Re: pole shift

Anders Sandberg (
Thu, 17 Jul 1997 10:58:50 +0200 (MET DST)

On Wed, 16 Jul 1997, Anton Sherwood wrote:

> Dad tells me that somebody did a simulation of planetary motion over
> the eons, and found that a planet's axis varies chaotically UNLESS
> the planet has a large moon!

Yes, I have seen this too (including on some astrophysics website). I
think it is true, since the "random" forces from the other planets
ought to induce (very slow) precession and change in the rotation
axis, while having a large moon would create a system where angular
momentum changes could be shared between the planet, moon and the
entire system (and since the system has a very large angular momentum
compared to the planet, the changes would be much smaller). Is this a
reasonable explanation, or just a sign of "what the thinker thinks,
the prover proves"?

Anders Sandberg Towards Ascension!
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y