One Step Closer to Time Travel? Pulses of Light Could Travel Through Wormholes
Luke Butcher, a research fellow at the University of Cambridge made science fiction fans very happy when he recently theorized that we may be able to send messages through wormholes in the form of pulses of light.
Wormholes, or Einstein-Rosen bridges, are hypothetical tunnels between two points of spacetime. Although wormholes are predicted by Einstein's theory of relativity, researchers have thus far found no observational evidence for their existence. Since each end of a wormhole can theoretically exist in two different points of time, they have long been theorized to potentially allow for time travel or instant communication. But as a result of their instability, they are inevitably collapsing at all times. They don't stay open long enough for anything, people, messages, etc., to get through.
Previous, unsuccessful attempts to theoretically keep wormholes open have been centered on the concept of Casimir energy, or negative energy. In the context of wormholes, if there were a metal plate at each end of the wormhole, then quantum fluctuations in spacetime would cause waves of energy. Some of these energy waves would be too large to be contained between the metal plates, so the space between them would have less energy than that surrounding them, resulting in negative energy. Many researchers have attempted to create a theoretically tenable way to keep wormholes open using this concept, but to no avail.
Butcher is attempting to improve on this theory; in his own words, "What if the wormhole itself could take the place of the plates?", or in other words, the tube-like shape of the wormhole could create the negative energy. If the mouth was several orders of magnitude longer than the throat of the wormhole, then the difference in size could create negative energy in the center. He qualifies, however, that "this energy isn't enough to keep the wormhole stable. It will collapse." But it will collapse much more slowly, and it might stay open for long enough that a pulse of light could make it through.
That hasn't stopped filmmakers from giving wormholes the Hollywood treatment, but more work needs to be done in order to confirm that other parts of the wormhole besides the center would stay open long enough for the pulse of light to make it through, and scientists are still a long way from turning theories into a physical wormhole.