Quantum-classical correspondence?

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In summary, the conversation discusses the question of why scientists investigate the quantum-classical correspondence and whether it can help solve problems in quantum mechanics. The participants also share their thoughts on the nature of this correspondence and different approaches to understanding it. They also mention potential applications of a correct interpretation of quantum mechanics in solving problems such as quantizing gravity and non-perturbative calculations in QCD.
  • #36
Fra said:
In the restriced sense we are talking about - absolutely. The laws of nature does not IMO distinguish in a fundamental sense, a general physical system, from biological systems.

If you think that "observer" means human, then clearly CI is baloney. But this is not what I have in mind. Observer has a wider meaning, having no relation per see to the human brain.

I'll comment more later...on my way out.

/Fredrik

I look at it the other way round. Its not that the laws of nature treat biology different than non biological matter, its that biology has emergent properties not available to non living material, hence biology has a distinct advantage and very differential relationship with the physical reality.

You seem to claim that reality exists without observers/definers. I reckon it does not.

No I don't think observer/definer has to be human. It could be any biology, including very primitive forms of life anywhere in the universe. I'm not sure where the dividing line is between what constitutes an observer/definer but i don't accept inanmiate matter has the same relationship with the universe as do living beings.

I think qm tells us this quite clearly.
 
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  • #37
Coldcall said:
You seem to claim that reality exists without observers/definers.

I definitely do not, which should be clear from most of my posts on this.
The you must have misunderstood me totally.

Coldcall said:
biology has emergent properties not available to non living material

Yes it has. This is fully in line with my view of emergent evolving law. I don't object to this. But this emergent process, is not unique to biology. The evolutonary process has IMO a common trait and logic. The origin of spieces and the origin of physical law, are somehow a similar problem, but applied at two different complexity scales.

It's exactly to understand how physical law, and the process whereby it evolves, does scale with the complexity of the observer, that I'm suggesting is the right focus.

In that sense, an observer could be anything from a quark, to a human, to a galaxy.

/Fredrik
 
  • #38
mn4j said:
Example: double slit diffraction with electrons. How does MWI explain the build-up of the pattern spec by spec. Unless the interpretation can explain what is ACTUALLY happening, it has not solved the measurement problem.

Can any MWI'er explain it?

In MWI there are no particles, just waves.
So there is absolutely no surprise that there is an interference pattern
The the wave hits the detector and it after a decoherence with it you see a tiy spot. Multiple branches are created in the Universe, in each universe spot is in a different place.
 
  • #39
Fredrik,

"definitely do not, which should be clear from most of my posts on this.
The you must have misunderstood me totally"


I apologise if i have misunderstood you. So would i be right in thinking that you feel an observer/definer is necessary for reality to occur? And you include an inanimate particle as an observer/definer?

"Yes it has. This is fully in line with my view of emergent evolving law. I don't object to this. But this emergent process, is not unique to biology. The evolutonary process has IMO a common trait and logic. The origin of spieces and the origin of physical law, are somehow a similar problem, but applied at two different complexity scales."

I agree, emergence acts upon all matter in the universe, living and non-living. And the more complex of that matter goes on to become primitive biology. But there is still an "experiential" distinction between the two levels of emergence. Yes we can see very complex non-living systems but they lack certain abilities including awareness, or the ability to self-reference and measure or define their environment.

If you feel so strongly about the veracity of emergent laws (and i join with you in that thinking) then why would it not follow that the capacity to experience reality is also an emergent property of bioloigcal systems?

If we take qm at face value, we have no right to talk about a reality which does not include biological systems. Or it must be a non qm reality, based on some other laws of nature.

These are my personal views only.
 
  • #40
Coldcall said:
So would i be right in thinking that you feel an observer/definer is necessary for reality to occur? And you include an inanimate particle as an observer/definer?

Yes that would be a reasonable summary. However the word "particle" is not one I would choose, it's easy to take too litteral and suggest mechanistic mental images.

