From: hinson@bohr.physics.purdue.edu (Jason W. Hinson)
Newsgroups: rec.arts.startrek.current,rec.arts.startrek.tech
Subject: Re: time-travel backwards possible? perhaps
Date: 29 Sep 92 15:39:01 GMT
Followup-To: rec.arts.startrek.current
Organization: Purdue University Physics Department

trw@spl1.spl.loral.com (Tim R Witort) writes:
>g92n3258@giraffe.ru.ac.za (MR RL NICOL) writes:
>|> 
>|> It was stated on the network (sorry, can't remember who) that time-travel 
>|> backwards is not possible, because if you went backwards and, say, killed 
>|> yourself as a baby, you end up with a paradox.
>|> 
>|> This is not the case in the time-tree theory...
>
>
>[time tree example deleted]
>
>   Yeah. That theory works quite nicely. It's probably the best 
>explanation I've heard to avoid paradoxes. And since time travel
>stories are all fictional anyway, any solution we can think up
>should be just as acceptable as the time travel itself. I find
>the idea of there being any number of time lines coexisting
>independently a lot harder to accept as possible than the act of
>time travel though. You really can't use this idea to refute the
>statement that time travel is impossible since it's just a nice
>piece of hand-waving. As far as we know in cosmology and quantum
>physics - time travel (meaning backwards) is not possible. Will
>this still be true in 400 years? I personally think so, but only
>God knows.
>
>-- Tim

OK, for anybody interested, please consider the idea I am using in 
a sci fi book I am writing (note: this is the first time I am
telling anyone about this).

In it, "time travel" is done by creating a field in which a sort 
of "mini-universe" exists that is an exact dupicate of the universe
we know of as it was at some previous time.  When you transport
yourself into a particular part of that universe, you become a part
of it. However, the universe and the "alternate time line" only
exists as long as the field is on, and it actually exists in the
present time.  When the field is cut off, the time traveler will
appear back his own time right where the field was being produced.

You could also reach in and pull someone from the "created universe"
into your own universe (but only if you "expel" energy equal to his
mass from the real universe in doing so) and see how a person from 
the past will interact with the future, however when the field is
shut off, the past person will cease to exist.

I think you can see that with such an idea, we can clearly keep
from violating causality. Also, I have kept the idea of one true
timeline, while the others are just copies that will be discarded
eventually.  I also tried to keep energy conservation in order in
that it takes energy to actually bring someone here from the 
created universe; and also, the created universe isn't truely
in existance unless you interact with it (I say that so that there
is no energy conservation involved in creating an entirely new 
universe inside our own.)

I don't know if the explination was completely clear, but I am
in a hurry, so I don't have time to re-read it.  I think it opens
up some interesting possibilities.

Any comments are welcome!

-Jay
Newsgroups: rec.arts.startrek.current