The advent of metamaterials has allowed scientists to learn about the very big — such as black holes and wormholes — by studying the very small. By permitting almost any spatial configuration of dielectric permittivity and magnetic permeability (which control how light interacts with a material), metamaterials can create benchtop analogues of cosmological problems that are otherwise hard to test. Now, Igor Smolyaninov of the University of Maryland and Evgenii Narimanov of Purdue University, both in the United States, have shown theoretically that metamaterials can be used to test a cosmological theory called the 'big flash'.
This theory holds that a reduction in the number of dimensions in the early universe led to a large flash of radiation. The American team showed that an appropriately constructed metamaterial could undergo a similar transition, leading to a flash of light and a test of the theory. They focus on a composite metamaterial made of thin semimetallic gallium wires inside a silica matrix. Femtosecond laser pulses can be used to melt these wires into liquid metallic phases, effecting a 'metric signature change' in the material that should lead to a release of a large number of infrared photons.