Philosophers, film fans and the chemically relaxed have regularly suggested over the decades that our universe might be a computer simulation. In recent years scientists have announced that it might be possible to actually test that theory - by looking for arbitrary limits in our universe that we also see in the model universes we've already constructed.
It's all interesting - if unfortunately conceptual right now - stuff. But the fact remains we have made model universes, for real. And now you can actually look at one.
The video below is made by the Argonne National Lab of their model, the Hardware/Hybrid Accelerated Cosmology Code. The model is a 1.1 trillion particle simulation of mass expanding in a universe - nearly four times as large as comparable simulations.
It's a long way from building a replica reality in a computer. But it's fascinating science all the same.