The Many-Worlds Interpretation of QM

[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)

 

[nazarbaz]

If physicists were more interested in philosophy, they would know that the diversity of interpretations is unsolvable and that there's no point to choose one of them over the others. My "personal view" (and I say this with a bit of detachment and irony) : if you could make a different choice, then don't choose at all : that's the only interesting aspect of the "shut up and calculate" approach.
The idea that science is self sufficent and self consistent is worst than the worst philosophical non sense I know of, though : it's an essentialist dogma or a religious belief. The real interest and function of philosophy is to exceed our actual limitations and to build an understanding to our experience : contain it into a mere epistemology is to underestimate and misuse it. Thinking about science results is dangerous but necessary. In that regard, philosphy - the real one - always begins when science stops.
The most fundamental issue modern science has to address is to know more about the way mathematics relates to reality : otherwise, we wouldn't be anything else than blind kids playing with colors and light. I doubt that the scientific method itself has something to say about it.
There's is no mystery per se out there, just a beautiful cosmic process yet to be discovered.

PS : sorry for my terrible english.

 

[Alexis1304]

M.Kaku

Folks, have alook how M.Kaku commented on Nobel Prize 2012, and how he talks about "electron been at 2 places" .He says "it means the universe has splitted":

http://bigthink.com/dr-kakus-universe/nobel-prize-awarded-to-two-quantum-physicists


Is electron at 2 places a "double slit" experiment?

For some reason,lately Kaku was criticized by few physicists

 

[Quotidian]

the human brain cannot cause a collapse when the computer does not.

Nowhere is it suggested that 'the human brain' causes a collapse. The act of observation 'collapses' the probability wave, but here the word 'collapse' is strictly metaphorical. A probability wave is not an actual phenomenon in the first place: it is simply the odds of locating the 'particle' in a particular location at the time the observation is made. Until the observation is made, the particle cannot be said to exist in a particular location. When it is observed, the chance of it being in some other location, apart from the one it was measured in, 'collapses' to zero. And this doesn't mean it was lurking somewhere until it was measured; until it is measured, it has no particular location. That, I believe, is the import of 'superposition'.

So the 'probability wave' itself is a purely intellectual construction. It is a way of predicting results, but it does not exist in reality. As an 'intellectual construction', I suppose one needs a brain to be able to grasp it, but the degree to which it 'exists in a brain' is surely a moot point.

Also with regards to your assertion of the equivalence of minds and computers - there's a very fundamental point you're missing in all of this. Minds understand the nature of representation. When a mind represents something by way of a symbol, the interpretation of the meaning of the symbol is the act of an intelligence. The etymology of the word 'intelligence' is from 'inte-legere', 'to read between'. Computers themselves never do that. They are entirely symbolic, not conscious or intellectual. Essentially a computer is a very complex abacus. This is the subject of John Searle's Chinese Room argument. But that is a separate topic.

The most fundamental issue modern science has to address is to know more about the way mathematics relates to reality

As you say, not a scientific question, as such. I rather like the Pythagorean approach, however, that number constitutes reality. If you contemplate the degree to which nearly everything in physics and cosmology is articulated by way of number, this might not seem such an exotic idea.

You might be familiar with this classic essay, but if not, it's worth knowing about - http://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html by Eugene Wigner.

 

[mfb]

Nowhere is it suggested that 'the human brain' causes a collapse.

Good. I read some posts where I got that impression.

So the 'probability wave' itself is a purely intellectual construction. It is a way of predicting results, but it does not exist in reality.

That is a possible interpretation, but not the only one.

Also with regards to your assertion of the equivalence of minds and computers - there's a very fundamental point you're missing in all of this. Minds understand the nature of representation. When a mind represents something by way of a symbol, the interpretation of the meaning of the symbol is the act of an intelligence. The etymology of the word 'intelligence' is from 'inte-legere', 'to read between'. Computers themselves never do that.

