Grant Sanderson: Math, Manim, Neural Networks & Teaching with 3Blue1Brown | Lex Fridman Podcast #118

1. 0:00 – 5:13

   Introduction

   1. LFLex Fridman0:00

      The following is a conversation with Grant Sanderson, his second time on the podcast. He's known to millions of people as the mind behind 3Blue1Brown, a YouTube channel where he educates and inspires the world with the beauty and power of mathematics. A quick summary of the sponsors: Dollar Shave Club, DoorDash, and Cash App. Click the sponsor links in the description to get a discount and to support this podcast, especially for the two new sponsors, Dollar Shave Club and DoorDash. Let me say as a side note, I think that this pandemic challenged millions of educators to rethink how they teach, to rethink the nature of education. As people know, Grant is a master elucidator of mathematical concepts that may otherwise seem difficult or out of reach for students and curious minds. But he's also an inspiration to teachers, researchers, and people who just enjoy sharing knowledge, like me, for what it's worth. It's one thing to give a semester's worth of multi-hour lectures. It's another to extract from those lectures the most important, interesting, beautiful, and difficult concepts and present them in a way that makes everything fall into place. That is the challenge that is worth taking on. My dream is to see more and more of my colleagues at MIT and world experts across the world summon their inner 3Blue1Brown and create the canonical explainer videos on a topic that they know more than almost anyone else in the world. Amidst the political division, the economic pain, psychological medical toll of the virus, masterfully crafted educational content feels like one of the beacons of hope that we can hold onto. If you enjoy this thing, subscribe on YouTube, review it with five stars on Apple Podcasts, follow on Spotify, support on Patreon, or connect with me on Twitter @lexfridman. Of course, after you go immediately, which you already probably have done a long time ago, and subscribe to 3Blue1Brown YouTube channel. You will not regret it. As usual, I'll do a few minutes of ads now and no ads in the middle. I try to make these interesting, but I give you timestamps so you can skip. But still please do check out the sponsors by clicking the links in the description, especially at the two new ones, DoorDash and Dollar Shave Club. They're evaluating us, looking at how many people go to their site and get their stuff in order to determine if they wanna support us for the long term. So you know what to do. (laughs) It's the best way to support this podcast, as always. This show is sponsored by Dollar Shave Club. Try them out with a one-time offer for only $5 and free shipping at dollarshaveclub.com/lex. Starter kit comes with a six-blade razor, refills, and all kinds of other stuff that makes shaving feel great. I've been a member of Dollar Shave Club for over five years now, and actually signed up when I first heard about them on the Joe Rogan podcast. And now, we have come full circle. I feel like I've made it now that I can do a read for them just like Joe did all those years ago. For the most part, I've just used the razor and the refills, but they encouraged me to try the shave butter, which I've never used before. So I did, and I love it. I'm not sure how the chemistry of it works out, but it's translucent somehow, which is a cool new experience. Again, try the Ultimate Shave Starter Set today for just five bucks, plus free shipping at dollarshaveclub.com/lex. This show is also sponsored by DoorDash. Get five bucks off and zero delivery fees on your first order of $15 or more when you download the DoorDash app and enter code LEX. I have so many memories of working late nights for a deadline with a team of engineers and eventually taking a break to argue about which DoorDash restaurant to order from. And when the food came, those moments of bonding, of exchanging ideas, of pausing to shift attention from the programs to the humans, were special. These days, for a bit of time, I'm on my own sadly, so I miss that camaraderie. But actually DoorDash are still there for me. There's a million options to fit into my keto diet ways. Also, it's a great way to support restaurants in these challenging times. Once again, download the DoorDash app and enter code LEX to get five bucks off and zero delivery fees on your first order of $15 or more. Finally, this show is presented by Cash App, the number one finance app in the App Store. When you get it, use code LEXPODCAST. Cash App lets you send money to friends, buy Bitcoin, and invest in the stock market with as little as $1. It's one of the best designed interfaces of an app that I've ever used. To me, good design is when everything is easy and natural. Bad design is when the app gets in the way, either because it's buggy or because it tries too hard to be helpful. I'm looking at you, Clippy. Anyway, there's a big part of my brain and heart that love to design things and also to appreciate great design by others. So again, if you get Cash App from the App Store or Google Play and use code LEXPODCAST, you get $10, and Cash App will also donate $10 to FIRST, an organization that is helping to advance robotics and STEM education for young people around the world. And now, here's my conversation with Grant Sanderson.

