http://www.extremetech.com/extreme/1...ses-in-the-lab

"While this is rather extraordinary, the experimental setup is actually
quite simple — though definitely rather unconventional. The multiverse
is created inside a solution of cobalt in kerosene. This fluid isn’t
usually considered a metamaterial, but lead researcher Igor Smolyaninov
and co found that by applying a magnetic field, the ferromagnetic
nanoparticles of cobalt line up in neat columns. When light passes
through these columns, it behaves as if it’s in a Minkowski universe."