Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/3/84; site talcott.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!panda!talcott!gjk
From: gjk@talcott.UUCP (Greg Kuperberg)
Newsgroups: net.space,net.physics
Subject: Re: reflection of photons from a lightsail
Message-ID: <337@talcott.UUCP>
Date: Fri, 8-Mar-85 00:28:11 EST
Article-I.D.: talcott.337
Posted: Fri Mar  8 00:28:11 1985
Date-Received: Sun, 10-Mar-85 07:20:52 EST
References: <141@ihlpa.UUCP>
Distribution: net
Organization: Harvard
Lines: 11
Xref: watmath net.space:3688 net.physics:2218

It is indeed the case that when light bounces off of a moving mirror/light
sail it red shifts.  This can be interpreted as follows:  Because the light
accelerates the craft with a light sail, it transfers some of its energy to
the ship.  The red shift is precisely this loss of energy.  And finally,
photons, shmotons---it works just as well with Maxwell's equations.  In
fact, special relativity predates photons by a decade or two.
---
			Greg Kuperberg
		     harvard!talcott!gjk

"2*x^5-10*x+5=0 is not solvable by radicals." -Evariste Galois.