In science fiction, space explorers routinely navigate spacetime wormholes connected by two black holes — celestial bodies so dense that not even light can escape their clutches.
But are black holes really gateways to wormholes? And will these wormholes look like their counterparts in “Star Trek”?
The short answer probably isn’t, although the mathematics of the universe doesn’t completely rule it out.
By itself, the only thing in the file center Black hole She is the singularity – the point of infinite intensity.
In theory, a black hole could pair up with a twin mirror, called a white hole, to form a wormhole. However, these theoretical wormholes wouldn’t look like the ones depicted in science fiction – conventional wormholes are expected to be incredibly unstable, meaning they would collapse the moment a single particle of matter entered.
Some physicists speculate that a wormhole could become more stable if it formed from a spinning black hole, but our understanding of what happens in this scenario is murky at best.
Scientists first discovered black holes not through observations in the universe, but through mathematics Einsteintheory general relativity. These equations showed that if you crush enough material into a small enough volume, then gravity It overwhelms every other force and shrinks the material down to a very small point, known as a singularity.
Black holes are one-way trips. Once someone crosses their limits, known as event horizons, they can never escape. Whereas black holes were once considered just a Einstein’s equations trickFinally, astronomical observations revealed that black holes exist in the universe.
But the same math also allows for the exact opposite of a black hole: a white hole. The white hole still has a singularity in its center and an event horizon that surrounds it. But instead of falling and finding it hard to escape, with a white hole in place, no one can reach the event horizon from the outside, because it is constantly spewing its contents into the universe faster than the speed of light.
Linking the paired singles of a black hole and a white hole together forms the simplest type of wormhole, also known as an Einstein-Rosen bridge.
Not very useful
Unfortunately, Einstein-Rosen bridges are not very useful for traversing the universe. First, the entrance to the wormhole is located behind the event horizon. Since a person cannot enter on the side of the white hole, they would have to fall into the black hole to enter. But once someone crosses the event horizon, they can never escape. This means that if you go into the wormhole, you will be stuck inside forever.
The other problem with Einstein-Rosen bridges is their stability. “This bridge is a kind of wormhole, but it is transient: it pinches before any object can use it to pass from side to side. In that sense there is really no wormhole, since one cannot traverse it,” Samir Mathur, physicist at Ohio State University , told Live Science in an email.
This instability exists because creating a wormhole requires careful and precise arrangement of the material. Anything that upsets this delicate balance—even a single beam of light, or a photon—would cause the wormhole to instantly collapse. The wormhole will rip itself apart like an elongated rubber band faster than the speed of light, preventing anything from traveling underneath.
In addition, physicists largely believe that white holes do not exist in our universe. Unlike their siblings, white holes are fantastically unstable. According to the mathematics, as soon as one bit of matter falls towards them, they instantly explode. So even if the white holes formed naturally, they would not last long.
The combination of the uncertainty about the existence of white holes, the instability of Einstein-Rosen bridges, and their relativistic uselessness means that if wormholes exist, they are likely not Einstein-Rosen bridges.
There might be a way to build a wormhole of a more complex type of black hole: consider its spin. All black holes rotate, but New Zealand mathematician Roy Kerr was the first to solve the mathematics of black holes’ rotation.
At the center of a rotating black hole, intense centrifugal forces spread the point singularity in a loop. It may be that the ‘ring singularity’ could become a wormhole entrance, but once again the problem of stability arises.
“The singularity of Kerr’s hole is surrounded by an ‘inner horizon’, which in turn is surrounded by an ‘outer horizon’. People believe that the inner horizon is not a stable concept, and that small amounts of infalling matter will completely change the area within that horizon, thus also modifying the singularity.” The end result of the instability is unclear.” The problem is that if matter falls in the direction of the ring singularity, it experiences two competing effects: the immense gravitational force of the singularity itself, and the intense centrifugal force of rotation at the center of the black hole, which will act in the opposite direction.
As you can imagine, this is not a very comfortable situation, and things are likely to go wrong very quickly. The situation is so unstable that it may even prevent the formation of a singularity completely. In this case, many physicists believe that the concept of a “ring singularity” from a rotating black hole will be replaced by a more realistic idea once we gain a better understanding of these things.
Originally published on Live Science.