Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site petrus.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!petrus!karn From: karn@petrus.UUCP Newsgroups: net.space,net.physics Subject: Re: Re: Light Sails Message-ID: <302@petrus.UUCP> Date: Mon, 4-Mar-85 10:18:11 EST Article-I.D.: petrus.302 Posted: Mon Mar 4 10:18:11 1985 Date-Received: Tue, 5-Mar-85 02:43:08 EST References: <861@mordor.UUCP> <6960@rochester.UUCP> Organization: Bell Communications Research, Inc Lines: 8 Xref: watmath net.space:3664 net.physics:2201 It would seem to me that photons reflected off a sail would indeed appear to be shifted in wavelength to an observer watching both the outgoing solar radiation and the reflected radiation. This would be due to the doppler shift caused by the relative motion of the sail with respect to the sun. The effect is equivalent to that which makes a police radar function. Energy is still conserved. Phil