This is one of my favourite episodes of Sean Carroll’s Mindscape podcast. He talks about his recent work in attempting to derive the kind of spacetime geometry we observe from little more than the mere existence of a universal quantum wavefunction.
Shownotes:
I suspect most loyal Mindscape listeners have been exposed to the fact that I’ve written a new book, Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime. As I release this episode on Monday 9 September 2019, the book will officially be released tomorrow, in print, e-book, and audio versions. To get in the mood, we’ve had several podcast episodes on quantum mechanics, but the “emergence of spacetime” aspect has been neglected. So today we have a solo podcast in which I explain a bit about the challenges of quantum gravity, how Many-Worlds provides the best framework for thinking about quantum gravity, and how entanglement could be the key to showing how a curved spacetime could emerge from a quantum wave function. All of this stuff is extremely speculative, but I’m excited about the central theme that we shouldn’t be trying to “quantize gravity,” but instead looking for gravity within quantum mechanics. The ideas here go pretty far, but hopefully they should be accessible to everyone.
I’m not sure exactly which paper he was referring to, but here are some relevant ones:
Someone named O. Stoica has published a refutation (but I haven’t read it yet): Refutation of Hilbert Space Fundamentalism (2021). They call it “Hilbert-Space Fundamentalism”, but I feel like that has a negative ring to it, given the connotations of the word “fundamentalism”.