Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!sri-unix!mcgeer%ucbkim@Berkeley)
From: mcgeer%ucbkim%Berkeley)@sri-unix.ARPA
Newsgroups: net.physics
Subject: Re: Do Positrons Have Negative Mass?
Message-ID: <528@sri-arpa.ARPA>
Date: Tue, 3-Sep-85 16:58:37 EDT
Article-I.D.: sri-arpa.528
Posted: Tue Sep  3 16:58:37 1985
Date-Received: Thu, 5-Sep-85 09:19:47 EDT
Lines: 15

From:  mcgeer%ucbkim@Berkeley (Rick McGeer (on an aaa-60-s))

	One thing they fail to mention is where all this anti-matter is
	supposed to come from.  It appears that the entire observed universe
	is made of matter, not anti-matter (why this is so is currently a
	puzzle),

I've heard this before, but I don't understand how anyone can make this
claim.  How can we tell that Andromeda, say, is composed of matter and not
anti-matter?  What observational differences would there be between a matter
galaxy and an anti-matter galaxy?  The only difference between a particle
and its anti-particle is charge, and large agglomertaions of matter are
electrically neutral.  No?

						-- Rick.