Entanglement And Wormholes

[sanctus]

In short he states that quantum entanglement and wormholes are the same thing.


Now this is interesting:
http://arxiv.org/pdf/1604.02589v2.pdf

Or in popular science terms:https://mic.com/articles/151808/er-epr-einstein-theory-wormholes-science-breakthrough?utm_source=policymicFB&utm_medium=future&utm_campaign=social#.NH0HO4mcc

 

Anyone knows anything about the author?

[A-wal]

I've never understood how what's described by general relativity leads to worm holes. What actually forms these tunnels? Or maybe that's just from scifi. Maybe they're more like portals with no tunnel, so they could be though of as infinite time dilation and length contraction between two points?

 

So is the author is suggesting that quantum entanglement involves time dilation and length contraction? That doesn't seem plausible.

[CraigD]

Anyone knows anything about the author?

I’m not especially good at recognizing names, but I recognize the author of the 24 Apr 2016 preprint you linked “Copenhagen vs Everett, Teleportation, and ER=EPR”. He’s Leonard Susskind, commonly called the “father of string theory”, and perhaps the most recognizable name in that subdiscipline. He’s a pretty old guy, and has done lots of famous work in non-string theory.

 

In short, he’s far from a crank, so I plan to give this paper a good reading. I expect it to be hard.

 

I've never understood how what's described by general relativity leads to worm holes. What actually forms these tunnels?

As I understand it, GR and the attractive-only kind of gravity, wormholes are the same thing as black holes, and, since they don’t connect points in ordinary space, aren’t very tunnel-like at all. In order to get a true (that is traversable) wormhole, you need repulsive gravity. Something that produces repulsive gravity, which is only vaguely suspected may exist, usually goes by the placeholder name “exotic matter”. Suspicious that such stuff can exist come mostly from the Casimir effect, which certainly does exist, leading theorists to conclude that it could be used to produce the repulsive gravity GR requires for a traversable wormhole.

 

Or maybe that's just from scifi. Maybe they're more like portals with no tunnel, so they could be though of as infinite time dilation and length contraction between two points?

Other than GR being a generalization of Special Relativity, based on the principle that gravitational force is equivalent to velocity-producing acceleration, I don’t think SR has much to do with wormholes.

 

From what I’ve read, you would expect the clock of an observer passing through a wormhole to agree with that of observers at either end, so time dilation and the related length contraction doesn’t apply to them.

 

I’m really comparing horses to unicorns here, though, since time dilation is known well to exist, while traversable wormholes, while not purely scifi, are at present pure speculation.

[A-wal]

As I understand it, GR and the attractive-only kind of gravity, wormholes are the same thing as black holes, and, since they don’t connect points in ordinary space, aren’t very tunnel-like at all. In order to get a true (that is traversable) wormhole, you need repulsive gravity. Something that produces repulsive gravity, which is only vaguely suspected may exist, usually goes by the placeholder name “exotic matter”. Suspicious that such stuff can exist come mostly from the Casimir effect, which certainly does exist, leading theorists to conclude that it could be used to produce the repulsive gravity GR requires for a traversable wormhole.

A singularity of negative/repulsive matter creates a white hole. So a warm hole has a black hole entrance and a white hole exit making it one-way? What entangles the supposed negative and positive singularities in the first place? Or is that not how it's supposed to work at all?

[CraigD]

A singularity of negative/repulsive matter creates a white hole. So a warm hole has a black hole entrance and a white hole exit making it one-way?

From all I’ve read and understood, a traversable wormhole could be traversed in either direction with equal ease. My math is too poor to follow the solutions of general relativity field equations that describe a traversable wormhole (and the not-known-to-be-possible repulsive gravity-causing exotic matter they require), but from hard science fiction like Steven Baxter’s 1992 Timelike Infinity and science popularizations like Kip Thorne’s 1994 Black Holes & Time Warps: Einstein's Outrageous Legacy, I get a rough picture of one as a pair of black holes (possibly little, artificial ones) “threaded” with a “shaft” of gravitationally repulsive exotic matter.

