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Press release

  • 3 June 2005
  • ‘Virtual cosmos’ reveals evolution of the Universe

    A simulation of how the Universe has developed since the Big Bang has been created by an international team of scientists, including Sussex astronomer Professor Peter Thomas.

    Professor Thomas, who is head of Physics and Astronomy at the University, was one of the founders of the Virgo Supercomputing Consortium more than 10 years ago. Since then, the group has been using massive computer simulations to follow the growth of structure in the Universe from its earliest times, shortly after the Big Bang, to the present day. 

    The latest model was created by scientists from the UK, Germany, Canada and the USA using a supercomputer at the Max Planck Institute for Astrophysics in Germany. The simulation used lasted for a month and occupied 512 processors and 1 terabyte (1 million megabytes) of memory, eventually producing 25 terabytes of data. The resulting model - the biggest and most realistic to date - shows scientists the evolutionary processes that, over the course of 13 billion years, brought about the 20 million or so galaxies that make up the local Universe.

    An article by the project scientists, published in science journal Nature this week, reveals the first findings from the simulation. It traces the Universe from its elementary structure - weak ripples in a sea of matter and radiation that manifest themselves in the cosmic microwave background radiation - to the dense and rich structures of galaxies we see today.

    Scientists also hope to unravel such scientific mysteries as black holes, dark energy and quasars. Dark energy accounts for just over 70 per cent of the Universe and is a so far unidentified force that is driving an ever-faster expansion of the Universe, despite the pull of gravity. Quasars are distant, bright objects that emit vast amounts of energy as light. Very distant quasars - revealed in the model at a point where the Universe was less than a tenth of the age it is now - are thought to host giant black holes, about a billion times bigger than our own sun.

    Professor Thomas says: "The immense scale of the simulation allows us for the first time to model galaxies within a region that is large enough to capture a representative volume of the Universe. Comparison of mock galaxy catalogues with observational surveys such as the optical SDSS and the infra-red SWIRE surveys, with which Sussex is also involved, will enable us to test models of galaxy formation and evolution. For the first time, we are starting to form a detailed picture and understanding of the Universe within which we live."


    Notes for editors 

    • For more information on the simulation project, please contact Julia Maddock in the Press office for the Particle Physics and Astronomy Research Council (PPARC), which funded the UK involvement in the project. Tel: 0)1793 442094 or see .
    • The accompanying photograph shows some of the striking images created by
      the supercomputer simulation. For further information, see
    • For information on physics and astronomy at Sussex, see and for information on the work of Sussex with the Virgo Consortium, see 

    University of Sussex Press Office contacts: Maggie Clune or Jacqui Bealing. Tel 01273 678 888 or email or


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