2. 5:13 – 9:41

   Richard Feynman

   1. LFLex Fridman5:13

      You've spoken about Richard Feynman as someone you admire. I think last time we spoke, we ran out of time. (laughs)

   2. GSGrant Sanderson5:20

      (laughs)

   3. LFLex Fridman5:21

      Uh, so I wanted to talk to, uh, to you about him. Um, who is, uh, Richard Feynman to you, in your eyes? What impact did he have on you?

   4. GSGrant Sanderson5:29

      I mean, I think a ton of people like Feynman. He's probably... It's a little bit cliché to say that you like Feynman, right? That's, um, almost like when you don't know what to say about sports and you just point to the Super Bowl or something as something you enjoy watching.

   5. LFLex Fridman5:41

      Yeah.

   6. GSGrant Sanderson5:41

      But I do actually think there's a layer to Feynman that, like, sits behind the iconography. One thing that just really struck me was this letter that he wrote to his wife two years after she died. So during the Manhattan Project, she had polio. Um, tragically, she died. They were just young, madly in love. And, you know, the i- the icon of Feynman is this, almost this, like, mildly sexist, womanizing philanderer, at least on the personal side.But you read this letter, and I can try to pull it up for you if I want, and it's just this absolutely heartfelt letter to his wife saying how much he loves her even though she's dead, and kind of what she means to him, how no woman can ever measure up to her. And it shows you that the Feynman that we've all seen in, like, Surely You're Joking, is different from the Feynman in reality. And I think the same kind of goes in his science, where, you know, he kind of sometimes has this output of being this "aw shucks" character. Like, everyone else is coming in this with these fancy falutin formulas, but I'm just gonna try to whittle it down to its essentials. Which is so appealing, 'cause we love to see that kind of thing. But when you get into it, like, what he was doing was actually quite deep, very much mathematical. Um, that should go without saying, but I remember reading a book about Feynman in a cafe once, and this woman looked at me and was like, uh, saw that it was about Feynman. She was like, "Oh, I love him. I read Surely You're Joking." And she started explaining to me how he was never really a math person. And, (laughs) uh, I don't understand how that can possibly be a public perception about any physicist, but for whatever reason that, like, worked into his aura, that he sort of shooed off math in s- in place of true science. The reality of it is, he was deeply in love with math and was much more going in that direction, and had a clicking point into seeing that physics was a way to realize that, and all the creativity that he could output in that direction, um, was instead poured towards things like fundamental, not even fundamental theories, just emergent phenomena and everything like that. So, to answer your actual question, like, what- what I like about, uh, his way of going at things is this constant desire to reinvent it for himself. Like, when he would consume papers, the way he described it is he's, he would start to see what problem it was trying to solve and then just try to solve it himself to get a sense of personal ownership, and then from there see what others had done.

   7. LFLex Fridman7:52

      Is that how you see problems yourself? Like, that- that's actually an interesting point. When you first are inspired by a certain idea that you maybe want to teach or visualize or just explore on your own, I'm sure you're captured by some possibility and magic of it. Do you read the work of others? Like, do you go through the proofs, or do you try to rediscover everything yourself?

   8. GSGrant Sanderson8:15

      So, um, I think the things that I've, like, learned best and have the deepest ownership of are the ones that have some element of rediscovery. The problem is that really slows you down. And this is, for my- for my part, it's actually a big fault. Like, this is part of why I'm, I'm not an active researcher. I'm not, like, at the depth of the field a lot of other people are. The stuff that I do learn, I try to learn it really well. Um, but other times you do need to get through it at a certain pace. You do need to get to a point of a problem you're trying to solve, so obviously you need to be well-equipped to read things, uh, without that reinvention component and see how others have done it. But I think if you choose a few core building blocks along the way and you say, "I'm really gonna try to approach this, um, before I see how this person went at it. I'm really gonna try to approach it for myself," no matter what, you gain all sorts of inarticulatable intuitions about that topic which aren't gonna be there if you simply go through the proof. For example, you're gonna be, um, trying to come up with counterexamples. You're gonna try to come up with, um, intuitive examples, all sorts of things where you're populating your brain with data, and the ones that you come up with are likely to be different than the one that the text comes up with. And that, like, lends it a different angle. So, that aspect also slowed Feynman down in a lot of respects. I think there was a period when, like, the rest of physics was running away from him. Um, but insofar as got- it got him to where he was, uh, I- I- I kind of resonate with that. I just, um, (laughs) I would, I would be nowhere near it, 'cause I'm not like him at all. But it's like a, a state to aspire to.