Computers do not do that as they are not programmed to do that. That is just a software thing, however.
Ignoring engineering issues: If you can fully scan and simulate a human brain on the level of individual molecules, the results of that computation (the simulated interactions with the environment) should be the same as the result of a real brain. The simulation can be written in current programming languages. I think an effective model of the cells would be sufficient to get the same results, but that is a technical detail.


@Maui: Okay, I am not going to reply to posts from you again, that is just pointless.

 

[Quotidian]

If you can fully scan and simulate a human brain on the level of individual molecules, the results of that computation (the simulated interactions with the environment) should be the same as the result of a real brain. The simulation can be written in current programming languages. I think an effective model of the cells would be sufficient to get the same results, but that is a technical detail.

Not. No matter how many, and what kind, of bricks you assemble, you can't build a violin. Violins are not made from bricks. That is an analogy for what you are suggesting here. 'An idea' is not something that exists in symbolic form. 'An idea' can be represented in symbolic form, but it always takes a perceiving subject for it to actually be 'an idea'.

The reason this is so easily overlooked is because you can safely assume that those to whom you are speaking are subjects and are conscious. Those subjects will understand the nature of representation, becuase they're intelligent. So it is then easy to project that ability onto artificial systems. But what you're seeing there, is simply a projection of your own intelligence. It is not something that the device actually possesses. It is not as if the device is actually intelligent. It seems intelligent, because humans know enough about intelligence to imbue the device with the simulcrum of intelligence. But it is not actually intelligent.

So saying that computers are not intelligent because they are not programmed to be intelligent, is like saying that they don't defy gravity becuase they're not programmed to defy gravity. Of course, they can't defy gravity, it is not something a device can be programmed to to.

This is all simply one of the common delusions of the technologicl society. But as it is tangential to the main point, I won't pursue it further.

 

[bhobba]

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.

There is a very large amount of scholarly literature and even standard textbooks that say otherwise eg:
https://www.amazon.com/dp/3540357734/?tag=pfamazon01-20

There are issues and they are being actively investigated but by no stretch of the imagination is the situation as bad as you say. For example the emergence of a classical world from the quantum is now pretty well understood. And the reality or otherwise of a system state has nothing to do with that emergence. The reason something 'real' can emerge from something that may be simply a theoretical concept is what emerges corresponds with what we experience. Its the same way gas laws emerge from the laws of probability even though probability does not exist is a real sense exactly like some think of quantum states.

The truth of the matter is eloquently described by the following Wikipedia article I linked to before and will quote again because it sums up the situation well:
'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".'

The issue here is '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.' Some believe we need more that an explanation of the appearance of wavefuntion collapse - but that is a matter of opinion - which this whole interpretational thing is - a matter of opinion - not the bleak picture you paint.

Thanks
Bill

 

[bhobba]

For some reason,lately Kaku was criticized by few physicists

The issue with Kaku when I have heard him wax lyrical about quantum stuff is he will say some very controversial statement such as the electron is in two places at once that is very interpretation dependent then say - get used to it. Not the most balanced view.

Thanks
Bill

 

[bhobba]

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.

That view is logically unassailable but leads to a very quirky view of the world especially from the view of computer science. It would mean the bits of information that travel around a computer system and studied by computer scientists do not objectively exist because they have not been observed. If you promulgated that view in a CS class its unlikely anyone would take you seriously. It wouldn't matter if your view was the only one that is possible but it isn't - not by a long shot.

Thanks
Bill

 

[bhobba]

If physicists were more interested in philosophy, they would know that the diversity of interpretations is unsolvable and that there's no point to choose one of them over the others.

They know that, philosophy or no philosophy. And most physicists don't ague about it - they have some interpretation that allows them to apply it and that's it. Sometimes research appears like Bells stuff and decoherence that sheds light on the issue and people may now think it suggests a new interpretation, makes a different one more appealing, or even disproves some previous ones. To apply QM you must choose an interpretation even if its the shut-up and calculate Minimal Statistical Interpretation that is simply the math - its unavoidable.

