Episode 45: Leonard Susskind on Quantum Information, Quantum Gravity, and Holography

Blog post with audio player, show notes, and transcript: www.preposterousuniverse.com/...
Patreon: / seanmcarroll
For decades now physicists have been struggling to reconcile two great ideas from a century ago: general relativity and quantum mechanics. We don’t yet know the final answer, but the journey has taken us to some amazing places. A leader in this quest has been Leonard Susskind, who has helped illuminate some of the most mind-blowing ideas in quantum gravity: the holographic principle, the string theory landscape, black-hole complementarity, and others. He has also become celebrated as a writer, speaker, and expositor of mind-blowing ideas. We talk about black holes, quantum mechanics, and the most exciting new directions in quantum gravity.
Leonard Susskind received his Ph.D. in physics from Cornell University. He is currently the Felix Bloch Professor of Physics at Stanford University. He has made important contributions to numerous ideas in theoretical physics, including string theory, lattice gauge theory, dynamical symmetry breaking, the holographic principle, black hole complementarity, matrix theory, the cosmological multiverse, and quantum information. He is the author of several books, including a series of pedagogical physics texts called The Theoretical Minimum. Among his numerous awards are the J.J. Sakurai Prize and the Oskar Klein Medal.

[@NuclearCraftMod]

Sean Carroll and Lenny Susskind... awesome :)

[@randallmcgrath9345]

2 of my favorites, along with Brian Greene, and increasingly, Alan Guth. I also found one of Alex Vilenkin's books.

[@aclearlight]

@@randallmcgrath9345 when i hit the wappijuu7

[@aclearlight]

M, what are YOUR intentions?

[@timenotspaceproduction]

i think that i'm supposed to be here right now , listening to this whole conversation while i'm working in the studio today 🧬

[@Bpaynes]

Leonard Susskind one of the most brilliant scientists of our generation; also sounds like he could beat the shit out of you in a bar fight lol

[@stephenkamenar]

Leonard Susskind is a living legend

[@zachfrazier8027]

"Your optimistic, I'm 78." Hilarious

[@alexmartos9100]

Have never clicked so fast in my life!

[@dumpsky]

just click PLAY 1x. the video then should play automatically.

[@cozy_af2090]

You always had and always will click as fast as was predetermined.

[@jaykingston2171]

I idolize Leonard Susskind, I've read and watched just about everything I can find that's been published by him. His fascinating YT lectures introduced me to science and they led me to seek further education. He's one of science's greatest minds.

[@ZacksMetalRiffs]

I'm a simple man. I see Susskind in the title and I click instantly.

[@CstriderNNS]

your lost

[@readingRoom100]

Only because all his previous talks have failed u lol

[@lukegratrix]

You recognize genius when you see it. Says something about you Zack

[@harsszeg]

U belong to the 90 percent ...do not worry Susskind is 0.01 percent, I love him and still get lost.....its not for everybody

[@rumidude]

Lenny Susskind is a delight! Thank you for having him on the Mindscape Podcast!!!

[@Jaroen66]

I rarely give instant likes on YT videos, but this one required it

[@jeremita0]

same here, instant like

[@pxlarquitectos]

wow your clicks are so wonderful and rare, Sean Carroll is a lucky man

[@bendavis2234]

I highly recommend watching his theoretical minimum lecture videos on KZbin. He explains many key equations and proofs without getting too deep into the weeds. He’s such a great lecturer.

[@erictko85]

59:24 "And the other thing that makes you think you're on the right track, is when something that you've been thinking about, turns out the same mathematics, the same sets of principles, turn up in another area..." awesome to hear stuff like that from one of the great theoretical minds I've had the pleasure of listening to. Thanks Drs. Carroll and Susskind,!

[@ed.puckett]

Dear Dr. Susskind, the story about your father at the end was very touching to me personally because you have become a teacher of mine as well. Thank you.

[@dianabudzik7636]

Immense thanks for having on the brilliant and wonderful Leonard Susskind!

[@manishsingh-vk8if]

This conversation was really very illuminating. Thank you Sean.

