Cosmic cookery: growing galaxies in a computer

Cosmic cookery The large scale structure of the universe as predicted by the Millennium simulation, which tracked the growth of structure due to gravity.

Professor Carlos Frenk FRS, Dr Carlton Baugh, Professor Richard Bower, Dr Vince Eke, Dr Lydia Heck, Dr John Helly, Dr Adrian Jenkins, Dr Nigel Metcalfe, Dr Takashi Okamoto, Dr Darren Reed and Dr Tom Theuns, University of Durham. Mr Djamel Hassaine and Dr Nic Hollimann, Durham eScience Research Laboratory. Dr Volker Springel, Max Planck Institut für Astrophysik, Germany. Dr Pete Edwards, Odgen Centre.

Scientists at the University of Durham are attempting to recreate the entire evolution of the Universe from the Big Bang to the present day using 'The Cosmology Machine', one of the 'top 500' supercomputers in the world. The supercomputer can perform 10 billion calculations a second, creating detailed simulations of how the Universe formed. Earlier this year Durham's Institute of Computational Cosmology completed a groundbreaking simulation of a realistic spiral galaxy with 'The Cosmology Machine'. The simulation, from the very first stars to the present day, will form the centrepiece of their exhibition at the Royal Society. 'How galaxies are made in the Universe is one of the biggest challenges facing cosmologists today', explains Carlos Frenk. 'Our techniques have reached a level of sophistication that lead us to believe the basic picture of how galaxies form is now in place'.

Ever since the 1930s when galaxies were confirmed as the fundamental building blocks of the Universe, their origin and evolution have remained a focus of physical cosmology. As with all problems in physics, the solution requires the interplay between theoretical ideas and experimental data. In this case the data are observations of galaxies stretching back over the history of the Universe.

Data on galaxy formation is obtained through powerful ground- and space- based telescopes. Light reaching us from galaxies travels vast distances before reaching these telescopes. The time it takes for the light to travel here means the data received is actually from far back in the evolution of the Universe's14 billion year history. The telescopes are, in effect, looking back in time. Until about 10 years ago it was only possible to detect galaxies from when the Universe was 75% of its current age. In 1996, startling images from the Hubble Space Telescope (the Hubble Deep Field Images) allowed scientists to examine galaxies from far earlier in the evolu