It doesn't have to be a "particle" in the ordinary sense. Any system able to hold and store information would do, wether we'd call it particle or not.

Coldcall said:
But there is still an "experiential" distinction between the two levels of emergence. Yes we can see very complex non-living systems but they lack certain abilities including awareness, or the ability to self-reference and measure or define their environment.

I do not experience other observers own experience of awareness, only my own. I only see how other people behave. This applies to other HUMANS, as well as to atoms.

The fact that I tend to identify myself more with other humans, than atoms does not mean there is some fundamental difference.

I agree with you that there is a sort of hierarchy of emergent properties and abilities that emerge with complexity, but this hierarchy runs IMO from the smallest imaginable level from the simplest possible Planck scale object to galaxies. I see a hierarchy of "distinctions" of you like, no magic distinction that makes higher life special. At least not a distinction that is relevant in this context.

I think that even an atom, does have an opinon of physical law, and belief of it's environment. But this doesn't mean I think atoms have "brains" or something similary silly. It means that I think this "opinion" and belief, is manifested by the atoms microstructure.

I do not adhere to the dedicated decoherence-programs, but I think Zurek said it very well when he said that "what the observer IS, is inseparable from what the observer KNOWS". that is in a nutshell, what I am also suggesting, but probably in a different way that Zurek did. But I like his phrase a lot :)

Coldcall said:
If you feel so strongly about the veracity of emergent laws (and i join with you in that thinking) then why would it not follow that the capacity to experience reality is also an emergent property of bioloigcal systems?

I don't follow this at all. Any system has as I see it the elementary properties needed to implement a way to "experience reality". The abstraction I use is that of, state, action and backreation. Any system, IS what it KNOWS.

I could probably expand on that, but to me it's put in an evolutionary context that an observer, that has evolved, and SURVIVED, does represent a compressed form of information about reality or nature. The fact that the system has survived, and is represented in the universes population, does contain information.

Anyway, a systems actions, should be infered from it's current state by an analogy to the principle of least action, which I call the principle of minimum speculation. Then there will be a backrection (the feedback) that the observer will have to merge with his prior state. The result is a modification both of the microstructure, and the microstate. It's a infinitesimal evolutionary step. Due to the intertia of compressed information, most of the "change" is manifested as the state vector adjusting. But there is also a slower movement of the state space itself.

All this, suggest that an observer can not be static. An observer is always challanged by it's environment, and the observer that is able to survive, does represent an "image of reality". So any object IS and "image of reality" in that sense.

However, transiently the state of an observer need not correlate well with reality, but the construction makes it reasonable to think that those observer whose behaviour are strongly at variance with the supposed laws of nature, would not be observed very frequently, in other words they would not populate the universe.

So just as the observed spectrum of spieces on earht tells us soemthing about the environment, the observed spectrum of subatomic particles tells use something about the laws of physics and the microphysical environment.

Coldcall said:
If we take qm at face value, we have no right to talk about a reality which does not include biological systems. Or it must be a non qm reality, based on some other laws of nature.

I don't understand from where you draw this conclusion? What does quantum mechanics has to do with biological systems as such? The observer in QM, really doesn't have nything to do with biological systems.

Unless you are thinking about that "I would not be entitled to talk about ANYTHING" unless there was life on earth. This is true, because then I wouldn't be here :)

I apologize in advance if I misunderstood You this time. I guess I don't understand why you insist focusing on biological observers. In a very obvious sense, there are only human first hand observer, moreover there is only one particular human observer even, and that's ME.

All other observers, are only observeed by me. That is of course true, but I don't it takes too much imagination to picture that this is how all observers see it. Even non-human observer, and even non-animate ones.

/Fredrik
 
  • #41
Fredrik,

"I do not experience other observers own experience of awareness, only my own. I only see how other people behave. This applies to other HUMANS, as well as to atoms."

True, but that's even more solipistic than me :-) I try to think humans are sharing the same reality to some extent. So in effect sharing the same quantum reality.

