Saturday, January 9, 2010

Planetary Models

Part of following both Science News and Science Daily is the huge overlap between them. Sometimes it produces odd differences:
From Science Daily: "How Earth Survived Its Birth"
From Science News: "Saving the Earth with dynamical simulations"

Both articles mention a "small problem"* with current planetary models.

*aka huge problem

"For the last 20 years, the best models of planet formation -- or how planets grow from dust in a gas disk -- have contradicted the very existence of Earth" (Science Daily)

"When astronomers simulate the formation of the solar system, disaster strikes: no planets survive. Under most models’ assumptions, protoplanets would have collided with the parent star before they had a chance to fully form. 'This contradicts basic observational evidence: the fact that we are here,' said Mordecai-Mark Mac Low" (aka Captain Obvious) (Science News)

I find the Science Daily articles have much better detail and less emotional writing. I forget why I added the Science News feed...

In this case, Science News leaves out a vital fact:
"'We used a one-dimensional model for this project,' says co-author Wladimir Lyra, a postdoctoral researcher in the Department of Astrophysics at the Museum. 'Three dimensional models are so computationally expensive that we could only follow the evolution of disks for about 100 orbits -- about 1,000 years. We want to see what happens over the entire multimillion year lifetime of a disk.'"

A one-dimensional model is a very low detail model. It is likely there are still huge problems with such a model. Also, it does nothing to address the problem that a model does not (necessary) have any connection to reality. I can give you very complicated, detailed, and self-consistent models for magic users (using a system like GURPS).

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