When John Crichton was in the cockpit of a spacecraft that traversed a wormhole in Farscape, he thought he’d hit major turbulence until he found himself on a living ship swarming with aliens. But is wormhole travel even possible?
There is no hard evidence for wormholes — yet. However, Einstein’s theory of gravity allows for them, which makes an interesting case for hypothetical wormhole travel. There is just one problem. Gaining entrane to a round wormhole would have to involve negative mass, which is scientifically impossible. While movies often imagine wormholes as round portals to another world billions of light years away, a duo of scientists from Tehran University have now determined that wormholes would have to be some weird asymmetrical shape to let anything through (if we ever find a way to zoom through the cosmos at the speed of light).
“For Einstein’s theory of gravity, it can be shown that it is impossible to have a traversable wormhole with ordinary matter, and exotic [matter] is needed. said R. Moti and A. Shojai, who recently submitted their study to the preprint journal arXiv. “The possibility of a traversable wormhole solution is usually searched for by considering a static spherical symmetric solution.”
Their proposal for a wormhole you could go through like Crichton has a catch. There can be no event horizon near the throat. The throat of a wormhole is the extremely narrow, constantly moving connection between one end and the other. Your ship couldn’t touch the event horizon because there would be no coming back to Earth, or anywhere else, if it did. The event horizon is the fringe of a black hole is the ultimate point of no return. Past that point, intense gravity pulls in anything with so much force that it is never to be seen again, though there are scientists who disagree if certain conditions are met. Black holes and wormholes are obviously not the same thing. Wormholes have, however, been theorized to exist inside black holes. A wormhole might also have a black hole as its entrance and exit.
Say the wormhole is not located in a black hole and has no event horizon. There can be an unlimited expanse of space before an after the throat of a wormhole, but a finite value must be reached at the throat location. You can’t exactly travel forever. How traversable the throat actually is also depends on how gravity flows inside. When a gargantuan amount of matter bends the fabric of spacetime by compressing itself into an infinitesimal opening, there are going to be issues.
“There are two important questions that should be addressed,” Moti and Shojai said. "They are: ‘How can the quantum effects change the traversability of wormholes?’, and ‘is it possible to have a quantum corrected wormhole that is traversable with non–exotic matter?’ To answer these questions, one has to have a quantum theory of gravity. Unfortunately, there is no established one yet.”
Quantum mechanics warps what could happen under general relativity. If you were to go through a black hole without twisting the rules, not only would it have to be round, but you would need negative mass. There has been no proof of negative mass ever existing. If it did, your life would be that much harder, because anything that moves one way would immediately move the opposite way. You would technically only be able to throw something forward if you threw it backwards. Driving would be a nightmare. However, the scientists found that if you reshape the entrance of a wormhole and stretch it around enough so it is no longer in a completely spherical shape, hypothetical wormhole travel could be possible without the also hypothetical negative mass.
“As the passenger approaches the throat, the rate of change of the expansion parameter, eventually becomes positive and grows up. This pushes the passenger through the throat and the wormhole becomes traversable," Moti and Shojai said, being careful to note that said passenger would also have to be unfathomably tiny to make it through.
If Crichton only knew what was actually happening to him and his ship as they flew through a wormhole, he would have been freaking out even more.