I The need for a "conscious observer"

[PeterDonis]

See the thought experiments in "Sneaking a Look at God's Cards" and "Quantum Mechanics and Experience".

Neither of those are textbooks or peer-reviewed papers. You referred to the many minds interpretation earlier, and I'm familiar with Albert's discussion of it in "Quantum Mechanics and Experience", but it's still just one interpretation among many, and not all interpretations require or involve consciousness in their explanations. If the only point you are making is that such interpretations exist, consider it made.

 

[PeterDonis]

With a measuring apparatus, something external has to extract the information stored in it's memory. You can extract that information without the need of an external agent.

These two sentences seem to contradict each other.

I think you need awareness of consciousness to know what branch of the wave function is being observed.

No, you don't, you just need macroscopic measuring devices that can register different outcomes.

Carroll basically tries to reduce the observer to a rock

Not at all. A rock is highly insensitive to what is going on around it, so it can't function as a measurement device except for extremely crude measurements ("did a volcanic lava flow pass through?", perhaps). Measuring devices can be much, much, much more sensitive without requiring consciousness.

and I think that doesn't make sense in light of recent experiments.

What specific experiments are you thinking of? Bear in mind that all interpretations of QM make the same predictions for experimental results.

 

[entropy1]

If QM from the view of the MWI is determistic, it might suggest that there is no free will. But could free will be accounted for if creatures that have it could have a say in which outcome, which world, which subjective path will be taken, when a measurement is made?

In case of MWI, this would not hold, because all paths are taken. In case of Copenhagen, a single observer can't be deciding outcomes for all other observers, so it wouldn't hold either.

So if this would exhaust all possibilities of concerning the existence of free will, it looks like there is none of it, and that might mean there is no subjective observer deciding outcomes of measurements?

EDIT: It occurs to me that free will could hide in the realm of measurement not made.

If I'm digressing, I apologize.

 

[physika]

.

"EVERYTHING is consciousness"

"nothing exists but OBSERVATIONS"

then, i ask again:

.- if Everything is consciousness, how can exist things out of consciousness ?

.- how can there be Observations of something outside of consciousness, if Everything is consciousness?

I would say consciousness is outside the realm of physical matter and exists independently of it

...your premises are inconsistent logically..

 

[PeterDonis]

If QM from the view of the MWI is determistic, it might suggest that there is no free will.

Only if you think free will is incompatible with determinism. Not everyone agrees with that; there is a large body of literature on the "compatibilism" viewpoint, which says that free will and deterministic physical laws are compatible.

We have had previous threads in which this was discussed in detail.

 

[StevieTNZ]

Neither of those are textbooks or peer-reviewed papers.

As far as I'm aware, they are textbooks used in Philosophy courses. And as being published by university presses, they are peer-reviewed books.

 

[PeterDonis]

As far as I'm aware, they are textbooks used in Philosophy courses.

This is a physics forum, not a philosophy forum. They're not textbooks on physics.

as being published by university presses, they are peer-reviewed books

Not all university press published books are peer reviewed.

 

[Lord Jestocost]

.- if Everything is consciousness, how can exist things out of consciousness ?

Why must something exist out of consciousness (or mind)? You can never be certain whether all of your putative experience of an - so to speak - outer "reality" is not mere imagining; everything could be purely mental. Maybe, you can call this the approach of idealism.

And it should be clear that science cannot - based upon the scientific method - prove whether there exists an outer "reality made of things". Physics cannot design an operational way to underpin, for example, the viewpoint of either idealism or materialism. No way! As Bertrand Russell remarks in "An Outline of Philosophy": „We cannot find out what the world looks like from a place where there is nobody, because if we go to look there will be somebody there.”

 

[PeterDonis]

You can never be certain whether all of your putative experience of an - so to speak - outer "reality" is not mere imagining; everything could be purely mental. Maybe, you can call this the approach of idealism.

The standard name for what you describe here in philosophy is "solipsism".

it should be clear that science cannot - based upon the scientific method - prove whether there exists an outer "reality made of things".

While this may be true from a philosophical viewpoint, it is irrelevant for the discussion in this thread, and indeed for any discussion in a physics forum. Theories in physics make predictions about what we will observe under particular circumstances; the fact that such theories make correct predictions means that our observations have a structure, which is there regardless of whether you believe there is a "reality made of things" which is the source of our observations or not.

The question under discussion in this thread is whether the theory of quantum mechanics requires a conscious observer to make correct predictions. The answer to that question, while it depends on which interpretation of QM you adopt, does not depend on whether there is a "reality made of things" or not, since QM makes predictions without making any commitment to an answer to that question at all.

 

[Lord Jestocost]

For all practical purposes, you can substitute a measuring device for a conscious observer.

Of course! As Nick Herbert remarks in his book “Quantum Reality: Beyond the New Physics”:

“While searching for a natural place to break his chain, von Neumann proved an important mathematical fact that deepens the mystery of measurement. Von Neumann showed that as far as final results are concerned, you can cut the chain and insert a collapse anywhere you please. This means that the results themselves can offer no clues as to where to locate the division between system and measuring device.” [italics in original, LJ]

Where you place the Heisenberg cut can thus be regarded as a “purely epistemological move without any counterpart in ontology” (as N.P. Landsman characterizes Heisenberg’s and Bohr’s reasoning with respect to the cut in his paper “Between classical and quantum”). So to speak – it’s in your head.

That’s the reason why I am always astonished when people try to “exorcise” consciousness from the thinking about quantum physics by making merely bold declarations without any proof.

