Planet Formation In Hundreds Of Years?
Supercomputer Simulation Says Possibly
I've long been leaning toward the view that the long geological time scales arrived at by extrapolating backward such things as the plate movements and sedimentation rates that we observe today are wrong, and such processes occurred much more rapidly in the past. Hence, things happened closer to the present than is generally thought, and the planet is not as old as is generally thought.
Ed Zahurak draws attention to a fascinating simulation study reported in PCS News, by the Pittsburgh Supercomputing Center, showing that Jupiter-like gas giants can form from planetary nebula in a matter of hundreds of years, rather than the millions of years that conventional models assume. (Findings published in Science, November 29, 2002.) This would help explain how such planets manage to have survived without their gas envelopes being blown away by their parent stars, and why they turn out to be so common -- almost 100 detected within the last decade.
The British astronomer W.H. McCrea concluded in the '60s, as others have since, that minor planets could not form by accretion inside the orbit of Jupiter because of its disruptive tidal effects, and R.A. Lyttleton showed in a fluid dynamic analysis of Jupiter's core that its rotation and accretion rates would cause it to become periodically unstable and fission to throw off excess mass. We're told that the gas giants don't have rock cores, but that has always struck me as preposterous, since even if they formed from pure gaseous concentrations initially, bodies of that size would surely attract heavier material thereafter. So conceivably gas giants formed rapidly in the way the Pittsburgh simulation depicts represent the first phase of a process that accumulates fast-spinning cores of heavier material that gets compressed down to rocky densities, and ejects them as a planet and comet factory.
Yet another instance of something that Velikovsky was ridiculed and vilified for proposing, finding its way quietly into respectable science though the back door fifty years later.