The Many-Worlds Interpretation of QM

[Quotidian]

you can probably come up with some weird view giving some kind of privileged status to human consciousness - and it looks like you did.

Right. So believing that 'observation requires an observer' is weird, but entertaining the idea of 'infinite proliferating worlds' is not.

In consciousness-based interpretations and (arguably) the Copenhagen interpretation, this is the case. In the MWI, it is not.

Again - at what cost? Your post #3 says 'There's nothing what singles out one outcome, so we can interpret each of them as belonging to a different world'. But are there actually 'different worlds'? Does it matter? And if it doesn't matter, then does this construction have anything to do with reality? Or is it just like a 'thought-experiment', a kind of conceptual model to do away with something that is 'conceptionally unsatisfying for many people'?

 

[HomogenousCow]

At the end of the day, without any real distinguishing evidence to go by, I think the subject of interpretations is a non-subject, for example if I choose to believe that there are parallel universes which cannot affect us in any way, you cannot prove me wrong but I cannot prove myself right either.
Or you know..if you believe there are omni-powerful beings present in the universe..Oh wait I have a warning point already.

 

[bhobba]

Right. So believing that 'observation requires an observer' is weird, but entertaining the idea of 'infinite proliferating worlds' is not.

MW is equally as weird IMHO as consciousness causes collapse. But weirdness is in the eye of the beholder. My Ensemble interpretation also has a weird aspect - namely exactly how is the improper mixture of decoherence converted into an actual mixture. Observationally they are identical - but their physical preparation is entirely different. Every single interpretation is weird in some way - you simply pick the one that is the least weird to you. Most people, because of the difficulties I alluded to with computers, and other reasons, would say consciousness causes collapse has too much baggage associated with it to be taken seriously - but that doesn't mean its not valid.

BTW in QM observation means any device capable of registering in the macro world - it's a misunderstanding thinking a priori observation requires an observer despite the semantic closeness of the terms. If that is what you believe you are not the only one to be confused by it.

Thanks
Bill

 

[bhobba]

Again - at what cost?

You asked me to justify:

I think consciousness causes collapse is basically rubbish - but heresy - no.

Notice the words - I think.

In any interpretation you are making a judgement - every single interpretation has baggage - it's purely a matter of which you think has the least baggage. But that is your choice - its not subject to experimental verification. Opinions are like bums - everyone has one - it doesn't make it correct.

Thanks
Bill

 

[bhobba]

I think the subject of interpretations is a non-subject

Not really. In order to apply QM you need a way to map the mathematical elements of its formalism to stuff out there. That's the job of an interpretation. Even if you are in the shut-up and calculate camp you still have an interpretation - its called the Minimal Statistical Interpretation.

Think of good old Euclidean Geometry. How to map it is usually very obvious physically and no issues arise. The interesting thing about QM is that mapping is not obvious so you have all these different interpretations and threads like this. Its in the nature of the material.

Interestingly in the past, say about the time Feynman was in his heyday, the shut-up and calculate view was predominate but these days its all over the place. As mentioned previously this may be a good or bad thing depending on how you look at it.

Thanks
Bill

 

[Quotidian]

Very true. Wise words indeed. It is just that us philosophically curious lay-persons are often informed by the likes of Lawrence Krauss and Stephen Hawking that 'physics has superseded philosophy'. Yet the question of 'interpretations' is very much a philosophical question - and one which, no disrespect intended, few physicists seem to have much of a handle on.

I think I will go back to Kant, Schopenhauer and Buddhist studies. Thanks for your responses.

 

[bhobba]

Very true. Wise words indeed. It is just that us philosophically curious lay-persons are often informed by the likes of Lawrence Krauss and Stephen Hawking that 'physics has superseded philosophy'. Yet the question of 'interpretations' is very much a philosophical question - and one which, no disrespect intended, few physicists seem to have much of a handle on.

I think I will go back to Kant, Schopenhauer and Buddhist studies. Thanks for your responses.

Most physicists are like myself and are a bit anti-philosophy along the lines of Feynman.

But note - that itself is a philosophy.

