The analogy between the physics of superfluid helium and general relativity is well known. The mathematics that describe these systems are essentially identical so measuring the properties of one automatically tells you how the other behaves.
Now Igor Smolyaninov at the University of Maryland has found another interesting mathematical analogy between optical metamaterials and general relativity. Metamaterials are substances in which the permittivity and permeability have been manipulated in a way that allows fine control over the behaviour of light. They have famously been used to create invisibility cloaks that hide objects from view.
But Smolyaninov has another idea. Why not create materials that reproduce the behaviour of light in various kinds of spacetimes. He gives the example of a metamaterial which is a formal equivalent to a (2+2) spacetime with two dimensions of space and two of time.
His piece de resistance, however, is a mathematical demonstration of an event in which a phase transition inside a (2+2) metamaterial leads to the sudden creation of a 2+1 spacetime (two dimensions of space and one of time) together with a large population of particles.
Think about that for a moment. What Smolyaninov is describing is an optical analogue of the Big Bang in which a spacetime is created along with the particles to populate it. “The characteristic feature of this phase transition appears to be a kind of toy “big bang”,” he says.
In principle that’s an experiment that could be done in the lab in which you could watch the Big Bang in action.
Ref: arxiv.org/abs/0908.2407: Optical Models of the Big Bang and Non-Trivial Space-Time Metrics Based on Metamaterials