Anti-realist Interpretations of QM

[DrChinese]

I think we're still talking past each other here. I'm not advocating the idea that a more complete specification of the system is possible. I can understand that a more complete specification might even be impossible in principle. But that we cannot have a more complete specification of the system doesn't mean that the specification we have is a complete specification of that system.

I guess I dispute your idea that we DON'T have a complete specification of the system. If we agree no greater detail is possible, we're done. And the reason we feel there is no greater detail possible is because it would lead to statistical contradictions. The property is fully blurred prior to measurement, and has no preferred value or basis that is in any way related to the outcome of a specific future measurement.

What CAN be said, for an entangled system, is that there is a conservation rule at play in that system. Such that A+B=k or A-B=k (k being some constant or initial value).

Of course, some interpretations say more detail exists, but it is unknowable in principle. So if you are tilting in that direction, all is good.

 

[Lynch101]

I guess I dispute your idea that we DON'T have a complete specification of the system. If we agree no greater detail is possible, we're done. And the reason we feel there is no greater detail possible is because it would lead to statistical contradictions.

My thinking is that there is a difference between 1) no greater detail being possible and 2) there being no greater detail period.

A possible explanation for 1) is that there is a limit beyond which we cannot probe. There would be further to probe, but we simply cannot probe that far due to limitations of our instruments or a fundamental limit in nature.

This is contrasted with 2) the idea that there is nothing whatsoever there to probe.

In the context of the moon analogy, it sounds a little to me like seeing a reflection of the moon and concluding that the reflection is a complete model of the moon. The reflection is a complete specification of what it is possible to see but it isn't a complete model of the moon itself.

The property is fully blurred prior to measurement, and has no preferred value or basis that is in any way related to the outcome of a specific future measurement.

My initial understanding of the anti-realist position was that it denied even the blurred property prior to measurement, but my interpretation of what @Morbert said previously is that it doesn't even talk about the blurred property prior to measurement, it only models the measurement outcome.

It's the idea that there is a blurred property prior to measurement, which isn't modeled in the anti-realist interpretation (and perhaps cannot even be modeled in principle) which is leading me to conclude the model is not a complete description of the system. If the property cannot be modeled even in principle then would seem to suggest that no complete model of the system is possible.

Of course, some interpretations say more detail exists, but it is unknowable in principle. So if you are tilting in that direction, all is good.

I think this is the direction I'm tilting but my reasoning is that this is the only direction that we can tilt.

The idea that there is no more detail whatsoever, sounds like the initial interpretation I had of anti-realism.

 

[Lynch101]

Maybe, but I think "matter" is another primitive notion that cannot be defined precisely.

This is probably true but I think it can be juxtaposed with [Cartesian] dualism, or other paradigms, to suggest what the alternatives might be and what the consequences of those are.

The materialist paradigm is generally juxtaposed with other paradigms which posit the existence of the supernatural entities or substances, such as "the soul". So, if we say that the quantum system doesn't have physical properties prior to measurement we must necessarily invoke a different paradigm and the consequences that flow from that.

On a separate but related note, does the point I am trying to make about the incompleteness of the anti-realist interpretation make sense to you or can you see what part of the argument I am missing?

 

[PeterDonis]

The materialist paradigm is generally juxtaposed with other paradigms which posit the existence of the supernatural entities or substances

It is? I thought the whole point of the materialist paradigm was to not posit the existence of supernatural entities or substances. See, for example, here:

https://plato.stanford.edu/entries/physicalism/

(As this article notes, "physicalism" is a synonym for "materialism".)

 

[Lynch101]

It is? I thought the whole point of the materialist paradigm was to not posit the existence of supernatural entities or substances. See, for example, here:

https://plato.stanford.edu/entries/physicalism/

(As this article notes, "physicalism" is a synonym for "materialism".)

Apologies, I could have worded that more clearly. It is the "other paradigms" which posit the supernatural. It is with those that materialism is usually juxtaposed to deny the supernatural.

 

[physika]

Would objects which exist and are real not have properties by necessity? Would real and existing not be properties in and of themselves?

.
Aristotle.
Properties; are characteristic qualities that are not truly required for the continued existence of an entity ((object, thing...) but are, nevertheless, possessed by the entity (object, thing...)

.

.

 

[Morbert]

Assuming I understand what you are saying: Your model provides that it has properties at t0 (before measurement) that are like its properties at t1 (at measurement). I guess that would literally meet the criteria you set, but wouldn't really be useful at any level that I can see.

The 2nd model isn't particularly useful, but it at least illustrates that the formalism does not privilege predictions over retrodictions. It's just the case that physicists are more interested in predictions.

(Though with that said retrodictions can be useful when reasoning through scenarios like the Vaidman bomb, or when reasoning about the trajectory of emitted particles.)

 

[RUTA]

I guess I dispute your idea that we DON'T have a complete specification of the system. If we agree no greater detail is possible, we're done. And the reason we feel there is no greater detail possible is because it would lead to statistical contradictions. The property is fully blurred prior to measurement, and has no preferred value or basis that is in any way related to the outcome of a specific future measurement.

What CAN be said, for an entangled system, is that there is a conservation rule at play in that system. Such that A+B=k or A-B=k (k being some constant or initial value).

Of course, some interpretations say more detail exists, but it is unknowable in principle. So if you are tilting in that direction, all is good.

Here is my Insight explaining the type of conservation at work for the Bell spin states. [I don't know why so many of the equation numbers have turned into ? when referenced and a couple of equations are cut in half. Hopefully, a Moderator can explain how to fix those.]