I don't think its fair to say, like Lawrence Krauss and Stephen Hawking says (and I have read what they say and they do say stuff like that), that science now supersedes philosophy. What is fairer to say is science makes extensive use of a tiebreaker in an argument - philosophical or otherwise - actual observation - that's the real issue. Truth is only held provisional while observation supports it. That's the key difference.

Thanks
Bill

 

[Fredrik]

In my opinion, philosophy has a very limited relevance to science and mathematics. It can handle questions like "What is science?", "What is mathematics?" and "What is the best way to define the term 'theory of physics'?". To note that terms like "state" can be defined in a theory-independent way is to do philosophy. To think about what whether QM can or can't be interpreted as a description of what's actually happening, is also to do philosophy.

Unfortunately I don't think philosophers are doing any of those things well. So I can't help wondering if philosophers have any relevance to science.

The only reason I'm not saying that the philosophy of science and mathematics should definitely be left to physicists and mathematicians is that they're not doing these things well either. Philosophers probably just don't understand the subject well enough. But physicists and mathematicians have an attitude problem. They think that this sort of stuff is beneath them.

 

[dx]

To note that terms like "state" can be defined in a theory-independent way is to do philosophy. To think about what whether QM can or can't be interpreted as a description of what's actually happening, is also to do philosophy.

I would like to mention this again, since it is a key point in the copenhagen interpretation (a term I reserve for Bohr's views alone)

"What is actually happening to the system" is clearly a meaningful concept as long as the behavior of the system can be observed without the act of observing the system influencing the system.

But in quantum mechanics, the existence of the quantum of action h implies that there is a lower limit to the interaction between the measuring bodies and the objects under investigation. One can try to control this interaction, by observing the measuring bodies themselves, but in that case those measuring bodies themselves become part of the system being observed, and the additional measuring bodies introduced will again have an uncontrollable interaction with the system.

So the point is, "what is happening to the system" cannot be separated from the question of the observation of "what is happening to the system"

 

[Fredrik]

I would like to mention this again, since it is a key point in the copenhagen interpretation (a term I reserve for Bohr's views alone)

"What is actually happening to the system" is clearly a meaningful concept as long as the behavior of the system can be observed without the act of observing the system influencing the system.

But in quantum mechanics, the existence of the quantum of action h implies that there is a lower limit to the interaction between the measuring bodies and the objects under investigation. One can try to control this interaction, by observing the measuring bodies themselves, but in that case those measuring bodies themselves become part of the system being observed, and the additional measuring bodies introduced will again have an uncontrollable interaction with the system.

So the point is, "what is happening to the system" cannot be separated from the question of the observation of "what is happening to the system"

QM says that any isolated system (or at least any isolated system that can be made to interact with a measuring device) has a state that changes with time as described by the Schrödinger equation. I would say that the main purpose of an interpretation of QM is to provide a possible answer to the question of what is actually happening to an isolated system, while it's still isolated.

Isn't what you're suggesting, and what those Bohr quotes in post #15 are suggesting, only that a measurement breaks the isolation? What is happening to to the system during the measurement can't be separated from the observation of what's happening to the system. I don't think this is relevant to what I had in mind, because when I was talking about the question of whether QM describes "what's actually happening" to a system, what I had in mind was an isolated system.

 

[Fredrik]

Not really. In order to apply QM you need a way to map the mathematical elements of its formalism to stuff out there. That's the job of an interpretation.

To me, the term "QM" refers to something that includes the correspondence rules that tell us how to interpret the mathematics as predictions about results of experiments. (QM is a theory of physics, not a piece of mathematics). So the kind of interpretation you're talking about here is already included in "QM".

So to me, an "interpretation of QM" is something else; it's an answer to the question of what's actually happening to an isolated system. But it can't be any guess. It has to be an answer that follows from QM itself*, once we have made a few statements about how to think about some of its mathematics.

Martinbn made the comment that when I tried to partially define the MWI, I seemed to be just assigning familiar but undefined terms with mathematical concepts. It seemed that way, because it was that way. I don't think there's any other way to define an interpretation of QM.

