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Were There Ever Empirical Reasons to Bring Human Consciousness into QM?

by jon4444
Tags: schrodinger's cat
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jon4444
#1
Mar6-12, 09:44 AM
P: 21
I'm wondering whether physicists in the 1930's ever had experimental reason to interpret, for example, Schrödinger's cat, as a true paradox (because of the role of a human observer). Why didn't they default to Bohr's interpretation, that an interaction with a geiger-counter, or any classically determined system, counts as an "observation."

Bohr's interpretation would seem to be the common-sense way of looking at the situation--interpretations requiring human-consciousness to be involved (which you can still frequently see in the popular press) would seem to reflect some sort of solipsism on the part of the interpreter. (In much the same way that early religious leaders insisted that the universe had to revolve around the planet where they existed.)
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Ken G
#2
Mar6-12, 10:10 AM
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But Bohr never said the human consciousness wasn't involved, he merely said that we needn't put the consciousness in separately from how we already do physics. I would say that Bohr, and anyone, can see fairly obviously that the human consciousness is indeed involved in how we do physics, but that is as true classically as in quantum mechanics. Bohr's point was simply that quantum mechanics is subjugated to classical physics, because we need to use our everyday understanding of how classical measurement apparatuses operate before we can even begin to formulate a testable version of quantum mechanics. This makes the paradox go away, because Bohr says that physics is not about what the cat is really doing, it is about what we think the cat is really doing, how we talk about cat behavior in the first place. That's where the human consciousness/intelligence/perceptions comes in (I won't attempt to distinguish those terms since we know so little about them).
lugita15
#3
Mar6-12, 03:42 PM
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Here's a response I gave to a similar question in another thread:
Quote Quote by lugita15 View Post
The reason there is still disagreement as to what constitutes measurement is that it makes no experimental difference according to quantum mechanics. The way QM works under the Copenhagen interpretation is that you have to split the world into two parts, the “observer” or measurement device, and the “observed” or the particles you’re measuring.

The measurement device is assumed to behave classically. The particles in the observed system are in a superposition of states described by the wave function which keeps evolving until it interacts with the classical measurement device. The question is where to draw the line. You could consider a photon to be the observed system and an atom to be the measuring device, but you can also consider the photon-and-atom system as in a superposition of states, and take a Geiger counter to be the measurement device. So there is this von-Neumann chain, going from elementary particles to Geiger counters to human beings, and we have to decide where to cut it off.

Von Neumann proved in his famous "Bible" of QM that regardless of where you cut the chain, you would get the same experimental results. But he argued that wherever you cut the chain you have things made out of particles on each side of the cut, so there’s no principled way to place the cut in the middle. So he decided that you should place the cut between the human mind and the human body, because he believed that the mind is non-physical. Hence "consciousness causes collapse" was born. Nowadays, the most popular view is decoherence, where there is no real collapse, it's just that when you have a large number of particles in the environment interacting with the system, the wave function becomes smeared out and looks like it has collapsed. So decoherence gives us a reasonable place to cut the chain, when the number of particles involved reaches a critical number so that interference effect become negligible.

jon4444
#4
Mar6-12, 07:32 PM
P: 21
Were There Ever Empirical Reasons to Bring Human Consciousness into QM?

Thanks. This sort of validates the sense I've been getting that the Von Neumann's of the Physics world in fact do exhibit some of the same Solipsism as that of religious fundamentalists. Also, some of this obsessive interpreting regarding QM effects feels pretty sterile (since it has no predictive value).
Ken G
#5
Mar6-12, 08:15 PM
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But there's a funny thing about thinking (obsessing?) about what your theories actually mean-- it can be used to find the problems in them, and indeed, it often has. We're not really in contact with the problems with quantum mechanics, but someday we will be, and it might help a lot to have thought about this stuff.
questionpost
#6
Mar6-12, 08:59 PM
P: 198
Why human consciousness? Why not just generalize all consciousness since its all only possible because of matter?
Ken G
#7
Mar7-12, 12:02 AM
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Quote Quote by questionpost View Post
Why human consciousness? Why not just generalize all consciousness since its all only possible because of matter?
Because human consciousness is the only one that is being used to do physics, that we know of. What we know of other consciousnesses is only insofar as they mimic ours-- nothing else.
questionpost
#8
Mar7-12, 07:38 AM
P: 198
Quote Quote by Ken G View Post
Because human consciousness is the only one that is being used to do physics, that we know of. What we know of other consciousnesses is only insofar as they mimic ours-- nothing else.
Animals use math and physics all the time, like when they are traveling distance or swimming or calculating where something will be. Even plants use math and physics to grow in the shapes they do. Humans are just the only ones who organize that information in terms of words rather than solely sub-conscious actions and feelings.
fellupahill
#9
Mar7-12, 10:56 AM
P: 62
Quote Quote by questionpost View Post
Animals use math and physics all the time, like when they are traveling distance or swimming or calculating where something will be. Even plants use math and physics to grow in the shapes they do. Humans are just the only ones who organize that information in terms of words rather than solely sub-conscious actions and feelings.
Interesting point.

