Recently, it was predicted that extraordinary light waves in hyperbolic metamaterials may exhibit two-time physics behavior. We report experimental observation of this effect via investigation of gravity-like nonlinear optics of iron/cobalt-based ferrofluid hyperbolic metamaterials. In addition to conventional temporal coordinates, the spatial coordinate oriented along the optical axis of the metamaterial also exhibits timelike character, which leads to very unusual two-time physics behavior in these systems on small scales.

Recently it was proposed that extraordinary light waves in hyperbolic metamaterials exhibit "two times" physics behavior (Phys. Rev. Lett. 105, 067402, 2010). We report experimental observation of this effect via investigation of gravity-like nonlinear optics of iron/cobalt-based ferrofluid hyperbolic metamaterials. In addition to conventional temporal coordinate, the spatial coordinate oriented along the optical axis of the metamaterial also exhibits timelike character, which leads to very unusual "two times" physics behavior in these systems.Electromagnetic metamaterials have enabled new ways to control and manipulate electromagnetic waves. One of the more unusual applications of metamaterials was the recent theoretical proposal to construct a physical system, which would exhibit "two times" (2T) physics behavior [1]. Theoretical investigation of the 2T space-time models had been pioneered by Dirac [2] and Sakharov [3]. More recent examples may be found

We report experimental observation of the self-focusing effect in ferrofluid-based self- assembled hyperbolic metamaterials, which is predicted to exhibit gravity-like nonlinear optical interactions.