Astrophysicists have created the most realistic computer
simulation of the universe's evolution to date, tracking activity
from the Big Bang to now -- a time span of around 14 billion years
-- in high resolution.
Created by a team at the Harvard-Smithsonian Centre for
Astrophysics (CfA) in collaboration with researchers at the
Heidelberg Institute for Theoretical Studies (HITS), the Arepo
software provides detailed imagery of different galaxies in the
local universe using a technique known as "moving mesh".
Unlike previous model simulators, such as the Gadget code,
Arepo's hydrodynamic model replicates the gaseous formations
following the Big Bang by using a virtual, flexible grid that has
the capacity to move to match the motions of the gas, stars, dark
matter and dark energy that make up space -- it's like a virtual
model of the cosmic web, able to bend and flex to support the matter and
celestial bodies that make up the universe. Old simulators instead
used a more regimented, fixed, cubic grid.
"We took all the advantages of previous codes and removed the
disadvantages," explained Volker Springel,
the HITS astrophysicist who built the software. Springel, an expert
in galaxy formation who helped build the Millennium Simulation to
trace the evolution of 10 billion particles, used Harvard's Odyssey
supercomputer to run the simulation. Its 1,024 processor cores
allowed the team to compress 14 billion years worth of cosmic
history in the space of a few months.
The results are spiral galaxies like the Milky Way and Andromeda
that actually look like spiral galaxies -- not the blurred blobs
depicted by previous simulators -- generated from data input that
stretches as far back as the afterglow of the Big Bang, thus
portraying a dramatic cosmic evolution (see the above video for a
sneak peek of that evolution from four billion years after the Big
"We find that Arepo leads to significantly higher star formation
rates for galaxies in massive haloes and to more extended gaseous
disks in galaxies, which also feature a thinner and smoother
morphology than their Gadget counterparts," the team states in a paper describing
Though the feat is impressive -- CfA astrophysicist Debora
Sijacki compares the high-resolution simulation's improvement over
previous models to that of the 24.5-metre aperture Giant Magellan Telescope's improvement over all telescopes --
the team aim to generate simulations of larger areas of the
universe. If this is achieved, the team will have created not only
the most realistic, but the biggest universe simulation ever.