How are galaxies formed? The question can feel unfathomable when the youngest galaxies are still billions of years old.
Now, thanks to supercomputers, researchers are simulating billions of galaxies - each obeying different laws of physics for how galaxies should be formed - in order to answer the big question.
8 million galaxies
Countless theories and models have been created in the pursuit of understanding the formation of our galaxy is.
Thankfully the night sky acts as a time machine of sorts: light transported from billions of light-years away give us an insight into the past, including the early formation, of the universe.
Thanks to the information gathered, researchers at the University of Arizona have been able to use the university's Ocelote supercomputer as a "Universe Machine." Ocelote has been programmed to generate millions of small universes so as to compare their formation to the real universe.
As Engadget reports, the galaxies are obviously rendered in very little detail compare to the real thing - these are entire galaxies we are talking about. However, they provide enough information to show us how galaxies progressively change under different applied laws of physics.
The researchers set out to find the galaxy simulations that most resembled our own - this would mean that the law of physics is most likely to have been a strong contributing factor in real, non-simulated, life.
Ocelote produced roughly 8 million virtual universes in only three weeks.
Challenging existing knowledge
In a press release, Peter Behroozi, the study's lead author said:
"On the computer, we can create many different universes and compare them to the actual one, and that lets us infer which rules lead to the one we see."
What's more, the findings from the simulations might challenge existing knowledge about our universe.
"As we go back earlier and earlier in the universe, we would expect the dark matter to be denser, and therefore the gas to be getting hotter and hotter," Behroozi continued.
"This is bad for star formation, so we had thought that many galaxies in the early universe should have stopped forming stars a long time ago. But we found the opposite: galaxies of a given size were more likely to form stars at a higher rate, contrary to the expectation."
The University of Arizona researcher's approach is an exciting new method for studying galaxy formation. It combines "20 years of astronomical observations," Behroozi says, with finding from "millions of mock universes."
These fake universes might be helping us to understand the real thing like never before.