A team of scientists from Durham is building a universe in a box.
The team, based at Durham University, is attempting to build a simulated universe on a comparable scale with a sizeable chunk of our own reality.
The supercomputer experiment known as EAGLE (Evolution and Assembly of GaLaxies and their Environments) will run experiments on the simulation on a scale that isn't possible in real life - for instance by modelling the known effects of dark matter and dark energy, and seeing if the result is anything that looks like the universe we can observe.
In a Reddit AskMeAnything Q&A the team made clear that the simulation (which you can explore here) is only an approximation of the universe. In fact, "the smallest particles in the simulation have the mass of a million suns". But the result is still impressive - a simulated cube about 300 million light years on one side. ("This is big enough to provide a whole zoo of different galaxy shapes and sizes, like the ones we see in the real universe.")
"In the simulations we assume the simplest forms of dark matter and dark energy, and we test if we can make galaxies similar to the real Universe - so far it looks good," the team said.
The experiment started with the PLANCK observations of the Cosmic Microwave Background, and models 7 billion particles and how they interact. It took more than one and a half months of computer time on 4000 compute cores of the DiRAC-2 supercomputer in Durham to run, and uses a heavily modified version of theGADGET-2 simulation code as its base.
"We don't have enough computing power (yet) to simulate down to a planet-size scale, but there are thousands of galaxies similar to our galaxy, the milky way [in the simulation," the team said. "Since we only have limited computer power, we simulate a 'small' patch of the Universe, which is big enough to represent the whole Universe - the whole zoo of galaxies we see. Just like the video game Asteroids, the simulation wraps around on itself."
The team also had good news for humanity -- they don't think that we're already living inside a simulation. This idea sounds outlandish but is actually given serious consideration by philosophers (and scientists), who point out that if a simulation is possible then it is mathematically more likely that we are inside one than not.
Luckily, the Durham team thinks this isn't likely.
"As for the "are we in a simulation" - I'll leave that to the philosophers," said team member Josh Burrow. "But if we were in a simulation (and they used EAGLE) they'd need an infinitely big computer, so it doesn't seem too likely."