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Re: Warm- vs. Cold-blooded Dinos



In a message dated 95-07-14 00:02:34 EDT, pwillis@ozemail.com.au writes:

>I think we are also talking cross-purposes. You are describing (using those
>very big words) how a rotating body can flip on its axis (I think) where as
>I am trying to consider (using jam donuts) how catastrophic such an event
>would be.
>
>If this is a fair summation of your arguement, I think we should finish this
>thread before we are leaped upon by the dinothought police out there
>who will accuse me of, yet again, straying for more than two posts
>without typing in the word "dinosaur".

I was describing how a rotating body can demonstrate stable rotational motion
for a long period of time and then, without any enternal forces, enter a
period of very erratic rotational motion.  The key point I was trying to make
was that it required no external forces to push the body into this period of
erratic behavior.

Your consideration of how catastrophic this would be on a planet like the
earth is well taken and a very important point to consider under such
circumstances.  I have enjoyed your replies, sir, and I am certainly not one
to criticize straightfoward discussion.

I have done no calculations on this final point, but as Glen Moore pointed
out in his solid reply, the largest intertia tensor of the earth is currently
very close to the poles, thus insuring stable rotational motion, but
continental drift, the accumulation of ice on the poles and large bollide
impacts would all have effects on the position of the spin axis with the
inertia tensors' positions.  This drifting of the inertia tensors, may or may
not have an effect on the rotational stability of the earth.  I have not had
time to model it, but it is a thing to consider.

V.S.