Sidney Coleman's opinion on interpretation in his Dirac lecture

[gentzen]

pines-demon quoted from Sidney Coleman's Dirac Lecture "Quantum Mechanics in Your Face" (https://arxiv.org/abs/2011.12671)

The other day I was looking at a British videotape of Feynman explaining elementary concepts in science to an interrogator, whom I think was the producer Christopher Sykes. He asked Feynman to explain the force between
magnets. Feynman hemmed and hawed for a while, and then he got on the right track, and he said something that’s dead on the nail. He said:

You’ve got it all backwards, because you’re not asking me to explain the force between your pants and the seat of your chair. You want me, when you say the force between magnets, to explain the force between magnets in terms of the kinds of forces you think of as being fundamental—those between bodies in contact.

Obviously, I’m not phrasing it as wonderfully as Feynman. But, well, as Picasso said in other circumstances, it doesn’t have to be a masterpiece for you to get the idea. We physicists all know it’s the other way around: the fundamental force between atoms is the electromagnetic force which does fall off as one over R squared. Christopher Sykes was confused because he was asking something impossible. He should have asked to explain the pants-chair force in terms of the force between magnets. Instead he asked to derive the fundamental quantity in terms of the derived one.

Likewise, a similar error is being made here. The problem is not the interpretation of quantum mechanics. That’s getting things just backwards. The problem is the interpretation of classical mechanics.

and martinbn added "the full quote" of what Sidney Coleman said before (and refers to here) to make things clearer:

“Every successful physical theory swallows its predecessor alive.” But it does so by interpreting the concepts of the old theory in terms of the new, NOT the other way around. Thus our aim is NOT “the interpretation of quantum mechanics.” It is the interpretation of classical mechanics.

Sidney Coleman's opinion on interpretation in these two quotes is:

• Thus our aim is NOT “the interpretation of quantum mechanics.” It is the interpretation of classical mechanics.
• The problem is not the interpretation of quantum mechanics. That’s getting things just backwards. The problem is the interpretation of classical mechanics.

However, more quotes are needed to capture Coleman's position in his Dirac lecture:

I want to stress that I have made no original contributions to this subject. There is nothing I will say in this lecture, with the exception of the carefully prepared spontaneous jokes—that was one of them—that cannot be found in the literature.

The position I am going to advocate is associated with Hugh Everett in a classic paper.

I will argue the there is

NO special measurement process​

NO reduction of the wave function​

NO indeterminancy​

NOTHING probabilistic​

in quantum mechanics.

ONLY deterministic evolution​

according to Schrödinger’s Equation​

Zurek has made major contributions to the theory of decoherence—where instead of just saying it’s ridiculous or absurd, he actually raised a question one can talk about. He said: “If this is so, why do I the observer perceive only one of the outcomes?” This is now the question I will attempt to address: Zurek’s question. If there is no reduction of the wave packet, why do I feel at the end of the day that I have observed a definite outcome, that the electron is spinning up or the electron is spinning down?
In order to ease into this, I’d like to begin with an analysis of Neville Mott.

In Tom Stoppard’s play Jumpers, there’s an anecdote about the philosopher Ludwig Wittgenstein.

Now people say the reduction of the wave packet occurs because it looks like the reduction of the wave packet occurs, and that is indeed true. What I’m asking you in the second main part of this lecture is to consider seriously what it would look like if it were the other way around—if all that ever happened was causal evolution according to quantum mechanics. What I have tried to convince you is that what it looks like is ordinary everyday life.

Sidney Coleman's position in these quotes is:

• I have made no original contributions to this subject.
• Zurek ... actually raised a question one can talk about.
• In order to ease into this, I’d like to begin with an analysis of Neville Mott.
• Now people say the reduction of the wave packet occurs because it looks like the reduction of the wave packet occurs, and that is indeed true.

The connection to the annecdote about Wittgenstein definitively was an original contribution. This raises the question whether it was the only original contribution. Another likely original contribution is his ambiguous reframing: "The problem is the interpretation of classical mechanics."

But I don't think Sidney Coleman was intentionally lying when he denied having made original contributions. The scientists mentioned in the quotes above are Neville Mott, Hugh Everett and Wojciech Żurek. (Other scientists are mentioned in: "Some of the things I’ll say about probability later come from a paper by Jim Hartle, and one by Cambridge’s own Eddie Farhi, Jeffrey Goldstone, and Sam Gutmann.") So I wonder whether his position can be justified as a non-original selection from published works of Mott, Everett and Żurek, or whether it must be considered as an original position, which was never peer-reviewed or even worked-out properly.