 

[kith]

But in quantum mechanics, the existence of the quantum of action h implies that there is a lower limit to the interaction between the measuring bodies and the objects under investigation. One can try to control this interaction, by observing the measuring bodies themselves, but in that case those measuring bodies themselves become part of the system being observed, and the additional measuring bodies introduced will again have an uncontrollable interaction with the system.

Using a collapse interpretation like the CI here gives contradicting predictions. As soon as the internal observer performs his measurement, collapse happens and one definite outcome is selected. The external observer however will also find other outcomes with non-zero probability.

Of course, this is only a gedanken experiment. But I don't think you can get a consistent version of the CI without postulating that there is a macroscopic world which doesn't obey the rules of QM.

 

[Fredrik]

Using a collapse interpretation like the CI here gives contradicting predictions. As soon as the internal observer performs his measurement, collapse happens and one definite outcome is selected. The external observer however will also find other outcomes with non-zero probability.

I think this is a valid line of reasoning if we identify the state vector with the system, i.e. if we assume that it represents all the properties of the system, that it describes the system, or however you would like to put it. But I would consider that assumption to be part of the MWI, not the CI.

There are undoubtedly many people who do think of that assumption as part of the CI, but I don't think that makes sense. When I argued against this view here, I still thought that this was the CI. Since then I've learned that everyone seems to mean something different by "the CI", so I try to avoid that term.

Of course, this is only a gedanken experiment. But I don't think you can get a consistent version of the CI without postulating that there is a macroscopic world which doesn't obey QM rules.

I think it makes more sense to just drop the idea that QM is a description of what's happening, and instead view it as a way to associate probabilities with possible results of experiments.

 

[kith]

Thanks Fredrik, what you write makes sense to me. So there is a more meaningful version of the CI than the one I mentioned. I agree that the term "CI" is notoriously ambigious, but somehow I still find myself using it from time to time.

 

[bhobba]

I think it makes more sense to just drop the idea that QM is a description of what's happening, and instead view it as a way to associate probabilities with possible results of experiments.

I reached that conclusion long ago. IMHO doing otherwise simply carries too much baggage and Ballentine also makes a strong case.

Einstein returns with a vengeance - except of course he believed not only that but it pointed to the incompleteness of QM. I personally haven't reached that conclusion but it sure whispers in your ear that could be the case.

Thanks
Bill

 

[Quotidian]

On the one hand

Unfortunately I don't think philosophers are doing any of those things well. So I can't help wondering if philosophers have any relevance to science.

On the other

I think it makes more sense to just drop the idea that QM is a description of what's happening, and instead view it as a way to associate probabilities with possible results of experiments.

So, really, this amounts to the admission that "physics is not actually informing us about reality' after all, but only making statistically accurate predictions about particular things - the kind of consideration, I would suggest, which is precisely within the ambit of philosophy, as distinct from physics

I think we're losing sight of something here. In the heyday of scientific materialism, which was ended with the discovery of relativity theory and QM, the idea was that the atom was the universal explanans - that in terms of which 'everything else can be explained'. That, after all, was the basis of 'philosophical materialism'.

Now we find that nobody can actually agree on what observations of the quantum world actually mean in relation to the actual world. Of course we can speculate in terms of M-theory, or whatever it is, but all such speculations to me, seem to be grounded in mathematical abstraction, which is hardly the same kind of thing as an indivisible point particle.

Not many people seem to get that.

That is one reason why I find an irony in this remark:

What is fairer to say is science makes extensive use of a tiebreaker in an argument - philosophical or otherwise - actual observation - that's the real issue.

When, by definition, Everett's 'many worlds' are not even observable in principle. Yet, because it is mathematically coherent, we are willing to disregard the apparent preposterousness of such an idea. And there are many fundamental theories of physics and cosmology which entertain equally non-observable notions, from multi-dimensional strings to infinite numbers of 'universes'.

I think Lewis Carroll saw all this coming.

The only reason that most philosophers aren't doing a good job of pointing it out, is because in Anglo--American analytical philosophy, they're all in the thrall of philosophical materialism, notwithstanding the fact that the very ground has been cut out from under their feet.

