Cumrun Vafa: String Theory | Lex Fridman Podcast

Cumrun Vafa is a theoretical physicist at Harvard. Please support this podcast by checking out our sponsors:
- Headspace: headspace.com/lex to get free 1 month trial
- The Jordan Harbinger Show: / thejordanharbingershow
- Squarespace: lexfridman.com/squarespace and use code LEX to get 10% off
- Allform: allform.com/lex to get 20% off
CORRECTIONS:
- I'm currently hiring folks to help me with editing and image overlays so there may be some errors in overlays (as in this episode) as we build up a team. I ask for your patience.
- At 1 hour 27 minute mark, we overlay an image of Brian Greene. We meant to overlay an image of Michael Green, an early pioneer of string theory: bit.ly/michael-green-physicist
- The image overlay of the heliocentric model is incorrect.
EPISODE LINKS:
Cumrun's Twitter: / cumrunv
Cumrun's Website: www.cumrunvafa.org
Puzzles to Unravel the Universe (book): amzn.to/3BFk5ms
PODCAST INFO:
Podcast website: lexfridman.com/podcast
Apple Podcasts: apple.co/2lwqZIr
Spotify: spoti.fi/2nEwCF8
RSS: lexfridman.com/feed/podcast/
Full episodes playlist: • Lex Fridman Podcast
Clips playlist: • Lex Fridman Podcast Clips
OUTLINE:
0:00 - Introduction
1:51 - Difference between math and physics
4:34 - Evolution of quantum mechanics
7:52 - Can mathematics lead humanity off track
8:51 - Beauty in mathematics
14:10 - Philosophers using symmetry
20:04 - How can ancient geometry be used to understand reality
23:16 - Key ideas in the history of physics
26:09 - Einstein's special relativity
29:46 - Physicists building intuition
37:44 - Best work by Einstein
39:28 - Quantum mechanics
49:30 - Quantum gravity
51:45 - String theory
1:07:54 - 10th Dimension
1:14:32 - Skepticism regarding string theory
1:25:37 - Key figures in string theory
1:29:56 - String Theory's Nobel Prize
1:33:01 - Edward Witten
1:41:39 - String Theory Landscape & Swamplands
1:50:29 - Theories of everything
2:04:55 - Advice for young people
2:07:57 - Death
SOCIAL:
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- Instagram: / lexfridman
- Medium: / lexfridman
- Reddit: / lexfridman
- Support on Patreon: / lexfridman

[@lexfridman]

Here are the timestamps. Please check out our sponsors to support this podcast. 0:00 - Introduction & sponsor mentions: - Headspace: headspace.com/lex to get free 1 month trial - The Jordan Harbinger Show: kzbin.info - Squarespace: lexfridman.com/squarespace and use code LEX to get 10% off - Allform: allform.com/lex to get 20% off 1:51 - Difference between math and physics 4:34 - Evolution of quantum mechanics 7:52 - Can mathematics lead humanity off track 8:51 - Beauty in mathematics 14:10 - Philosophers using symmetry 20:04 - How can ancient geometry be used to understand reality 23:16 - Key ideas in the history of physics 26:09 - Einstein's special relativity 29:46 - Physicists building intuition 37:44 - Best work by Einstein 39:28 - Quantum mechanics 49:30 - Quantum gravity 51:45 - String theory 1:07:54 - 10th Dimension 1:14:32 - Skepticism regarding string theory 1:25:37 - Key figures in string theory 1:29:56 - String Theory's Nobel Prize 1:33:01 - Edward Witten 1:41:39 - String Theory Landscape & Swamplands 1:50:29 - Theories of everything 2:04:55 - Advice for young people 2:07:57 - Death

[@TerminallySerious]

Really grateful for the voice you bring to the global community right now Lex. Thank you! Ps. The @BitClout community are getting the decentralised future of social media ready for ya my man. 😉💯🔥

[@funtimes8296]

Where's meaning of life?

[@Loinvoyant78]

when subtitles are available ? tomorrow ? sooner ?

[@MrGOTAMA420]

thiswas one of your best

[@VaidasBagdonas]

When is the Andrew Huberman episode coming out?

[@franzswitches]

I major in theoretical physics and I gotta say, he is without a doubt one of the brightest and most talented physicists out there in recent years. I couldn't stop listening to his interesting stories and philosophy and watched this entire video to the very end. It was such a pleasure to hear directly from the guy, and I appreciate you Lex for doing this interview.

