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What is the orthodox formulation of QM? Link?
The orthodox formulation of QM (given in Griffiths and most other modern QM texts) is the following:
Time evolution of an isolated system is governed by the time-dependent Schroedinger equation (this includes einselection when the system is no longer isolated).
The Born rule: after a measurement is performed on a system in a given state, the probability of observing a given eigenstate is given by the square modulus of the system's state's projection onto the eigenstate.
Note that there is no mention of collapse. The Born rule is the miracle step in the orthodox approach (and is an open problem in physics), just like it is in any other approach, including the MWI (EY admitted as much, if you want an argument from authority).
The interpretational confusion starts once you try to invent the reasons behind the Born rule. A proper scientific way to address the issue would be to construct a model which explains the Born rule AND makes other testable predictions separate from the orthodox QM. This conjunction is essential. There is no way to simply "dissolve" the question.
Here's Griffiths on what he calls the "orthodox position" on quantum indeterminacy. This is from pages 3-5 of his text:
Going by Griffiths' own account (and I picked Griffiths because he's the authority you cited), what Eliezer says about the orthodox interpretation is not a strawman. In fact, Griffiths explicitly discusses the view you call the "orthodox formulation", except he doesn't call it "orthodox". He describes it as an alternative to the orthodox position, and labels it the "agnostic position".
I think your flavor of instrumentalism is a respectable position in the foundational debate, but to describe it as the standard position is incorrect. I think there was a time when physicists in general had a more operationalist bent, but things have changed.
Hmm, I suppose my personal classification is slightly different. Thanks for pointing that out.
The agnostic position is "shut up and calculate", which is basically resigning to one's inability to model the Born rule with anything better.
The instrumentalist position is to admit that doing research related to the Born rule origins is essential for progress in understanding the fundamentals of QM, but to also acknowledge that interpretations are not interesting physical models and at best have only an inspirational value.
The realist position (hidden variables are fundamental, collapse is fundamental, or MWI is fundamental, or Bohmian mechanics is fundamental) is the one that is easiest to falsify, as soon as it sticks its neck out with testable predictions (Bohm and collapse do not play well with relativity, local hidden variables run afoul of the Bell theorem, MWI makes no testable predictions whatsoever).
I suppose the confusion is that last paragraph: "There are, then, two entirely distinct kinds of physical processes: "ordinary" ones, in which the wave function evolves in a leisurely fashion under the Schrodinger equation, and "measurements", in which [it] suddenly and discontinuously collapses." This is a realist position, so I don't favor it, because it does not make any testable predictions.
OK, I will stop calling it standard, just instrumental.
How?
Okay, the Orthodox QM is an informal specification of anticipated experimental results, and acknowledges decoherence as a thing. That is good to know.
My base claim is that decoherence can and will become macroscopic given time. Some physicists seem to disagree. Why? To my best expertise it is obviously implied by the mathematics behind it.
I am well aware the Born Rule is a mystery. Where the Born Probabilities come from, idk. Mangled Worlds seems like it might have the structure of a good explanation, it smells right, even if it isn't.
Now that was uncalled for.
OK, as pragmatist pointed out, calling it orthodox is misleading. Sorry. From now on I'll be calling it instrumentalist. As for "informal", it's as formal as it gets, pure math.
That's an experimental fact, you don't need to claim anything.
Really? Who?
Feel free to outline the math. The best sort-of-derivation so far, as far as I know, is given by Zurek and is known as einselection.
Perception of groups are often skewed. Mine was.
That update out of the way, why are we arguing? We do not disagree.
Aumann ftw!
I wouldn't call it “orthodox”, but see this:
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