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From: bill@utastro.UUCP (William H. Jefferys)
Newsgroups: net.physics
Subject: Re:  Dean Drive Possible?
Message-ID: <274@utastro.UUCP>
Date: Mon, 14-May-84 12:44:39 EDT
Article-I.D.: utastro.274
Posted: Mon May 14 12:44:39 1984
Date-Received: Wed, 16-May-84 04:02:10 EDT
References: <683@sri-arpa.UUCP>
Organization: UTexas Astronomy Dept., Austin, Texas
Lines: 19

> When the angular momentum is constant the orientation is changing at a constant
> rate unless the orientation vector is aligned with the axis of rotation in 
> which case the proportionality constant is zero.  When the direction of
> something, e.g. a telescope, on a satellite is changed it is sometimes done,
> at the expense of a compensating change in the opposite direction of something
> else, by "gyro torquing".  Is this the "internal motion" you mean?

What is being referred to is the same effect that allows a cat to right itself
in the air after being dropped (with no net angular momentum) from a reasonable
height.  Athletes can also change their orientation in midair, starting and
ending with zero angular momentum.  There was a good article on this a few
years back, probably in Scientific American, which showed precisely how it
can be done.
-- 

	Bill Jefferys  8-%
	Astronomy Dept, University of Texas, Austin TX 78712   (USnail)
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