[@andromeda121]

Cumrun Vafa is phenomenal. So articulate, so knowledgeable, so humble and just amazing physicist!

[@MLG85]

well endowed too! with a name like that youd wanna be 😂

[@alirezaromina5049]

First Persian guest on the show. Cannot thank you enough for all of this Lex. You changed my life, hope I can pay you back in the future.

[@ehsanmazandarani2511]

😃

[@sembutininverse]

I'm grateful too.

[@MMATopGs]

Iranian or Persian? The name of country is Iran known internationally. Italy was Rome one day

[@Hippiekinkster]

@@MMATopGs - I lean towards Persia(n), myself. I had a couple Calculus & Chemistry classes with two guys (roommates) from Persia/Iran. Both Atheists, BTW.

[@4bidden1]

@@MMATopGs people like to identifying with winning ...Persian empire was way more successful than the current Iranian. Government...kinda like how everybody is a Tom Brady fan ....or laker fan...

[@Mwilke3789]

Dr. Vafa's face of pure joy when he explains the outcome of something is wonderful.

[@depschemashty142]

Cumrun is great at explaining complex theories in simple terms.

[@dinobotpwnz]

What a special interview! Unlike most other physicists you're likely to see on a podcast (and there are many good ones), this isn't a guy who's taking a break from research. Hard hitting papers by him come out all the time. And if you give a talk about something he's worked on before, it comes back to him in an instant and leads to a huge discussion.

[@justinschofield9083]

Finally someone who explains it completely in timeline order and with examples that non professional can grasp he is smarter than genius great good man you good too Lex

[@nurk_barry]

You’re on fire Lex, Constantine last week and now Cumrun Vafa, two scientists whose work I greatly admire….awesome. The interview with Constantine was incredible, and it kept my mind occupied as I worked.

[@richardmartinbishop]

His excitement is contagious and he really captured my attention. I think I finally understand the concept of string theory at least, great podcast.

[@Erichop108]

This guy is good. He's able to explain things in a way that even an idiot like me can understand

[@snskt9492]

I don't think you're an idiot :)

[@kwsrge]

true and real :)

[@teresaflorida]

I've tried to read/understand physics and frequently feel incapable of grasping concepts. I'm not college educated but became interested after reading about CERN.

[@____uncompetative]

I don't think you are an idiot either

[@badsanta7356]

@@snskt9492 you don't know him

[@morningcoffeepottery5416]

Lex Fridman clearly explains string theory in 20 seconds. Love this show.

[@chelseaandhobbes]

‘It takes an intelligent person to explain complicated things is a simple manner’ - The fact that I can understand a fair chunk of this is testsmount to the intelligence and intellect of these two incredible men!

[@Henry-kv7zl]

Grammar seems dece, you're fine. Typical mildly above average intelligence (maybe way more! Maybe way less! Nevermind!) Acutely aware of your own stupidity. Just like me!

[@abdul-ganiyumannir7560]

This man knows his stuff. My God!

[@dinobotpwnz]

In terms of renown within the field, this is as big as it gets.

[@Jaba6798]

Cumrum is awesome. You can tell he has actual expertise by the way he describes the mechanics of the equations. That type of expertise only comes through thousands & thousands of hours of pounding on your craft.

[@Ken-vl4wk]

Love how Vafa is so passioned about physics.

[@vikramchandrasekhar12]

Among my favorite interviews so far. Cumrun Vafa's clarity of thought shows deep understanding of physics and his enthusiasm is contagious. I listened over and over to his examples borowing intuition in 2D and 3D to glean intuition of higher dimensional objects. I will come back to this interview and rewatch it some day.

[@dyer308]

Always a pleasure to listen to Cumrun Vafa!

[@ikramnaurang]

Very clear explanations! One of the best interviews in this series so far

[@dalriada]

This is first time I've heard someone explain higher dimensional physics in a way that I think I can almost understand it. A superior teacher for sure.

[@bensaeltube]

One of the best podcasts! Sir Cumrun Vafa is an awesome storyteller.

[@miinyoo]

Love these deep dives Lex. This kind of abstract thinking fills me with joy for no tangible reason whatsoever like taking a ride on a bicycle with no destination.

[@scottjones-singersongwrite6193]

Wow. Cumrun Vafa is my new favourite theoretical physicist. Not easy to make this stuff intelligible. His philosophical prowess and enthusiasm shine through. Brilliant!

