@S1-A.ARPA,@MIT-MC.ARPA:amon@cmu-ri-fas.arpa (08/13/85)
From: Dale.Amon@CMU-RI-FAS I suspect there is a bit of unpredicatability to it all because the earth is not a simple precessing gyroscope. It is a gyroscope with a buch of lead weigths stuck on it at various odd places. And to make it all the more interesting, they keep moving around, interact with each other, and with the internal heat flux environment of the earth, which in turn affects and is affected by the earth's magnetic field. I you were to write a precise equation, it would HAVE to predict the locations of thermal plumes that cause thinning and thickening of the crust and the consequent effects on continental drift. I suspect this means we can do no better than approximate a calculation by extending current drift rates back for a few 10's of millions of years. But before that our knowledge is probably not sufficient to do more than take a stab at it. True, ROUGH continental sizes and latitudes are guessed at by geomagnetic domain data, but I doubt it is sufficiently accurate to help much. This may even have some effects in shorter periods of time, because over the short history of man, the distance between Europe and America has changed by many miles, and that HAS to have a significant effect on precession. It may even be the cause of the 'unexplained' 4 inch per year pole drift mentioned earlier.