Remember the philosophical argument our universe is a simulation? Well, a team of astrophysicists say they’ve created the biggest simulated universe yet. But you won’t find any virtual beings in it—or even planets or stars.

The simulation is 9.6 billion light-years to a side, so its smallest structures are still enormous (the size of small galaxies). The model’s 2.1 trillion particles simulate the dark matter glue holding the universe together.

Named Uchuu, or Japanese for “outer space,” the simulation covers some 13.8 billion years and will help scientists study how dark matter has driven cosmic evolution since the Big Bang.