Kind of brings up the discussion, is their any difference between human consciousness and animal consciousness? Which will ultimately lead to religious talk. And whenever religious people have a better explanation than the science, science hasn't advanced enough yet to decide :)
Neandethal00
#10
Mar7-12, 12:09 PM
P: 168
Quote Quote by jon4444 View Post
I'm wondering whether physicists in the 1930's ever had experimental reason to interpret, for example, Schrödinger's cat, as a true paradox (because of the role of a human observer). Why didn't they default to Bohr's interpretation, that an interaction with a geiger-counter, or any classically determined system, counts as an "observation."

Bohr's interpretation would seem to be the common-sense way of looking at the situation--interpretations requiring human-consciousness to be involved (which you can still frequently see in the popular press) would seem to reflect some sort of solipsism on the part of the interpreter. (In much the same way that early religious leaders insisted that the universe had to revolve around the planet where they existed.)
I think very recently physicist Penrose is bringing up QM to explain consciousness. He has the nagging problem of explaining how does microscopic quantum world relates to ourselves, the pathways to the humans.

I personally think our consciousness comes from our constituent matters, cells, super molecules, molecules, atoms, and finally elementary particles. That is why QM is emphasized in consciousness. This statement is equivalent to saying 'matters or even elementary particles may have certain type (unlike ours) of consciousness. Our consciousness is a collective 'consciousness' (for the lack of correct word) of particles.

Unfortunately our current Math is not equipped to uncover this mystery. Modern physics heavily rely on Math, and this Math is totally materialistic, void of any 'sensory system' (again, for the lack of better words). Probably quantum Math with its Wave Function come a little closer to a consciousness world but still far away.
bohm2
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Mar7-12, 12:39 PM
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Quote Quote by Neandethal00 View Post
I personally think our consciousness comes from our constituent matters, cells, super molecules, molecules, atoms, and finally elementary particles. That is why QM is emphasized in consciousness. This statement is equivalent to saying 'matters or even elementary particles may have certain type (unlike ours) of consciousness. Our consciousness is a collective 'consciousness' (for the lack of correct word) of particles.
I've come across some interesting arguments that do agree very much with this position; that is, in order to explain how the mental/consciousness/subjectivity/qualia emerge from "matter", there must be some fundamental change in our conception of "matter" or "physical", perhaps by a future physics, etc. But as per the "hard" problem, there's no hint of how one can get subjectivity out a complex network of neural connections, etc. (as presently understood). The gap between mind and matter seems immense. They just don't seem to mesh. Consciousness seems to “provide us with a kind of ‘window’ on to our "brain", making possible a transparent grasp of a tiny corner of a materiality that is in general opaque to us" but we haven't the slightest clue of how to mesh it together with what we presently call "matter". An interesting Lockwood passage on this topic:
Do we therefore have no genuine knowledge of the intrinsic character of the physical world? So it might seem. But, according to the line of thought I am now pursuing, we do, in a very limited way, have access to content in the material world as opposed merely to abstract casual structure, since there is a corner of the physical world that we know, not merely by inference from the deliverances of our five sense, but because we are that corner. It is the bit within our skulls, which we know by introspection. In being aware, for example, of the qualia that seemed so troublesome for the materialist, we glimpse the intrinsic nature of what, concretely, realizes the formal structure that a correct physics would attribute to the matter of our brains. In awareness, we are, so to speak, getting an insider's look at our own brain activity.
Neutral Monism
http://plato.stanford.edu/entries/neutral-monism/#7.2

I'm not sure what to make of these arguments but in general I think I agree with Strawson's/Russell's/Eddington's statements that are skeptical about progress in this area happening primarily because mathematics (the language of physics) cannot possibly do that:

This is the “structuralist” point familiar in the 1920s and 1930s (now severely underappreciated outside the philosophy of science, but reviving). It consists in the observation that the propositions of physics are equations, equations that contain numbers, terms that refer without describing, many other mathematical symbols, and nothing else; and that these equations, being what they are, can only tell us about the abstract or mathematically characterizable structure of matter or the physical world without telling us anything else about the nature of the thing that exemplifies the structure. Even in the case of spacetime, as opposed to matter or force—to the doubtful extent that these three things can be separated—it’s unclear whether we have any knowledge of its intrinsic nature beyond its abstract or mathematically representable structure.
Mental Reality
http://mitpress.mit.edu/books/chapte...13102pref2.pdf
jon4444
#12
Mar7-12, 04:20 PM
P: 21
"Unfortunately our current Math is not equipped to uncover this mystery. Modern physics heavily rely on Math, and this Math is totally materialistic, void of any 'sensory system' (again, for the lack of better words). Probably quantum Math with its Wave Function come a little closer to a consciousness world but still far away."

I like this way of thinking about it, as it seems natural to assume consciousness must rely on some as-yet-discovered physical phenomenon (since the essential aspect of human consciousness--being aware of your awareness--doesn't correlate with any known phenomenon.)
Ken G
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Mar7-12, 07:22 PM
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Quote Quote by questionpost View Post
Animals use math and physics all the time, like when they are traveling distance or swimming or calculating where something will be. Even plants use math and physics to grow in the shapes they do. Humans are just the only ones who organize that information in terms of words rather than solely sub-conscious actions and feelings.
When you say "animals use math", what you mean is that you recognize what they are doing based on something you do. If you had no idea what math was, you'd have no idea what those words mean. So you are using your own understanding of what math is, that's what I mean by only knowing animals by seeing them as some kind of versions of ourselves. The fact is, we have no idea what animals minds are actually doing when we claim they are doing math, but we suspect that they are doing something vaguely similar-- but only because they are already similar (our brains evolved along similar lines).
Ken G
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Mar7-12, 07:37 PM
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Quote Quote by bohm2 View Post
I've come across some interesting arguments that do agree very much with this position; that is, in order to explain how the mental/consciousness/subjectivity/qualia emerge from "matter", there must be some fundamental change in our conception of "matter" or "physical", perhaps by a future physics, etc. But as per the "hard" problem, there's no hint of how one can get subjectivity out a complex network of neural connections, etc. (as presently understood). The gap between mind and matter seems immense.
And indeed we probably should never have expected them to mesh, except in the dualistic way that the momentum and position of a particle mesh. The common idea that thought "emerges from" the actions of the material brain is an impossible claim to demonstrate, because every iota of language we have to discuss the material brain comes from thought. So the common claim is that the material world causes thought to occur, and thought describes what the material world is. Eliminating the middle man, this is the claim that material describes, or understands, itself. But I can equally frame it the other way around, and say that thought causes the material world to occur, which then in turn is described by thought. Either way, all we get is a tiger chasing its own tail, so it is obviously impossible to distinguish which is the tiger and which is the tail. Indeed, the entire tiger/tail dichotomy is seen to be bogus-- all we have is a tiger-and-tail relationship that is completely indeterminate about which is which. And we expect the tiger to mesh with its tail? Then you'd have a tiger chasing itself, which is reductionism gone mad-- complete monism is absent of meaning, there needs to be some kind of contrast or tension to have anything nontrivial.
questionpost
#15
Mar7-12, 10:07 PM
P: 198
Quote Quote by Ken G View Post
When you say "animals use math", what you mean is that you recognize what they are doing based on something you do. If you had no idea what math was, you'd have no idea what those words mean. So you are using your own understanding of what math is, that's what I mean by only knowing animals by seeing them as some kind of versions of ourselves. The fact is, we have no idea what animals minds are actually doing when we claim they are doing math, but we suspect that they are doing something vaguely similar-- but only because they are already similar (our brains evolved along similar lines).
We actually have a lot of idea on what animals minds do because we can see what chemicals exist in their brain and what they get released in response to as well as see which parts of their brain activate in response to certain things. We've actually found through chemical testing that even fish release endorphin into their blood stream when harmed and even that the same parts of the brain responsible for fear activate at the same time in a person and another animal in the same situation. If anything, animals minds practically are human minds but with different chemical responses and cognitive limitations. You can still see that 1+1=2 without putting the information into words, or even see the slope of a line by noticing how much it goes up by in comparison to how much it goes forward by. There's tons of math that animals and even plants do, just not in terms of words. Things can still exist in specific values without being symbols on a piece of paper.
Ken G
#16
Mar8-12, 08:56 AM
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Quote Quote by questionpost View Post
We actually have a lot of idea on what animals minds do because we can see what chemicals exist in their brain and what they get released in response to as well as see which parts of their brain activate in response to certain things.
Yes but that's just my point. We have no idea what chemicals like that "should" do, we only know what they do in our own brains, because we can correlate two things we understand-- we understand the chemicals, and we understand what our brains are doing (from the internal perspective). Remove either of those pillars and we have nothing that we could call understanding, we have only correlations (when chemical X does Y, animal A does B, but we can say that for a stimulant or a pesticide). None of that can be called "using math" or even "thinking", because we only know what those things are because we do them. Indeed the very definitions of these terms reveal the extent to which we rely on our own minds to give meaning to these terms.
We've actually found through chemical testing that even fish release endorphin into their blood stream when harmed and even that the same parts of the brain responsible for fear activate at the same time in a person and another animal in the same situation.
And that should not be too surprising-- fish brains and human brains evolved along similar lines. I'm not saying fish think differently from us (we should expect both similarities and differences), I'm saying that everything we can say about how fish think relates directly to how we think, because that's how we understand what thought (and math) are. So we are always looking in the mirror to some extent, and that's not a bad thing-- it's just how we understand.
jon4444
#17
Mar8-12, 09:07 AM
P: 21
Quote Quote by Ken G View Post
I'm saying that everything we can say about how fish think relates directly to how we think, because that's how we understand what thought (and math) are.
But if we compare our thinking to what we see in animal behavior, I think it's fair to draw general conclusions on basic mental processes common to both. For example, when I watch my cat follow a familiar path to get to a place to hunt, he's clearly using some mental process that has a kinship to my following a "train of thought"--I'm just using language and the self-awareness of "concepts," etc. for the cat's equivalent of markers in the environment. It seems fair to conclude that a core aspect of consciousness, common to both me and my cat (i.e., "mammals") is that of "following a trail."

