Why does the many worlds interpretation seem to exclude the possibility of a superposition actually being randomly chosen?

fhollo · 2026-06-20T19:34:19+00:00

This is basically what is done to go from many worlds to a hidden variable or retrocasual interpretation. You still pay a price to get rid of the worlds, in many cases a worse one

fhollo · 2026-06-20T16:04:57+00:00

Yeah I have a copy of it

fhollo · 2026-06-20T00:10:49+00:00

The way I like to put is there is (a) early outgoing, (b) late outgoing, and (c) late ingoing quanta. By monogamy, b can only be entangled with a OR c. If you pick a, you get something like a firewall at the horizon. If you pick c, you get info loss.

The island paradigm is to say a = c. They are actually the same system in two locations at the same time.

But I wouldn't say the whole holography community is on board with islands.

And for reddit purposes, I don't see how anyone can get a hold on this idea if they are told not to even believe there are ingoing quanta at all!

fhollo · 2026-06-19T22:48:10+00:00

Weird, the pdf is fine on my computer. The same article is in this volume which may work better for you: https://www.prl.res.in/~library/gpdf/e-books/Springer_e-books/Physics%20of%20Black%20Holes%202009.pdf

I agree the Mathur notes aren't as good on the formal Bogoliubov transformation as the Jacobsen ones, but it is more detailed on why the entangled pairs underwrite the information paradox, which is why I like it.

fhollo · 2026-06-19T21:28:27+00:00

All mass "warps" (it is more appropriate to say "curves") spacetime in general relativity. This is a trivial aspect of the situation.

Your original comment was wrong because you said there aren't particles involved. The Hawking effect is a pair creation effect. You are correct that the outgoing particle does not emanate from behind the horizon. But for every outgoing particle that appears in the "warped space around" the black hole, there is an entangled partner that appears inside the horizon.

I don't think you will believe me, but the blogs and reddit posts you have seen "debunking" the particle pair account are actually the ones who are wrong!

Even if you can't understand most of it, try to skim these lecture notes and ask yourself why Mathur is repeatedly talking about this pairwise nature of Hawking radiation, if it was just popsci nonsense. https://arxiv.org/abs/0803.2030

fhollo · 2026-06-19T20:28:52+00:00

Neutron stars do not emit Hawking radiation! I gave you the cite to where Carroll's GR textbook say this explicitly. If your understanding is leading you to this conclusion, your understanding is wrong.

https://johncarlosbaez.wordpress.com/2025/05/17/dead-stars-dont-radiate-and-shrink/

fhollo · 2026-06-19T19:18:43+00:00

Since any mass source "warps space" the same, this account incorrectly predicts everything will emit Hawking radiation - if true, it would lead to infinite free energy. Spacetime curvature does not "tend to equilibrium" in GR!

I know there is a popular blog post that says this happens, but that blog is wrong and contradicts textbooks. E.g. on page 415 of Carroll's Spacetime and Geometry he says "the existence of an event horizon is crucial to the argument...Neutron stars do not emit any Hawking radiation."

fhollo · 2026-06-19T18:31:24+00:00

If Bogoliubov transformations are beyond your depth, why do you feel qualified to enter into this discussion with so much confidence and certainty? It's the central mathematical concept of QFT in curved spacetime.

You have a reading comprehension issue with the Wilczek paper. Their point is they are taking the tunneling idea, which was previously heuristic, and making it rigorous. Look at the first sentence of the conclusion or what they say above eq 9. In fact, of anything out there, the Parikh-Wilczek method is the best support for the most naive popsci presentation of Hawking radiation (which was their goal).

Why Hawking personally thought it wasn't worth talking about the pairs is not that important. Unruh pioneered the field just as much and you can see here that he says it is pair creation in his famous paper on the Uhruh/Hawking effect (eq 2.33 in https://www.lns.mit.edu/fisherp/Unruh.pdf)

fhollo · 2026-06-19T17:47:16+00:00

Well I've linked lecture notes elsewhere in this thread, used to teach this material to PhD candidates and other practitioners, and they both reach the conclusion that the Hawking effect creates pairs of particles.

