Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!mcvax!botter!klipper!biep
From: biep@cs.vu.nl (J. A. "Biep" Durieux)
Newsgroups: sci.philosophy.tech
Subject: Re: Causality (Was: Aspect experiment)
Message-ID: <793@klipper.cs.vu.nl>
Date: Fri, 5-Jun-87 04:45:41 EDT
Article-I.D.: klipper.793
Posted: Fri Jun  5 04:45:41 1987
Date-Received: Tue, 9-Jun-87 04:40:19 EDT
References: <567@sri-arpa.ARPA> <785@klipper.cs.vu.nl> <1904@sphinx.uchicago.edu>
Reply-To: biep@cs.vu.nl (J. A. "Biep" Durieux)
Organization: VU Informatica, Amsterdam
Lines: 38
Keywords: causality special relativity FTL paradox

Things started like this:
>What is so bad about FTL communication?  Granted, it would mean there
>is either an absolute frame of reference somewhere or causality can be
>violated.  Most likely the latter.				...Keith

In article <785@klipper.cs.vu.nl> biep@cs.vu.nl (that's me) writes:
>Not even necessary. Causality only would show not to be bound by
>light speed, as was thought until now. Before Einstein many people
>thought that, and didn't seem to have any problems with it.

In article <1904@sphinx.uchicago.edu> ogil@sphinx.UUCP (Lord Julius) gives
a longish detailed example of an FTL paradox, ending with:
>In order to preserve causality, one has to throw out special
>relativity, which has been confirmed too many times to be false.
>Thus, FTL information transfer is impossible (unless you want to go
>all the way and eliminate causality! :-).

Well, what I meant to say was that, given FTL information transfer, I would
be more inclined to drop relativity theory than to drop causality (at least
on our macroscopic scale). But that doesn't necessarily mean choosing a
fixed reference frame, does it? There might be other possibilities. Or again,
there might be an absolute reference frame, and another explanation for
the observations in favour of Einstein.

Anyway, thanks for the paradox description. In this case it wasn't necessary
for me, but it's things like that which make it a pleasure to read the net.
Please, people, don't just ask questions about details of theories and give
answers supposing intimate knowledge with the field. Lots of people prefer
*much* reading a short intro to a specific problem.

An example (nothing personal): there was some discussion about epistemic
logic, where people talked about S4, S5 and T as appropriate bases.
It would be very nice (and not too much work, I suppose) to type in the
axioms in the different sets, so that everybody could follow and under-
stand the problem, and learn something from it.
-- 
						Biep.  (biep@cs.vu.nl via mcvax)
			My F-key has autorepeat