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Path: utzoo!utcs!mnetor!fred
From: fred@mnetor.UUCP (Fred Williams)
Newsgroups: net.physics
Subject: Re: Light
Message-ID: <1157@mnetor.UUCP>
Date: Thu, 4-Jul-85 14:33:32 EDT
Article-I.D.: mnetor.1157
Posted: Thu Jul  4 14:33:32 1985
Date-Received: Thu, 4-Jul-85 16:13:58 EDT
References: <344@sri-arpa.ARPA>
Reply-To: fred@mnetor.UUCP (Fred Williams)
Organization: Computer X (CANADA) Ltd., Toronto, Ontario, Canada
Lines: 20
Summary: 

In article <344@sri-arpa.ARPA> infinity%udel-cc-vax2.delaware@udel-louie.ARPA writes:
>
>The speed of light is constant? oh, I was under the impression that
>it changed velocity in substances such as glass, etc.  If it did change
>velocity in such substances why wouldn't it change velocity in a higher
>density of Ether?  Why wouldn't this change in velocity be seen as a
>'bending' of light? much as light 'bends' in glass or water.
>
>						Eric

	The speed of light in a vacuum is constant. In a transparent
material medium light is absorbed by atoms in its path. The time
taken for an atom to become excited, (an electron pushed to a
higher level), and then re-emit the photon is what "slows" the 
effective velocity of light in these substances. 
	Maxwell's equations still hold in the empty space between
the molocules, and the speed of light is invariant. 

Cheers,		Fred Williams