Where Do Black Holes Lead?

You are going to jump into a black hole, so there you are. What may possibly be in store for you if, all all odds, you survive? 

If you could find a way back, where would you end up and what fascinating stories could you tell?

Who knows is the fundamental response to all of these questions, according to Professor Richard Massey. Massey is highly versed in the enigmas surrounding black holes due to his position as a Royal Society research fellow at Durham University's Institute for Computational Cosmology. He said that crossing an event horizon is equivalent to physically going beyond the veil since once someone has done so, no one would ever be able to communicate with them again. I don't think somebody falling through would go anywhere because of the tremendous gravity, which would shatter them to bits.

That reaction certainly seems depressing and terrible, and it is. It has been known that black holes arise when a big star dies, leaving behind a tiny, dense remnant core since Albert Einstein's general theory of relativity was supposed to have predicted black holes by coupling space-time with gravity's action. This core would be overcome by gravity to the point that it collapses in on itself into a single point, or singularity, which is believed to be the black hole's endlessly dense core, if it had more mass than three times that of the sun.

The ensuing uninhabitable black hole's gravitational pull would be so powerful that even light would be impossible to escape. There is no way out if you get at the event horizon, which German astronomer Karl Schwarzschild described as the boundary where light and matter may only travel inward. Your body would be reduced to strands of atoms by tidal forces, a process known as "spaghettification," and finally crushed at the singularity. It seems completely impossible that you might suddenly emerge anywhere, possibly at the other side.

What about a wormhole?

But is it? Over the years, researchers have looked at the potential that black holes might connect to neighboring galaxies via wormholes. They may even be a gateway to another world, as some have speculated.

Such a notion is not new; in 1935, Einstein and Nathan Rosen proposed building bridges that linked two separate locations in space-time. However, it received some new momentum in the 1980s when physicist Kip Thorne, one of the world's foremost authorities on the astrophysical applications of Einstein's general theory of relativity, sparked a debate regarding whether or not things could really move through them.

When I was younger, reading the well-known book on wormholes by Kip Thorne ignited my interest in physics, according to Massey. On the other hand, wormholes don't seem to exist.

Indeed, in his book "The Science of Interstellar," Thorne, who provided his professional guidance to the Interstellar production team, stated: "We observe no things in our universe that may become wormholes as they age" (W.W. Norton and Company, 2014). Thorne claims that because there is little solid evidence that a black hole could permit such a route, traveling via these hypothetical tunnels would probably remain the stuff of science fiction.

However, the issue is that we are unable get near enough to see for ourselves. Due to the fact that light cannot escape a black hole's intense gravity, we are unable to even imagine what takes on there. As it is, theory predicts that everything that crosses the event horizon is simply added to the black hole. In addition, since time seems to move exceedingly slowly near to this limit, answers won't be found anytime soon.

Professor of astronomy and physics at Harvard University Douglas Finkbeiner said, "I suppose the conventional idea is that they lead to the end of time." "A distant spectator won't see their astronaut buddy slipping into the black hole. As they grow closer to the event horizon [due to gravitational red shift], they will only become redder and fainter. However, the companion immediately sinks into a location beyond "forever."

A black hole might perhaps lead to a white hole.

There must be something on the other side of black holes if they actually go to other galaxies or universes. Igor Novikov, a Russian cosmologist, hypothesized that this may be a white hole back in 1964. A black hole is connected to a white hole in the past, according to Novikov's theory. A white hole, as contrast to a black hole, enables light and matter to leave but not to enter.

The probable relationship between black and white holes has continued to be studied by scientists. In a 2014 publication that appeared in the journal Physical Review D, Carlo Rovelli and Hal M. Haggard said that "there is a traditional metric fulfilling the Einstein equations outside a bounded space-time sector where matter goes into a black hole and subsequently emerges from a while hole." In other words, black holes may eject all of the matter they have consumed upon dying, turning them into white holes.

