Physicists come close to resolving the black hole information paradox (2020)
quantamagazine.orgDr Sabine Hossenfelder explained why this is all just an an illusion:
>What’s going to happen with this new solution? Most likely, someone’s going to find a problem with it, and everyone will continue working on their own solution. Indeed, there’s a good chance that by the time this video appears this has already happened. For me, the real paradox is why they keep doing it. I guess they do it because they have been told so often this is a big problem that they believe if they solve it they’ll be considered geniuses. But of course their colleagues will never agree that they solved the problem to begin with. So by all chances, half a year from now you’ll see another headline claiming that the problem has been solved.
>And that’s why I stopped working on the black hole information loss paradox. Not because it’s unsolvable. But because you can’t solve this problem with mathematics alone, and experiments are not possible, not now and probably not in the next 10000 years.
http://backreaction.blogspot.com/2022/04/i-stopped-working-o...
This sounds quite unreasonably defeatist. That argument (can not be solved without an experiment) can be made for pretty much anything, but it has a few counterexamples in physics, and many more in math and theoretical computer science.
How can that argument be made for pretty much anything?
I thought Sabines point is that the measurements required to confirm the theory aren't possible, so it's largely lots of money and time going into pointless speculation right now - even if you find the right solution you have no means to test it.
Mathematics you can make your own proofs on paper, physics is not the same.
A solution might have predictions for other areas of physics. Predictions for other areas of physics that we _can_ test.
Quanta is great at explaining deeply technical scientific topics like these. They put the effort into making analogies and comparisons for even the most esoteric theoretical constructs like the ones in this article. I can't judge if they're accurate, owing to not being a theoretical physics Ph.D., but it's always an entertaining read.
The prominent statement in the subtitle "physicists have proved that black holes can shed information" really irks me. Proof is just... not how science works. It is a pervasive and damaging understanding of the process of science.
Proof, in the strict logical/mathematical sense, of facts about models is an important component of science (it's a big part of how, among other things, you derive falsifiable predictions from models), and this is strict sense proof of an implication of a model.
(2020)
Clicked this thinking it was about the double slit experiment observer-effect. Maybe that's not exactly a paradox, but I still can't wrap my head around it.
The easiest way to wrap your head around is to:
1. Abandon for a moment the idea that we are special
2. Imagine what the most simplified agent that "experiences" things would look like. For example a simple machine that observed am experiment and reduces it into a simple "do I see interference bands or do I see only one band?" and records it to some simple memory.
3. Let the wave in superposition interact with the machine and compute what happens to the machine now that it is itself entangled with the wave
4. Very hard math
5. The machine is in a superposition state of various state, each observing the wave collapse
> observed am experiment
> Let the wave in superposition interact with the machine
This is the key point right, that an observation cannot be made without a very real, physical, interaction, that necessarily influences the thing being observed?
No, it's even more bind bending: the observation influences the observer!
An eye that isn't influenced by what it sees is usually called “blind”.
Well yes that's technically true but that's not the kind of effect I meant.
After the interaction your become part of the same quantum system and that affects what you can observe next.
When you become a system where the state is a superposition of "electron spin up + you see an electron spin up" and "electron spin down + you see an electron spin down" then you when you observe the electron in spin down you'll always see the electron as spin down because, you guessed it, the "you" in this story is the "you see an electron spin down" you of the superposition of yous
I don't think anyone fully has their head around wave-particle duality. There are many different interpretations and as I understand it none of them (or none of the major ones) are even falsifiable.
My gut says though, that the main problem is probably thinking it is ever possible to be outside the experiment.
> I don't think anyone fully has their head around wave-particle duality.
Other than taking enough physics to get a EE degree, I don't know physics. One explanation I've heard from a physicist appeals to me. He said something like:
All the confusion about wave/particle duality is because we explain physics in terms of intuitions we have in our daily lives. Sometimes the analogy that is most convenient is to use a wave metaphor, and sometimes the best analogy is to use a particle metaphor ... but in both cases it is neither particle nor wave.
I believe that is called super-determinism, but would welcome correction or refinement.
I believe you're right: https://www.youtube.com/watch?v=JnKzt6Xq-w4
I'm at the same level of partial knowledge where I agree with you. My understanding is that everything in the universe interferes with everything else, but we assume, with some justification and empirical success, that the impact of sufficiently distant or indirect effects is negligible. That's demonstrably close to true for systems of a certain small size or complexity, but it doesn't seem remarkable to me that the assumption might fall apart with a wider perspective.
Can you explain what you mean?
When I think of wave-particle duality, I think its just the expression of 2 facts. Matter waves show interference effects. Matter waves are only ever observed in a definite position, never in a superposition.
But position isnt special right? We never observe a superposition of momentum (move at 2 speeds) either. And neither are macroscopic states, we never observed an (1/sqrt(2))(alive + dead) cat either.
So evolution isn't observation and intermediate states aren't real.
MWI and pilot-wave are decent explanations. The effect, by itself, isn't mind bending; its verification is.
> Particle by particle, the information needed to reconstitute your body will reemerge.
No. What might emerge are hydrogen molecules (following quark confinement, free neutron decay, chemistry, etc.). The "information" to "reconstitute" the unfortunate astronaut's body is diffused forever.
Why do people write this stuff?
For that matter, try this wild speculation: Lenny Susskind, "Dear Quibitzers" GR=QM[0], in which he reifys[1] his toy models and carries on as if they were (almost) objective reality.
He's a professor at Stanford. I'm reminded of Pauli's remark, "Your theory is crazy. But is it crazy enough?" It seems that a physicist can say almost anything these days.
[0] https://arxiv.org/abs/1708.03040 [1] https://en.wikipedia.org/wiki/Reification_(fallacy)