Metamaterials are substances in which physicists have fiddled with a material’s ability to support electric and magnetic fields. They can be designed to steer electromagnetic waves around, over and behind objects to create invisibility cloaks that hide objects.
If that sounds a little like the way gravitational fields can bend light, then you won’t be surprised to learn that there is a formal mathematical analogy between optical metamaterials and general relativity.
The idea that anything Einstein can do, metamaterials can do too has fueled an explosion of interest in “electromagnetic space”. Physicists have already investigated black holes that suck light in but won’t let it out and wormholes that connect different regions of electromagnetic space.
Today, Igor Smolyaninov at the University of Maryland in College Park says that the analogy with spacetime can be taken much further. He says it is possible to create metamaterials that are analogous to various kinds of spaces dreamt up by cosmologists to explain aspects of the Universe.
In these theories, space can have different numbers of dimensions that become compactified early in the Universe’s history, leaving the three dimensions of space and one of time (3+1) that we see today. In symmetries of these spaces depend on the dimensions and the way they are compactified and this in turn determines the laws of physics in these regions.
It turns out, says Smolyaninov, that it is possible to create metamaterials with electromagnetic spaces in which some dimensions are compactified. He says it is even possible to create substances in which the spaces vary from region to region, so a space with 2 ordinary and 2 compactified dimensions, could be adjacent to a space with just 2 ordinary dimensions and also connected to a 2d space with 1 compactified dimension and so on.
The wormholes that make transitions between these regions would be especially interesting. It ought to be possible to observe the birth of photons in these regions and there is even a sense in which the transition could represent the birth of a new universe.”A similar topological transition may have given birth to our own Universe,” says Smolyaninov.
He goes on to show that these materials can be used to create a multiverse in which different universes have different properties. In fact it ought to be possible create universes in which different laws of physics arise.
That opens up a new area for optical devices. Smolyaninov gives the example of electromagnetic universes in which photons behave as if they are massive, massless or charged depending on the topology of space and the laws of physics this gives rise to.
Just what kind of devices could exploit this behaviour isn’t clear yet. If you think of any, post them here. This is clearly a field that for the moment appears to be limited only by the mind of the designer.
Ref: arxiv.org/abs/1005.1002: Metamaterial “Multiverse”
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