Why can't there be a Universal Interpretation of Quantum Mechanics?

[Quantum Alchemy]

Why can't there be a Universal Interpretation of Quantum Mechanics? If you unite Copenhagen and Many Worlds than all other interpretations will fall under the umbrella of a Universal Interpretation of Quantum Mechanics.

The main problem with interpretations seems to be the role of the observer and consciousness. On one side, you have many worlds proponents who want to reduce the role of the observer. On the Copenhagen, QBism side, the observer is very important.

If both sides give a little, then you can have a Universal Interpretation of Quantum Mechanics. How would it look?

You would have Quantum Field Theory(QFT) that describes objective reality and an underlying field of probability densities. You would have QM that describes the observers local experience. This would be wave function collapse which means a local observer can just observer one probable state at a time of the underlying quantum field of probability densities.

Wouldn't this satisfy all interpretations of Quantum Mechanics? In this case the wave function would act as a mediator between the underlying objective Quantum Field and the local observers experience.

Can this be put into mathematical form? Maybe someone with more mathematical knowledge could say if a Universal Interpretation of Quantum Mechanics is plausible.

 

[PeroK]

Can this be put into mathematical form? Maybe someone with more mathematical knowledge could say if a Universal Interpretation of Quantum Mechanics is plausible.

The mathematics of QM is the same in all interpretations. The various interpretations are different interpretations of the same mathematics.

 

[Quantum Alchemy]

The mathematics of QM is the same in all interpretations. The various interpretations are different interpretations of the same mathematics.

I know that but isn't there away to mathematically describe an underlying objective world of probability and also the subjective experience of the observer within QM? If you can't, it would seem to me that all interpretations of QM are useless. Anyone smart enough can come up with an interpretation and in an ad hoc way fit it with the mathematics of QM.

So my point is, within the existing mathematics, is there room for a Universal Interpretation of QM that satisfies all sides.

 

[PeterDonis]

Why can't there be a Universal Interpretation of Quantum Mechanics?

Because different interpretations say things that contradict each other.

If you unite Copenhagen and Many Worlds

You can't, because they say things that contradict each other.

Wouldn't this satisfy all interpretations of Quantum Mechanics?

No. What you describe is inconsistent with the MWI since in what you describe, local observations have single outcomes.

 

[Quantum Alchemy]

Because different interpretations say things that contradict each other.
You can't, because they say things that contradict each other.
No. What you describe is inconsistent with the MWI since in what you describe, local observations have single outcomes.

They don't really say things that contradict each other. Again, uniting Copenhagen and MWI would just be saying there's an objective world of probability and a subjective world of experience that occurs because the observer reduces the interference between probable states. So when an observer collapses the wave function it's collapsing interference between probable states and having a subjective experience. Probable states don't collapse just the interference between these states for the local observer.

We have Scientific evidence to support this:

Quantum Theory Demonstrated: Observation Affects Reality

In a study reported in the February 26 issue of Nature (Vol. 391, pp. 871-874), researchers at the Weizmann Institute of Science have now conducted a highly controlled experiment demonstrating how a beam of electrons is affected by the act of being observed. The experiment revealed that the greater the amount of "watching," the greater the observer's influence on what actually takes place.

The research team headed by Prof. Mordehai Heiblum, included Ph.D. student Eyal Buks, Dr. Ralph Schuster, Dr. Diana Mahalu and Dr. Vladimir Umansky. The scientists, members of the Condensed Matter Physics Department, work at the Institute's Joseph H. and Belle R. Braun Center for Submicron Research.

Apart from "observing," or detecting, the electrons, the detector had no effect on the current. Yet the scientists found that the very presence of the detector-"observer" near one of the openings caused changes in the interference pattern of the electron waves passing through the openings of the barrier. In fact, this effect was dependent on the "amount" of the observation: when the "observer's" capacity to detect electrons increased, in other words, when the level of the observation went up, the interference weakened; in contrast, when its capacity to detect electrons was reduced, in other words, when the observation slackened, the interference increased.

https://www.sciencedaily.com/releases/1998/02/980227055013.htm

I'm not naive though, and I realize this view would never be accepted because a fight over the role of the observer is just a proxy fight about consciousness. So for a strict materialist to give an inch on the role of the observer is tantamount to admitting God exists. Even though it's not, it's obvious that strict materialist want to reduce the role of the observer to nothing and this has everything to do with consciousness.

