Philosopher Eddy Keming Chen (UC San Diego) comments.
UPDATE: Philosopher David Wallace (Pittsburgh) writes:
I saw you flagged Eddy Chen’s recent paper on the blog. A quick observation in case you’re interested: the article is engaging and provocative but risks encouraging a regrettably-common confusion, in that it mostly conflates 'the wave-function is representational' with 'the wave-function is real'. Consider: there are c.10,000 students at Pitt, and they take four courses per semester, so the academic results of the undergraduate body each semester are represented by a single point in 40,000-dimensional 'grade space'. Is the grade-space point representational? Does it represent objective mind-independent features of the world? Yes, obviously; indeed, we know what those features are - I'm supposed to be determining some of them now instead of writing this note. Is it real? That depends on your philosophy of math, but at most it's real in the sense that numbers are real. Is there an *object* it represents? No. Do Pitt undergraduates, collectively, live in 40,000-dimensional space? Obviously not.
It probably is the majority view in physics that the wave-function is representational, indeed that it represents inter alia the ordinary macroscopic features of the world. But that doesn't entail that the wave-function is real, or that the universe is a wavefunction. You can motivate that as a further move - it's not silly in the way that reifying grade space is silly - but it doesn't in any way follow automatically. It's a very substantive (and in my view incorrect) additional metaphysical move, by no means a consensus view in philosophy of physics and very heterodox in physics proper, even among those who agree that the wave-function is representational. Many physicists of a cosmological bent might assent to 'the wave-function represents all the dynamical properties of the Universe'; few indeed would assent to 'the universe is a wave-function'.
Chen himself appreciates the distinction, I'm sure, and the article occasionally acknowledges it ("One dominant interpretation of the wave function is that it in fact represents physical reality – some even argue that the universe as a whole is just a quantum wave function") but they're often conflated in the text and even more so in the headings and provocative title, though I appreciate Chen might not have written these himself.
