Figuring out how our reality has materialized for billions of years is no easy task for scientists. Theories of how the Big Bang played and the immediate aftermath are twentieth, but researchers led by a University of Arizona team think they may uncover some of the secrets of galaxy formation by asking a supercomputer to simulate millions of virtual universes and see which of them closest to what we see today.
In a new research paper published in Monthly Notices of the Royal Astronomical Society, the team explains how they used a supercomputer system nicknamed the "Universe Machine" to watch billions of (virtual) years of galaxy formation play before their eyes.
"On the computer, we can create many different universes and compare them to the real one, and that leaves us inferring which rules lead to what we see," Peter Behroozi, lead author of the study, said in a statement.
This approach allowed scientists to test long-standing theories of how galaxies formed in the aftermath of the Big Bang, and it has already offered some hidden insights. Hot gas building in the galaxy due to the action of black holes, star bursts and gravitational pull of dark matter should be a death sentence for a galaxy, making it impossible to form new stars. The researchers say that in simulations that match real-world observations, this does not happen.
"When we come back earlier and later in the universe, we would expect the dark matter to be thicker, and therefore the gas will get hotter," Behroozi explained. "This is bad for star formation, which is why we thought that many galaxies in the early universe should have stopped forming stars long ago. I'm waiting. "
All this work required some intense computer power, and the researchers enlisted help from NASA as well as resources from German scientists, combined with their own supercomputer at the university, to make it happen. A total of 2,000 processors ran simultaneously over three weeks to generate over 8 million virtual universes.