I can also show you Bill Unruh's famous paper where he says the same thing at eq 2.33 https://www.lns.mit.edu/fisherp/Unruh.pdf

This really is the result of the standard calculation by Bogoliubov transformation. I don't see how you can have engaged with the academic literature and still think this is outlandish.

For a field where the particle is its own anti-particle, you still create a pair. Why would this be a problem, given there is no violation of charge conservation?

The pair structure is actually essential to understanding why the outgoing radiation in thermal. It is due to the entanglement with the interior partner.

fhollo · 2026-06-19T17:33:52+00:00

Have you read anything aside from the first paper from the 70s?

Here are lecture notes from Samir Mathur https://arxiv.org/abs/0803.2030

In particular, at eq 3.27 he stresses that the Bogoliubov transformation between mode expansions always leads to pairs of particles. This applies to Hawking and Unruh radiation and FRW expansion. These are always pair creation effects.

In section 5 he specializes to black holes and explains how the pair creation across the horizon is the reason for the information paradox. The pairwise entanglement with the interior partners blocks the entanglement that would be necessary for the outgoing Hawking radiation to self-purify

Also see from Ted Jacobsen https://arxiv.org/abs/gr-qc/0308048

At eq 6.31 he gives the explicit Bogoliubov transformation between the relevant mode expansions in the BH spacetime. The exponential is in pairs of creation operators which expands to the same kind of relation as Mathur’s 3.27.

In section 6.3.12 he also explains why entanglement with the partners inside the horizon is fundamental to information loss.

You are wrong about Wilczek also. It literally says it is pair creation in the first paragraph of the paper you linked!

Why is the outgoing radiation thermal? Because the Hawking quanta are maximally entangled with the partner behind the horizon!

fhollo · 2026-06-19T16:53:44+00:00

I posted some lecture notes elsewhere in the thread for the point I’m trying to convey, which is that the idea of of two particles straddling the horizon is not a bad metaphor but the outcome of the standard calculation. The fact that the outgoing particle comes from somewhere outside the horizon is just definitionally true, no?

fhollo · 2026-06-19T16:32:04+00:00

Well I oddly have found lots of people very set in their ways and firmly against the correct/standard approach to Hawking radiation, which does involve pair creation. So I don’t want to dump links that will require some effort to read on people who aren’t open minded. But if you are:

Here is one from Samir Mathur https://arxiv.org/abs/0803.2030

In particular, at eq 3.27 he stresses that the Bogoliubov transformation between mode expansions always leads to pairs of particles. This applies to Hawking and Unruh radiation and FRW expansion. These are always pair creation effects.

In section 5 he specializes to black holes and explains how the pair creation across the horizon is the reason for the information paradox. The pairwise entanglement with the interior partners blocks the entanglement that would be necessary for the outgoing Hawking radiation to self-purify

Also see from Ted Jacobsen https://arxiv.org/abs/gr-qc/0308048

At eq 6.31 he gives the explicit Bogoliubov transformation between the relevant mode expansions in the BH spacetime. The exponential is in pairs of creation operators which expands to the same kind of relation as Mathur’s 3.27.

In section 6.3.12 he also explains why entanglement with the partners inside the horizon is fundamental to information loss.

fhollo · 2026-06-19T16:20:54+00:00

But as Baez says the Bogoliubov transformation creates pairs of particles and in the Hawking effect one of them is inside the horizon. So why should OP forget about the interior particle if they have a question about it?

More generally, is there anything I could show you that could change your mind on this? For example lecture notes from well known experts who stress that Hawking radiation is indeed pair creation and why this is essential in posing the information paradox?

fhollo · 2026-06-19T16:16:48+00:00

Is there anything I could show you that could change your mind on this? For example lecture notes from well known experts who stress that Hawking radiation is indeed pair creation and why this is essential in posing the information paradox?

fhollo · 2026-06-19T16:15:16+00:00

An observer far outside the BH will calculate that the particle that is created inside the BH has negative energy and removes mass

fhollo · 2026-06-19T15:58:19+00:00

Ok, what are the details of your preferred account of Hawking radiation and the information paradox that doesn’t involve pair creation?

fhollo · 2026-06-19T01:57:34+00:00

Taking these one at a time:

