Newfound Wormhole Allows Information to Escape Black Holes | Hacker News Reader

Newfound Wormhole Allows Information to Escape Black Holes

quantamagazine.org

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This is the "traversable" part: throw a qubit into black hole A. Measure a particle of its Hawking radiation & transmit the result of the measurement through the external universe to the other black hole B; then use this knowledge to operate on a Hawking particle coming out of black hole B to "reconstruct" the original qubit.

I feel like if I were a pop science writer I would spin this more as a "teleportation" story.

> throw a qubit into black hole A

This would take infinite time (from the POV of the external observer), so I'm unclear how this is supposed to work.

Only in strict GR - when quantum effects are taken into account, the entire black hole will evaporate into Hawking radiation in a finite time.

> Only in strict GR

Even in strict GR, the statement is not correct. See my response upthread.

> This would take infinite time (from the POV of the external observer)

No, that's not correct. What is correct is that, in the idealized case where the hole is eternal (i.e., it never evaporates), it would take an infinite time for the external observer to see the qubit cross the horizon. But the qubit reaches the horizon and crosses it in a finite time.

But we are talking about an external observer - so how is this traversable plan going to work?

It's not, because this is all theoretical. Not a single thing here has ever been proven experimentally. Black holes do not exist, nor does hawking radiation.

[citation needed]

There's no direct proof yet, but we have detected the magnetic fields that theories predict, and of course observe the gravitational effects. The Event Horizon Telescope[0] will probably deliver something more tangible by 2018. [0]http://www.nature.com/news/how-to-hunt-for-a-black-hole-with...

> pov

so, light. which is not the medium used.

I known nothing of quatum shrnanigans, but I am thinking that in terms of protocols :)

Which is a good way to do it. QM is basically the most general protocol possible and most of the math can be derived from assumptions about what can in principle be communicated. For example:

http://www.mdpi.com/1099-4300/19/3/98/htm

This article was an interesting read even though I know close to nothing about quantum mechanics. The part you highlight made me think of Diffie-Hellman key change.

Silly but looking at the "octopus" it's like Hawking radition is SSH connections to the inside of the black hole :-)

You forget the part where the wormholes need to be prepared. First you need to feed the hawking radiation from one black hole into another.

When the call a wormhole "traversable" does this mean that an macroscopic object can actually survive a wormhole intact? Or are the referring to something more along the lines of a sub-atomic particle?

edit: the article eventually starts talking about "qubits" explicitly, so I am assuming this is sub-atomic particles only unless someone knows more.

Even more specifically, it says that which falls into A comes out of B as Hawking radiation. You can then transfer an external message (at the speed of light) between A and B to turn that Hawking radiation into the original object via hand-wavy quantum teleportation. I get the feeling that you'd have to trap _all_ of the relevant, escaping radiation from B to actually reconstruct your object.

Definitely the latter, “traversible” means “in principle”

From what I understand they are describing a mechanism through which information can escape black holes.

The problem with black holes is that a classical black hole would result in loss of information which is a big no no.

The initial proposal for Hawking radiation lacked a mechanism through which information can escape the black hole this wormhole of sorts provides this mechanism.

I’m not entirely sure how different it is to the holographic principle in which the information is encoded on the surface of the black hole which allowed the Hawking radiation to “pick up” a bit of information on its way back sort of like light projector.

> From what I understand they are describing a mechanism through which information can escape black holes.

A hypothesized mechanism. None of this has any experimental confirmation, nor is any likely any time soon. It's an interesting theoretical advance, but that's all.

Yes everything here is theoretical including the Hawking radiation itself.

> I’m not entirely sure how different it is to the holographic principle in which the information is encoded on the surface of the black hole...

Kind of off topic, but once I learned about the holographic equivalency of black holes, and the idea that our entire universe may be nothing more than a hologram on a 2D surface, it always seemed plausible to me that the expansion of our universe could be thought of as actually an accelerating shrinkage. In other words, if you imagine the universe as a 2D membrane of fixed size, but ever-increasingly complex holographic encoding on the membrane, then the 3D projection of that encoding would appear to be expanding (from the perspective of someone inside the hologram) relative to the fixed membrane size. However, from an outside observer, the 3D projection would appear to be shrinking as the hologram grows more complex.

I realize that this metaphysical idea implies information is being constantly created to fuel the increasing complexity of the hologram. In my mind this is like propogating waves on an enclosed plane like an imperfect sphere, continually interfering with themselves on the return trip, gerating exponentially more wavelets at each encounter.

Are there any theories out there like this (i.e. our universe expanding or shrinking, depending upon the perspecing of the observer)? I've always been curious.