Thanks
Bill

 

[bhobba]

If you can fully scan and simulate a human brain on the level of individual molecules, the results of that computation (the simulated interactions with the environment) should be the same as the result of a real brain. The simulation can be written in current programming languages. I think an effective model of the cells would be sufficient to get the same results, but that is a technical detail.

I think you are correct and believe anyone who thinks otherwise is a bit kooky, but it must be said there are people like Roger Penrose who do not agree with it. The tenant of books like the Emperors New Mind is that consciousness has qualities that can not be simulated. I suspect it is that kind of view the consciousness causes collapse crowd adhere to.

As an aside I actually did believe in another view of Penrose's - the literal existence of a Platonic world where the truths of math and physics literally reside - nearly everyone believed that was kooky as well - but it did explain some puzzling things like what was espoused in Wigners famous essay:
http://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html

Then I came across some writings of Murray Gell-Mann on how emergence solves the issue and quickly converted to it. My suspicion is the consciousnesses causes collapse crowd haven't understood the latest research such as decoherence that also renders consciousness causes collapse redundant in the same way. Wigner did - but for some reason it still holds sway in certain circles.

Thanks
Bill

 

[Quotidian]

As regards Wigner's 'kooky' essay on 'the Unreasonable Efficiency of Maths', let's not loose sight of the fact that he won the Nobel for atomic physics. I seem to recall he was one of the pioneers of the concept of mathematical symmetries. This has actually proven to be an extremely influential notion in physics, has it not? Yet it is all based on mathematical predictions, that is, patterns of symettry that appear in the purely intellectual realm, which have been subsequently validated, in some cases, by real-world discoveries. In other words, mathematics makes accurate predicitions about nature, which we would have no way of knowing through mere experience. Through mathematical reasoning, Einstein made predictions which could not even be validated until half a century after he made them. as the instruments did not exist.

Or Galileo, who said that 'the book of nature is written in mathematics'. Is that also 'kooky'?

As regards Penrose's view of Platonism - it is not a matter of trying to imagine a literal 'realm' within which numbers are 'real' floating around 'out there'. Number is, in some sense, simply an abstraction of a general attribute of reality itself. Why? Because it holds in regards to all different kinds of material particulars. If you have 'three' of something, then it doesn't matter what kinds of thing you are referring to - bananas, electrons, or planets. Similarly with logical laws, like the law of the excluded middle: these are not true in regard to particular things. They express general truths about the nature of thought itself. That is why they are called 'the laws of thought'. So the general Platonist idea is that such things as logical and numerical truths, are on a deeper level of truth than material particulars, because they are true in all times and places. Indeed it was that type of understanding which made the whole notion of a general theory possible, and one of the main reasons that the scientific revolution happened in the West. But now science has lost sight of the very type of reasoning which made it possible in the first place.

In actual fact, Wigner, Heisenberg, and many other scientists came to the view that the fundamental constituents of reality were much more like numbers than like material objects. And the point about numbers is, they are only real for a rational intelligence. Creatures are incapable of grasping such ideas, because they are not rational. Only a rational being is capable of grasping rational concepts such as number, and in the natural realm, there is only one type of being that satisfies that requirement.

The tenant of books like the Emperors New Mind is that consciousness has qualities that can not be simulated.

'Tenet'. Indeed he does say that. It has never been remotely shown that an artificial device is conscious. As I said above, in order to believe that, you have to believe that a symbol is itself capable of awareness, which is obviously fallacious. A computer is a box of switches that manipulates code which represents symbols that are understood by humans. The computer understands nothing in its own right, however.

Actually there's an amusing irony that I have thought about. I note many people vehemently deny that a human is anything other than a computer. If you take issue with that, they become annoyed.

Do computers become annoyed?

 

[kith]

A computer is a box of switches that manipulates code which represents symbols that are understood by humans. The computer understands nothing in its own right, however.

