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Experiments spell doom for physical-collapse explanation of quantum weirdness

quantamagazine.org

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Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#21

Post by Comevius »

ericmay wrote: post #14
wongarsu wrote: post #12

Earlier quoted context omitted.

To be fair, the Copenhagen interpretation doesn't really fit today's world view. We have largely moved away from viewing humans or "consciousness" as something special, so the notion that an observer collapses the wave function just seems weird now. "Many worlds" or "the wave function never collapses, you are in a superposition" both make much more sense with how we currently view the world

I’d say a good heuristic would be to include all mammals in any theory about consciousness, wave function collapse, quantum consciousness, etc. and then see if the theory still holds up. If it does, you are probably on to something. I think scientifically we will look back on “humans are uniquely conscious” as a categorical differentiation instead of a gradient with other mammals to be as absurd as believing the eart…

No interpretation of quantum physics proposed by scientists ever required a conscious observer, that's more of a misinterpretation of what an observer is. It's an interaction, not a person or animal.

As for the theory of consciousness, of course we are not special, it's information-processing, and it looks like thermodynamics is responsible for the emergence of information-processing structures.

https://arxiv.org/abs/1203.3271

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#22

Post by im3w1l »

rocqua wrote: post #19
im3w1l wrote: post #5

In true collapse-of-the-gaps style, what if collapse happens when an entangled system becomes so large that the edges of it are outside of each others event horizons due to cosmic inflation?

Why would that force collapse? I would almost expect that the lack of communication over those distances forces _more_ uncertainty (i.e. a wider probability distribution) rather than less uncertainty.

It's kind of a joke, which is what I meant by -of-the-gaps. If two particles are outside of each others event horizons, they can't communicate so you can't tell whether they are entangled (AA or BB) or whether the system has collapsed into say AA.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#23

Post by andrewgleave »

dzdt wrote: post #4

There is an often-repeated statement that different quantum mechanical theories are equivalent. This is an over-simplification. Is wave function collapse is a real thing or just an approximation of what happens when a large system is entangled? Some smart people have tried to make theories where wave function collapse is a real thing. These new experiments are working to rule out those ideas. My feeling is that Evere…

The Logic of Experimental Tests, Particularly of Everettian Quantum Theory:

https://arxiv.org/pdf/1508.02048.pdf

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#24

Post by criddell »

dzdt wrote: post #4

There is an often-repeated statement that different quantum mechanical theories are equivalent. This is an over-simplification. Is wave function collapse is a real thing or just an approximation of what happens when a large system is entangled? Some smart people have tried to make theories where wave function collapse is a real thing. These new experiments are working to rule out those ideas. My feeling is that Evere…

> My feeling is that Everett's "many worlds" interpretation is the clear favorite

But what are the worlds?

My feeling is that Max Tegmark has it right. Everything is mathematics.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#25

Post by hotpotamus »

ThalesX wrote: post #6
Comevius wrote: post #3

Looking out for quantum consciousness in articles about quantum physics would be a good drinking game, though here it is handled with a proper amount of scepticism. The pressure is enormous for writers to include mumbo-jumbo, because people click on these articles expecting to find out that it's possible to alter the Universe with psyhic abilities, which is how quantum physics is represented in social media, especial…

Having been passionate about this for awhile, I have a layman’s surface overview of the state of physics, or I like to believe so. It amused me to no end when my elderly aunt came to ask me for a tl;dr; on Quantum Physics. She stopped me shortly asking how she can control the universe with her mind. I tried to explain a bit about the famous interpretation (Copenhagen, not Von Neumann–Wigner) but she would have none o…

I don't really understand much of quantum physics - I'd say as much as someone with a passing interest in chemistry would need to (and that's pretty focused on what groups of electrons get up to), but every once in awhile I'll read about the actual problems and experiments that the old Nobel laureates got up to and all of a sudden something will fall into place. A big key was reading about the ultraviolet catastrophe and how Max Planck basically just played around with equations and sort of hit on quantizing energy levels and almost accidentally invented quantum mechanics. If my education had just been a history of all the discoveries in physics from the end 19th to mid 20th centuries (and to be fair to my education that was mixed in a bit), I think I would have been served a lot better, but I also acknowledge that could be down to my individual way of learning.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#26

Post by gus_massa »

im3w1l wrote: post #5

In true collapse-of-the-gaps style, what if collapse happens when an entangled system becomes so large that the edges of it are outside of each others event horizons due to cosmic inflation?