[@georgiosapostolides1944]

Lex you should do another episode with Cumrun there is something really profound to the way he explains and paints the picture of things.. I enjoyed so much this episode thank you!

[@sombh1971]

Masterful explanations of deep topics, kudos!

[@simiansockpuppet9416]

So refreshing to hear that Dr. Vafa values philosophy :-)

[@imrematajz1624]

and we are not scared...now I am not scared in 11 dimensions! I listened to Lex and Mr. Vafa all day. I can't get enough of it. Try it. You may stumble on more and more great stuff. Thanks a million!

[@TrueNero]

Wow! I learned so much about String Theory from this Podcast. Cumrun paints such a lovely and transparent picture of the 'Canvas' in which life emerges. Thank you so much for all of your Podcasts with all of the incredible humans on it. I enjoy experiencing your creations so much. I look forward to exploring new horizons through your videos. I love you.

[@MajidHormati]

So glad you interviewed Cumrun!

[@sydneymorey6059]

Cumrun Vafa. So humble for a genius. Thank you Lex. You’re pretty special yourself.

[@springford9511]

This is an AMAZING podcast. I can't stop listening to it. Will I wear out youtube if listen to it 100 times?

[@derekbentley334]

The leap was the crash course in depth and amount shown taught and comprehending

[@guitarpick335]

This is the best advise for younger people that I've heard 02:05:09. Absolutely correct and comes from experience.

[@janshkreli2172]

Lex, your podcast is a gift to the world. I don't think anyone has done more to help intellectual discourse than you, at least not in this global scale. Cheers :)

[@dan85lewis]

Lex, just wanted to say thankyou for consistently producing fantastic podcasts for the past few months. I absolutely love your humor, insight, thoughtfulness and empathy. Keep up the great work! 👌😁

[@walterclements3669]

Lexs outline in the descriptions goated

[@onlyguitar1001]

I wish I could like twice, I really loved this podcast with Cumrun Vafa. Thank you Lex

[@robertgiardino3314]

Looks like I won’t be going to sleep yet

[@stevebaldock]

Fantastic discussion overall, but especially at the end regarding death. Beautifully said.

[@abhisheksingh1143]

this is such an insightful episode....really intrigued by the discussion.....

[@Mmmmkaaay]

The 12 year old in me so bad wants to say something...

[@_SimpleSam]

Had to scroll far too long for this.

[@jefftaf6361]

We all in the same boat, but as fans of this podcast, we all know better hahaha

[@redfox2035]

We’ve all had one or two of those. Am I right, Lady Bohemia?

[@joech1065]

Please, tie me up, folks, it's so hard to resist the temptation. The puns just keep coming into my head. I'm gonna go and do some breathing exercises, or go run (on a clean road), before I fail Lex once again.

[@theliftedbar4610]

@@_SimpleSam Cumrun Vafa her lips....

[@matinamin3008]

OMG I’m so proud and excited to watch this cuz he is a fellow Iranian💪🏻🇮🇷

[@hartmut-a9dt]

5:15 since years I want understand principle of least action, and now this man explains it so intuitively that I got it in one shot.

[@pmeekins003]

Ty brother, we live in a beautiful time when a regular dude can hear this kind of conversation.

[@shivendhania7724]

you have no idea how much you mean to me Lex, you're the best

[@samarthsai9530]

This was such a great conversation. Dr. Vafa has a great way of explaining things. Most people when talking about QM would tell how weird it is and how modern physics is so counter intuitive but not really giving a true picture , it feels as if they are trying to force fascination by telling just a few bits and by sounding mystical but truly great scientists like Vafa, Witten, Susskind, Maldacena etc. avoid doing that and tell what it really is, within the constraint of talking to laymen, but the truth to me is much more satisfying and in fact very entertaining as compared to the mystical things.Thank you so much for the wonderful conversation.

[@DaGrybo]

As a physician, I dedicated my life to studying the human body and mind, rather than the outside world, and it's always fascinating to listen to the ones who did the opposite. Especially on this level. I want to point out that it's the consciousness in the first place that gives rise to these theories. And to unify the "outside" and the "within" is quite an easy leap. Conscious experience in the brain is based on exactly the same rules that govern the world.

[@CyberAnalyzer]

Now this man is truly passionate!!🤩 What a man!

[@abhiseksahu822]

Cumrun makes all these complicated ideas so simple. It is an absolute delight to watch him. Great questioning from Lex as well! Just a side comment: at 1:27:06 I think the 'Green' being referred to is Michael Green, a British String theorist who pioneered the subject in the 70s alongside Schwarz. He is also the author of the standard textbook in String Theory, co-authored with Schwarz and Witten. Brian Greene came later.