I was recently watching videos from Closer to the Truth and this illustrates my point. These Scientist were asked to explain the role of the observer and Sean Carroll a strict materialist/atheist reduced the role of the observer to that of a rock and Paul Davies says the observer is very important.

So these interpretations all point back to consciousness by proxy through the observer. I think a Universal Interpretation of QM makes more sense because you're saying QM and QFT are describing 2 different realities. One that's objective and contains all of these probable states and one that's subjective and looks at how local observers experience one of these probable states or the other. I don't see why based on what we know, both objective and subjective realities can't coexist.

 

[PeterDonis]

They don't really say things that contradict each other.

Yes, they do. MWI says all results of any measurement happen. Copenhagen says only one does. Those are contradictory statements.

We have Scientific evidence to support this

This "evidence" does not support what you are claiming. It certainly does not support the claim that no QM interpretations say things that contradict each other.

 

[Demystifier]

If you unite Copenhagen and Many Worlds

How exactly would you do that?

Speaking of unification, in my "Bohmian mechanics for instrumentalists" I proposed a unification of Copenhagen and Bohmian interpretation.

 

[Quantum Alchemy]

Yes, they do. MWI says all results of any measurement happen. Copenhagen says only one does. Those are contradictory statements.

They're not contradicting statements at all. Again, it all comes down to the role of the observer but statements can be true at the same time.

You can have the reality of the wave function where all measurements are realized. You can also have the subjective experience of local observers where one measurement is realized. Here's a paper published in Annalen der Physik.

On decoherence in quantum gravity

It was previously argued that the phenomenon of quantum gravitational decoherence described by the Wheeler-DeWitt equation is responsible for the emergence of the arrow of time. Here we show that the characteristic spatio-temporal scales of quantum gravitational decoherence are typically logarithmically larger than a characteristic curvature radius R−1/2 of the background space-time with a factor under the logarithm proportional to M2P/R. This largeness is a direct consequence of the fact that gravity is a non-renormalizable theory, as the corresponding effective field theory is nearly decoupled from matter degrees of freedom in the physical limit MP→∞. Therefore, as such, quantum gravitational decoherence is too ineffective to guarantee the emergence of the arrow of time at scales of physical interest. We argue that the emergence of the arrow of time is directly related to the nature and properties of physical observer.

https://arxiv.org/abs/1508.05377

In other words, MWI needs a strong Observer like in Copenhagen. It's like the paper I mentioned earlier, the stronger the observation the weaker the interference between probable states. The weaker the observation, the stronger the interference between probable states. So the observer collapses the interference between probable states and not the probable states themselves.

So when an event occurs, all timelike directions for that event occur. We could be moving in a backwards timelike direction but because of entropy and the conscious observer we're under the illusion that we're moving in the forward direction as the paper in the Annalen der Physik spells out. Einstein also said:

“The distinction between the past, present and future is only a stubbornly persistent illusion.”

It's like the illusion of seeing a wheel spin backwards. We know it's not spinning backwards but that's the way we perceive it. If the published paper is correct, then we can be in a backwards or diagonal timelike direction but our perception of entropy gives our reality a persistent illusion or distinction between past, present and future.

This would also mean that there's other universes or events moving in opposite timelike directions to ours and all observers in these timelike directions would think they're moving in a forward direction because of entropy. So there could be universes moving in forward, backward, sideways and diagonal timelike directions and we don't know which timelike direction we're moving in unless we can compare our timelike direction to other timelike directions.

If the papers I listed are correct, then it's easy to see how Copenhagen and MWI are compatible.

 

[PeroK]

Yes, they do. MWI says all results of any measurement happen. Copenhagen says only one does. Those are contradictory statements.