3. 9:41 – 13:56

   Learning deeply vs broadly

   1. LFLex Fridman9:41

      You know, just to- to look at a small point you made, that you're not a quote-unquote "active researcher." Do you... You're swimming often in reasonably good depth about a lot of topics. Do you sometimes want to, like, dive deep at a certain moment and say, like... 'Cause you probably built up a hell of an amazing intuition about what is and isn't true within these worlds. Do you ever want to just dive in and see if you can discover something new?

   2. GSGrant Sanderson10:15

      Yeah. I, I think one of my biggest regrets from undergrad is not having built better relationships with the professors I had there. And I think a big part of success in research is that element of, like, mentorship and, like, people giving you the kind of scaffolded problems to carry along. For my own, like, goals right now, I feel like, um, I'm pretty good at exposing math to others and, like, want to continue doing that. For my personal learning, I... Are- are you familiar with, like, the hedgehog-fox dynamic? I think this was, um, either the ancient Greeks came up with it or it was pretended to be something drawn from the ancient Greeks. I- I don't know who to (laughs) point it to, but the i-

   3. LFLex Fridman10:53

      Probably Mark Twain.

   4. GSGrant Sanderson10:54

      (laughs) It is that you've got two types of people, or especially two types of researchers. There's, uh, the fox that knows many different things and then the hedgehog that knows one thing very deeply. So, like, von Neumann would have been the fox. He's someone who knows many different things, just very foundational in a lot of different fields. Um, Einstein would have been more of a hedgehog, thinking really deeply about one particular thing. And both are very necessary for making progress. Um, so between those two, I would definitely see myself as, like, the fox, where, uh, I'll try to get my paws in, like, a whole bunch of different things. And at the moment, I just think I don't know enough of anything to make, like, a significant contribution to any of them. But I do see value in, um, like, having a decently deep understanding of a wide variety of things. Like, most people who, uh, know computer science really deeply don't necessarily know physics very deeply, or, uh, many of the aspect, like different fields in math even. Let's say you have, like, an analytic number theory versus an algebraic number theory. Like, these two things end up being related to very different fields, like some of them more complex analysis, some of them more like algebraic geometry. And then when you just go out so far as to take those adjacent fields, place one, you know, PhD student into a seminar of another one's, they don't understand what the other one's saying at all. Like, you take the complex analysis specialist inside the algebraic geometry seminar, they're as lost as you or I would be. But I think, uh, going around and, like, trying to have some sense of what this big picture is certainly has personal value for me. I don't know if I would ever make, like, new contributions in those fields. But I do think I could make new, like, expositional contributions, where there's kind of a notion of...... uh, things that are known but, like, haven't been explained very well.

   5. LFLex Fridman12:30

      Well, first of all, I think most people would agree, your videos, your teaching, the way you see the world is fundamentally often new. Like, you're creating something new. Uh, and it almost feels like research, even just like the visualizations, uh, the m- the multidimensional visualization we'll talk about. I mean, you're revealing something very interesting that, uh, yeah, just feels like research, feels like science, fee- feels like the cutting edge of the very thing of which, like, new ideas and new discoveries are made of.

   6. GSGrant Sanderson13:03

      I do think you're being a little bit more generous than is necessarily

   7. NANarrator13:06

      Yeah.

   8. GSGrant Sanderson13:06

      And I- I promise that's not even false humility, because I- I sometimes think when I research a video, I'll learn like 10 times as much as I need for the video itself and it ends up feeling kind of elementary. Um, so I have a sense of just how far away, like, the stuff that I cover is from the actual depth.

   9. LFLex Fridman13:22

      I think that's natural, but I think that could also be a mathematics thing. (laughs) I feel like in the machine learning world, you're like, two weeks in you feel like you've ba- basically mastered the field.

