Challenges in Quantizing Gravity and the Finite Nature of the Observable Universe

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.

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The end of this episode includes a bonus, a short snippet from the audio book, read by yours truly. Audio excerpted courtesy Penguin Random House Audio. And here are links to some of the technical papers mentioned in the podcast.

• Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime
• "Thermodynamics of Space-Time: The Einstein Equation of State" (Jacobson)
• "Space from Hilbert Space: Recovering Geometry from Bulk Entanglement" (Cao, Carroll, and Michalakis)
• "Bulk Entanglement Gravity without a Boundary: Towards Finding Einstein's Equation in Hilbert Space" (Cao and Carroll)
• "Mad-Dog Everettianism: Quantum Mechanics at Its Most Minimal" (Carroll and Singh)