So they spend most of their time arguing about the meaning of propositions. That is why they're useless, not because philosophy itself has nothing to say. Philosophy has very important questions to ask about what qualified as 'knowledge' and what role the mind has in the construction of what we regard as reality.

 

[bhobba]

When, by definition, Everett's 'many worlds' are not even observable in principle. Yet, because it is mathematically coherent, we are willing to disregard the apparent preposterousness of such an idea.

Who is this 'we' Kemosabe?

Some are willing to accept the idea of world splitting for the sake of mathematical elegance and beauty - namely on the basis of a poll about 20% - 80% aren't - but like all things, when observation can't decide, it comes down to personal taste - there is no absolute right/wrong here - get used to it.

Although there is no agreement on this issue there is 100% agreement on the underlying math - that's pretty good compared to philosophy - in fact I don't think philosopher's can claim that distinction on any issue - but I could be wrong.

So, really, this amounts to the admission that "physics is not actually informing us about reality'

The problem with that is no one, philosophers, mathematicians, scientists - no one - can agree what 'reality' is - so its a bit hard to decide if physics is telling us anything about it.

I believe it does because I believe 'reality' is what physics tells us - but getting agreement on that is not likely - not likely at all.

And yes there is multiple views on QM that can't all be right - but the math is agreed by all so that is what I accept as realty. Actually that is something really weird - why the math of physical theories is - well - so effective:
http://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html

Murray Gell-Mann thinks he knows the answer - self similarity. If true that would be a major and profound insight into 'reality'.

Thanks
Bill

 

[Quotidian]

Hot off the press - literally published today - http://amzn.com/019979054X by Alyssa Ney.

This is a new volume of original essays on the metaphysics of quantum mechanics. The essays address questions such as: What fundamental metaphysics is best motivated by quantum mechanics? What is the ontological status of the wave function? Does quantum mechanics support the existence of any other fundamental entities, e.g. particles? What is the nature of the fundamental space (or space-time manifold) of quantum mechanics? What is the relationship between the fundamental ontology of quantum mechanics and ordinary, macroscopic objects like tables, chairs, and persons? This collection includes a comprehensive introduction with a history of quantum mechanics and the debate over its metaphysical interpretation focusing especially on the main realist alternatives.

OUP, too. Not some fly-by-night publishing house.

 

[jambaugh]

So, really, this amounts to the admission that "physics is not actually informing us about reality' after all, but only [...]

Physics informs us of actuality (what happens) rather than about reality (what is). One can only speculate about reality. Actuality slaps us in the face every morning. Which would you rather know about?

[edit] PS The philosophical issues are not lost on the Western camp. There has been a quiet battle between positivists (who stay out of philosophy departments and journals) and the post modernists who want to rebrand mysticism as science for the sake of their cherished realities.

Positivism resolves the issue nicely but in some it leaves a feeling of disquiet, like when they begin to understand that there is no Santa Claus.

 

[bhobba]

OUP, too. Not some fly-by-night publishing house.

Had a look at a preview on Amazon.

It's not quackery or anything like that but it is written by philosophers for philosophers. Trouble is philosophers view of QM often (not always - but often) leaves a lot to be desired.

Its certainly cheap though and I will have a bit more of a look at its contents and may even get it.

Thanks
Bill

 

[bhobba]

and the post modernists who want to rebrand mysticism as science for the sake of their cherished realities.

Oh dear - trouble is its probably true. Witness the popularity of consciousness causes collapse amongst SOME philosophy types that post - I rarely see it from actual practicing scientists - about the only modern adherent I know of is Penrose.

Thanks
Bill

 

[jambaugh]

I think consciousness causes collapse is basically rubbish - but heresy - no.

The problem people have with orthodox CI is that indeed consciousness does cause collapse, because collapse occurs in the conceptualization, not in the material world. One as an act of consciousness collapses one's manifold of speculations about how something might behave to the singular point of how it has behaved in a given instance.