The information a black hole swallows would not be destroyed, but rather its fall would be stopped. Instead, it would undergo a quantum bounce, which would let information get out. If true, it would clarify a theory put out in the 1970s by Stephen Hawking, a theoretical physicist and former Cambridge University cosmologist, according to which black holes emit thermal heat in the form of particles and radiation as a consequence of quantum fluctuations.

"Hawking claimed a black hole doesn't persist forever," Finkbeiner said. According to Hawking's 1976 study in Physical Review D, radiation would cause a black hole to lose energy, shrink, and eventually vanish. The black hole's detonation would destroy a vast quantity of data, according to his assertions that the radiation it would release would be random and would not include any information about what had fallen into it.

Since information cannot be destroyed according to quantum theory, Hawking's hypothesis was in violation of this. According to physics, information just becomes harder to locate since, if it were to disappear, it would be impossible to know the past or the future. The "black hole information paradox," which has long baffled physicists, was birthed by Hawking's hypothesis. Some have claimed that Hawking was just incorrect, and the scientist acknowledged his error in 2004 at a scientific conference in Dublin.

So, should we revisit the notion that black holes emit stored information that is released via a white hole? Jorge Pullin at Louisiana State University and Rodolfo Gambini at the University of the Republic in Montevideo, Uruguay, applied loop quantum gravity to a black hole in their 2013 study, which was published in Physical Review Letters. They discovered that gravity increased toward the core but decreased and flung anything entering into a different region of the universe. The results confirmed the idea that black holes may act as portals. This research does not consider the singularity, thus it does not create an unbreakable wall that crushes whatever it comes into contact with. Additionally, it implies that information does not vanish.

Maybe black holes go nowhere

However, physicists James Sully, Joseph Polchinski, Donald Marolf, and Ahmed Almheiri thought Hawking was onto something. They were built upon the AMPS firewall idea, sometimes referred to as the black hole firewall hypothesis. Their calculations suggested that quantum mechanics might transform the event horizon into a huge wall of fire, causing anything that came into touch with it to instantly catch fire. As a result of the fact that nothing could ever enter one, black holes inherently lead nowhere.

This defies Einstein's general theory of relativity, however. Since an item would be in free fall and, according to the equivalence principle, that object — or human — would not feel the overwhelming effect of gravity, someone crossing the event horizon shouldn't go through a lot of difficulty. Even if it does not go against Einstein's principle, it would undermine quantum field theory or suggest that information may be lost. It could follow physics principles observed in other parts of the universe.

A black hole of uncertainty

Come forward once again, Hawking. He challenged the concept of an event horizon in a study he released in 2014, asserting that gravitational collapse would instead result in a "apparent horizon."

This horizon would exist for a "period of time" and stop light beams from trying to escape the black hole's center. His new understanding is that apparent horizons momentarily contain matter and energy before releasing them later. This explanation is in line with the predictions of quantum theory, which asserts that information cannot be destroyed and, if true, suggests that anything may escape from a black hole.

Hawking also suggested that black holes may not even exist. He suggested that black holes be reclassified as metastable bound states of the gravitational field. While gravity would compel the visible field to move inward, it would never reach the center and concentrate inside a dense mass, therefore there wouldn't be a singularity.

Even so, whatever is released won't be the same as the data that was ingested. It would be hard to determine what went in by examining what is going out, which has challenges of its own, not the least of which would be for, example, a person who found themselves in such a worrying situation. They would never experience that feeling again!

There is little doubt that this specific conundrum will eat up a lot of research time for a very long period. Hawking's paper on black holes and "soft hair" was published in 2018 and describes how zero-energy particles are left around the event horizon — an idea that suggests information is not lost but captured. Rovelli and Francesca Vidotto recently proposed that a component of dark matter could be formed by remnants of evaporated black holes.

The no-hair theorem, developed by physicist John Archibald Wheeler, claimed that two black holes would be indistinguishable to an observer because none of the unique pseudo-charges associated with particle physics would be preserved. The idea is fascinating, but it has a long way to go before it's recognized as the answer to where black holes go. It would be great if we could learn how to leap into one.