Leban%hp-hulk.csnet@csnet-relay.arpa (07/27/85)
From: Bruce <Leban%hplabs.csnet@csnet-relay.arpa>
*SPOILER*
> From: uvacs!rwl@topaz.arpa (Ray Lubinsky)
> Nah, Marty I going back in time is actually Marty I going to the
> 1950's in the-universe-in-which-Marty-I-goes-to-the-50's (ie, universe
> II).... My question is, what happens to Marty II when he takes off in
> the DeLorean for the ``past?'' Does he go to the 1950's of universe I
> -- or somewhen else entirely? Off hand, I'd have to vote for the
> latter; a closed loop in the multiverse seems to be a pretty nasty
> violation of causality in the system.
Personally, I think the time-travel "system" BTF was based on is one
where the universe adapts when you change the past, rather than there
being lots of parallel universes.
One thing I don't understand in either interpretation is the clock in
the Professor's house (at the beginning of the movie) which has a man
hanging off the face of a clock. Where did he get that clock?
The parallel universe does raise some interesting questions. Assuming
Marty I travels back to Universe II, then Marty II has to take off for
Universe III (the Universe which is just like Universe II, except that
the Marty who travelled back in time into that universe had already
lived through a Universe where Marty I had travelled back in time).
Marty III of course goes to Universe IV, etc. It seems that we have an
infinite number of Universes.
1) Since no Marty travels to Universe I, it seems that we end up
with one less Marty. This is OK, since infinity-1 = infinity, but from
the standpoint of Universe I, some matter has just ceased to exist
(i.e., one DeLorean and one Marty). Isn't that illegal or something?
2) Do the Universes converge?
3) Each travel back in time creates a new countably infinite
dimension of universes, so the total number of universes at any given
time (sic) is countable. Is there any way to create an uncountable
number of universes?
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