[@behrad9712]

Wow, when someone talks about philosophy, he or she is on another level...thank you so much from Iran!👌

[@barren8589]

I guess because of his background like Salam they are often interested in philosophy & tolerant towards religion; this was also my experience with a graduate student classmate from Iran.

[@behrad9712]

@@barren8589 definitely! we Iranians (of course not people you see in news from Iran😊) love equilibrium and interaction between ideas in order to achieve more complete forms! We're not in one place in terms of concepts, even from geographical point of view we're neither east nor west! (Mesopotamia)in "kurosh (cyrus) and "darush"age we were almost anything like greek to indian to african thought plus mithraism and ...even in practice and political aspect those races lived together in peace many years under empire of cyrus!

[@Vlow52]

Thank you, Lex!

[@digita1dope]

This is amazing! It seems to be simple, but the certain things that I had not thought about before became clear. Theories are tools that people come up with to solve problems. Some less perfect than others, but you may never know which one is closer to the truth and which one is easier to improve, so it is better to improve yourself while working with all those of your interest, study new ones and try to apply them. Great talk. Lots of spiritual food for the mind.

[@robertpirsig5011]

This is very insightful interview.

[@SzTz100]

Excellent interview, good thing I didn't forget to watch it.

[@benmanahan9356]

Two uploads in the same weekend?! Lex coming in clutch for the work week!

[@daarom3472]

Upgrades :D

[@ermanakar]

I want to see Sabine Hossenfelder as a guest so much I can get excited about thinking about it.

[@asphaltpilgrim]

YEEEEESSSS!!

[@Loinvoyant78]

we neeeeeeed zabine !

[@Arimaquinador]

In her last video she still considers string theory science. I think it would be a good Interview, but harder for Lex to conduct.

[@ermanakar]

@@Arimaquinador would def be harder for Lex to conduct which makes it even more fun! Also, I am excited about all these on the edge ideas on the podcast but eventually agree with Sabine and her stance on keeping science and scientific discovery “effective” and within reason. And herself being “vigilant” about this is imho so useful. It’s so German too 😂. I love it

[@nicolasallegra9893]

He was talking about Michael Green when mentioning string theory pionners, not Brian Greene

[@stevedabish9107]

I am hooked on this wonderful podcast

[@nicknygaard4122]

Wonderful interview

[@sembutininverse]

please consider having Nima Arkani Hamed as one of your next guests.

[@painguin111]

Wow this was amazing, love this guy

[@videos2pick]

Thank you very much,... it was a very nice and informative talk!

[@billybobmonroe3166]

Wow never thought you'd have Jizzsprint on the podcast, great episode.

[@saulm2007]

Lex making the MOST out of his philosophy degree! I love it!

[@arunangshu218dutta]

this podcast inspired me to study more physics.

[@MMA4ALL7]

This is the guest/type of people lex needs to get more of.

[@KiiishawnTv]

Lex Friedman & Jordan Peterson will be a spectacular treat

[@joech1065]

No Peterson please. I don't find him intellectually compelling at all. The guy is an infinite generator of unfalsifiable word salad, and, at this point, I'm not even sure that Peterson himself knows what are his tangible claims.

[@HassanWorld]

Going to enjoy this episode, thanks Lex.

[@saeedansari]

I love the way he always smiles as he explains.

[@musicalfringe]

That intro about string theory was beautiful. Unflinchingly critical yet optimistic.

[@NinjaofApathy]

I'd love to hear more conversations with engineers from various different disciplines.

[@vivekrbs]

Amazing interview. Just wow

[@darakdjian]

“Imagine 9 dimensions” + “No problem” - Dr. Vafa

[@devonk298]

Lovin' the new suit Lex!

