Einstein thoughts on the quantum

[Demystifier]

This is why I'm flip-flopping about whether the CI and the SI are two different interpretations or one and the same. The only definition of the CI that I'm comfortable with is CI=SI, but almost no one seems to define it that way.

Yes, I understand why do you think so. One might say that SI is a refined version of CI, with controversial and/or vague aspects of CI removed. Or more formally
SI = CI - BF
where "BF" stands for Bad Philosophy.

 

[Varon]

Yes, I agree.


1. Sounds like the statistical intepretation, plus an attitude problem.
2. Sounds like the statistical interpretation, plus perhaps something else. I'm not sure what that would be though.
3. Isn't the whole point of introducing "collapse" to try to avoid the conclusion that assumption (1) implies many worlds? It might avoid the contradiction I mentioned above, but it introduces another one by saying that some systems with component parts that obey the laws of QM, do not obey the laws of QM.
4. Sounds like the statistical interpretation, restated to try to hide what it really is.

I think 3 can be dismissed because of the artificial quantum/classical border, and I think 1,2 and 4 are only adding confusion to the statistical/ensemble interpretation.

Not correct. In 3 which is mentioned thus:

"3. Collapse interpretation - when the measurement is performed, then the wave function collapses. (von Neumann)"

Note von Neumann was proposing that all is quantum.. that is why there is Process 1 (Collapse) and Process (2) Deterministic and one can insert the cut anywhere (remember von Neumann cut) because he considered everything is quantum in contrast to Bohr's who distinguishes between classical and quantum system. So in von Neumann, there is no artificial quantum/classical border.

Anyway. After reading many strings of threads with your messges and thoughts. I think what you are trying to say is that if wave function describes single system, it's Many Worlds. If multiple system, it's Ensemble Interpretation.

Consequence of this is that. If there is no Many worlds and it's single system. Wave function is invalid since it's for ensemble. So it's like we need a new law of physics to describe single system in ensemble (statistical) interpretation. Hmm...

This is why I'm flip-flopping about whether the CI and the SI are two different interpretations or one and the same. The only definition of the CI that I'm comfortable with is CI=SI, but almost no one seems to define it that way.

 

[Fredrik]

Not correct. In 3 which is mentioned thus:

"3. Collapse interpretation - when the measurement is performed, then the wave function collapses. (von Neumann)"

Note von Neumann was proposing that all is quantum.. that is why there is Process 1 (Collapse) and Process (2) Deterministic and one can insert the cut anywhere (remember von Neumann cut) because he considered everything is quantum in contrast to Bohr's who distinguishes between classical and quantum system. So in von Neumann, there is no artificial quantum/classical border.

I disagree with this. I think any kind of "cut" is inconsistent with QM, unless of course all the talk about a "cut" is just another way to express the ideas of the statistical interpretation in a more confusing way. I don't know exactly who said what, but I don't believe that Bohr believed that there are truly classical objects. This seems to be an opinion attributed to him only by people who misunderstood what he actually said.

After reading many strings of threads with your messges and thoughts. I think what you are trying to say is that if wave function describes single system, it's Many Worlds. If multiple system, it's Ensemble Interpretation.

Yes, that's how I think of it.

 

[Varon]

I disagree with this. I think any kind of "cut" is inconsistent with QM, unless of course all the talk about a "cut" is just another way to express the ideas of the statistical interpretation in a more confusing way. I don't know exactly who said what, but I don't believe that Bohr believed that there are truly classical objects. This seems to be an opinion attributed to him only by people who misunderstood what he actually said.

For over half a century, the following words from John von Neumann's 1932 "Mathematical Foundations of Quantum Mechanics" haunted our mind. Here he described that the cut is arbibrary, and there is no division between classical and quantum. Yet you said you disagree. Pls. comment and elaborate why you think such a cut is inconsistent with QM.

von Neumann said in 1932:

In a simple example, these concepts might be applied about as follows: We wish to measure a temperature. If we want, we can pursue this process numerically until we have the temperature of the environment of the mercury container of the thermometer, and then say: this temperature is measured by the thermometer. But we can carry the calculation further, and from the properties of the mercury, which can be explained in kinetic and molecular terms, we can calculate its heating, expansion, and the resultant length of the mercury column, and then say: this length is seen by the observer.