[@robertglass1698]

So, great. Even though I've spent several hours listening to both of these guys talking before, I now understand the Holography better from this than I ever had before.

[@johnqpublic2718]

Great way to start my work day listening to these two brains.

[@AstroFerko]

So glad you made this episode! Thanks! :)

[@tomwimmenhove4652]

I am ridiculously excited about this one :)

[@TheSchultzZ]

i love listening to this even tho i dont understand anyting thanks sean love u

[@FABRIZIOZPH]

What I like about him is that he always proceeds with caution with what he says,, Even in response to some of Sean's comments, Because he values very much the meaning and power of every single word, And that is because the only way to truly understand every concept and make real progress with a theory is to be very very clear about the type of questions you ask and the framework your start from

[@freeair9460]

GREAT pod cast..! Several of my favorite subjects of science

[@grahamhenry9368]

Seeing the title of this episode was like Christmas morning as a little kid. My two favorite people to listen to on the same podcast? The only thing I wish they had discussed in more detail is the ER = EPR idea

[@joyecolbeck4490]

Thoroughly enjoyable - an hour too short! Huge thanks to Lenny and Sean for another great podcast. 😎

[@gloomyend7452]

I've listened to all your podcasts, I'm addicted to your voice and knowledge. Thank you 🖤

[@Anita_Bath]

Even so, "i'm addicted to your voice" is a creepy thing to say in general.

[@gloomyend7452]

@@Anita_Bath not when it calms down my panic attacks.

[@readingRoom100]

@@gloomyend7452 have u considered a 12 step program

[@Well_Earned_Siesta]

Yes! Figured/hoped you'd get around to having Susskind on the podcast!

[@Cnidarian64]

Just discovered this podcast from KZbin recommended. Now I have 45 episodes of science podcasts to listen to 😀

[@bikashthapa7316]

thank you so much i've been waiting for this so long

[@LiorSL1]

As a computer science student and physics enthusiast i think the collaboration of both fields is amazing as was stated here , Awesome podcasts ! :)

[@vr_37300]

Haven't listened to, but already liked. Kudos for inviting a legend.

[@wilfredoaldarondo5649]

Me too. I was waiting to hear the latest Leonard's thinking about recent findngs and the future of probing string theory and holografic principle.

[@ugowar]

I can only wish this chat had gone for another hour at least, always a pleasure to listen to Leonard.

[@AstroFerko]

This episode is absolute gold

[@brinx8634]

Great guest and an interesting talk, thank you Sean.

[@nathanmiller200]

I enjoy listening to both of you. Listening to Susskind is like my Morgan Freeman. I hope one day I can continue my physics degree. I majored in physics in college but college became too pricey.

[@aerx]

Omg I have not even watched and I know this is going to be great!

[@WildAnimalChannel]

I like listening to geniuses. There's no flim flam and waffle. Just pure thoughts.

[@asylumofglass]

OMG He did it! He really did it! Thanks so much for this!

[@volaireoh883]

Superb thank you Sean and Lenny.

[@georgefrichter4596]

physicist and fan of Susskind for ~ 30 years, what great fun!

[@georgefrichter4596]

My dissertation used the Kogut-Susskind Hamiltonian as a starting point for lattice computation experiments. Thanks Lenny!

[@sinarain101]

It was delightful listening to this podcast

[@michaelbruns449]

Profound bedtime stories, listening to these mind bending nightmare inducing discussions, through real headphones in the dark.

[@yaserthe1]

Brilliant, lets get the snacks and coffee ready. This should be awesome.

[@elphidium]

Hi Sean, I really enjoy your podcast! Keep up the good work! Have you ever considered talking with Max Tegmark about his idea of the "Mathematical universe"?

[@jaimecassar8427]

Thanks Sean & Lenny!

[@johnphil2006]

The most awaiting one ....!

[@Ascendlocal]

Absolutely phenomenal exchange between two of the smartest, respected and cutting edge theorists of our species

[@HouseJawn]

Of our species?

[@SolSystemDiplomat]

Just bought your book *spacetime and geometry, an introduction to general relativity* Can’t wait for it to arrive in the mail!!

