Natural selection and cosmology

I’ve just finished reading a book called “COSM” by Gregory Benford. The story is about a universe which is created by accident in a particle accelerator and which manifests in our universe as a small shiny ball – COSM is a truncation of cosmos. Benford is a physicist and the ideas that he has in the book are based on ideas which have actually appeared in physics papers.

Apart from the whole concept that it might be possible to create a universe by smashing together particles at high energy, which is fascinating in itself, he also briefly mentions the idea that if universes can effectively create other universes then the evolutionary concept of natural selection may apply to them. So, the reason that our universe seems to be so finely tuned for life is that those universes which are favourable for the existence of intelligent life are more likely to “reproduce” (since said intelligence may create other universes by design or accident), similar to the Darwinian concept of biological evolution – I guess that could make our “God” a physicist in another universe !!!

Of course, it still doesn’t address the question of how the first universe happened, which seems to “mirror” the problem in biology of how the first living thing appeared.

The relevant articles are “Is it possible to create a universe in the laboratory by quantum tunneling?” by Alan Guth and co which appeared in Nuclear Physics, B 339, p 417 in 1990 (I can only find the abstract online) and one by Edward Harrison which appeared in the Quarterly Journal of the Royal Astronomical Society, Volume 36, pages 193-203 (which I can’t even find the title of). There is however a Popular Science article on the whole idea written by Marcus Chown here.

Geostationary satellites

I just completed one of the questions in the physics assignment I’m working on and was convinced I must have the wrong answer. The question involved finding the height at which a geostationary satellite orbits – ie one which orbits the earth in 24 hours thus effectively remaining stationary above a point on earth.

Now I’ve see heaps of diagrams of satellites in orbit where the earth covers most of the diagram and the satellite orbits are circles seemingly just above the earth’s surface, so I was expecting an answer which was small in comparison to earth’s radius. What I got was an answer that is some five and a half times the earth’s radius – so I drew a rough scale diagram and it looked nothing like what I expected.

After some research on the Internet I discovered that those diagrams I was used to seeing were of satellites in Low Earth Orbit (just above most of the earth’s atmosphere at between 300 to 1000 kms) and that a geostationary satellite really does orbit at nearly 40,000 kilometres above the earth’s surface.

Somehow it annoys me to realise I have reached my early forties without knowing this – almost as much as it did when I learnt a year or so ago that the earth’s magnetic field is produced by the rotation of its molten core, but that’s another story.