Recently a few articles have come out which posit, seriously, that we may be living in a simulated universe (ala The Matrix). Here’s a little from the University of Washington researchers:
Observable consequences of the hypothesis that the observed universe is a numerical simulation performed on a cubic space-time lattice or grid are explored. The simulation scenario is first motivated by extrapolating current trends in computational resource requirements for lattice QCD into the future. Using the historical development of lattice gauge theory technology as a guide, we assume that our universe is an early numerical simulation with unimproved Wilson fermion discretization and investigate potentially-observable consequences. Among the observables that are considered are the muon g-2 and the current differences between determinations of alpha, but the most stringent bound on the inverse lattice spacing of the universe, b^(-1) >~ 10^(11) GeV, is derived from the high-energy cut off of the cosmic ray spectrum. The numerical simulation scenario could reveal itself in the distributions of the highest energy cosmic rays exhibiting a degree of rotational symmetry breaking that reflects the structure of the underlying lattice. (retrieved from: http://arxiv.org/abs/1210.1847)
Basically, it posist that were cosmic rays to not travel out in all directions with equal force, but instead to travel more readily diagonally across a lattice, then there is at least enough evidence that we need to investigate further the notion that we are simulated. Pretty crazy. And it gets a little crazier because were this to be true, then there are probably many “layers” of simulation, as whenever a culture becomes advanced enough to model a universe, they will do so and create a new “layer.”
If you want to read more, you can read a good explanation of the lattice theory here: http://mashable.com/2012/12/17/the-lattice/.
and a good philosophical argument against it here: http://philosophynow.org/issues/75/The_Simulated_Universe.
*Thanks Anji for the spell-check!