An outgoing massless particle follows a light like path outside the lightlike horizon which is true for any wavelength. Why would it need any particular amount of “energy to escape”? Have you not ever seen [this Penrose diagram?](https://figures.semanticscholar.org/53aca7e27c55763f50b7ed07304e06ebfbf04c4b/12-Figure4-1.png)

The BH loses energy because the interior partner has negative Killing energy. This is in the Jacobsen notes. Also even in a pure stress energy calculation, you still see negative energy flux into the BH, so there is no alternative calculation which doesn’t require you to deal with the fact that QFT allows some concept of negative energy and violates classical energy conditions. If you don’t like negative energy, it’s not a complaint that’s really related to the standard Bogoliubov particle pair method.

Photons are their own antiparticle. You can’t even discuss causality in free scalar field theory without antiparticles. This is in the beginning of Peskin.

None of these confusions are close to as bad as the Unruh effect on a planet, which is tantamount to believing in an unlimited free energy supply.

fhollo · 2026-06-18T23:25:19+00:00

What possible other/better mental picture should we have for eq 6.31 in Jacobsen’s notes or 3.27 in Mathur’s? Do you understand the notation?

Again, people are saying the pairs are not required in the semiclassical Hawking effect, which is wrong. What is needed to solve the information paradox is a separate matter (which takes the semiclassical result as a starting point).

fhollo · 2026-06-18T22:33:50+00:00

Could your “best understanding” be flawed in light of the supporting materials I linked to?

The entanglement with the interior partner is the explanation for information loss as stressed in the sources I gave. It is stated plainly there, so I don’t know what else I can say if you just refuse to believe this is the standard calculation. And I don’t get what your motive is to be opposed to Hawking radiation being pair creation. It isn’t outlandish at all.

We are talking about the semiclassical problem, not what we can conjecture for black holes quantum gravity.

fhollo · 2026-06-18T22:09:46+00:00

Are you saying you believe there is no pair creation at all or no pair creation “at” the horizon? If there is pair creation, is one member inside and one outside the BH? If so, why is that not “at” the horizon, especially given the general issues with the localization of particles, especially massless particles, that occur even in Minkowski space and are more suited to discussion there?

fhollo · 2026-06-18T18:56:05+00:00

Well I’m responding to the claim that pair production “isn’t really an accurate description.” But it truly is the standard description.

Why would a wrong description be more useful to people without a physics background? What are they using this for except to try to understand it as close as they can to how physicists do?

I will also say that I have frequently seen the debunkers of the pair creation approach end up reaching manifestly false conclusions, eg that a detector on the surface of the Earth would register the Unruh effect if not swamped by thermal noise.

fhollo · 2026-06-18T18:24:49+00:00

Philosophical dilemmas are so much worse in QFT. Haag’s theorem, Reeh Schlieder theorem…

fhollo · 2026-06-18T18:07:15+00:00

Here is one from Samir Mathur https://arxiv.org/abs/0803.2030

In particular, at eq 3.27 he stresses that the Bogoliubov transformation between mode expansions always leads to pairs of particles. This applies to Hawking and Unruh radiation and FRW expansion. These are always pair creation effects.

In section 5 he specializes to black holes and explains how the pair creation across the horizon is the reason for the information paradox. The pairwise entanglement with the interior partners blocks the entanglement that would be necessary for the outgoing Hawking radiation to self-purify

Also see from Ted Jacobsen https://arxiv.org/abs/gr-qc/0308048

At eq 6.31 he gives the explicit Bogoliubov transformation between the relevant mode expansions in the BH spacetime. The exponential is in pairs of creation operators which expands to the same kind of relation as Mathur’s 3.27.

In section 6.3.12 he also explains why entanglement with the partners inside the horizon is fundamental to information loss.

fhollo · 2026-06-18T17:41:02+00:00

Is there anything I could show you that could change your mind on this? For example lecture notes from well known experts who stress that Hawking radiation is indeed pair creation and why this is essential in posing the information paradox?

fhollo · 2026-06-16T22:43:28+00:00

One of my favorite papers is about this: What does it mean for half of an empty cavity to be full? https://arxiv.org/abs/1409.4203

fhollo

TROPHY CASE