The Universe in a Computer

A team of scientists has created the largest and most realistic simulation to date of how our universe was formed.

Photo courtesy of Carlos Frenk The Millennium Simulation zooms in on a massive cluster of galaxies and highlights its structure on different scales.

The universe is a very big place. It is crowded with billions of galaxies, an uncountable numbers of stars and a mysterious force called dark energy that is making it even bigger. In the last ten years, thanks to amazing images sent back by the Hubble Space Telescope, scientists have come up with a plausible explanation of how the universe began, starting with the Big Bang 13.7 million years ago and expanding into the stunning cosmos that exists today. But we are still far from fully understanding our universe and scientists are always looking for new tools to help them fill in the picture. One such tool is a model of the universe - inside a computer - recently created by scientists at the University of Durham in the U.K. Called the Millennium Simulation, it has been described as 'the largest and most realistic simulation ever of the growth of cosmic structure' and may help scientists unlock some of the elusive secrets of our universe.

How was the universe formed?

In the first few million years after the Big Bang, the universe was a dark, cold place full of swirling clouds of hydrogen and helium. But over billions of years, these gas clouds formed enormous galaxies made up of billions of stars. From these stars came all the scores of elements that our planet is made from - and which are also the building blocks of life. But how was all this complexity created?

At the University of Durham, physicist Carlos Frenk is testing out some important ideas about why the universe evolved the way it did. He is a member of the international team of scientists and programmers who created the Millennium Simulation. In particular, Frenk was interested in testing the role played by dark matter: a mysterious substance made from tiny particles that don't emit light that may make up 70% of the universe.