Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!tektronix!hplabs!hpda!fortune!amdcad!amd!dual!mordor!space@mit-mc
From: space@mit-mc
Newsgroups: net.space
Subject: Re: Light Sails
Message-ID: <937@mordor.UUCP>
Date: Tue, 5-Mar-85 03:12:36 EST
Article-I.D.: mordor.937
Posted: Tue Mar  5 03:12:36 1985
Date-Received: Sat, 9-Mar-85 10:50:43 EST
Sender: daemon@mordor.UUCP
Lines: 23

From: Paul Schauble 

rochester!nemo writes:

> There are these little globes with vacuum and a paddle/pivot mechanism
> inside which work on this principle.  The four paddles are arranged so
> that the intersection of the two planes is the axis of rotation of the
> pivot.  Each paddle has a black side and a silver side with radial
> symmetry.  Placed in light, the paddle(s) on one side of the pivot
> will reflect the light, the one(s) on the other will absorb the light.
> The absorbing surface gets only the inelastic momentum change, or mv,
> while the reflecting surface gets the 2mv momentum change.  This
> creates a torque on the paddle structure, and the little bugger
> rotates.  Available at novelty stores near you!  
> Nemo
                                                            

This says that the beast should rotate witht he white (reflective) side
retreating. Take a close look at one. They rotate in the other
direction!
Now, would anyone care to provide an explanation??

          Paul