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From: jmc@riccb.UUCP (Jeff McQuinn )
Newsgroups: net.physics,net.sci,net.philosophy
Subject: Re: Re: Re: A Sane Man Proposes A Time Travel Experiment
Message-ID: <722@riccb.UUCP>
Date: Thu, 7-Aug-86 05:52:55 EDT
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Posted: Thu Aug  7 05:52:55 1986
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> >                                                The first event to unhappen
> >would be that I tried to move back in time (which may short circuit the 
> >attempt).  Secondly, since my time is firmly locked together with the rest
> >of the universes time, my events unhappening would need to drag the rest
> >of the universe along (to back up to yesterday I would need the earth to back
> >up one revolution and so on and so on because universal movements were an
> >event that happened during my time).  Next, my concept of having this time
> >trip would have to unhappen.  So here I somehow am an hour before with no
> >concept of having gotten here, and no idea of whats going to happen.  Since
> >my time trip unhappened I didn't do it and since I don't know I didn't do it
> >I couldn't prove that I didn't (-: do it.  I would expect a short circuit on
> >the attempt and see no results...
> 
> But you _could_ prove it!  You need a non-deterministic random-number
> generator, one based on atomic decay for instance.  Use this device to
> generate a random number in the range 0 to 99.  Then, if the number is
> not 42, use your experimental time-machine to reset time to just before
> the number was generated.  Repeat this procedure 10,000 times.  If the
> time-machine works, you will observe that the random-number generator
> generated the same number, 42, 10,000 times.
> 

No, I can't prove it, if backing up in time causes things to "unhappen".  If I
can back up without short circuiting time I would lose knowledge of the fact
that I did it.  Granted it would look like I hit 42 every time but I will never
know I tried to back up in time and thus would not be able to prove that time
travel was responsible for the radom number generator getting stuck.  In fact
since every attempt to back up in time "unhappens" it could be argued that 
successful attempts at time travel were never made.  But they were never made
because they were successful!

What I'm advocating here is that time travel cannot change the structure of the
time traveled to.  If you travel back to a time before your birth and you 
actually show up then, the structure of the time you show up in has changed
and isn't really the same as it was (because you are there) so it can't be
the same time that it was.  If you travel to the time of your birth then you
must show up as a new born baby.  Time is a measure of the passage of events.
To back up in time you must pass those events in reverse.  Like a movie where
the film stops and then starts running in reverse.  The pictures on the film
don't change, and new characters don't appear, and the hero still doesn't know
whodunit.

Since the events of the future have not yet happened, their time has not been
created, there is no future "time" to travel to.  The best you can do is
travel at the speed of light so that time on Earth passes more quickly then
yours.  Not really time travel just a different perspective.

				Jeff McQuinn just VAXing around