Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ames.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!tektronix!hplabs!hpda!fortune!amdcad!amd!dual!ames!al From: al@ames.UUCP (Al Globus) Newsgroups: net.space Subject: Re: Momentum transfer in light sails Message-ID: <841@ames.UUCP> Date: Mon, 4-Mar-85 14:18:38 EST Article-I.D.: ames.841 Posted: Mon Mar 4 14:18:38 1985 Date-Received: Sat, 9-Mar-85 10:50:15 EST References: <794@mordor.UUCP> Organization: NASA-Ames Research Center, Mtn. View, CA Lines: 12 > > > After reading Rick McGeers' description of momentum transfer between > photons and a light sail, it seems to me that all momentum imparted to the > sail must be radial to the sun. Is there any way to impart momentum to the > sail in a tangential direction? Yes. The acceleration is normal to the plane of the sail. Draw the vectors in 2D in a piece of paper with the photon comming in at an angle. Take the vector sums and maintain conservation of momentum in all directions and you'll see what I mean. I wish I could put my Mac drawings on this thing.