csc@watmath.UUCP (Computer Sci Club) (05/15/84)
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It is quite possible to change your orientation is free space. Hold the
dumbells close to your body. Rotate them 60 degrees right(with respect to
the fixed stars). You will rotate left say 20 degrees. Extend your
arms. Rotate the dumbells 60 degrees left (i.e. back to their original
position with respect to the fixed stars). You will rotate say 30 degrees
right. Pull in your arms. The dumbells are now where they started, you are
again at rest, and you have an angular diplacment of 10 degrees right
(with respect to the fixed stars). Obviously by varying and repeating
the above routine you can obtain an arbitrary displacement. Cats do
a similar routine (extending and retracting legs) to turn over and land
on their feet. There was an excellent article on this in Scientific
American a few years back. They had actually dropped cats (nasty
scientists) and filmed them at high speed to see what they did.
William Hughes
By rotate 60 degrees, I mean accellerate and decellerate the dumbells
to bring them to rest (fixed stars) with a net displacement of 60 degrees.