That’s not just the premise of many
Hollywood movies, it’s also a serious physics questions. And now, theoretical
physicists have come up with a way to test whether we’re all living inside
a simulated universe:
First, some background. The problem with all simulations is that the
laws of physics, which appear continuous, have to be superimposed onto
a discrete three dimensional lattice which advances in steps of time.
The question that Beane and co ask is whether the lattice spacing imposes
any kind of limitation on the physical processes we see in the universe.
They examine, in particular, high energy processes, which probe smaller
regions of space as they get more energetic
What they find is interesting. They say that the lattice spacing imposes
a fundamental limit on the energy that particles can have. That’s because
nothing can exist that is smaller than the lattice itself.
So if our cosmos is merely a simulation, there ought to be a cut off
in the spectrum of high energy particles.
It turns out there is exactly this kind of cut off in the energy of
cosmic ray particles, a limit known as the Greisen–Zatsepin–Kuzmin
or GZK cut off.
Read more over at MIT’s Technology Review: Link