Going still further, and taking the light source into consideration, we could find out the reflection of the light quanta on the opaque mercury column, and the path of the remaining light quanta into the eye of the observer, their refraction in the eye lens, and the formation of an image on the retina, and then we would say: this image is registered by the retina of the observer.

And were our physiological knowledge more precise than it is today, we could go still further, tracing the chemical reactions which produce the impression of this image on the retina, in the optic nerve tract and in the brain, and then in the end say: these chemical changes of his brain cells are perceived by the observer. But in any case, no matter how far we calculate -- to the mercury vessel, to the scale of the thermometer, to the retina, or into the brain, at some time we must say: and this is perceived by the observer. That is, we must always divide the world into two parts, the one being the observed system, the other the observer. In the former, we can follow up all physical processes (in principle at least) arbitrarily precisely. In the latter, this is meaningless.

The boundary between the two is arbitrary to a very large extent. In particular we saw in the four different possibilities in the example above, that the observer in this sense needs not to become identified with the body of the actual observer: In one instance in the above example, we included even the thermometer in it, while in another instance, even the eyes and optic nerve tract were not included. That this boundary can be pushed arbitrarily deeply into the interior of the body of the actual observer is the content of the principle of the psycho-physical parallelism -- but this does not change the fact that in each method of description the boundary must be put somewhere, if the method is not to proceed vacuously, i.e., if a comparison with experiment is to be possible. Indeed experience only makes statements of this type: an observer has made a certain (subjective) observation; and never any like this: a physical quantity has a certain value.

 

[Fredrik]

I agree with all of that, so I probably shouldn't have said "any kind of cut". I'm really just opposed to the idea that there are systems that QM simply can't be applied to. I guess that no one significant ever actually believed that there are such systems. If von Neumann's "collapse" is just an application of the idea described in that quote, I have to change my assessment of Demystifier's list of versions of the CI from

1. This is the SI in disguise.
2. This is the SI in disguise.
3. This is nonsense.
4. This is the SI in disguise.

to

1. This is the SI in disguise.
2. This is the SI in disguise.
3. This is the SI in disguise.
4. This is the SI in disguise.

 

[Varon]

I agree with all of that, so I probably shouldn't have said "any kind of cut". I'm really just opposed to the idea that there are systems that QM simply can't be applied to. I guess that no one significant ever actually believed that there are such systems. If von Neumann's "collapse" is just an application of the idea described in that quote, I have to change my assessment of Demystifier's list of versions of the CI from

1. This is the SI in disguise.
2. This is the SI in disguise.
3. This is nonsense.
4. This is the SI in disguise.

to

1. This is the SI in disguise.
2. This is the SI in disguise.
3. This is the SI in disguise.
4. This is the SI in disguise.

Besides you. What do you think is the mainstream thought about the idea of collapse say in your colleagues? Do they think the collapse is just in the calculation or do they think the collapse is actual? Can you think of an experimental setup where different observers can have different wave functions yet there is only one true wave function of the systems? I'm still a bit confused about what the mainstream think about collapse and all this. Before trying to sort all this out. I want to know first what you think most physicists believe as in actually believing when it comes to collapse and wave function. Most pop-sci books I read doesn't mention about this distinction, so we the public are not aware of the subtle distinctions and inconsistency.

 

[Varon]

Maybe you misunderstood me. I'm pretty sure that physics can explain the behavior of biological systems, including the behavior that we usually think of as a "conscious" behavior. But that's exactly what the problem is. We can explain the BEHAVIOR in terms of known PHYSICAL mechanisms. But these mechanisms do not involve anything like subjective conscious experiences. Subjective conscious experiences are simply not needed to explain the objective behavior. In fact, the whole scientific method explores the objective, not the subjective. I can measure your voice when you cry, I can measure your EEG waves in the brain when I torture you, but I cannot measure your FEELING of pain. I cannot even conceive how to measure someone's feeling of anything.


