Skip to comments.The Most Famous Paradox in Physics Nears Its End
Posted on 10/30/2020 3:38:08 AM PDT by Candor7
......................................And that led to a remarkable twist in the story. Because the radiation is highly entangled with the black hole it came from, the quantum computer, too, becomes highly entangled with the hole. Within the simulation, the entanglement translates into a geometric link between the simulated black hole and the original. Put simply, the two are connected by a wormhole. Theres the physical black hole and then theres the simulated one in the quantum computer, and there can be a replica wormhole connecting those, said Douglas Stanford, a theoretical physicist at Stanford and a member of the West Coast team. This idea is an example of a proposal by Maldacena and Leonard Susskind of Stanford in 2013 that quantum entanglement can be thought of as a wormhole. The wormhole, in turn, provides a secret tunnel through which information can escape the interior.
Theorists have been intensely debating how literally to take all these wormholes. The wormholes are so deeply buried in the equations that their connection to reality seems tenuous, yet they do have tangible consequences. Its hard to answer whats physical and whats unphysical, said Raghu Mahajan, a physicist at Stanford, because theres something clearly right about these wormholes.
But rather than think of the wormholes as actual portals sitting out there in the universe, Mahajan and others speculate that they are a sign of new, nonlocal physics. By connecting two distant locations, wormholes allow occurrences at one place to affect a distant place directly, without a particle, force or other influence having to cross the intervening distance making this an instance of what physicists call nonlocality. They seem to suggest that you have nonlocal effects that come in, Almheiri said. In the black hole calculations, the island and radiation are one system seen in two places, which amounts to a failure of the concept of place. Weve always known that some kind of nonlocal effects have to be involved in gravity, and this is one of them, Mahajan said. Things you thought were independent are not really independent.
At first glance, this is very surprising. Einstein constructed general relativity with the express purpose of eliminating nonlocality from physics. Gravity does not reach out across space instantly. It has to propagate from one place to another at finite speed, like any other interaction in nature. But over the decades it has dawned on physicists that the symmetries on which relativity is based create a new breed of nonlocal effects.
This past February, Marolf and Henry Maxfield, also at Santa Barbara, studied the nonlocality implied by the new black hole calculations. They found that the symmetries of relativity have even more extensive effects than commonly supposed, which may give space-time the hall-of-mirrors quality seen in the black hole analyses.
All this reinforces many physicists hunch that space-time is not the root level of nature, but instead emerges from some underlying mechanism that is not spatial or temporal. To many, that was the main lesson of the AdS/CFT duality. The new calculations say much the same thing, but without committing to the duality or to string theory. Wormholes crop up because they are the only language the path integral can use to convey that space is breaking down. They are geometrys way of saying the universe is ultimately nongeometric. The End of the Beginning
Physicists not involved in the work, or even in string theory, say they are impressed, if duly skeptical. Hats off to them, since those calculations are highly nontrivial, said Daniele Oriti of the Ludwig Maximilian University of Munich.
But some feel uneasy about the tottering pile of idealizations used in the analysis, such as the restriction of the universe to less than three spatial dimensions. The previous wave of excitement over the path integral in the 80s, driven by Hawkings work, fizzled out in part because theorists were unnerved by the accumulation of approximations. Are todays physicists falling into the same trap? I see people make the same hand-waving arguments that were made 30 years ago, said Renate Loll of Radboud University in the Netherlands, an expert on the gravitational path integral. She has argued that wormholes need to be expressly forbidden if the integral is to give sensible results.
Skeptics also worry that the authors have overinterpreted the replica trick. In supposing that replicas can be connected gravitationally, the authors go beyond past invocations of the maneuver. They are postulating that all geometries connecting different replicas are allowed, but its not clear how that fits into the framework of quantum rules, said Steve Giddings of Santa Barbara.
Given the uncertainties of the calculation, some are unconvinced that a solution is available within semiclassical theory. Theres no good choice if you restrict to quantum mechanics and gravity, Warner said. He has championed models in which stringy effects prevent black holes from forming in the first place. But the upshot is broadly similar: Space-time undergoes a phase transition to a very different structure. Related:
Hologram Within a Hologram Hints at Fate of Black Holes The Fuzzball Fix for a Black Hole Paradox Wormholes Reveal a Way to Manipulate Black Hole Information in the Lab Wormholes Untangle a Black Hole Paradox
Skepticism is warranted if for no other reason than because the recent work is complicated and raw. It will take time for physicists to digest it and either find a fatal flaw in the arguments or become convinced that they work. After all, even the physicists behind the efforts didnt expect to resolve the information paradox without a full quantum theory of gravity. Indeed, they thought the paradox was their fulcrum for prying out that more detailed theory. If you had asked me two years ago, I would have said: The Page curve thats a long way away, Engelhardt said. Were going to need some kind of [deeper] understanding of quantum gravity.
But assuming that the new calculations stand up to scrutiny, do they in fact close the door on the black hole information paradox? The recent work shows exactly how to calculate the Page curve, which in turn reveals that information gets out of the black hole. So it would seem as though the information paradox has been overcome. The theory of black holes no longer contains a logical contradiction that makes it paradoxical.
But in terms of making sense of black holes, this is at most the end of the beginning. Theorists still havent mapped the step-by-step process whereby information gets out. We now can compute the Page curve, and I dont know why, said Raphael Bousso at Berkeley. To astronauts who ask whether they can get out of a black hole, physicists can answer, Sure! But if the astronauts ask how to do it, the disquieting reply will be: No clue.
BKMK for later when the coffee kicks in.
Nice OP, thanks!
Black hole anti matters.
To wit: any entanglement or wormhole could nullify the validity of the data on either end as the portal, be it virtual or physical, is bi-, or even omni-, directional based on the number of entanglements. Therefore, the potention for data loss or corruption becomes unknowable at our point of the interface. Since when does supposition provide any base for valid results. My hair ison fire so your toes are green. What nonsense.
Why da Hole gots to be Black you rasis ?
I don’t know anything about the physics of this, but there is an article evaluating the movie Interstellar, and the theory was sound. They also spent time determining what a black hole would look like and it looks like the picture above.
If information gets out of a black hole, why doesn’t it get out of the FBI? Have they been swallowed by some sort of super ultra black hole or perhaps by a super worm hole, aka a snake hole?
That’s where galaxies go to die.
I feel strangely connected to that article, but am afraid to examine why lest the cat dies and my connection to reality is severed.
Looks to me it is work for a mathematician and not a physicist.
Mathematics are all about solving paradoxes between two theories or results, in the abstract.
I have zero confidence in today’s physicists in advancing physics theory because the mother topic of such is Philosophy. Back in the days of Einstein and especially before, the scientists like Newton were philosophers and they based their science on philosophy. Now we do the opposite, which is absurd. The result is politization of science and a high difficulty in parsing real science from BSers writing bobo articles for fund raising.
Kitties are more focused on string theory!
Wormholes exist, but only at the hearts of gas giant planets and their very existence is zealously guarded by the Dwellers who live in the gas giants.
I want to understand, but why?
They also spent time determining what a black hole would look like and it looks like the picture above.
How would they know what one looks like since the construct has never actually been seen by anyone’s naked eye ball?
Why can I see the square root of 2 if I can’t define it. That is the biggest paradox.
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