I agree as far as present day technology is concerned, but not in principle. Natural history suggests that unconscious beings evolved into conscious ones. If we accept this, I don't see a reason why a sophisticated enough machine shouldn't be capable of consciousness as well.

 

[ImaLooser]

I agree as far as present day technology is concerned, but not in principle. Natural history suggests that unconscious beings evolved into conscious ones. If we accept this, I don't see a reason why a sophisticated enough machine shouldn't be capable of consciousness as well.

Concepts that assign a superior status to human beings tend to be more popular.

 

[mfb]

Not. No matter how many, and what kind, of bricks you assemble, you can't build a violin. Violins are not made from bricks. That is an analogy for what you are suggesting here.

Bricks are not Turing complete, but computers (with software) are. It is possible to accurately simulate the interaction of particles in a computer, and a brain is made out of particles - no experiment found anything else yet.

'An idea' is not something that exists in symbolic form. 'An idea' can be represented in symbolic form, but it always takes a perceiving subject for it to actually be 'an idea'.

You can share ideas with others via the internet. In other words, it is possible to encode an idea in a computer (in strings of English, for example). You "just" need a software which can work with those ideas, like a human brain can do it.

Only a rational being is capable of grasping rational concepts such as number, and in the natural realm, there is only one type of being that satisfies that requirement.

Sure, but there is no known law of physics "a rational intelligence has to be a human", and I think such a law would be really strange. There is no sharp line between humans and other animals anyway - we evolved out of other species!

It has never been remotely shown that an artificial device is conscious.

It has never been shown that a spacecraft can travel at 1% the speed of light either, but there is no reason to expect a fundamental problem with that. In addition, consciousness is hard to define and quantify, even for humans.

A computer is a box of switches that manipulates code which represents symbols that are understood by humans.

A human is a box of neurons that manipulate electric potentials and currents. Its output can be understood by other humans (sometimes).

Do computers become annoyed?

If the AI is good, it will probably have something which can be described as "annoyed".

 

[jambaugh]

If physicists were more interested in philosophy, they would know that the diversity of interpretations is unsolvable and that there's no point to choose one of them over the others. My "personal view" (and I say this with a bit of detachment and irony) : if you could make a different choice, then don't choose at all : that's the only interesting aspect of the "shut up and calculate" approach.

Your are correct about there being no point in choosing one over the other but...It is solvable within science via the power tool of Occam's razor. The lack of empirical distinction between ontological interpretations prescribes that we excise ontological interpretation!
And as you say the proper choice is "not to play the game" (of ontological [re]interpretation). QM already has an existing operational interpretation before these questions of re-interpretation come up. Your conclusion is exactly the resolution made in the Copenhagen Interpretation. Since the "underlying reality" is not empirically testable it is meaningless in the context of science and should be excised along with the luminiferous aether and other such artifacts of our reflex to build models. So abandon reality and "shut up and calculate" so to speak.

The idea that science is self sufficent and self consistent is worst than the worst philosophical non sense I know of, though : it's an essentialist dogma or a religious belief.

Not true! science is self sufficient (sufficiency being contextual) it is just that e.g. science is insufficient to tell me what tastes good, only how to better prepare something with a given taste. It is not sufficient to define aesthetics, but it provides knowledge about techniques for achieving aesthetic goals. Add two or three other examples here from ethics, politics, et al.

Science is a specific discipline of epistemology, a specific school of thought within a specific branch of philosophy. Few advocates of science that I've ever heard of claim it is sufficient to all branches, but I as a positivist claim it is sufficient as an epistemology to all branches.

Logic can only bridge assumptions (axioms) to conclusions (proved statements). To test one's assumptions one has to invoke some epistemological method. I can invoke an authority but you may not accept that authority. Which authority to accept (which religious text or prophet e.g.) is a meta-epistemological question. Accepting any authority on faith is an abdication of one's personal responsibility to one's self to find the best means to truth. (Take my word for that, I got a PhD so you shouldn't question me!) The meta question of whether to accept a given authority is again resolvable via the epistemology of empiricism. Has that authority in the past been correct on their testable claims? The positivists like myself point out that the only epistemological foundation which can be shared in a social setting (e.g. a courtroom) is the epistemology of science. IT says, don't take my word for it if you doubt, go and do your own empirical observations and you will see what I see, or if you don't, tell me and I'll recheck my premises.