As far as QM goes, you could extend this to both me and my cat take in stimuli and draw some sort of conclusion based on characteristics of the stimuli (e.g., specific wavelength of light). Thus, cat consciousness, at this level, is roughly equivalent to human consciousness.
Neandethal00
#18
Mar8-12, 05:04 PM
P: 168
Quote Quote by bohm2 View Post
I've come across some interesting arguments that do agree very much with this position; that is, in order to explain how the mental/consciousness/subjectivity/qualia emerge from "matter", there must be some fundamental change in our conception of "matter" or "physical", perhaps by a future physics, etc.
The quotes you used in your post are more interesting than the materials in the Links.
People have been thinking about the source of our consciousness for centuries. Centuries ago science was not deveoped enough, as a result the topic of consciousness went to the philosophers. This made all answers concerning consciousness very subjective.

Now consciousness is not philosophy anymore, it is Science. It is necessary to take a scientific approach if we intend to discover the source of our consciousness. That brings up my grief about mathematics.

I'm surprised very few scientists spoke out about the limitation of mathematics. Solution of an equation will always contain ONLY the variables used in the equation. You can solve a complicated differential equation, its solution will contain ONLY the variables, coefficients used in the equation. In other words, a mathematical equation (solution) can not 'invent' or 'discover' or 'introduce' a NEW variable (or even a 'constant', which always depends on the values of the variables used) in the solution. One day I took one look at one of Einstein's equations for General Relativity. I immediately knew where the idea of Dark Matter and Dark Energy had come from.

So, it boils down to how truly our mathematical model represent a system. But the system we model is generally physical, with known physical properties. Our mathematics will never be able to discover unknown properties of the system. If consciousness is a 'field', unlike electric, magnetic, or gravitational field, a mathematical model for consciousness will produce a solution for the field in terms of physical properties of humans. Which will not tell us how to detect the 'field'.

I'm hoping QM would evolve. I do not know the current states of QM, I took graduate level QM with dinosaurs and never looked back. If wavefunctions evolve and can model complex phenomena, someday QM may open a path to understanding ourselves. But I also fear there is a huge discontinuity between particle's unknown property we are looking for and our physical sensory system.


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