Monday, November 28, 2005

So I was contemplating making a video about the effects of traveling near the speed of light and have bagged the idea. Below is the transcript of my emails with a relativity expert.

Thomas Asmuth
to kavs
More options Nov 27 (1 day ago)
Hi I am in the pursuit of making a film about Special Theory of
Relativity. To develop my film I have been trying to construct a
thought experiment. I was wondering if you would look at my thought
experiment and see if it follows mathematical/physics predictions
about the situation I pose. Any help is greatly appreciated.

Thank you for your time.
Thomas Asmuth
Room 206A
SJSU Art&Design


here's my supposition:

Two Friends, Thomas and Samoht decide to celebrate the centennial
anniversary of STR with a martini cocktail. Befitting this occasion
they decide to do have a relativistic toast and cocktail party. In
order to facilitate this idea Thomas will remain in a frame of
reference that is at rest while Samoht accelerates to approximately
98% of the speed of light in his special developed vehicle. They have
agreed prior to the launch of Samoht that they will have a
synchronized toast to the history of STR when Samoht's ship reaches a
prescribed point of distance from Thomas' ship. Each colleague knows
that mixing the proper cocktail takes exactly 3:15 minutes and thus
they will start the drinks 3:30 min. (3:15 plus 15 seconds) before the
synchronized point X, giving them a few moments to repose with the
cocktail before they begin the toast at the agreed coordinates.

This assumes they are experimenting in a section of space completely
devoid of any other bodies other than the ships that Thomas and Samoht
occupy. Assuming instantaneous communication exists so that Thomas and
Samoht can telepresently monitor one another, what would Thomas and
Samoht each witness?

I believe that Thomas would witness a slow motion (5x slowdown) of
Samoht as he prepares and toasts. Thomas would see Samoht start at
17:30 minutes before the point of synchronization but it would appear
to take Samoht 5 times as long to prepare.

Logic tells me Samoht's monitor would show the opposite: Thomas would
appear that he waits to the last second achieving the task in 42
seconds (5 times as fast) instead of 3:30 minutes.

Thomas Asmuth
Room 206A
SJSU Art&Design

To which Ken replied:

Ken and Vicki to me
Nov 27 (1 day ago)
Yes okay, I'm delighted to be of assistance. Well, I'm afraid your suppositions are nearly 100% incorrect... and the assumption of "instantaneous communication", even though it is merely a fictional assumption, introduced solely to simplify your thought experiment, it cuts straight against the fundaments of relativity. Relativity is entirely premised on the impossibility of instantaneous communication between remote locales! But OK, we'll let that assumption stand anyway; I'm in a charitable mood.

The main problem with your write-up is that the distortions of relativity in flat space (what is generally classified as 'Special Relativity')... those distortions are completely covariant, ie. mutual. So, quite simply, whatever Thomas witnesses of Samoht, Samoht will witness of Thomas. They both see each other's time slow down! A second problem with your write-up is that the entire notion of simultaneity between two disparate frames becomes utterly moot (ie. undefined) under relativity. Only if Samoht came to a dead stop with respect to Thomas could the two of them then establish any real premise of simultaneity. Of course, by then, the accelerations that the one undergoes has thrown things off considerably.

And yet still another problem in your write-up is the fact that the "prescribed point" where Samoht will drink his toast is a predefined distance from Thomas' ship! Once the two fellows are in motion with respect to one another, that distance becomes distorted (by Samoht's reckoning), and that changes things considerably.

To better understand the complexities involved, please read that section of my web site labelled Addendum IV,

Thanks for your interest,
Sincerely, Ken

Add the fact that I then saw the ways of my error:

Thank you for the feedback. As I thought on this after I had emailed
you I came up with similar misgivings. So the conclusions I come to is
that the only way to measure or compare is for the two to return to
the same frame (i.e. Samoht to return) and compare clocks. If Thomas
accelerates though to catch his friend, it will distort time and space
similarly and probably negate any effectual difference.
Am I on target?

Thank you,

Ken's affirmation of my understanding:

Yes, you're on target, assuming Thomas undergoes the precise same
accelerations and motions that his friend had, their clocks will agree once
they are together again.

SO I decided I am not ready to make this film because I can not solve these issues in mind artistically or not, thus I defer this work until another day.

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