Scientists unveil ‘most accurate’ virtual representation of universe

Our section of the universe has been mapped into the “most accurate simulation to date” by scientists using a supercomputer.

The simulations, which were unveiled at Durham university, capture the Big Bang to the present and the entire evolution of the cosmos.

Scientists used advanced statistical techniques so that the simulations were conditioned to reproduce our specific patch of the universe – therefore containing the present-day structures in the vicinity of our own galaxy.

At the centre of the simulation is a pair of galaxies – virtual representations of our own Milky Way and the Andromeda galaxy.

Research suggests that our local patch of the universe is unusual as the simulation predicted a lower number of galaxies in an average region of the universe due to a local large-scale underdensity of dark matter.

The underdensity could have consequences for how scientists interpret information from observed galaxy surveys – though it is not believed to be a challenge to the standard model of cosmology.

Named Sibelius-Dark, the new simulation is part of the Simulations Beyond the Local Universe (Sibelius) project and covers a volume up to a distance of 600 million light-years from Earth.

It is also represented by more than 130 billion simulated particles – which need many thousands of computers working in tandem over several weeks and producing more than one petabyte (1,000 terabytes) of data.

The simulation was performed on the DiRAC COSmology MAchine (Cosma) operated by the Institute for Computational Cosmology at Durham University.

The researchers involved came from all over the world, including Durham University, and were led by the University of Helsinki.

The findings have been published on arXiv.org and as a pre-print in the Monthly Notices of the Royal Astronomical Society journal.

Professor Carlos Frenk, of the Institute for Computational Cosmology at Durham University, said: “It is immensely exciting to see the familiar structures that we know exist around us emerge from a computer calculation.

“The simulations simply reveal the consequences of the laws of physics acting on the dark matter and cosmic gas throughout the 13.7 billion years that our universe has been around.

He added that being able to reproduce these familiar structures provides “impressive support for the standard Cold Dark Matter model” and also shows scientists are on the right track to “understand the evolution of the entire universe”.

Former Durham PhD student Dr Stuart McAlpine, who is now a postdoctoral researcher at the University of Helsinki, said that simulating the universe as we see it means “we are one step closer to understanding the nature of our cosmos”.

He added: “These simulations show that the current leading theory of cosmology, the Cold Dark Matter model, can produce all the galaxies we see in our local habitat, an essential benchmark for simulations of this kind to pass.

“This project provides an important bridge between decades of theory and astronomical observations.”