Physicists have discovered a strange twist in spacetime that can mimic black holes — as long as you get up close. Called „topological solitons,” these theoretical kinks in the fabric of space-time may be lurking throughout the universe—and finding them could push our understanding of quantum physics forward, according to a new study published April 25 in the journal Science. Physical examination d (opens in new tab).
Black holes It may be the most repulsive substance ever discovered in science. Einstein’s general theory of relativity predicts their existence, and astronomers know how they form: all a massive star has to do is collapse under its own weight. With no other force available to oppose it, gravity continues to pull all of the star’s material until it is compressed into an infinitesimally small point. That singularity is an event horizon, an invisible boundary that marks the edge of a black hole. Whatever crosses the event horizon can never leave.
But the main problem with this is that points of infinite density cannot actually exist. So when General relativity predicts the existence of black holes, and while we’ve found many astronomical objects that behave exactly according to Einstein’s theory, we still know we don’t have the full picture. We know that integrity must be replaced by something more reasonable, but we don’t know what it is.
Related: Are black holes wormholes?
Finding it requires an understanding of very strong gravity at very small scales – called quantum gravity. To date, we do not have a viable quantum theory of gravity, but we do have several candidates. One of those candidates String theoryA model that suggests that all the particles that make up our universe are actually made up of tiny, vibrating strings.
Those strings don’t just vibrate in the usual three spatial dimensions, to explain the different types of particles that inhabit our universe. String theory predicts the existence of extra dimensions, all of which curl up on themselves at some inexplicably small scale—we cannot say that those dimensions exist.
Collapsing extra spatial dimensions into incredibly small sizes can lead to very interesting objects.
In the new study, the researchers proposed that these small extra dimensions could lead to defects. Like a wrinkle that won’t come out no matter how much you iron your shirt, these defects are fixed, permanent defects in the fabric of spacetime—a topological soliton. Physicists have suggested that these solitons look, act, and smell mostly like black holes.
The researchers studied how rays of light behave when passing near one of these solitons. They found that solitons can affect light just like a black hole. Light bends around the solitons to form stable orbital rings, and the solitons cast shadows. In other words, the Famous images from the Event Horizon TelescopeIn 2019 the black hole magnified in M87* would be almost the same if the solitons were at the center of the image rather than the black hole.
But up close that mimicry is over. Topological solitons are not singularities and therefore do not have event boundaries. You can get close to a soliton, and you can always get out if you want (assuming you’ve packed enough fuel).
Unfortunately, we don’t have enough black holes to dig into, so we can only rely on observations of distant objects. If any topological solitons are ever discovered, it will not be a major insight into the nature of gravity, but it will help directly probe the nature of quantum gravity and string theory.