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Re: Warm- vs. Cold-blooded Dinos



In a message dated 95-06-29 07:03:39 EDT, pwillis@ozemail.com.au writes:

>The problem in changing the tilt of the earths axis is one of energy.
>Have
>you considered how much energy it would take to achieve this feat?
>This
>leads to two further problems; where would that energy come from and
>how
>would you disappate it?

I am not suggesting anything about the pole behavior of the earth, but a
non-symmetric rigid body spinning about its intermediate inertia tensor will
spin stablely for a period inversely related to the initial deviation of the
intermediate intertia tensor from the spin axis.  

Try this: take an expendable book and wrap it with a rubber band to keep it
closed.  Hold the book so that the title faces you and throw the book up in
the air so that it spins top over bottom.  No matter how hard you try, you
will not be able to spin the book stablely for any length of time.  The book
might spin stablely for a moment or two but it will suffer a "pole flip."  If
the spinning book is completely isolated, no energy is being lost or added to
it and that is my point.  

I simulated this behavior in several computer programs I wrote a few years
ago to test a suspected error in a well known classical dynamics physics
text.  One of the programs was written in QuickBASIC and I may still have a
copy.  If anyone is interested, I'll hunt for it.

V. Smith