 

The term “white hole” is used to describe so many hypothetical objects that it’s practically worthless without defining which meaning is intended. In the 1960s, for instance, some astronomers played with an explanation for quasars as begin the “white hole” radiating energy passed through wormholes from the black hole consuming lots of mass-energy (now most agree that quasars radiate in an ordinary way from vast, hot accretion disk surrounding a galaxy’s central black hole, a region called an active galactic nucleus). Now some cosmologists play with the idea that the big bang may have been a kind of white hole. All these varied uses have in common is that a “white hole” is something that a lot of stuff that got there in a weird way comes out of, and that they have something to do with black holes.

 

It’s important to note that GR-based descriptions of wormholes, and GR in general (no pun intended) require only classical, not quantum, mechanics.

 

(I like how Thorne in BHaTWEOL described the difference between classical and quantum physics, on the level of the emotions of physicists working with them, as one being like “smooth, infinitely divisible marble”, the other “knotty wood”)

 

What entangles the supposed negative and positive singularities in the first place? Or is that not how it's supposed to work at all?

I think what Susskind means by “the ER (meaning Einstein-Rosen bridge, a synonym for wormhole) = EPR (meaning Einstein-Podolsky-Rosen entanglement, an early, skeptical description of quantum entanglement) principle” in his "Copenhagen vs Everett, Teleportation, and ER=EPR" (which is a summary of a 3-seminar lecture he gave this year) is that wormholes are a way to explain how entanglement works. A deep and affirming understanding of the ER=EPR principle might be a bridge between the intuitively sensible, cause-produces-effect feel of classical mechanics, and the “that’s just the way it is” feel of quantum mechanics.

 

The paper’s not as hard as I feared. I got through the first third of it on my short AM bus ride. I recommend that everyone read it. Susskind is a good science communicator.

 

On page 9, he gives a example of “converting” the kind of quantum entanglement most of us have read about (for example, from shining a laser into a BBO crystal to convert a photon into a pair of entangled photons, or doing something more difficult to get entangled electrons) to the something involving black holes: Alice and Bob just create lots of entangled particle pairs, take them far apart, and compress them to create a pair of black holes. Much of his argument for EP=EPR relies on this fungibility, converting from one scenario to another to show that they arise from the same underlying physics.

 

This is deep stuff – I expect I’ll need to read and ruminate for a few days to get a good intuitive feel for it. I love it. :)

[A-wal]

I meant the term white whole as a complete mirror to black holes, not that I believe in white holes. I'm just trying to understand worm holes. I was just thinking that a singularity of negative mass is what would be needed to create that version of a white hole.

 

Can you explain conceptually how two black holes can be linked like that? If it's a tunnel then where in spacetime does that tunnel exist and why can't it be physically felt from the outside? If it's more like a portal then why don't the two black holes occupy the same spacetime from the outside. This feels very much like infinite time dilation and length contraction connecting two points but if that's the case then it would be gradual effect (as an inverse square of the distance), not a bounded tunnel/portal.

 

I don't believe in worm holes because I've never heard a description of them that makes any kind of sense but I'm trying to keep an open mind. I just think a mathematical error probably created a paradox and worm holes were the interpretation.

 

As far as I'm aware neither white holes or worm holes are considered established science so this view shouldn't be in any way controversial.

Edited August 19, 2016 by A-wal

[CraigD]

Can you explain conceptually how two black holes can be linked like that?

The two holes (not all solutions require them to be black holes, or even have mass at all) on the ends of a wormhole are linked by folding the 3-dimensional space they’re in to put them close together. In most illustrations, including the ones in Susskind’s lecture, this is done by drawing space as only 2-D, then folding it like a piece of paper in a 3rd dimension, then poking a hole in it.

If it's a tunnel then where in spacetime does that tunnel exist and why can't it be physically felt from the outside?

The tunnel exists in the extra spatial dimension(s) used for the folding. It can’t be felt from the outside, in the 3-D “sheet of paper”, except at its ends, because the paper isn’t folded that way. I think you could in principle fold it so that the tunnel touches many places, but that this is more complicated, so not usually done.

