Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mnetor.UUCP 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