Wednesday, June 08, 2005

A universe in a box!

An extraordinary paper in the current issue of Nature, titled Simulations of the Formation, Evolution and Clustering of Galaxies and Quasars, has not attracted nearly the attention it deserves. A group of European theoretical cosmologists, after 20 years of preparation, have modeled the Big Bang in a month-long run on a supercomputer, tracking trillions of particles. They plugged in what we think we know about the relevant physics, and let the computer spin out a universe -- 20 million galaxies in a cube 2.23 light-years on a side -- from the first moments of creation to the present day. And -- this is the kicker -- the simulated universe looks stunningly like the one we live in. Crucially, the model seems to confirm the existence of the so-called "dark matter" and "dark energy" that supposedly account for most of "what's there."

Einstein's wife Elsa was once asked if she understood her famous husband's theory of relativity. She replied, "Oh, no, although he has explained it to me many times -- but it is not necessary to my happiness." Well, it's necessary to my happiness. I don't particularly care what sort of universe we live in -- whether infinite or finite, big bang or steady state -- but it thrills me to know that the human mind can build a machine that mimics the creation.