[@silentbooks3879]

How was it?

[@diraziz396]

Nice recommendation 4 years later. Good talk. now have to check the latest..

[@robatalan]

I'm putting my headphones on for this one 😎

[@theomanification]

Cool fact...Sean actually played the intro live with Lenny on base

[@Erwanito123]

I think we can all thank lenny for doing what he's doing, I myself am a computer science student and this type of talk is amazing I never thought about learning such things in a field that distant of mine (I figured out not that distant actually lol)

[@mitchkahle314]

Wonderful. Thank you.

[@michaelmcmurray9252]

Very nice discussion. Stimulating !

[@user-ep6qc6by7x]

two brilliants I admire!

[@coecovideo]

great guest thank you

[@RKarmaKill]

2 genius personalities coming together for our beautiful entertainment and learning Pure

[@DongLabUTHSCSA]

Great job Sean

[@jakelabete7412]

Awesome. Two of my favorites.

[@HouseJawn]

Great podcast, abrupt ending 😆 "okay gotta go!"

[@lukegratrix]

Dream big like these two and share your crackpot thoughts, because the next Sean and Lenny are already out there thinking deeply and trying to make sense of the world. Best possible interview on the subject IMHO!

[@keith.anthony.infinity.h]

I love listening to Leonard Susskind he is very direct and clear with how he presents things. But the main thing I love about him is his ideas because I am working on something which focuses on the topic of quantum information and black holes. I found an equation which shows how surface area entropy can be used to conserve information about different quantum properties of electrons in atoms as body of mass collapses to a black hole. If anyone wants to hear about it and discuss please feel free to watch the videos on my channel.

[@Fritzybedeek]

I wish the two of you would address Roger Penrose's CCC. Seriously.

[@AlphaFoxDelta]

I have never had an hour go by so fast

[@studham1]

Cool... Sean inviting some Tim Morton ideas into the convo... i love when physicist bring up philosophers and vice versa

[@sawwil936]

Just started listening, already know this is historical

[@YoshiTatsu1]

This deserves billions of more likes

[@CriticalPhemomenon]

This is awesome ...

[@ThalesPo]

The content was very good, but as I always say, you have to get a volume compressor in order for the audio to be good.

[@hmbs1630]

Have always wanted to ask Sean why there has been such a great deal of resistance from physicists to write technical books for a public audience. Lenny really has pushed the envelope in this regard and has largely been a sole outlier.

[@calvingrondahl1011]

I respect all the scientists but being a retired editorial cartoonist I am more monkey than human. Your honesty with humor is what I need the most.

[@MoebiusUK]

This is such a treat

[@doodlepadhi9103]

He is truly Leonard

[@Jason-gt2kx]

Sean, my hypothesis that Dark Matter is not a WIMP, but maybe is a deformation of space-time by which the curvature of space-time ALONE is the cause of the gravitational effect. Gravity is the consequence of the curvature of space-time. It may be possible that the structure of space-time itself could be warped without the presence of mass. Space-time has been shown to react like a fabric by warping, twisting, and propagating independent of mass. These properties have been proven with observations of gravitational lensing, frame dragging, and now gravitational waves. Fabrics can be stretched, pressured, and/or heated to the point of deformation. Such extreme conditions were all present during inflation, so it is plausible that space-time’s elastic nature could have hit its yield point and permanently deformed. Therefore, if gravity is the consequence of the warping of space-time, and fabrics can be permanently deformed, then a deformation could create a gravitational effect independent of mass. Thus, the unidentified dark "matter" that seems to be so elusive to modern science may not be matter at all but merely warped deformities causing gravitational effects. DM could be a microscopic black hole with no mass at the center... Prediction: Spacetime's elastic property hits a yield point, so only that part of geodesic's "stretch marks" would remain after inflation stopped. These steep gravitational wells would not follow the inverse square law. Any thoughts?

[@amadexi]

If space-time had plasticity, it would make it much less fundamental than what it seems to be.