If you have only one particle of the entangled pair, you can't do any experiment to check if they pair is still entangled or someone else has done something to the other particle and broke the entanglement. Someone else is not necessarily a person. May be a device or just a brick.

In a common case, when you measure your particle you get 50% "yes" and 50% "no". So if you have a stream of particles that are one half of an entangled pair, you just get a random sequence.

It doesn't matter if the other half is still flying happily in vacuum, got into a detector like the one you have, or it just hit a wall. You just get a random sequence. Otherwise, it could be used to build a FTL "walkie talkie".

If you later can talk with someone in the other side that measured the other half of the pairs, then both of you can compare notes and notice that the two random sequences are equal or oposite or something in between according to which experiment each of you have done.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#27

Post by gus_massa »

pfortuny wrote: post #17
bowsamic wrote: post #7

Earlier quoted context omitted.

I have a PhD in theoretical quantum optics and I can assure you that it absolutely was (and still is) a mainstream explanation EDIT: I misread the article, I thought it was about whether collapse occurs in general, not about physical explanations for collapse

Yep: the article seems to say "there is no collapse" (in the title) but then it turns out to say "collapse as explained by these models may not be". Two very different things. I was caught as you by the title.

I was initially confused too.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#28

Post by snowwrestler »

Comevius wrote: post #21
ericmay wrote: post #14

Earlier quoted context omitted.

I’d say a good heuristic would be to include all mammals in any theory about consciousness, wave function collapse, quantum consciousness, etc. and then see if the theory still holds up. If it does, you are probably on to something. I think scientifically we will look back on “humans are uniquely conscious” as a categorical differentiation instead of a gradient with other mammals to be as absurd as believing the eart…

No interpretation of quantum physics proposed by scientists ever required a conscious observer, that's more of a misinterpretation of what an observer is. It's an interaction, not a person or animal. As for the theory of consciousness, of course we are not special, it's information-processing, and it looks like thermodynamics is responsible for the emergence of information-processing structures. https://arxiv.org/abs…

A mental trick that helped me understand the concept of “an observer” in particle physics is to imagine it like playing billiards in a pitch black room.

In normal human-scale billiards, there are immense numbers of photons flying around bouncing off everything. The photon interactions are far too small to affect the path of a moving billiard ball, but we can detect them easily with our eyes. So we can use photons to passively observe the balls rolling around.

But when you’re trying to observe a photon itself… there are no tiny photon-equivalents flying around. It’s like playing billiards in pitch black: the only way to know which direction a ball is rolling is to touch it. And you can’t touch a rolling billiard ball without changing its path somehow. Likewise, you can’t “observe” a single photon without interacting with it in some way.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#29

Post by spywaregorilla »

Comevius wrote: post #16
wongarsu wrote: post #12

Earlier quoted context omitted.

To be fair, the Copenhagen interpretation doesn't really fit today's world view. We have largely moved away from viewing humans or "consciousness" as something special, so the notion that an observer collapses the wave function just seems weird now. "Many worlds" or "the wave function never collapses, you are in a superposition" both make much more sense with how we currently view the world

The Copenhagen interpretation never defined an observer that way. It's a non-interpretation basically, just shut up and calculate, which is still the most widely accepted approach among scientists, since there are no other falsifiable interpretations.

I'm reminded of learning about the grandfather paradox as a kid. I recall hearing shit about scientists saying if you were to travel back in time, you would be compelled by a universal force to do things that don't alter the future and create a paradox. Even as a kid, that sounded so idiotic. In retrospect it was almost certainly the reporting that was wrong.

Re: Experiments spell doom for physical-collapse explanation of quantum weirdness

#30

Post by spywaregorilla »

criddell wrote: post #24
dzdt wrote: post #4

There is an often-repeated statement that different quantum mechanical theories are equivalent. This is an over-simplification. Is wave function collapse is a real thing or just an approximation of what happens when a large system is entangled? Some smart people have tried to make theories where wave function collapse is a real thing. These new experiments are working to rule out those ideas. My feeling is that Evere…

> My feeling is that Everett's "many worlds" interpretation is the clear favorite But what are the worlds? My feeling is that Max Tegmark has it right. Everything is mathematics.

Mildly different wobbled electrons.
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