The real interest and function of philosophy is to exceed our actual limitations and to build an understanding to our experience : contain it into a mere epistemology is to underestimate and misuse it.

Firstly "exceeding one's actual limitations" is an oxymoron. If exceeded they were not limitations. The phrase is properly used with the implied qualifier "(perceived) limitations" and in that context you're use is improper. Secondly you're reversing things here, science does not claim to be all of philosophy (that is to say, scientists don't make that claim). The positivist claims it is the culmination of epistemology, the first best method. Only you have made this underestimation and misuse. I perceive that you are setting up a rationalization in your mind to disregard the value of science in the way you are "twisting" claims here. Rethink your motivations in this and see if I'm off base or not.

Thinking about science results is dangerous but necessary. In that regard, philosphy - the real one - always begins when science stops.

By what criterion do you select "the real one"? and why should I accept your criterion? How do we decide? This is a question of semantics, what is "the real philosophy"?

The most fundamental issue modern science has to address is to know more about the way mathematics relates to reality : otherwise, we wouldn't be anything else than blind kids playing with colors and light. I doubt that the scientific method itself has something to say about it.
There's is no mystery per se out there, just a beautiful cosmic process yet to be discovered.

PS : sorry for my terrible english.

You're English is quite good, better than some of my students' (in the US btw). I agree with your last sentiment except there are mysteries to resolve about the nature of that beautiful cosmic process. I don't quite agree with your "most fundamental issue". Specifically science isn't just doing the math. It can be done without mathematical tools. When a chef doesn't simply take the time in the oven as given but sticks a knife in the pie to see if it is done, he is practicing science, i.e. knowing by checking empirically. In the courtroom where empirical evidence must be presented in support of the assertions of the accuser, or else their claims are rejected, then you again have science. Again it is the only rational means to knowledge in a social setting and I become quite passionate about defending the integrity of science when some attempt to twist its meaning into mysticism (believe in e.g. realities which can't be observed), or side-step it (implementing policies in government based on assertions with no foundation in empirical evidence...).

I don't see this as just an academic debate. It is an issue of the foundations of our civilization and quite literally life and death hang in the balance. (And I despair sometimes at the trends I see in our society to move away from or disfigure science.)

 

[Quotidian]

Good post above. Well stated.

A human is a box of neurons that manipulate electric potentials and currents

Says who? Humans are obviously not boxes, and neurons obviously not switches. Fails even as a metaphor.

a brain is made out of particles

Which explains what? There once was a time when the idea that 'things were made out of particles' was thought to be explanatory of practically everything. Now, however, the 'particles' themselves are things which are devilishly hard to explain - hence this thread, hence a lot of what is written in this forum.

In addition, consciousness is hard to define and quantify, even for humans.

You got that right.

 

[yossell]

You're English is quite good

Irony much? (Sorry - I couldn't resist! Did like your post though!)

 

[bhobba]

As regards Wigner's 'kooky' essay on 'the Unreasonable Efficiency of Maths', let's not loose sight of the fact that he won the Nobel for atomic physics. I seem to recall he was one of the pioneers of the concept of mathematical symmetries. This has actually proven to be an extremely influential notion in physics, has it not?

Sorry if what I wrote wasn't clear.

Wigner was a very great Nobel prize winning mathematical physicist - one of the greatest that ever lived. That essay was not kooky in any way - in fact it raised a very difficult to answer issue that led me to the kooky view of Penrose for the literal existence of a Platonic realm. However I recently came across some writings by Murray Gell-Mann on emergence that solved the issue to my satisfaction without invoking such a weird idea.

