They are just the typical reference
> frames in which according to mainstream SR those time dilation effect
> *do* take place.
> In the good old logic we call that a contradiction or an
> inconsistency.

You miserably confuse event times as measured by
different observers with clockrates as measured by
different observers.
That is exactly the same good old habit that makes
you say things like:
      "A > B" and "B > A" are true all the time.

[snip]

> > > > It seems that you somehow missed page 1.
> > > > Have you been learning SR from the Internet?
> > > > Where did you get this idea about "A > B" and "B > A"?
> >
> > So where did you get this idea?

So where did you get this idea?

Dirk Vdm

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