[@MetaPhysStore0770]

Theres a symplistic but profound difference between wound and unwound strings on musical instruments, not all strings sound the same or bend the same. Since strings vibrate, they bend stiffer when "wound" and sound richer, they can be "flat-wound" being smoother and warmer, its not "only" that they are strings, but "round wound" or "flat wound" make a huge variation in vibrational difference in the limited constraints of 3 spacial dimentions. In electronics , some wire is braided, some wire is twisted, some wire is sleeved, some wire is coaxial, like a wire inside a wire braided sleeve, there is also triax cable, it seems like string theory needs some common pedestrian input, if it has obvious benefits and uses. If a "wound string" is ancedotally better and/or distictly different, it makes sense that string within a sleeve string, within another sleeved string, whether round-wound or flat-wound, it would make a huge difference, but the real "gravity" of my example😂 is if dark matter was what was flat wound or round wound on the strings or if dark matter was the sleeve around a "coaxial string" type string theory, then there could be a super position of dark matter and baryonic matter happening to create all the extra mass in the universe. Im sure nobody cares or ever reads these comments.😂😂😂

[@Hakor0]

Yes! Thanks, Lex & Co. I actually understood most of this. Imagine if Cumrun was your Science teacher in highschool. The infinite reflections in two mirrors and fractals ,still trip me out, i was wondering how they would look in extra dimensions if possible.

[@Shaiski95]

This man is truely a genius of our time and I hope one day we speak of him as highly as Einstein

[@des7638]

Wow. Amazing guest and ideas

[@calivein]

Thank you for making videos!

[@rjhayward1]

Great interview, this stuff is very hard to understand, Dr. Vafa does a wonderful job of explaining it.

[@KJBtheMosFett]

This is the best podcast episode I've ever seen.

[@ek4172]

"This *greater environment into which you are emerging* is a physical reality governed by physical laws, the laws of nature that you are aware of. Do not concern yourselves here with the *possibilities of other dimensions* , for that will not be your need and concern. It is this greater reality in which humanity has always lived and in which your world has always existed that *must become your focal point now* ." *Life in the Universe* Chapter 1: *Facing a Greater Community of Life* by *Marshall Vian Summers*

[@thehereticalinvestigation]

Lol, didn’t expect a New Message quote around here.

[@johnchapman5125]

Thank you, E K.

[@hyoyoung2631]

Thank you. E K

[@nenani1817]

Awwwwe I'm so Glad to see him here. I remember the first day his theory was published and I was in hurry to buy the Physic magazine. Thank you for this meeting and arrangements❤ آقای کامران وفا ممنون از وقتی که گذاشتید❤

[@PearlmanYeC]

looks interesting, saved to watch latter list.

[@ILYICH_NOW]

1:11:28 Such a wonderful storyteller and an endless source of knowledge! In the case of the multi-dimensional outline, would you consider that you "as a human"/"your being" is a meeting point of two different higher-demensional forms from two different planes of existence?

[@rg10870]

Love how humble he is with respect to us as a species essentially not knowing shit when it comes down to it.

[@Democritum]

Lex. It is time to bring Sabine Hossenfelder to the show!

[@derekbentley334]

Awakening with full awakening realizations with design and ideas

[@juancuelloespinosa]

cumrun's explanation of how string theory intuits higher dimensions by using our 3, describing how they would intersect at lower dimension finally let me understand those pictures I thought were silly, since to me they were obviously 3 dimensional shapes

[@JAYMOAP]

Keep up the great work Lex.

[@0willow0]

Sense of beauty/taste/expression almost seems to be our pattern-seeking part of our brains working out new material and ideas in a constant effort to grow, train and hone itself for beneficial outcomes in more practical fields, like physics, engineering, architecture, etc. Over a very long time our sense of beauty has been trained by our ancestors to learn an appreciation for symmetries because understanding and appreciating the relationship between asymmetries and symmetries is very conducive to broad success in life.

[@gmotionedc5412]

So Fascinating

[@iamwhoyousayiam6773]

Your channel is amazing

[@alo_11]

Very much enjoyed!

[@BackassWordsWeirdworld]

Great show. Thank you. God bless.

[@susanwoodward7485]

??Would you consider having Dr. Vafa and Dr. Wal Thornhill together to debate their perspectives? Your podcast, with your moderator skills, is the perfect venue. Thanks so much for these superb thinking/learning experiences.

[@olivercroft5263]

Incredible. Also, very credible!

[@granand]

If Cumrun was my teacher, I think I would relish, understand and strive to prove equations and love math.

[@thebenc1537]

i am going to name my first daughter Cumrun! Hopefully she becomes a stripper.

[@granand]

@@thebenc1537 Well that's what you hope, but when she learns why you named her Cumrun, she will run away from you to do something good for self & others hopefully.

[@plato2030]

This shows how lucky some people are to study with a great master

[@nicolascooper4714]

thanks for saving Elias n Nick and teaching us about air awareness

[@Blank-zp8th]

looking forward to this lex