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

[@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?

[@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

[@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 🧬

[@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.

[@rumidude]

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

[@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.

[@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

[@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,!

[@Jaroen66]

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

[@zaratustra00]

same here, instant like

[@pxlarquitectos]

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

[@zachfrazier8027]

"Your optimistic, I'm 78." Hilarious

[@rinket7779]

You're*

[@CptCalicoJack]

You're

[@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.

[@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.

[@tomwimmenhove4652]

I am ridiculously excited about this one :)

[@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

[@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.

[@gloomyend7452]

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

[@hotpotts]

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

[@gloomyend7452]

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

[@readingRoom100]

@@gloomyend7452 have u considered a 12 step program

[@TheSchultzZ]

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

[@joyecolbeck4490]

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

[@manishsingh-vk8if]

This conversation was really very illuminating. Thank you Sean.

[@LiorSL1]

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

[@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

[@aerx]

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

[@dianabudzik7636]

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

[@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.

[@freeair9460]

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

[@michaelbruns449]

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

[@Ascendlocal]

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

[@HouseJawn]

Of our species?

[@ugowar]

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

[@bikashthapa7316]

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

[@Palau_Legend]

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?

[@WildAnimalChannel]

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

[@johnqpublic2718]

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

[@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.

[@AstroFerko]

This episode is absolute gold

[@AstroFerko]

So glad you made this episode! Thanks! :)

[@Cnidarian64]

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

[@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!

[@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.

[@brinx8634]

Great guest and an interesting talk, thank you Sean.

[@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.

[@Well_Earned_Siesta]

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

[@tsentenari4353]

17:30 "and likewise of course of you just jumped in...": complete layman question: Why can't I jump in, read the first copy, and then somebody outside collects all the radiation and reflects it to the inside so that I can read that one, too?

[@schmetterling4477]

One can't reflect gravitational waves.

[@YoshiTatsu1]

This deserves billions of more likes

[@johnphil2006]

The most awaiting one ....!

[@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)

[@sinarain101]

It was delightful listening to this podcast

[@theomanification]

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

[@diraziz396]

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

[@yaserthe1]

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

[@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!

[@jaimecassar8427]

Thanks Sean & Lenny!

[@asylumofglass]

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

[@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"?

[@robatalan]

I'm putting my headphones on for this one 😎

[@nda4591]

Fascinating conversation!!!!

[@studham1]

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

[@coecovideo]

great guest thank you

[@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.

[@RKarmaKill]

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

[@Fritzybedeek]

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

[@volaireoh883]

Superb thank you Sean and Lenny.

[@sawwil936]

Just started listening, already know this is historical

[@user-ov5nd1fb7s]

43:59 the buzzword is not "exponentially hard". Its part of computational complexity theory and they are called NP-complete problems. One example is the traveling salesman problem. Most NP-complete problems do grow exponentially (kind of) but not all exponential problems are NP-complete. It has to do with wether you can break down the problem into smaller tasks that have lower complexity or not. Also, classical computers CAN solve them. The problem is that it is not efficient and it is an approximation (good enough result). For reference, NP-complete, NP-hard or any of the other ones are called complexity classes. Linear, Exponential, logarithmic are time complexity classes. What does easy and hard mean in complexity theory? If you have a set of integers and you want to read the first integer, this is "easy" classified as constant time because it doesn't matter how large the set is, you always read 1 integer. What is harder? If you had to read every integer in the set, now you have linear time because the number of integers in the set is equal to the number of times you need to read. What is even harder? Suppose you had to build a 2 dimensional set from this. now your algorithm time complexity is quadratic.

[@cameron1004]

1:05:00 one of the world's leading theoretical physicists confirms flat earth

[@cmdr.shepard]

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

[@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.

[@AlphaFoxDelta]

I have never had an hour go by so fast

[@DongLabUTHSCSA]

Great job Sean

[@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.)

[@mitchkahle314]

Wonderful. Thank you.

[@quantumcat7673]

Two great scientists amazingly good communicators! Lenny is now 85 (aug. 2024) and still going strong. I suspect he rides on asymptotic freedom!

[@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?

[@michaelmcmurray9252]

Very nice discussion. Stimulating !

[@maxvalsaez]

Woohoo saw the title and clicked immediately

[@ZacksMetalRiffs]

Same man. These guys are great.

[@ecruzd3rd]

Wish there was video for this as well

[@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.

[@CriticalPhemomenon]

This is awesome ...

[@panlan1]

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

[@vinnyvdalidemonet8527]

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

[@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.

[@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.

[@HamCar1000]

When Lenny says (at 34:40) that ADS/CFT began describing the interior of a black hole and it's surface, then was shown to describe a region of space without a black hole in it is he saying that the correspondence implies that the universe, though it appears flat as far as we can measure does have negative curvature (meaning we are actually in ADS) and that the boundary of the universe (its 2D projection) is infinitely far away? I know he would say he's only talking mathematics, so why does he say " a region of space". Is he still talking pure geometry?

[@HamCar1000]

Ok, thanks for that. Can you tell me how we know that we are not in an ADS universe? Is it possible that space only appears flat on the scales we can measure?

[@doodlepadhi9103]

He is truly Leonard

[@johnjoseph9823]

Two Geniuses discussing a great subject

[@mrspiers27]

I wonder about quantum information loss when merging black holes partially evaporate due to gravity waves?

[@Nahulanham]

If one adheres to the idea of 'virtual' particles rising from the black hole, as did hawking, doesn't that dismiss his following assumptions that nothing can escape therefore it can't be recontructed?

[@emmanuelkoutsoudakis4614]

Physics cosmology and the experts philoshophy and culture of science humanitarian

[@robertnewhart6969]

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

[@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!

[@Mr4NiceOne]

The plumber is here!

[@babylongate]

ProbablyNotMe why you hate him ? He’s brilliant you fucking brain dead 💀

[@Cemselvi1988]

@@babylongate and you are?

[@babylongate]

Shoopaah me what? Why you hate Susskind? He’s the best man ever

[@Erwanito123]

@@babylongate I think he's talking about the end of the talk where susskind said he's dad was a plumber, not making fun of him :)

[@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, ??

[@彭祖年]

two brilliants I admire!

[@ferggill9461]

My experience of physics through a screen - Sean Carroll (TV), Walter Lewin (YT) and Leonard Susskind (YT)

[@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).

[@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.

[@MoebiusUK]

This is such a treat

[@SensSword]

An intro for Susskind is as necessary for armchair physicists as it is for introducing Bob Ross to a hobbyist painter.

[@jakelabete7412]

Awesome. Two of my favorites.