It's even more egoistic than you think. It's not about humans, but about myself (or yourself). I feel only my feelings, and nobody else's. If I could experience someone else's feelings, then they would no longer be purely subjective, but objective phenomena researchable by the scientific method. But I can't.

Demystifier. About this subjective conscious experience which you said is not part of our current physics. Don't you think the quantum is related to it? At this point. Let me emphasize I know quantum coherence has nothing to do with the brain and classical states is sufficient for the mechanical brain. But qualia, are you absolutely certain it has nothing at all to do with the quantum? What's your killer arguments?

Also why are you biased about liking Bohmian mechanics which is quite mechanical. At least in a variant of Copenhagen, observers create reality. This has more degrees of freedom for subjective conscious experience. But Bohmiam, what you would have are just boring classical particles and balls... unless you believe Bohm implicate order can override and control them? But still you can't transmute or interchange matter and energy by this Bohmian mechanics.

Also since you believe subjective conscious experience or qualia has more to do with time. What if it has more to do with quantum spacetime? Do you think there is a possibility that physicists won't be able to unite quantum mechanics and general relativity without taking subjective conscious experience into account? or are they unrelated? What's your proof that they are not related at all? this Qualia and quantum spacetime (I prefer calling it this rather than quantum gravity because gravity is just a specific case.. the general case of the unification of qm and gr is really quantum spacetime).

So in this message. Try to prove that:

1. Subjective conscious experience is not related to anything quantum
2. Subjective conscious experience is not related to quantum spacetime (or quantum gravity) [although it may be related only to time in your case]

(For those fellows not updated with neuroscience. Try to read up books like Jeffrey Grey "Creeping up the Hard Problem" where you would be exposed to the science inability to explain subjective conscious experience and latest one like Antonio Damacio "Self comes to Mind". We who discuss brains and quantum mechanics are not ignorant or not unaware of neuroscience. We are updated more than the man on the street)

 

[Demystifier]

Demystifier. About this subjective conscious experience which you said is not part of our current physics. Don't you think the quantum is related to it?

No, I don't.

But qualia, are you absolutely certain it has nothing at all to do with the quantum?

I'm not absolutely certain, but I don't see compelling evidence for it.

But Bohmiam, what you would have are just boring classical particles and balls...

Sure, it's boring. But note that my nick name (partially explaining why I like this boring approach) is not Entertainer.

Try to prove that:

1. Subjective conscious experience is not related to anything quantum
2. Subjective conscious experience is not related to quantum spacetime (or quantum gravity) [although it may be related only to time in your case]

As I said, I cannot prove it, but I don't see compelling evidence for it.

 

[unusualname]

Sure, it's boring. But note that my nick name (partially explaining why I like this boring approach) is not Entertainer.

That is really funny, I do like a cool sense of humour.

Varon. Varon Varon, what the hell do you expect here? The Ultimate answers? geez, calm down man.

It is very probable that we are going through a stage where science comes to terms with an ontological probability in nature. In retrospect all the interpretations will be "ahh that's why" type moments, except for the deterministic ones which will be seen like 19th century aether theories.

But it will take time, until someone proposes a scheme which predicts something new, or reformulates everything known so simply that Occam has to apply. I think once it is correctly formulated it will predict something new (and pretty amazing stuff we can do), but "qualia" will be seen to be a new area of science which doesn't immediately appy to the "Standard Model" for example.

 

[Varon]

No, I don't.


I'm not absolutely certain, but I don't see compelling evidence for it.


Sure, it's boring. But note that my nick name (partially explaining why I like this boring approach) is not Entertainer.


As I said, I cannot prove it, but I don't see compelling evidence for it.

Without subjective conscious experience (qualia). The world would simply be populated by Zombies.. here we won't see smiles, joy, meaning. There would be no arts, no poetry, no paintings, no literature, no movies, In such deprived world, sex would be mechanical, and only missionary position would be possible since zombies only know this positions. Likewise, in Bohmian mechanics, the boring particles are like zombies, going their ways in deterministic manner. Hmm... is this why Bohm proposed the Implicate Order which is like qualia?

