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Out of This World! Virtual Universe Looks Like the Real Thing

A view of Illustris's largest cluster, showing dark matter density (left) and gas density (right). Illustris

A team of astronomers has created the most realistic simulation of our universe ever made — a 14-billion-year history that took months of work by supercomputers to render.

Observing the universe directly is great, but sometimes an object or event is too far away, or happened too long ago (which amount to the same thing in many ways) to watch. That's why astronomers and physicists rely on simulations using known data and laws to produce virtual galaxies and black holes, watching them and comparing the results to real life.

The most accurate and high-resolution of these simulations, called Illustris, has just been completed by a team from MIT and Harvard. They set 8,000 CPUs to work for three months, and the result is satisfyingly realistic.

Galaxies in the simulation not only look like ones we've observed, but behave the same way over (simulated) time. Illustris

It doesn't attempt to recreate our universe exactly, but is limited to a cube large enough (millions of light years across) to contain all the expected features. And while you won't find the Milky Way, you might find a galaxy very much like it — as indeed the astronomers did when they looked closely. That the simulation lines up so well with the universe as we've observed is very promising.

But the simulation goes so deep you'd need a few different degrees to get the most of it. The invisible web of dark matter and energy tying the universe together is recreated to the best of our knowledge, and the elements that make up stars and planets can be observed forming and coalescing.

If astronomers wanted to know, for instance, what would happen if a certain constant were a little higher, or if early helium concentrations were a little lower, all they have to do is adjust a few settings — and then wait while the supercomputers work up a brand-new universe based on those principles.

The video is fascinating and beautiful, and no doubt this line of research, enabled by today's powerful supercomputers, will only improve and become more important. The paper describing the simulation was published in the May 8 issue of the journal Nature.