 

Reading Susskind’s lecture, I realize that the deep idea he’s actually hinting at is that out metaphorical paper really is crumpled into a nearly unimaginably complicated wad, in which entangled particles – which by the ER=EPR principle are connected by “Planckian” (meaning very small) wormholes – are each connected to many others in complex networks, and that the evolution of these networks could resolve the deeply weird paradox that the Copenhagen and Many Worlds interpretations of quantum mechanics fail to, following something along the lines of the Wigner’s Friend thought experiment. The paper raises some interesting, not unknown but not widely known bits of history of Everett, Wheeler, DeWitt, Graham, and how Everett’s Relative State Formulation morphed into the MWI in a way Everett describes as “bullshit”.

 

Deep stuff :thumbs_up

 

When A-wal asked and I offered the explanation

 

I've never understood how what's described by general relativity leads to worm holes. What actually forms these tunnels?

As I understand it, GR and the attractive-only kind of gravity, wormholes are the same thing as black holes, and, since they don’t connect points in ordinary space, aren’t very tunnel-like at all. In order to get a true (that is traversable) wormhole, you need repulsive gravity. Something that produces repulsive gravity, which is only vaguely suspected may exist, usually goes by the placeholder name “exotic matter”.

 

I hadn’t read Susskind’s paper fully, so I fear we turned down a false trail. The equivalent to quantum entanglement wormholes he’s writing about are “classical” ones like Einstein and Rosen wrote about, without exotic matter making them traversable “tunnels” like we see in science fiction (like Carl Sagan’s 1985 novel Contact, which directly provoked a lot of mathematical physics about wormholes, specifically the Morris-Thorne wormhole). Classical wormholes (ERBridges) can’t be traversed, but information from either end can meet in the middle – the interiors of the linked black holes/entangled particles are shared. I don’t fully understand what being hinting at, but believe its that interaction of these particles with un-entangled ones – the ordinary quantum mechanical interactions that underlie the act of measurement works via these 2+ way in, 0 way out ERBs (the proof is left as an exercise for the reader ;) ).

 

On top of the drama of Everett not agreeing with how Wheeler et. al. interpreted his RSF into the MWI, another interesting branch of physics lore this thread led me to is the mathematical physicist Homer G Ellis, who’s credited (by Wikipedia, among others) with written in 1973 the first complete mathematical model of a traversable wormhole, the “Ellis drainhole”. He’s still writing interesting papers, several recent ones published on ArXiv.

 

This is fun stuff! :)

[A-wal]

Thanks for the description but I'm not really talking about that aspect of it.

The two holes (not all solutions require them to be black holes, or even have mass at all) on the ends of a wormhole are linked by folding the 3-dimensional space they’re in to put them close together. In most illustrations, including the ones in Susskind’s lecture, this is done by drawing space as only 2-D, then folding it like a piece of paper in a 3rd dimension, then poking a hole in it.

I understand that but what I don't understand is how you get from general relativity's description of gravitation as objects following straight paths in curved spacetime to two points in spacetime being connected.

 

The tunnel exists in the extra spatial dimension(s) used for the folding. It can’t be felt from the outside, in the 3-D “sheet of paper”, except at its ends, because the paper isn’t folded that way. I think you could in principle fold it so that the tunnel touches many places, but that this is more complicated, so not usually done.

That would require a fifth dimension.

[A-wal]

(the dark evil Stalin/Nazi-like, DMT using, side of the 1℅)

What's wrong with DMT? It opens a door out of our tiny slice of reality to show us what else there is.

 

Current science is interesting but it's only a minuscule fraction of reality.

[Super Polymath]

What's wrong with DMT? It opens a door out of our tiny slice of reality to show us what else there is.

 

Current science is interesting but it's only a minuscule fraction of reality.

I agree about DMT. It is the spirit molecule, but the Peruvian format that works is kept from us common folk.

 

This is off topic, I apologize for this. I'll delete my former comments as I believe they've been rude. I mean well, and I like this thread and the science behind it. :-D

[messy]

the media must be faster than a conductor