[@kennelson5096]

somewhat late on checking this out but simply brilliant

[@Fritzybedeek]

Missed asking Roger Penrose about information being lost. Too bad. Hope you get Lee Smolin or someone from Perimeter Institute. Would be nice to hear some deeper critique of Inflation and Quantum Mechanics.

[@chrisrecord5625]

In anticipation of the Scott Aaronson interview, see the article by Ben Lindbergh, in The Ringer, where he discuss time travel in the Avengers:Endgame, and he interviews Aaronson referring to Aaronson, as today's Tony Stark, even though Aaronson has yet to see the movie.

[@chrisrecord5625]

If I accidentally drop my library book into a black hole and by ER=EPR, the two black holes are maximally entangled, do each of the black holes contain the information in the book? Nota bene to both of you as a liberal arts major, I appreciate so much you continued efforts to instruct the scientifically unwashed. (Nevertheless, are the black holes liable for the library fines? Me so ornery.)

[@vinnyvdalidemonet8527]

Richard Feynman & Leonard Susskind would have been hilarious to hang around. Can you imagine those 2, just chilling together? Ah haha 😄.

[@ecruzd3rd]

Wish there was video for this as well

[@slamrn9689]

Have you ever had David Gelernter on? I am sure you could come up with a topic. Great show btw.

[@robertnewhart6969]

Can you use quantum entanglement to create instant communications (ftl) between vast distances as long as the 2 communication stations start out together?

[@constpegasus]

Love these videos.

[@panlan1]

instant click and like ..this is like the main billing ..

[@Mike-nf6nf]

Sean, can you try to get Nima Arkani-Hamed on? If I recall correctly, you two disagree on whether particles are point-like or waves. It would be interesting to hear you discuss this on the podcast. Thanks!

[@chrisstewart4288]

Great video!

[@RyanWalshGuitar]

omg SO EXCITED!!!!!!!!

[@DanielFoland]

ZOMG Best guest ever. First of a series? We need a Many Worlds vs. Hologram deathmatch, please. An hour of "WHO DO YOU THINK YOU ARE TO SIT AT THAT DESK? I KNEW THAT MAN!" from Dr. Susskind would be 12 kinds of awesome.

[@Nahulanham]

One has to bare in mind, regardless of derivatives sciences, that fundamentally the models we use are just that 'individual pictures,' and not to be misconstrued of evidence of what the universe really is outside of these pictures. Art, in this sense, precedes math and not vice versa.

[@michaelmcmurray9252]

Qubits may not increase switching capacity at all. Signal manipulation in weak nucleus on the other hand offers much faster information transfer.

[@cmdr.shepard]

17:00 How can you jump inside event horizon and leave? What does "jump in" mean? Something else?

[@johnmcntsh]

Wow, just wow.

[@ddavidjeremy]

Great scott!

[@johnjoseph9823]

Two Geniuses discussing a great subject

[@maxvalsaez]

Woohoo saw the title and clicked immediately

[@ZacksMetalRiffs]

Same man. These guys are great.

[@atagkr]

Two great scientists

[@rohitrathi4552]

Is the plank length on the shell the same as the plank length inside the shell ie our plank length? It shouldn’t be?

[@user-ep6qc6by7x]

Susskind is even beyond Feynman in explaining something clearly and interestingly

[@CstriderNNS]

i dont know where they get there info from "( they only have QC of a feu qbits ") , considering the pentagon just purchased a 500 qbit DWave QC form google, ??

[@cryptolicious3738]

so awesome!

[@PavlosPapageorgiou]

Question to Leonard: Are black hole horizons particularly unique places where the holographic principle applies? In a universe described by quantum fields, can't we take any arbitrary surface and say that what happens on the boundary, the waves and particles that cross the boundary in the totality of time, fully describe what's knowable about the universe on the other side? I thought that as soon as you accept relativistic fields some form of the holographic principle applies and maybe black hole horizons are interesting limit cases of this universal principle.

[@KSignalEingang]

I am not an expert but it sounds to me like you've just described one way of looking at the holographic principle. The edge of the observable universe is sometimes cited as another kind of EH. (Except in that case we're on the inside looking out).