But in this Implicate order. Wave particle duality comes back in full force. I think Bohm mentioned how when everything is in implicate order, all is wave, and when they are expressed in explicit order, they become particles. So maybe in the latter part of his life. Bohm tried to put away his earlier all particle approach and got back to this wave-particle approach like Bohr. Therefore what you Bohmians may be doing is reviving Bohm earlier approach which he already disowned. Well? Try to refute that Implicate/Explicate Order is not Wave/Particle duality being reintroduced by Bohm later in his life.

 

[Varon]

Without subjective conscious experience (qualia). The world would simply be populated by Zombies.. here we won't see smiles, joy, meaning. There would be no arts, no poetry, no paintings, no literature, no movies, In such deprived world, sex would be mechanical, and only missionary position would be possible since zombies only know this positions. Likewise, in Bohmian mechanics, the boring particles are like zombies, going their ways in deterministic manner. Hmm... is this why Bohm proposed the Implicate Order which is like qualia?

But in this Implicate order. Wave particle duality comes back in full force. I think Bohm mentioned how when everything is in implicate order, all is wave, and when they are expressed in explicit order, they become particles. So maybe in the latter part of his life. Bohm tried to put away his earlier all particle approach and got back to this wave-particle approach like Bohr. Therefore what you Bohmians may be doing is reviving Bohm earlier approach which he already disowned. Well? Try to refute that Implicate/Explicate Order is not Wave/Particle duality being reintroduced by Bohm later in his life.

I was researching about this angle the past couple of hours in the net and I found the following information:

http://www.tcm.phy.cam.ac.uk/~mdt26/PWT/lectures/bohm8.pdf

It says something like Bohm was bored with his boring old Bohmiam Mechanics by 1957.. and
found bigger game to hunt.. Bohm said:

“One thus sees that a new kind of theory is needed which drops these basic commitments and at most recovers some essential features of the older theories as abstract forms derived from a
deeper reality in which what prevails is unbroken wholeness.”

Therefore Demystifier. Don't say Bohm Implicate Order is just philosophical rumblings to explain the quantum potential. It is much more. It is seed to a new kind of theory altogether that is independent from Bohmian mechanics.

It is mentioned further that:

"Today we briefly survey Bohm’s other more ambitious projects between late 1950s and his death in 1992.

• Bohm was looking to capture what is essential about the more fundamental architecture of the physical world, as revealed in quantum, relativistic and mental phenomena.
• Basic concepts of relativity and QM in complete contradiction. Relativity emphasizes continuity, locality and determinism. QM emphasizes discontinuity, non-locality and indeterminism. Customary to talk about ‘elementary particles’ but these also have wave properties and properties that strongly violate any mechanistic scheme (non-locality, discontinuity of movement, etc..). New ideas required"

In fact, Bohm wrote a book in 1990 called "Wholeness and the Implicate Order" and said:

“All things found in the unfolded, explicate order emerge from the holomovement in which they are enfolded as potentialities, and ultimately they fall back to it. They endure only for some time, and while they last, their existence is sustained in a constant process of unfoldment and re-enfoldment, which gives rise to their relatively stable and independent forms in the explicate order.”

Therefore we must develope this theory and make it a primary one that can compete with Bohm old de Broglie/Bohmians mechanics, Many Worlds, etc. We can also make a Implicate Order/Copenhagen hybrid that is compatible with the Bohr postulate that "In the absence of measurement to determine its position, a particle has no position".

There's hope to boring old mechanical Bohmian Mechanics which even Bohm himself realized in 1957 can be superceded with a more modern Bohrish approach...

 

[Fredrik]

Without subjective conscious experience (qualia). The world would simply be populated by Zombies.. here we won't see smiles, joy, meaning. There would be no arts, no poetry, no paintings, no literature, no movies, In such deprived world, sex would be mechanical,

I think you have misunderstood the term.

and only missionary position would be possible since zombies only know this positions.

