A wormhole can be visualized as a tunnel with two ends at separate points in spacetime (i.e., different locations, different points in time, or both). Wormholes are consistent with the general theory of relativity, but whether wormholes actually exist remains to be seen.
No one has yet seen a wormhole, but theoretically they could provide shortcuts to distant parts of the universe, or to other universes entirely, if they exist (SN: 7/27/17).
While researchers have never found a wormhole in our universe, scientists often see wormholes described in the solutions to important physics equations. Most prominently, the solutions to the equations behind Einstein's theory of space-time and general relativity include wormholes.
In reality, they are purely theoretical. Unlike black holes—also once thought to be purely theoretical—no evidence for an actual wormhole has ever been found, although they are fascinating from an abstract theoretical physics perceptive.
Unless the wormhole was thoroughly cleaned out and everything else blocked from entering it, falling in would mean certain death. “Whenever you travel close to the speed of light, any particle or dust grain or anything that you hit will be problematic. Even a photon would cause you trouble,” says Maldacena.
The nearest "portal"
American and German scientists recently reported that they had discovered the closest known black hole, called Gaia BH1. It is about ten times the size of the Sun and is 1,566 light years from Earth. This may be a wormhole. Gaia BH1 has a Sun-like star orbiting it.
A wormhole can be visualized as a tunnel with two ends at separate points in spacetime (i.e., different locations, different points in time, or both). Wormholes are consistent with the general theory of relativity, but whether wormholes actually exist remains to be seen.
In May 2022, scientists revealed the historic first image of the supermassive black hole at the center of our galaxy — Sagitarrius A*.
The major distinction between a wormhole and a black hole is that a wormhole is a funnel-shaped space-time tunnel between two points between universes, whereas a black hole is a cosmic body with extreme gravity from which nothing can escape.
Black holes have two parts. There is the event horizon, which you can think of as the surface, though it's simply the point where the gravity gets too strong for anything to escape. And then, at the center, is the singularity. That's the word we use to describe a point that is infinitely small and infinitely dense.
Unless the wormhole was thoroughly cleaned out and everything else blocked from entering it, falling in would mean certain death. “Whenever you travel close to the speed of light, any particle or dust grain or anything that you hit will be problematic. Even a photon would cause you trouble,” says Maldacena.
The nearest "portal"
American and German scientists recently reported that they had discovered the closest known black hole, called Gaia BH1. It is about ten times the size of the Sun and is 1,566 light years from Earth. This may be a wormhole. Gaia BH1 has a Sun-like star orbiting it.
In May 2022, scientists revealed the historic first image of the supermassive black hole at the center of our galaxy — Sagitarrius A*.
From the outside, a classical wormhole would just look like two black holes at separate locations in space-time.
"You can go into the future or into the past using traversable wormholes," astrophysicist Eric Davis told LiveScience. But it won't be easy: "It would take a Herculean effort to turn a wormhole into a time machine. It's going to be tough enough to pull off a wormhole."
With the knowledge and technology we have today, wormhole detection seems to be close but not quite there yet. With current detection methods that are possible, there is no way to distinguish between wormhole candidates and black holes.
Time travel to the past is theoretically possible in certain general relativity spacetime geometries that permit traveling faster than the speed of light, such as cosmic strings, traversable wormholes, and Alcubierre drives.
Fortunately, this has never happened to anyone — black holes are too far away to pull in any matter from our solar system. But scientists have observed black holes ripping stars apart, a process that releases a tremendous amount of energy.
Near a black hole, the slowing of time is extreme. From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole. Inside a black hole is where the real mystery lies.
Black holes are dark, dense regions in space where the pull of gravity is so strong that nothing can escape. Not even light can get out of these regions. That is why we cannot see black holes—they are invisible to our eyes. Because nothing can get out of black holes, physicists struggle understanding these objects.
In reality, however, Einstein's theory of general relativity shows that it would not be possible for matter to actually cross these “tunnels through space”. But physicists are still considering whether that hypothesis is false: quantum effects could play a role in refuting this hypothesis.
Theoretically, a wormhole might connect extremely long distances such as a billion light years, or short distances such as a few meters, or different points in time, or even different universes.
Black hole news: Standing on edge of black hole would cause 700 years to pass in 1 minute.