I suppose it depends what you mean by "contradictory" statements. I was thinking of an analogy of the way a knight moves in chess. One "theory" is that the knight goes one square in any direction and two squares in a perpendicular direction. The alternative theory is that the knight goes two squares in any direction, then one square in a perpendicular direction.

In these two theories the knight clearly takes a different path between its initial and final squares. But, unless you "observe" a knight mid-move, or have some rule that limits a knight's movement due to other pieces, the two are not really contradictory.

You could argue that MWI and Copenhagen are only really contradictory if they result in some observable difference. Otherwise, they may be saying "the same thing" in two different ways.

 

[Demystifier]

I suppose it depends what you mean by "contradictory" statements. I was thinking of an analogy of the way a knight moves in chess. One "theory" is that the knight goes one square in any direction and two squares in a perpendicular direction. The alternative theory is that the knight goes two squares in any direction, then one square in a perpendicular direction.

In these two theories the knight clearly takes a different path between its initial and final squares. But, unless you "observe" a knight mid-move, or have some rule that limits a knight's movement due to other pieces, the two are not really contradictory.

I like this analogy.

 

[A. Neumaier]

I was thinking of an analogy of the way a knight moves in chess. One "theory" is that the knight goes one square in any direction and two squares in a perpendicular direction. The alternative theory is that the knight goes two squares in any direction, then one square in a perpendicular direction.

In the many-worlds interpretation of chess, each time a move is made, the universe splits into into a huge number of multiple universes, where the figure making the (same) move moves differently, according to all possibilities (not only the two mentioned above). Or do the worlds split only when someone actually observes the details of the move? A vexing question that cannot be answered, even in principle, though chess is much simpler than quantum mechanics.

In the Copenhagen interpretation of chess, the knight has no definite location in between two moves (aka between preparation and detection). The Copenhagen interpretation avoids all the maddening imagery of the MWI and keeps things simple, by restricting attention to measurement protocols - the essence needed to replay the game FAPP, and by being silent about its detailed relation to reality.

The consistent histories interpretation of chess just asserts that each game following the rules of chess is a possible game, and that one of these actually happened. This is the elegant way of saying nothing at all.

The Bohmian interpretation of chess says that pieces always have definite positions, and the rules of chess form a pilot wave deterministically dictating the positions of the pieces. Different possible outcomes of a sequence of games in a chess match are explained by the initial conditions of the match being in pre-ordained chess equilibrium.

 

[Quantum Alchemy]

I suppose it depends what you mean by "contradictory" statements. I was thinking of an analogy of the way a knight moves in chess. One "theory" is that the knight goes one square in any direction and two squares in a perpendicular direction. The alternative theory is that the knight goes two squares in any direction, then one square in a perpendicular direction.

In these two theories the knight clearly takes a different path between its initial and final squares. But, unless you "observe" a knight mid-move, or have some rule that limits a knight's movement due to other pieces, the two are not really contradictory.

You could argue that MWI and Copenhagen are only really contradictory if they result in some observable difference. Otherwise, they may be saying "the same thing" in two different ways.

Excellent analogy!

 

[PeterDonis]

They're not contradicting statements at all.

Sorry, if we're not going to use the same words to mean the same things, there's no possibility of having a useful discussion.

Thread closed.

 

[PeterDonis]

I suppose it depends what you mean by "contradictory" statements.

I think "only one result happens" and "all possible results happen" are pretty clearly contradictory statements.

I was thinking of an analogy of the way a knight moves in chess.

Your analogy has nothing to do with the difference between MWI and Copenhagen. Your analogy illustrates that we cannot attribute definite values of observables to quantum systems in between observations. But the difference between MWI and Copenhagen that I was talking about (and which the OP erroneously claims is not contradictory) is about what happens at observations--one result vs. all possible results. It has nothing whatever to do with unobservability between observations.

 

[PeterDonis]

If anyone other than the OP wants to continue the discussion following up with my responses above, please let me know by PM and I will spin those posts off into a separate thread, since this one is closed.