[ExI] QT and SR

Jeff Davis jrd1415 at gmail.com
Wed Aug 20 18:59:40 UTC 2008

Extropes and all ships at sea,

I want to finish this discussion off.  So here it is.  No one will be
surprised when I say that I cannot offer a decisive or authoritative
conclusion. I cannot compete with Mr. Bell's rep on this matter, nor
can I agree with him.  So I'm screwed.  Ah, well, such is life.

I asked John C for clarification of his last posting on this matter,
wherein he  judiciously rose in support of Bell's position ("Verily,
the string breaketh").  The source of my question, my question, and
John's response are shown below.

On Mon, Aug 18, 2008 at 12:30 PM, John K Clark <jonkc at bellsouth.net> wrote:
> Me:
>>> An instant after you start moving you receive
>>> a report from  the fellow at the other end of
>>> the string saying he hasn't started moving yet.
> "Jeff Davis" <jrd1415 at gmail.com>
>> I don't understand.  According to the setup both acceleration
>> profiles are identical.  You and your counterpart at the other end of the
>>  string know this.  So why then would you get such a message
> Light does not move at an infinite speed, so any message I receive
> must have originated sometime in the past; hence if I receive a message from
> the other end of the string the instant I start moving it is going to say
> that end hasn't started moving yet.

I had hoped that the time lag above would be John's way of introducing
a simultaneity issue, which I have found more confusing and difficult
to unravel than Lorentz contractions.  Then I could have thrown up my
hands and said, "This simultaneity weirdness is too much for me,
absent a return to the source materials for some serious study, (which
is precluded in my "retirement" by the ever-expanding requirements of
my honey-do list)."  But alas, the time lag thing upon which Johns
argument is built is merely the plain vanilla time lag of information
transmitted by speed of light EM, and can be disposed of with a mere
wisp of effort.

The ships are assembled in space ready for departure.  They are  in
the same reference frame.  Their clocks are synchronized.  The
programs for acceleration are set to go, and are identical in both
ships.  Off they go.  Messages are sent in both directions confirming
initiation followed by progress reports at regular intervals.  Each
message is time-stamped when sent and time-stamped upon receipt.
John's time lag (communication latency) is anticipated, and then
confirmed.  There is not the slightest confusion or divergence from
plan.  Both ships accelerate in perfect formation, motionless with
respect to each other, firmly ensconced in the same reference frame.
Laser measuring devices, redundantly deployed on both ships monitor
the distance between the two, and report... what?  Well, you tell me.

No matter how hard I try I can't find anything to suggest that
anything unusual happens. From the point of view of the observers on
the two ships, nothing happens.  Distances remain the same.  Clocks
run steady and remain synchronized.  Re the string: no strain, no
stretch, no sag, no break.

So I'm trapped in a disputatious position with the vastly more
authoritative Mr. Bell (and of course, John C).  It's a nightmare.
Very distressing.
Perhaps I should change my name...

As Lee said at the outset,  half the scientists at Cern got the answer
wrong.  But which half?

Sorry for the anti-climax.

Best, Geoff Davies

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