...but at least you have a sense of humor about it.

 

[Demystifier]

I think you have misunderstood the term.

You are right. Philosophical zombies, by definition, behave in exactly the same way as normal humans do, and nobody is able to see a difference. The only difference is that the zombies are not conscious about themselves (or anything else).

Of course, this philosophical zombie
http://en.wikipedia.org/wiki/Philosophical_zombie
relevant for the discussion of the philosophy of qualia, should not be mixed with the ordinary horror-movie zombie
http://en.wikipedia.org/wiki/Zombie

 

[Fredrik]

I actually meant that he must have misunderstood "qualia". (I recognize your definition of "zombie", but didn't even think about it when I read Varon's post since he explained what he meant). Qualia isn't a concept that I've spent any significant amount of time thinking about, but I think I understand it well enough to say that it's not safe to conclude that only boring people would exist in a world without qualia.

 

[Demystifier]

... it's not safe to conclude that only boring people would exist in a world without qualia.

I would agree with that too.

 

[atyy]

Isn't being bored a qualum (what's the singular of "qualia"?)

 

[lugita15]

Isn't being bored a qualum (what's the singular of "qualia"?)

quale

 

[Varon]

You are right. Philosophical zombies, by definition, behave in exactly the same way as normal humans do, and nobody is able to see a difference. The only difference is that the zombies are not conscious about themselves (or anything else).

Of course, this philosophical zombie
http://en.wikipedia.org/wiki/Philosophical_zombie
relevant for the discussion of the philosophy of qualia, should not be mixed with the ordinary horror-movie zombie
http://en.wikipedia.org/wiki/Zombie

But what you don't understand is that emotional intelligence is related to qualia (subjective experience). Without qualia, there would be no emotion. So the Zombies (without qualia) won't even know how to be happy or smile. If they win a 200 million lotto for example, they would project how to use the money in the future. But they won't have any sense of enjoyment or bliss. Emotion, like qualia is not in our physics yet. Emotion means Energy in Motion. So physics must explain what energy it is in motion if you want Emotion to be explainable by physics and biochemistry. No amount of programming can give a computer emotion even if you would load it up with sensors. They won't know what is pain. For example. If you rig the computer with explosives if it tries to jump up a building. It would just calculate what would happen and won't have qualia and emotion. Even its learning mode would be ruled by logic. After Scientists discover Quantum Gravity and the Higgs. Do you think they would finally have time to study qualia or emotion? Or would they go to even deeper endeavors like knowing what happens before the big bang or other impossible activities that would soak up a hundred or thousand more years while ignoring the most important questions that actually concern every human on the planet?

 

[Fredrik]

Without qualia, there would be no emotion.

What gave you that idea?

 

[Varon]

What gave you that idea?

Neuroscientist Antonio Damasio. See his latest book "Self comes to Mind"

 

[Fredrik]

I'm not going to read a book about it. But I checked the Wikipedia page. Turns out there are many different definitions. This is the first one:

One of the simpler, broader definitions is "The 'what it is like' character of mental states. The way it feels to have mental states such as pain, seeing red, smelling a rose, etc."​

If we use this one, you're obviously right. Since we're all experiencing this type of qualia all the time (I know that I am, and you know that you are), we can already rule out the possibility that qualia doesn't exist.

The definition I had seen resembles the one attributed to Frank Jackson (1982):

"certain features of the bodily sensations especially, but also of certain perceptual experiences, which no amount of purely physical information includes"​

If we use this definition, your claim would be unjustified.

 

[Varon]

That is really funny, I do like a cool sense of humour.

Varon. Varon Varon, what the hell do you expect here? The Ultimate answers? geez, calm down man.

It is very probable that we are going through a stage where science comes to terms with an ontological probability in nature. In retrospect all the interpretations will be "ahh that's why" type moments, except for the deterministic ones which will be seen like 19th century aether theories.