 

[StevieTNZ]

I believe the approach "all interpretations give the same predictions" is fundamentally flawed. See the thought experiment in "Sneaking a Look at God's Cards" + page 129 "The Character of Consciousness" by David J Chalmers, OUP

 

[StevieTNZ]

This is a physics forum, not a philosophy forum.

I'm well aware of that, but you said they weren't textbooks in your original post.

 

[PeterDonis]

you said they weren't textbooks in your original post

They aren't physics textbooks. Which is what I said when I responded to you. I thought that response was sufficient clarification of what I meant.

 

[physika]

Why must something exist out of consciousness (or mind)? You can never be certain whether all of your putative experience of an - so to speak - outer "reality" is not mere imagining; everything could be purely mental. Maybe, you can call this the approach of idealism.

And it should be clear that science cannot - based upon the scientific method - prove whether there exists an outer "reality made of things". Physics cannot design an operational way to underpin, for example, the viewpoint of either idealism or materialism. No way! As Bertrand Russell remarks in "An Outline of Philosophy": „We cannot find out what the world looks like from a place where there is nobody, because if we go to look there will be somebody there.”

hey soothe relax

he said that, not me

I would say consciousness is outside the realm of physical matter and exists independently of it (which can give rise to something observing the beginning of the universe). This is basically the essense of the mind-body problem in philosophy.

i just, showed to him a logical inconsistency in his premises.
re-read, that way you will understand..

 

[physika]

The question under discussion in this thread is whether the theory of quantum mechanics requires a conscious observer.

I agree..

 

[AlexCaledin]

Agnosticism seems the only scientific answer! If every observed property is collapse-generated, then how can our science ever know how exactly that collapse works...

(So, the theory has to consider toy systems - real cats not allowed! - with abstract collapse.)

 

[EPR]

[

Agnosticism seems the only scientific answer! If every observed property is collapse-generated, then how can our science ever know how exactly that collapse works...

(So, the theory has to consider toy systems - real cats not allowed! - with abstract collapse.)

I agree. Measurement is everything."Our experiment confirms Bohr’s view that it does not make sense to ascribe the wave or particle behaviour to a massive particle before the measurement takes place."

https://www.nature.com/articles/nphys3343

 

[EPR]

As for the observer question - we're basically animals, like the other animals found in Nature.

I feel there's a strong probability that our perception is quite limited wrt the world out there.
As I've argued before here(and got thread banned), how we 'see' the world is a construct(a mental representation) in the brain. Reality out there probably looks a bit like it appears to us... but surely(looking at our current physical theories) the senses and perception are very basic, primitive, limited and filter out the unnecessary elements for survival.

With better models, we could one day find all the intricacies that were left out of our arcane perception during evolution(be it many worlds, other realities, multiple hidden dimensions, etc.). Einstein said the world out there is weirder than we can imagine. It is.
I do have a feel that our brains play some role in how we perceive the world as a classical reality picking out elements and creating sensations like the icons on your desktop which are there but the inner workings and mechanisms of their manifestation remain hidden and invisible.

The observer is still mostly blind to the wider reality. But we're slowly getting better thanks to scientists who don't believe we've reached the end of the road, yet.

 

[Jehannum]

With the exception of the Wigner interpretation (for which even Wigner himself eventually withdrew support), a conscious observer plays absolutely no role in any of quantum mechanics.
Collapse of the wave function (assuming an interpretation that posits it) is unrelated to consciousness, else the universe could never have evolved a conscious observer.

In a superposition of wave functions of the universe, one of them would contain a conscious observer that could cause collapse. Consciousness is therefore inevitable!

Not that I think any of this is true, I hasten to add. It's just an intriguing idea I heard a long time ago.

 

[physika]

As for the observer question - we're basically animals, like the other animals found in Nature.
I feel there's a strong probability that our perception is quite limited The observer is still mostly blind to the wider reality.

...and who will know how exaggeratedly wide it is

.

 

[physika]

In a superposition of wave functions of the universe, one of them would contain a conscious observer that could cause collapse. Consciousness is therefore inevitable!

.

observers before the Big Bang, how ?.

 

[Jehannum]

The wave function is a mixture of all possibilities, at least one of which would contain conscious observers.

Note: I was only kidding about this.

 

[edmund cavendish]

Bishop Berkeley claimed that "esse est percipe" to be is to be perceived. His view was that in the absence of a human observation, God 's perception sustained the universe This may come from a different angle but it takes the argument beyond the necessity of human observation. Arguably whatever does that validates the claim.

 

[atyy]

Bishop Berkeley claimed that "esse est percipe" to be is to be perceived. His view was that in the absence of a human observation, God 's perception sustained the universe This may come from a different angle but it takes the argument beyond the necessity of human observation. Arguably whatever does that validates the claim.

https://arxiv.org/abs/quant-ph/0306072
p22 "The Existential Interpretation" has a picture that seems to mean the universe observing itself

 

[Sunil]

Actually, it's more subtle than that. Information exists only wrt minds. A computer is a collection of transistors which act as electrical gates. What you see on the monitor is photons emitted by diodes according to the momentary state of the gates in the microprocessor. You need a mind for this emitted light to become information. Otherwise, it's just light(photons). Like this sentence. It has meaning wrt to minds, but not wrt to photons with different wavelengths being emitted in a particular way.

No, that's wrong.

IIRC Feynman has explained that nicely in his lectures. Imagine a double slit, and use some photon to measure which slit is used. And then forget about the photon completely. So, that photon is not information for any mind, and plausibly will never become such information.

But it acts in exactly the same way as if it is information for some mind. The superposition will be destroyed, you will not see an interference picture.

 

[PeterDonis]

This thread has run its course and is now closed.