Mindscape 63 | Solo: Finding Gravity Within Quantum Mechanics

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.

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.

[LeRoyalWitCheeze]

First episode I've heard, just came over from your interview with Joe Rogan that came out today. When I heard you tell Joe about spacetime/gravity emerging from quantum mechanics, my heart jumped! I went to a physics colloquium at UCSB (either 2017 or 2018 in Webb Hall across from Broida) where you were giving a talk on spacetime and gravity potentially being emergent properties of a finite dimensional Hilbert Space. Had a great time at that talk; I'll have to look for my notes on it to re-live it somewhat! Wish I had your (to be written) entanglement-centric textbook over Griffitfths when I took QM!


Just want to say thank you for being such a wonderful communicator of science, and champion of understanding the reality of quantum mechanics, rather than simply the most complex systems we can successfully predict or conceive. Keep it up!

[georgemccaffery]

I'm glad the universe split for this version of me in such a way I found Sean Carroll and these podcasts.

[virajelix]

Just would like to mention honestly and without flattery, that Sean Carroll knows how to elaborate things very well and with simple voice tonality, which reflexes non-arrogance tick that makes it for the audience a pleasant thing to listen. Thanks a lot for all the effort sharing knowledge in such a way.

[interdictr]

Just want to say thanks for doing these podcasts. I have recently found your channel and I am greatly enjoying them. You are an excellent host!

[robbowman]

I've read and listened to a great deal concerning quantum mechanics and gravity, and I feel sure that this podcast contains more, way more, interconnected ideas than anything I have encountered before. I'll be chewing on this for some time, I think, which of course is a compliment.

[drwaynebuck]

I want a Mindscape T-shirt that says "As quantum as you can get"

[phoenixrising]

Hi Sean, I had the pleasure of meeting you this morning at the Milwaukee airport, right before our mutual (cancelled) flight. Hope you made it back home without too much trouble! Thanks for doing this new podcast. I'm subscribed. Looking forward to more of them. Take care.

[Tore_Lund]

I like this podcast a lot : Either I try to follow your university lectures with most of the stuff outside my math capabilities, or your open lectures which are generalized to to a point where they leave too many questions. In this video however, you explain everything and remember the details and footnotes to build up to your arguments, which makes this much easier to follow. Especially your insights of how to visualise the Quantum world an large scale is an eye opener.

[meahoola]

I recently did some exercises programming a quantum computer. I was surprised how much this could teach me about quantum theory in general.

For quantum computing you don't even need to understand physics, if you accept some unitary state transition matrices. And then it's entanglement over and over again that lets you achieve some computational task.

I recommend this experience to all physics students.

[salty]

this is one of the few best thing that happened to the internet. I'm a huge fan of you sean ✌

[cadorin]

Excellent explanation of QM and the way you link concepts like entanglement, emergence, decoherence, locality and many others. Hope you soon edit and publish the QM book for undergraduates you announce. Tomorrow "Something Deeply Hidden" arrives and I am lovely expecting it. I like the way you refer to the cat as awaken or slept, for those who love cats it is very gentle and respectful to these cute creatures.

[oriangalore]

This is by far my favorite episode so far!! Thank you Sean.

[Unhingedanduninformed]

It's refreshing when someone with such a deep, advanced knowledge of cosmology can break very deep topics down into bite sized, manageable pieces for an average person

[ChancellorMarko]

These podcasts are awesome ….specially the ones on physics. Looking forward to listening to more. THANKS!

[andrewpotapenkoff]

Did i just find a Sean Carroll's channel?! Thank you, YouTube!

[kzeich]

Your podcasts are wonderful, Sean and you are the most articulate science educator I've had the pleasure to listen to.

[TheJonlamb]

In my 7 years of doing physics I’ve never heard anyone describe fields in this way. Thanks for teaching me that! I really enjoy your podcast and all of your books!

[dude]

Really enjoying these solo episodes, Carroll is a legend.

[dustysoodak]

I really like the intellectual honesty in his approach to quantum mechanics and the clarity of his descriptions.

[dajandroid]

Extremely clear and helpful summary - thank you! I have been tasting the individual ingredients listed in a recipe (my past education in QM and physics) for a delicious horizon shaped pizza and this podcast has allowed my mind to taste the finished pie.