BTW Penrose is also a great mathematical physicist and when I say his ideas are a bit kooky that's because they are a bit different to the generally held views - his stature means they must be taken seriously.

Thanks
Bill

 

[Alexis1304]

The issue with Kaku when I have heard him wax lyrical about quantum stuff is he will say some very controversial statement such as the electron is in two places at once that is very interpretation dependent then say - get used to it. Not the most balanced view.

Thanks
Bill

Hi Bill,
What exactly is controversial? I think "electron at 2 positions at the same time" is known fact in Quantum Mechanics,the question is what it means? For Kaku and some others it means the universe "splitted" but as I understand there is no consensus about it. And the work of these Nobel Laureats was great achievement in that one team succeded to put photons in superposition and another to put ion at different energy at the same time. But I'm puzzling by Kaku's statement about electron in 2 places as "universe splitted".

On the side note, I aksed one of the most known quantum physicist of Great Britain about this article of Kaku about Nobel Prize. He responded,that it is great achievement,but just confirmation of standart QM predictions

 

[Nugatory]

What exactly is controversial? I think "electron at 2 positions at the same time" is known fact in Quantum Mechanics, the question is what does it mean?

The known fact is somewhat weaker, something more along the lines of "we get really good predictions of experimental results from a mathematical formalism that doesn't always allow us to ask which position the electron is in".

But you are right about the question: What does that mean? "It means the electron is in two positions at the same time" is one possible answer, but it that is neither non-controversial nor the only answer.

 

[Alexis1304]

The known fact is somewhat weaker, something more along the lines of "we get really good predictions of experimental results from a mathematical formalism that doesn't always allow us to ask which position the electron is in".

But you are right about the question: What does that mean? "It means the electron is in two positions at the same time" is one possible answer, but it that is neither non-controversial nor the only answer.

Hi,thanks for the reply.

Have You read the article by Kaku that I linke in one of my previous posts? He analyzes the work of Nobel Laureats, but I think his mention of "electron in 2 positions" was well known before this work of Wineland and Haroche. He also says that until now this superposition was only theoretical but they demonstrated is as practical.Anyway, I think that "electron in 2 places" is a well known double-slit. Or I am wrong

 

[bhobba]

I think "electron at 2 positions at the same time" is known fact in Quantum Mechanics,the question is what it means?

Well some interpretations of QM like the ensemble interpretation do not ascribe any proprieties to an object like an electron until its measured. Its subtleties like that that Kaku glosses over with statements like that. But to be fair its not really possible get across QM in shows like Kaku appears on without broad statements like that. I am certain he knows more than enough of QM to realize its not quite that 'easy'.

Thanks
Bill

 

[bhobba]

The known fact is somewhat weaker, something more along the lines of "we get really good predictions of experimental results from a mathematical formalism that doesn't always allow us to ask which position the electron is in".

But you are right about the question: What does that mean? "It means the electron is in two positions at the same time" is one possible answer, but it that is neither non-controversial nor the only answer.

Like it

Thanks
Bill

 

[bhobba]

Anyway, I think that "electron in 2 places" is a well known double-slit. Or I am wrong

That's only one way of looking at it - others exist. Its neither right or wrong simply interpretation dependent. Pick one - anyone - and decide for yourself. As you learn more QM you may change it - but that's cool.

Under my interpretation it doesn't have any property until its made 'real' as a mixed state by decoherence.

Thanks
Bill

 

[Alexis1304]

Well some interpretations of QM like the ensemble interpretation do not ascribe any proprieties to an object like an electron until its measured. Its subtleties like that that Kaku glosses over with statements like that. But to be fair its not really possible get across QM in shows like Kaku appears on without broad statements like that. I am certain he knows more than enough of QM to realize its not quite that 'easy'.

Thanks
Bill

So, You mean that "electron being in 2 places at one" DOESN'T nescesseraly mean "universe splitted" and other interpretations of that are available?