   10. GSGrant Sanderson13:32

       (laughs)

   11. LFLex Fridman13:33

       (laughs) In mathematics, it's like Well, everything is either trivial or impossible, and it's like a shockingly thin line between the two- (laughs)

   12. GSGrant Sanderson13:40

       ... where you can find something that's totally impenetrable, and then after you get a feel for it, it's like, "Oh, yeah, that whole, that whole subject is actually trivial in some way." So maybe that's what goes on, and every researcher is just on the other end of that hump and it feels like it's so far away, but one step actually gets them there.

4. 13:56 – 18:43

   Telling a story with visualizations

   1. GSGrant Sanderson13:56

   2. LFLex Fridman13:56

      What do you think about, uh, sort of Feynman's teaching style or another perspective is ho- of use of, uh, visualization?

   3. GSGrant Sanderson14:05

      Well, his teaching style is interesting because people have described like the Feynman effect where while you're watching his lectures or while you're reading his lectures, everything makes such perfect sense. So as an entertainment session, it's wonderful because it gives you this, um, this intellectual satisfaction that you don't get from anywhere else that you, like, finally understand it. But the Feynman effect is that you can't really recall what it is that gave you that insight, you know, even a week later. And this is, um, this is true of a lot of books and a lot of lectures where the retention is never quite what we hope it is. Um, so there is a risk that, uh, the stuff that I do also fits that same bill, where at best it's giving this kind of intellectual candy on giving a glimpse of feeling like you understand something. But unless you do something active like reinventing it yourself, like doing problems, um, to solidify it, um, even things like spaced repetition memory to just make sure that you have like the building blocks of what do all the terms mean. Unless you're doing something like that, it's not actually gonna stick. So the very same thing that's so admirable about Feynman's lectures, which is how damn satisfying they are to consume, might actually also reveal a little bit of the flaw that we should, as educators, all look out for, which is that that does not correlate with long-term learning.

   4. LFLex Fridman15:24

      We'll talk about it a little bit, I think. Well, you've done some in- interactive stuff. I mean, even in your videos, the awesome thing that Feynman couldn't do at the time is you could, since it's programmed, you can, like, tinker, like, play with stuff. You could take this value and change it. You can, like... Here, let's take the- the value of this variable and change it to build up an intuition, to move along a surface, or to- to change the shape of something. I think that's almost, uh, an equivalent of you doing it yourself. It's not quite there, but, uh, y- as a viewer. Um, yeah, uh, d- do you think there's some value in that interactive element?

   5. GSGrant Sanderson16:04

      Yeah. Well, so what's interesting is you're saying that... And the videos are non-interactive in the sense that there's a play button and a pause button. Um, and you could ask like, "Hey, while you're programming these things, why don't you program it into an interactable version that, you know, make it a Jupyter Notebook that people can play with?" Which I should do, and that, like, would be better. I think the thing about interactives though is most people consuming them, um, just sort of consume what the author had in mind. Uh, and that's kind of what they want. Like, I- I have a ton of friends who make interactive explanations. And when you look into the analytics of how people use them, there's a small sliver that genuinely use it as a playground to have experiments, and maybe that small sliver is actually who you're targeting and the rest don't matter. Um, but most people consume it just as a piece of, um, like, well-constructed literature that maybe you t- tweak with the example a little bit to see what it's getting at. But in that way, I do think like a video can get most of the benefits of the interactive, like the interactive, um, app as long as you make the interactive for yourself and you decide what the best narrative to spin is. Um, as a more concrete example, like my process with... I made this video about, um, SIR models for epidemics, and it's like this agent-based modeling thing where you tweak some things about how the epidemic spreads, and you wanna see how that affects its evolution. Um, my- my, uh, format for making that was very different than others where rather than scripting it ahead of time, I just made the playground and then I played a bunch, uh, and then I saw what stories there were to tell within that.

   6. LFLex Fridman17:29

      Mm-hmm.

   7. GSGrant Sanderson17:29

      Um...

   8. LFLex Fridman17:30

      Yeah, that's cool. So y- your video had that kind of structure. It had, uh, like five or six stories or whatever it was, and like it was basically, "Okay, here's a simulation. Here's a model. What can we discover with this model? And here's five things I found after playing with it." (laughs)

   9. GSGrant Sanderson17:47

      (laughs) Well, 'cause he- the thing is, a way that you could do that project is you make the model and then you put it out and you say, "Here's a thing for the world to play with."