Likewise Everett's MWI is compatable with CI IF one understands that the manifold of parallel realities are parallel reality models within one's conceptualization. One should understand that we use "reality" as a model for what is out there but that the actual objective reality is a model in our heads, that "what is out there" is a system of material phenomena which at the quantum level is not a point state within a continuum sea of possibilities but just "stuff happening".

Example: A chair is a chair because we sit in it. If I hit you over the head with a chair it hasn't suddenly "collapsed" into a club in its "reality" (well actually it has but..) rather in its material actuality, it has in our conceptualization of its typical behavior. The chairness is in its function.
(And there are an infinite variety of other "objective states of utility" for that chair, such as door stop, art object, magician's prop,... the "many worlds" of the chair.)


At the quantum level material systems are "all function". Electrons are electrons because they behave like electrons and that is the sum total of their electronness. How they behave is described as precisely as can be observed by the quantum mechanical description of electron observations. One may propose a deeper quantum theory describing electrons as quantum composites of some more basic phenomenon (parton theories etc) but you can't go backwards and build quantum systems out of empirically verifiable classical (as in objective reality based) ones.

Objective reality is dead. It is only the voodoo of the intransigent metaphysicists who keep it in its current zombie state... the walking dead.

 

[Alexis1304]

F.Tipler and non-locality as evidence for many-wolrds

Folks, I was going to open new thread, but maybe it is enough to ask it here. As for interpretations of QM I am open-minded agnostic.But: what about F.Tipler's article "Nonlocality as evidence of myltiverse cosmology", where he uses nonlocality and argue for MWI? Here:

http://arxiv.org/pdf/1008.2764.pdf

What is non-mwier response to that?Or -does there even NEED to be a response?...

 

[Maui]

Oh dear - trouble is its probably true. Witness the popularity of consciousness causes collapse amongst SOME philosophy types that post - I rarely see it from actual practicing scientists - about the only modern adherent I know of is Penrose.

Thanks
Bill

“When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.”
― Arthur Conan Doyle, the book of Sherlock Holmes by this i don't mean just the search for context in contextual systems in quantum mechanics(they all are, this widely agreed upon), but the lesson from the cornerstone of the quantum world - the inherent uncertainty of quantum systems. Whatever reality is, the aqcuisition of knowledge is inseparable from what it is and how it is observed. The acquisition of knowledge requires that information is meaningful to someone. Sure, one can claim that instruments completely replace the observer, but the observer is never entirely replaced by instruments; for if he were, he could obviously obtain no knowledge whatsoever. Many helpful devices can facilitate this work but they must be read! The observer’s senses have to step in eventually.The most careful record, when not inspected, tells us nothing. And in the cornerstone of quantum theory(the HUP), availablity of information about systems properties is what determines what will be observed.

 

[jambaugh]

Another random comment. Some object to reducing the wave function to "knowledge about the system" and equally to "observer caused [physical] collapse" because they feel it smacks of solipsism. The thing to remember is that in a scientific context there is rigorous constraints on the meaning of an observation and indeed in QM the act of observing, of knowing something in a scientific sense, is a physical act. Saying I know the electron is in a spin z up "state" is saying I have via devices of some type physically interacted with the system in question.

This arises also in understanding Entropy. The proper definition of entropy is as a function of our ignorance about a system. But that doesn't mean it is subjective or meaningless. It is the function of necessary ignorance given the physical constraints in the system's definition and thus this "observer knowledge" has specific indirect connection to the physical world. Not some spooky mind over matter but the hard causal connection between the phenomena and the interaction which causes us to know in the scientific sense. I ask you metaphysicists trying for an ontological (re)interpretation to consider this and reconsider your gut objections to the orthodox non-ontological interpretation.

 

[Quotidian]

Objective reality is dead. It is only the voodoo of the intransigent metaphysicists who keep it in its current zombie state... the walking dead.

whom I would have thought would be the remaining 'philosophical materialists', that is, those who advocate the view of the ultimate mind-independence of reality.

The word 'objectivity' itself was only coined in the 19th century - centuries after metaphysics in its classical sense was written down.