But it will take time, until someone proposes a scheme which predicts something new, or reformulates everything known so simply that Occam has to apply. I think once it is correctly formulated it will predict something new (and pretty amazing stuff we can do), but "qualia" will be seen to be a new area of science which doesn't immediately appy to the "Standard Model" for example.

Unusualman, you know what. There are 3 kinds of people who delve into the the quantum.

1. Man on the street who doesn't care about it.. because they think their experience is Newtonian. And occasionally read about them for entertainment or just a passing fancy.

2. Scientists who think the quantum has to do with electron, quarks and particle scale... and who focus the quantum on behavior of them like in quantum chemistry, electronics, etc.

3. Neuroscientists and proponents who believe qualia is not explained by current physics and want to seek out answers. I belong to this group. We know that it is increasingly difficult to accept quantum coherence works in the brain as refuted already by Tegmark and company. But if qualia is not part of the quantum (which is related to matter), then what is it part of? Special Relativity? But there is no matter in SR (only Spacetime). This is why we can't avoid the quantum which deals with matter. But if you can categorically prove 100% that qualia is not part of the quantum. Then state so in order that we can move on with this quantum headache and nightmare. The amount of time some of us spend in the QM interpretations for example can make us master of other subjects. I've spend 8 years analyzing this with bits of mathematics that makes bits of understanding after reading hundreds of popular science quantum books. The 8 years spent here would make one take major course in Economics or even Medicine (here all the facts are real and every paper you read make you gain solid knowledge unlike in quantum interpretations where only 2% can eventually be true). So if you someone of you have proof that qualia is just a programming algorithm and nothing to do with new undiscovered physics. Then let us know and let us avoid a possible lifetime of time wasted on understanding dozens of interpretations and hundreds of papers about it.

 

[atyy]

quale

Thank you!

 

[unusualname]

Unusualman, you know what. There are 3 kinds of people who delve into the the quantum.

1. Man on the street who doesn't care about it.. because they think their experience is Newtonian. And occasionally read about them for entertainment or just a passing fancy.

2. Scientists who think the quantum has to do with electron, quarks and particle scale... and who focus the quantum on behavior of them like in quantum chemistry, electronics, etc.

3. Neuroscientists and proponents who believe qualia is not explained by current physics and want to seek out answers. I belong to this group. We know that it is increasingly difficult to accept quantum coherence works in the brain as refuted already by Tegmark and company. But if qualia is not part of the quantum (which is related to matter), then what is it part of? Special Relativity? But there is no matter in SR (only Spacetime). This is why we can't avoid the quantum which deals with matter. But if you can categorically prove 100% that qualia is not part of the quantum. Then state so in order that we can move on with this quantum headache and nightmare. The amount of time some of us spend in the QM interpretations for example can make us master of other subjects. I've spend 8 years analyzing this with bits of mathematics that makes bits of understanding after reading hundreds of popular science quantum books. The 8 years spent here would make one take major course in Economics or even Medicine (here all the facts are real and every paper you read make you gain solid knowledge unlike in quantum interpretations where only 2% can eventually be true). So if you someone of you have proof that qualia is just a programming algorithm and nothing to do with new undiscovered physics. Then let us know and let us avoid a possible lifetime of time wasted on understanding dozens of interpretations and hundreds of papers about it.

Science is usually considered to be about what we can observe (measure) and make quantitative predictions about. We can't measure qualia to make quantitative predictions so this is not part of (current) science (eg PET scans or fMRI of the biological brain are not measurements of qualia).

I doubt Quantum Mechanics can explain our conscious experience of the world any more than Maxwell's theory of electricity and magnetism can.

However, Quantum Mechanics does show us that the world is not a mechanical deterministic one, like ancient people used to think (some still do!), and hints at a more sophisticated nature to reality.

I think it will become clearer once we properly understand QM what we are missing and where we must next look.

 

[unusualname]

btw, in reply to your comment in post #1 about Einstein's reluctance to give up realism, there is a famous quote attributed to Einstein from a discussion with Heisenberg, where Heisenberg was making a similar point to you and Einstein replied that the abstraction of spacetime was all nonsense, and not to be taken literally, just a mathematical framework for making predictions of nature.