I'm not attempting to claim subject matter expertise but I would like to raise two points.

1) If your hypothesis assumes that information is actually created then it's either wrong (as it's contradictory to our current understanding of physics) or you need to describe a mechanism through which information can be created or added to our universe from an external source. You might be able to contrive a mechanism through which the expansion is simply a byproduct of the every increasing entropy but I don't understand why would it then appear to an observer that the total area of the hologram is shrinking.

A hologram cannot hold more data without expanding it's surface area (adding additional dimensions to a hologram to make it more complex would also impact "our universe" in this analogy), the popular science "formula" for the total information that can be stored in a hologram is basically it's information density (which has a limit) x it's surface area. Now you can say that our universe is encoded in a hologram that hasn't reached the Bekenstein bound so the information density of it can increase but again that would require some sort of a mechanism that I'm not aware off, but I'm not an expert or even particularly knowledgeable in this matter to be able to have a truly constructive discussion.

2) A theory that describes the "true nature" of the universe is useless unless it gives new predictions or new tools to explain existing phenomenon. It doesn't really matter if our universe is encoded on the surface of a black hole in another universe, is one of many bubbles of the foam that makes up the multiverse or is it one of many marbles in the marble bag of some alien teenagers from the trans dimensional universe five-nine-alpha.

Good stuff. Thanks for the thoughtful reply. I do think that if the driver for our universe's accelerated expansion were understood to be a matter of perceiveing an effect of the activity on the holographic membrane rather than 'a push' from some yet do be discovered energy source in a non-holographic model, that could open the door to new discovery. Regardless, I think I'm going to stick with the 59A Marble Bag hypothesis and crawl back into my mechanical engineering design site where I belong.

It's important to understand when physicists talk about the theoretical perfect preservation of information in these contexts, it's like... if you could pause the universe and evaluate every particle, every "thing," all at once you could understand where it all came from and know the previous step and from there the previous step and so on infinitely until the "beginning." The idea being that the entire universe's "state" if you will, is derived continuously from its origin, observably.

It's not about whether you as a human could use a black hole as a cosmic... blackboard.

In an entirely mechanistic nonprobabilistic universe, where state C always follows state B, which always follows state A, etc, then if State X ever equals a prior state, say state B, then the universe enters into an infinite loop. A-B-C-D-X-C-D-X...

That's true, but why is it important?

No big bang, no great crunch, Pantera will have more live shows, etc.

As constructed, it is true. But important? Probably not. Even if the universe was total mechanistic, and should be described as a series of discrete states, the probability of ever entering into identical states would be very near zero, except perhaps in some hypercooled state, or something. am not sure that the laws o thermodynamics would even allow that to happen. But I am no physicist..just a dude, who had a thought.

I think most people wouldn't assume a discrete nature of finite state changes as I take from your comment. A cauchy series for example orbits around a limit point.

Fixed states would be enumerated by Natural numbers that are extensionally defined in set theory for example as

   ( 0 ), [ 1, ( 0 ) ], { 2, [ 1, ( 0 ) ] }, ...

Be 0 the empty set, then this is the Von Neumann construction [1]. This is a very tangible notion that represents a total order. So a state is a sequence of inputs and the natural number represents the recursion depth of the successor funtion (succ). But the complexity of that function alone is less than NP, so it would not have arbitrary consequences, so cycles would be the least of a problem. A P-adic numbers field Q_p on the other hand isn't even well ordered. Or Pi, it contains many different fixed length versions of itself in its remainder.

[1] https://en.wikipedia.org/wiki/Natural_number#Von_Neumann_con...

[2] https://en.wikipedia.org/wiki/Mealy_machine

All of which could be straightforward if the universe is indeed a simulation.

Being a simulation has nothing to do with it. It's previous states are knowable from current states.

I believe Susskind was of the opinion that that one could create an ER=EPR wormhole between two entangled black holes, and that jumping into one of the black holes would allow one to access the wormhole, and meet someone "in the middle" who had jumped into the other wormhole, but it would be impossible after that for either person to get out of the wormhole.

Additionally, because the entropy of the wormhole increases with time, the "length" of the wormhole seems to also increase with time.

A black hole is a fast scrambler and very quickly comes to thermal equilibrium (max entropy). However, the complexity continues to increase long after thermal equilibrium, and that's what is thought to be analogous to the length of the wormhole growing (at the speed of light, no less).

[0]: https://www.youtube.com/watch?v=9crggox5rbc&t=1202s

Doesn't "Newfound Wormhole Allows Information to Escape Black Holes" rather strain the meaning of "found"? I get that it's "found" in a mathematical sense. But in a physical sense, it's more like "possible".

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