 

[Quotidian]

There's an interesting essay here which addresses exactly the question that I raised in the original post. It explains why 'an observing intelligence' is implicated in the 'collapse of the wave function', and concludes:

If the mathematics of quantum mechanics is right... and if materialism is right, one is forced to accept the Many Worlds Interpretation of quantum mechanics. And that is awfully heavy baggage for materialism to carry.

If, on the other hand, we accept the more traditional understanding of quantum mechanics that goes back to von Neumann, one is led by its logic ...to the conclusion that not everything is just matter in motion, and that in particular there is something about the human mind that transcends matter and its laws.

(Emphasis added.)

 

[bhobba]

There's an interesting essay here which addresses exactly the question that I raised in the original post. It explains why 'an observing intelligence' is implicated in the 'collapse of the wave function', and concludes:

Von Neumann's argument was that the collapse could be put anywhere but if you keep tracing it back the only place that looks different to anywhere else is human consciousness (at least that's my recollection). A few bought into it including Wigner but since then great strides have been made in the understanding of decoherence.

http://en.wikipedia.org/wiki/Quantum_mind%E2%80%93body_problem
'Decoherence does not generate literal wave function collapse. Rather, it only provides an explanation for the appearance of wavefunction collapse, as the quantum nature of the system "leaks" into the environment. That is, components of the wavefunction are decoupled from a coherent system, and acquire phases from their immediate surroundings. A total superposition of the universal wavefunction still exists (and remains coherent at the global level), but its fundamentality remains an interpretational issue. "Post-Everett" decoherence also answers the measurement problem, holding that literal wavefunction collapse simply doesn't exist. Rather, decoherence provides an explanation for the transition of the system to a mixture of states that seem to correspond to those states observers perceive. Moreover, our observation tells us that this mixture looks like a proper quantum ensemble in a measurement situation, as we observe that measurements lead to the "realization" of precisely one state in the "ensemble".'

When Wigner heard about decoherence from some early work of Zureck he realized consciousness was no longer required - it provides the natural place to put collapse - not consciousness.

I do not know much about philosophy, materialism and such but I find it hard to believe interpretations like Bohmian Mechanics, GRW etc do not satisfy its tenants just as well as Many Worlds.

Thanks
Bill

 

[Quotidian]

When Wigner heard about decoherence from some early work of Zureck he realized consciousness was no longer required - it provides the natural place to put collapse - not consciousness.

Be that as it may, the Wikipedia article on 'Quantum Decoherence' which the above article links to, says that:

Specifically, decoherence does not attempt to explain the measurement problem.

Besides which, as I have said before, 'quantum decoherence' is not an idea that can be meaningfully rendered in English (indeed same article is said not to be understandable to laypersons.)

But it least it serves the purpose of enabling 'the physicists' to say they can trump 'the philosophers' in arguments over 'interpretation of QM'

 

[bhobba]

But it least it serves the purpose of enabling 'the physicists' to say they can trump 'the philosophers' in arguments over 'interpretation of QM'

There are philosophers that know the details - if you want to read what one of those think check out:
http://arxiv.org/pdf/1111.2187v1.pdf
'Decoherence explains why it is that quantum theory nonetheless works in practice: it explains why interference does not, in practice spoil the probabilistic interpretation at the macro level. But because decoherence is an emergent, high-level, approximately-defined, dynamical process, there is no hope of incorporating it into any modification of quantum theory at the fundamental level.'

Decoherence does not attempt to explain it because it doesn't need to - 'Rather, decoherence provides an explanation for the transition of the system to a mixture of states that seem to correspond to those states observers perceive. Moreover, our observation tells us that this mixture looks like a proper quantum ensemble in a measurement situation, as we observe that measurements lead to the "realization" of precisely one state in the "ensemble".'

I don't necessarily hold entirely to that - my view is its still there but now not a problem.

Thanks
Bill

 

[Quotidian]

Interesting article! I shall *try* and take it in. But as far as I am concerned, as long as an element of mystery remains, I sleep OK too.

