From morbius@minerva.phyast.pitt.edu Tue May 16 23:50:00 EDT 1995
Article: 178397 of alt.atheism
Path: newsfeed.pitt.edu!minerva!morbius
From: morbius@minerva.phyast.pitt.edu (Edouard Morbius)
Newsgroups: alt.atheism
Subject: Re: A conversation between an atheist and a Christian
Date: 17 May 1995 03:44:53 GMT
Organization: Department of Physics & Astronomy, University of Pittsburgh

In article <sewalter-1105950924450001@i4067120.cfa.ilstu.edu> sewalter@ilstu.edu (Scott Walters) writes:
>I am not arguing against the theory of the Big Bang, but rather that the
>Big Bang "just happened."  Most science is built on the idea of
>cause-and-effect, but unfortunately it quickly runs into the problem of
>the first cause.  At this point, both science and religion requires a
>similar leap of faith into the realm of the Uncaused Event or the Eternal
>Being.  Is the idea that the Big Bang "just happened" any more logical or
>scientific than the idea that God "always existed"? Both ideas cause our
>minds to boggle, because they ask us to discard all of the rules of the
>universe we have come to accept unquestioningly.

No such leap of faith is needed to assume that the universe is uncaused,
Cause and effect only operate in certain types of structures -- those in
which different "events" can be defined and in which there is some means
to propagate causal influence from cause events to effect events.
Spacetime is one such structure. Its events (simplifying thigs a bit) are
the spacetime points and the matter (and other) fields which are spread
out over them. Causal influence is propagated by "propagators", operators
which determine how the field at one spacetime point is affected by the
field of some other spacetime point. The familiar properties of cause and
effect (Cause must precede effect; Causal influence cannot be propagated
faster than the speed of light) are due to the group of physical
symmetries which the propagator must preserve (the spacetime part of this
symmetry group is called the Poincare group). While spacetime is the only
causal structure which we know, there could conceivably be other types of
causal structures. 

Spacetime is a part of the universe, so any cause of the universe must be
a cause of spacetime as well. However, the cause of spacetime obviously
cannot be an event within spacetime. If one is to assume that the universe
has a cause, then that cause must lie outside of the universe, and this
presupposes that both the universe and its cause are events in some higher
level causal structure. If such a structure does not exist, then the
universe *cannot* have a cause. 

Conclusion: There is no evidence that such a higher-level causal structure
exists, so there is no reason to believe that the universe has a cause. 
Hence, it is "just there", until proven otherwise.

Edouard Morbius