"Possibly I did use this kind of reasoning," Einstein told Heisenberg, "but it is nonsense all the same ... on principle it is quite wrong to try founding a theory on observable magnitudes alone. In reality the very opposite happens. It is the theory which decides what we can observe."

http://www.aip.org/history/heisenberg/p07c_text.htm

 

[Varon]

btw, in reply to your comment in post #1 about Einstein's reluctance to give up realism, there is a famous quote attributed to Einstein from a discussion with Heisenberg, where Heisenberg was making a similar point to you and Einstein replied that the abstraction of spacetime was all nonsense, and not to be taken literally, just a mathematical framework for making predictions of nature.



http://www.aip.org/history/heisenberg/p07c_text.htm

Note realism has particular meaning in physics which means there are properties even between measurement. So Einstein can even believe a world existing with merely spin as the observable can be put under realism so long as it has deteministic values in between measurement. Einstein is so advanced with his spacetime physics but why couldn't he go one step further and believe there was no properties before measurement. Maybe because it can falsify his spacetime idea. So the incompatibility between QM and GR already started in the Bohr Einstein debate in 1927 at the Solvay Congress. But at that time, they never plan to unite QM and GR. Did Einstein plan to do that? I wonder what year was this attempt at unification of QM and GR become a serious endeavors or programme. Anyone?

 

[unusualname]

Note realism has particular meaning in physics which means there are properties even between measurement. So Einstein can even believe a world existing with merely spin as the observable can be put under realism so long as it has deteministic values in between measurement. Einstein is so advanced with his spacetime physics but why couldn't he go one step further and believe there was no properties before measurement. Maybe because it can falsify his spacetime idea. So the incompatibility between QM and GR already started in the Bohr Einstein debate in 1927 at the Solvay Congress. But at that time, they never plan to unite QM and GR. Did Einstein plan to do that? I wonder what year was this attempt at unification of QM and GR become a serious endeavors or programme. Anyone?

Unification of QM and GR isn't a problem of realism, it's a problem of developing a field theory which is renormalizable. If that could be done for quantum gravity (like for QED and QCD) then it wouldn't distinguish between realist and non-realist interpretations of QM (but we have the experiments of Zeilinger and others which deal with that).

Einstein already tried to develop a unified field theory in 1920s after hints from Kaluza that a fifth dimension could unify EM and gravity.

Einstein was a master of statistical physics and classical field theories and he firmly believed that all of reality could be described by physical theories founded on these two pillars. He had been right before when only a minority believed his theories and this must surely have made him ultra stubborn against the "baby-face kids" that created QM (heisenberg, pauli, jordan, dirac were all in their early 20s when QM was established, only Bohr, Born and Schrodinger were from Einstein's generation).

Einstein wasn't naive though, he recognised that Bohm/de Broglie's attempt was too simplistic for instance, but he didn't like the almost mystical way the Copenhagen Interpretation seemed to explain reality. I think today he would be satisfied with decoherence and the post-Bell advances in QM experiments which seem to have shown simple ideas of reality are surely wrong,

 

[Varon]

Unification of QM and GR isn't a problem of realism, it's a problem of developing a field theory which is renormalizable. If that could be done for quantum gravity (like for QED and QCD) then it wouldn't distinguish between realist and non-realist interpretations of QM (but we have the experiments of Zeilinger and others which deal with that).

Einstein already tried to develop a unified field theory in 1920s after hints from Kaluza that a fifth dimension could unify EM and gravity.

Einstein was a master of statistical physics and classical field theories and he firmly believed that all of reality could be described by physical theories founded on these two pillars. He had been right before when only a minority believed his theories and this must surely have made him ultra stubborn against the "baby-face kids" that created QM (heisenberg, pauli, jordan, dirac were all in their early 20s when QM was established, only Bohr, Born and Schrodinger were from Einstein's generation).