 

[mfb]

by this i don't mean just the search for context in contextual systems in quantum mechanics(they all are, this widely agreed upon), but the lesson from the cornerstone of the quantum world - the inherent uncertainty of quantum systems. Whatever reality is, the aqcuisition of knowledge is inseparable from what it is and how it is observed. The acquisition of knowledge requires that information is meaningful to someone. Sure, one can claim that instruments completely replace the observer, but the observer is never entirely replaced by instruments; for if he were, he could obviously obtain no knowledge whatsoever. Many helpful devices can facilitate this work but they must be read! The observer’s senses have to step in eventually.The most careful record, when not inspected, tells us nothing. And in the cornerstone of quantum theory(the HUP), availablity of information about systems properties is what determines what will be observed.

Following your argument, can you show me the difference between those setups?
a) A computer records an experiment and displays the result to you
b) A human records an experiment and tells you the result
If you see a difference, where does it come from? Is there a fundamental difference between neurons and transistors?
If you do not see a difference, however, imagine a computer (with some advanced AI) asks you the same question. Is this different from me, asking the question?

There is no known physical process which makes human brains special in any way. On the other hand, there are good arguments that it is possible (at least in theory) to fully implement a human brain in electronics.

 

[Maui]

Following your argument, can you show me the difference between those setups?
a) A computer records an experiment and displays the result to you
b) A human records an experiment and tells you the result

These are both the same. The argument is whether a machine recording a reading and displaying it to a wall, chair or a bridge without there ever being a way for it to be read by a perceiving observer is the same as the result being read be an observer. A few experiments and the HUP suggest that classical behavior depends on knowledge about the properties of the quantum systems.

If you see a difference, where does it come from?

No. In your example there is no difference but it wasn't part of what i was discussing - the quantum mechanical counterfactual definiteness in abscence of obeserver.

There is no known physical process which makes human brains special in any way. On the other hand, there are good arguments that it is possible (at least in theory) to fully implement a human brain in electronics.

There are also good arguments why a conscious brain will never be implemented in electronics, so this point is moot.

 

[mfb]

If it does not matter if a computer or a human record the results of the observation, the human brain cannot cause a collapse when the computer does not. Unless you consider collapses are pure "personal" events - so every brain gets its own physics with different collapses. I have no idea how that should work.

There are also good arguments why a conscious brain will never be implemented in electronics, so this point is moot.

Note that "consciousness", independent of the definition (which is problematic anyway) is irrelevant to others, as you confirmed in your post. We can just ignore it for a description of the system.
I don't think that those arguments are good, however. Electronics can do the same as neurons can. Or you can build artificial neurons, if you like.

 

[Maui]

If it does not matter if a computer or a human record the results of the observation, the human brain cannot cause a collapse when the computer does not. Unless you consider collapses are pure "personal" events - so every brain gets its own physics with different collapses. I have no idea how that should work.

You also have no idea how the 'environment' induces collapse, so it's hardly relevant what belief you subscribe to. Believing this wonderful classical world can emerge out of potentials which are not even grounded in anything physical, is as much a fairy-tale as believing in gods. It's dubious if it's even valid philosophy.
So we have an emerging classical reality for which no straight-forward quantum mechanical explanation exists that is in accord with sensory experience, and you consider the fundamental machinery of the world to be potentials that develop in time to single outcomes. OK. The problem with that position is that it makes no sense. What about personal experience, awareness? The behavior of the so called potentials is found to be dependent on knowledge through the complementary nature of the quantum world, so knowledge and awareness cannot simply be passive, emergent phenomena of quantum potentials.

By the same metric, the so called brain is also an emergent and decoherent 'object', so i object to the inference that i ever implied that brains cause collapse. I did not.

Note that "consciousness", independent of the definition (which is problematic anyway) is irrelevant to others, as you confirmed in your post. We can just ignore it for a description of the system. I don't think that those arguments are good, however. Electronics can do the same as neurons can. Or you can build artificial neurons, if you like.

The argument only goes so far without breaking the forum rules. I've seen nothing in quantum theory that suggests or proves that personal experience is not fundamental. For that, you need to resort to sensory experience and beliefs you've been accustomed to hold by the society and which are... well, impossible to logically hold while simultaneously holding onto quantum mechanics(bad philosophy aside that is, and that includes the MWI imo)