"I think that even an atom, does have an opinon of physical law, and belief of it's environment. But this doesn't mean I think atoms have "brains" or something similary silly. It means that I think this "opinion" and belief, is manifested by the atoms microstructure."

I don't think so. An atom's infrastructure is relatively simple compared to even the tiniest microbe, let alone humans.

We talked about emergence. Where is the necessary emergence in an atom, which matches the incredible complexity in any biology? If awareness is an emergent property of biology - which i believe it is - then an atom is an unlikely candidate for any type of awareness, or an ability to perceive reality.

"I don't follow this at all. Any system has as I see it the elementary properties needed to implement a way to "experience reality". The abstraction I use is that of, state, action and backreation. Any system, IS what it KNOWS."

Again, "knowing" is a human concept. I think you are endowing primordial material with consciousness. I think Henry Stapp also believes that all matter is conscious in some format. I love reading his articles, but i don't agree with the idea.

"All other observers, are only observeed by me. That is of course true, but I don't it takes too much imagination to picture that this is how all observers see it. Even non-human observer, and even non-animate ones."

How can an inanimate thing, with no sensory functions be an observer/definer? Where does it store the experience?
 
  • #42
Coldcall said:
"I do not experience other observers own experience of awareness, only my own. I only see how other people behave. This applies to other HUMANS, as well as to atoms."

True, but that's even more solipistic than me :-) I try to think humans are sharing the same reality to some extent. So in effect sharing the same quantum reality.
"to a some extent" - absolutely, I agree.
I was deliberately giving the argument an extra edge to make the point :)
Coldcall said:
"I think that even an atom, does have an opinon of physical law, and belief of it's environment. But this doesn't mean I think atoms have "brains" or something similary silly. It means that I think this "opinion" and belief, is manifested by the atoms microstructure."

I don't think so. An atom's infrastructure is relatively simple compared to even the tiniest microbe, let alone humans.
You are I think missing what I mean. I use the words konwn from human philosophy for analogy, and provoce the thought. But I do not mean that atoms have belief in the sense that they are "minuature philosophers".

I am suggesting that the physical makeup up a system, and it's physical behavioural pattern in fact images and partly reveals indirectly it's belief.

You know the saying that you can tell from what questions a person asks, what they know. Now apply that analogy to physical interactions, and my version of "physical belief".
Coldcall said:
We talked about emergence. Where is the necessary emergence in an atom, which matches the incredible complexity in any biology? If awareness is an emergent property of biology - which i believe it is - then an atom is an unlikely candidate for any type of awareness, or an ability to perceive reality.

"I don't follow this at all. Any system has as I see it the elementary properties needed to implement a way to "experience reality". The abstraction I use is that of, state, action and backreation. Any system, IS what it KNOWS."

Again, "knowing" is a human concept. I think you are endowing primordial material with consciousness. I think Henry Stapp also believes that all matter is conscious in some format. I love reading his articles, but i don't agree with the idea.
No, I am not thinking in terms of consciousness as philosophers of mind use it! I am not aware of Henry Stapp.

My use of the meaning know, has a specific mening in terms of fitness and survival. The whole point with knowing your environment, is that it helps you survive. I assign no ontological meaning of "knowledge" beyond that context. Knowing simply means, to possesses information about something.

Which leads to your good question about how inanimate objects sense and store.
Coldcall said:
"All other observers, are only observeed by me. That is of course true, but I don't it takes too much imagination to picture that this is how all observers see it. Even non-human observer, and even non-animate ones."

How can an inanimate thing, with no sensory functions be an observer/definer? Where does it store the experience?
The sensory functions are simply the physical onces in that case. Some small systems can "sense" acceleration/gravity, electric and magnetic fields and so on. These are the sensory functions I refer to in this context.

It's microstructure works as a memory device. It's experience is store in it's own microstate. The distinguishable microstates encodes information, just like the electrical states of a physical memory device.

That's the simple response. But I picture this in a deeper sense. An evolved organism, or structure can also be thought of as a compressed and reduced information about it's history.

/Fredrik
 

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