Albert Einstein’s general theory of relativity fundamentally changed our thinking about basic concepts in physics, such as space and time. But it also left us with some deep mysteries. One was black holes, which were only unequivocally discovered over the last few years. Another was “wormholes” – bridges that connect different points in space-time, which in theory provide shortcuts to space travelers.
Wormholes are still within the realm of imagination. But some scientists believe that we too will soon be able to find them. Over the last few months, several new studies have suggested exciting ways forward.
Black holes and wormholes are special types of solutions to Einstein̵
Since the theory allows the substance to be stretched and bent in space-time, one can imagine all possible configurations. In 1935, Einstein and physicist Nathan Rosen described how two sheets of space-time could be joined, creating a bridge between two universes. This is a kind of wormhole – and since then many others have been imagined.
Some wormholes can be “passable”, meaning humans may be able to travel through them. For that, however, they should be large enough and kept open against gravity, which tries to close them. Pushing spacetime outward in this way would require enormous amounts of “negative energy”.
Sounds like sci-fi? We know that negative energy exists and small quantities have already been produced in the laboratory. We also know that negative energy lies behind the accelerated expansion of the universe. So nature may have found a way to create wormholes.
Spotting wormholes in the sky
How can we ever prove that there are wormholes? In a new paper published in the monthly announcements of the Royal Society, Russian astronomers suggest that they may be at the center of some very bright galaxies, and suggest some observations to find them. This is based on what would happen if fabric coming out of one side of the wormhole collided with fabric that was about to fall in. The calculations show that the crash would result in a spectacular display of gamma rays, which we could try to observe with telescopes.
This radiation could be the key to distinguishing between a wormhole and a black hole that was previously thought to be distinguishable from the outside. But black holes must produce fewer gamma rays and push them out into a beam, while radiation produced through a wormhole would be limited to a giant sphere. Although the kind of wormhole considered in this study is transparent, it would not provide a comfortable ride. Because it would be so close to the center of an active galaxy, the high temperatures would burn everything to a sharp. But this would not be the case for all wormholes, such as those further away from the galactic center.
The idea that galaxies can accommodate wormholes in their centers is not new. Take the case of the supermassive black hole in the heart of the Milky Way. This was discovered by carefully tracing the orbits of the stars near the black hole, a great achievement awarded the Nobel Prize in Physics in 2020. But a recent article has suggested that this gravity may instead be caused by a wormhole.
Unlike a black hole, a wormhole can “leak” some gravity from the objects on the other side. This eerie gravity would add a little kick to the movements of the stars near the galactic center. According to this study, the specific effect should be measurable in observations in the near future, when the sensitivity of our instruments becomes a little more advanced.
Coincidentally, yet another study has reported the discovery of some “strange radio circles” in the sky. These circles are strange because they are huge and yet not connected to any visible object. For now, they defy any conventional explanation, so wormholes have been advanced as a possible cause.
A can of worms
Wormholes have a strong grip on our collective imagination. In a way, they are a wonderful form of escapism. Unlike black holes, which are a little intimidating as they capture everything that ventures in, wormholes may allow us to travel to distant places faster than the speed of light. In fact, they can even be time machines that provide a way to travel backwards – as suggested by the late Stephen Hawking in his last book.
Wormholes also appear in quantum physics, which governs the world of atoms and particles. According to quantum mechanics, particles can jump out of empty space, only to disappear a moment later. This has been seen in countless experiments. And if particles can form, why not wormholes? Physicists believe that wormholes may have formed in the early universe from a foam of quantum particles popping in and out of existence. Some of these “wormholes” may still exist today.
Recent experiments with “quantum teleportation” – a “disembodied” transfer of quantum information from one place to another – have been shown to work in an eerie way as two black holes connected through a wormhole. These experiments seem to solve the “quantum information paradox”, suggesting that physical information may permanently disappear in a black hole. But they also reveal a deep connection between the notoriously incompatible theories of quantum physics and gravity – with wormholes relevant to both – which may have contributed to the construction of a “theory of everything”.
The fact that wormholes play a role in this fascinating development is unlikely to go unnoticed. We may not have seen them, but they could definitely be out there. They can even help us understand some of the deepest cosmic mysteries, such as whether our universe is the only one.
How to see what’s on the other side of a wormhole without traveling through it
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Citation: Wormholes may be lurking in the universe – and new research suggests ways to find them (2021, January 13) retrieved January 13, 2021 from https://phys.org/news/2021-01-wormholes-lurking-universeand-ways .html
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