Einstein wasn't naive though, he recognised that Bohm/de Broglie's attempt was too simplistic for instance, but he didn't like the almost mystical way the Copenhagen Interpretation seemed to explain reality. I think today he would be satisfied with decoherence and the post-Bell advances in QM experiments which seem to have shown simple ideas of reality are surely wrong,

Ok. So serious attempt at quantum gravity occurred after t'Hoof discovered that QED was renormalizable, right?

 

[Fredrik]

Unification of QM and GR isn't a problem of realism, it's a problem of developing a field theory which is renormalizable.

...or a quantum theory of gravity that isn't a field theory at all.

 

[unusualname]

...or a quantum theory of gravity that isn't a field theory at all.

yes, the field theories may just be effective low energy descriptions of something completely different.

 

[unusualname]

Ok. So serious attempt at quantum gravity occurred after t'Hoof discovered that QED was renormalizable, right?

Well, depends what you mean by serious. We may still be at a stage as hopeless as Einstein's attempts at unification due to ignorance about what actually exists in nature (Einstein didn't know the weak and strong forces existed). But assuming it's no more than standard model (+SUSY maybe) + gravity then potentially workable theories have been developed only in the last few decades. Physicists aren't that bothered about mathematical rigour as long as the theory makes correct physical predictions. Feynman et al got the Nobel for qed long before it was made mathematically rigorous. Feynman himself proposed graviton theories in the 1950/60s which was a "serious" attempt at QG.

 

[Varon]

In a message to Alxm, Demystifer wrote:

Maybe you misunderstood me. I'm pretty sure that physics can explain the behavior of biological systems, including the behavior that we usually think of as a "conscious" behavior. But that's exactly what the problem is. We can explain the BEHAVIOR in terms of known PHYSICAL mechanisms. But these mechanisms do not involve anything like subjective conscious experiences. Subjective conscious experiences are simply not needed to explain the objective behavior. In fact, the whole scientific method explores the objective, not the subjective. I can measure your voice when you cry, I can measure your EEG waves in the brain when I torture you, but I cannot measure your FEELING of pain. I cannot even conceive how to measure someone's feeling of anything.


It's even more egoistic than you think. It's not about humans, but about myself (or yourself). I feel only my feelings, and nobody else's. If I could experience someone else's feelings, then they would no longer be purely subjective, but objective phenomena researchable by the scientific method. But I can't.

Demystifier. There is a question that bothered me the whole weekend. Do you think this subjective conscious experience or qualia can be modeled by math? Or could they belong to a realm that is outside math altogether. Is this possible? Or are all things in the universe eventually modellable and describable by the language of math. What do you think?

 

[Demystifier]

Demystifier. There is a question that bothered me the whole weekend. Do you think this subjective conscious experience or qualia can be modeled by math? Or could they belong to a realm that is outside math altogether. Is this possible? Or are all things in the universe eventually modellable and describable by the language of math. What do you think?

It seems to me that it cannot be modeled by math. Which is exactly why science is silent about it.

 

[Varon]

It seems to me that it cannot be modeled by math. Which is exactly why science is silent about it.

Do you think there is unification program that is akin to it. I mean. Is there possibility for example that quantum mechanics and general relativity are emergence of a third theory that is no longer describable by math.. meaning we will never have a quantum gravity or quantum spacetime because it would be beyond physics already. Is this possible? Why and why not?

 

[Demystifier]

Varon, ultimately anything is possible
http://www.fqxi.org/community/forum/topic/466
but that particular idea does not seem very appealing to me.

 

[Fredrik]

a third theory that is no longer describable by math..

If math can't deal with it, then it's not a theory.

meaning we will never have a quantum gravity or quantum spacetime because it would be beyond physics already. Is this possible? Why and why not?

It's conceivable that "the ultimate reality" can't be described by math, but considering how successful the mathematical approach has been so far, it seems more likely that it can be. However, that only means that there is a final description. However, it's possible (I would say very likely) that we will never find it. Even if we do, it may not be falsifiable. (That's why I said "final description" rather than "final theory"; if it's not falsifiable, it's not a theory).