Researchers have used a method to investigate spacetime structures using inhomogeneous materials and thereby create a type of ‘wormhole’, or rather something analogous to a wormhole, by producing the phenomenon within a curved laboratory frame.
The aim of the study was to more fully understand the propagation of a wormhole within a curved space and to investigate wave redirection, tunneling and virtual caustics of the wormhole.
A wormhole is a theoretical structure linking disparate points in spacetime. A wormhole can be thought of as a tunnel with two ends, each at separate points in spacetime – which means different locations or different points of time).
To create the wormholes the researchers used a process called transformation optics, which applies metamaterials (materials engineered to have a property that is not found in naturally occurring materials) in order to produce spatial variations. These variations can direct selected bandwidths of electromagnetic radiation. The function can lead to the development of new composite artificial devices, as might be used in computing.
According to Chris Lee, transformation optics deploys the mathematical similarity between optics and general relativity, turning an optical problem into trajectories through space.
He adds: “Simply bend and stretch space to get your trajectories right. Bending and stretching in space correspond to changes in refractive index in optics. It is a relatively simple matter to return to the real world and… Um, yes, at this point, you run into some problems.”
The existence of wormholes can be demonstrated mathematically but proving this in practice has yet to done. One reason for this is with finding corresponding materials with the right refractive indices. The study with transformation optics was designed to be a step towards finding the right materials for this task.
This is possible since transformation optics is about the behavior of a wave passing through an optical system. This happens to be similar to the path of an object traveling through curved space. This makes the study of ‘impossible objects’ like wormholes at least theoretically possible. To achieve this with the study, the researchers created a curved two-dimensional surface in a three-dimensional world – for the purpose of the experiment. This helped to make something that is very complicated easier to visualize and to interpret.
The new research has been published in the journal Physical Review Letters. The article is titled “Elastic Waves in Curved Space: Mimicking a Wormhole.”
