Ever wanted a technical understanding of the Many Worlds Interpretation of quantum mechanics? Then join Sean Carroll and I at The Cartesian Cafe for a mathematical-philosophical whiteboard session on the foundations of QM and emergent spacetime:
We start with a basic overview of textbook quantum mechanics: states in a Hilbert space, the Schrodinger equation, wave function collapse, and the Born rule. We quickly get to the two basic foundational problems: the nature of measurement and reality.
Then we describe how the MW Interpretation fits in. We discuss the EPR paradox, entanglement, decoherence, and the density matrix formalism. Significantly, we get into the philosophical details of indexical uncertainty and deriving the Born rule, an important step for MW. Lots of additional topics: observation, emergence, Schrodinger’s cat, and whether there are infinitely many worlds. There’s no free pass at the Cartesian Cafe: we also talk about objections. And Sean highlights a bad objection to Many Worlds: “It’s not falsifiable!” Additional discussion topics include Bohmian mechanics, Bell’s theorem and what the Nobel prize committee got wrong, some of David Deutsch’s views, quantum mereology, the path integral and virtual worlds, and emergent spacetime (where spacetime is no longer fundamental!)
It was a lot of fun engaging with Sean on the math, physics, and philosophy in such an interwoven way at The Cartesian Cafe. As part of a side interview, Sean and I also discussed a few key figures from the Intellectual Dark Web (aka “IDW”) that Sean’s met, namely Joe Rogan, Sam Harris, and Eric Weinstein:
Timothy Nguyen 