   10. LFLex Fridman17:54

       Yeah.

   11. GSGrant Sanderson17:54

       "Like, come to my website where you interact with this thing." Um, and- and people did, like, sort of remake it in a, um, JavaScript way so that you can go to that website and you can test your own hypotheses. But I think a meaningful part of the value to add is not just the technology, but to give the story around it as well. And like, that's kind of my job. It's not just to, like, make the, uh, the visuals that someone will look at. It's to be the one to decide what's the interesting thing to walk through here. Um, and even though there's lots of other interesting paths that one could take, that can be kinda daunting when you're just sitting there in a sandbox and you're given this tool with like five different sliders and you're told to like play and discover things. It's like, "Wh- what order do you do? Where do you start? What are my hypotheses? What should I be asking?"

   12. LFLex Fridman18:35

       Yeah.

   13. GSGrant Sanderson18:35

       Like...... a little bit of guidance in that direction can be what actually sparks curiosity to make someone want to, um, imagine more about it.

5. 18:43 – 23:52

   Topology

   1. GSGrant Sanderson18:43

   2. LFLex Fridman18:43

      A few videos I've seen you do, I don't know how often you do it, but there's almost a tangential, like, pause where you, "Here's a cool thing." You say, like, "Here's a cool thing, but it's outside the scope of this video essentially, but I'll leave it to you as homework-"

   3. GSGrant Sanderson18:59

      (laughs)

   4. LFLex Fridman18:59

      ... "essentially to, like, figure out it's a cool thing to explore."

   5. GSGrant Sanderson19:02

      I wish I could say that wasn't a function of laziness (laughs) , right? And that's like, you've worked so hard on, uh, making the 20 minutes already that to extend it out even further would take more time.

   6. LFLex Fridman19:12

      In one of your cooler videos, the homomorphic, like from the Mobius strip to the, the, uh, three-

   7. GSGrant Sanderson19:18

      With the inscribed rectangle?

   8. LFLex Fridman19:19

      Yeah. That's a super... And you're like, "Yeah, you can't, uh, you can't transform the Mobius strip into a, into a surface without it intersecting itself. But I'll leave it to you to, to see why that is." (laughs)

   9. GSGrant Sanderson19:36

      (laughs) Well, I hope that's not exactly how I phrase it, 'cause I think what, what my hope would be is that I leave it to you to think about why you would expect that to be true-

   10. LFLex Fridman19:44

       Mm-hmm.

   11. GSGrant Sanderson19:45

       ... and then to want to know what aspects of a Mobius strip do you want to formalize such that you can prove that intuition that you have? 'Cause at some point, now you're starting to i- invent algebraic topology. If, uh, you have these vague instincts like, "I want to get this Mobius strip, I want to, um, fit it such that it's all above the plane, but its boundary sits exactly on the plane. I don't think I can do that without crossing itself. But that feels really vague, how do I formalize it?" And as you're starting to formalize that, that's what's gonna get you to try to come up with a definition for what it means to be orientable or non-orientable. And, like, once you have that motivation, a lot of the otherwise arbitrary things that are sitting at the very beginning of a topology tex- textbook start to make a little more sense.

   12. LFLex Fridman20:27

       Yeah, and I mean, that, that whole video beautifully was a motivation for topology is cool.

   13. GSGrant Sanderson20:32

       That was my... Well, my hope with that is I feel like topology is, um... I don't want to say it's taught wrong, but I do think sometimes it's popularized in the wrong way, where, uh, you know, you'll hear these things of people saying, "Oh, topologists, they're very interested in surfaces that you can bend and stretch, but you can't cut or glue." Are they?

   14. LFLex Fridman20:51

       Why?

   15. GSGrant Sanderson20:51

       Well (laughs) -

   16. LFLex Fridman20:52

       Yeah.

   17. GSGrant Sanderson20:52

       ... there's all sorts of things you can be interested in with random, like, imaginative, uh, manipulations of things. Is that really what, like, mathematicians are into? And the short answer is not, not really. That's, uh... It's not as if someone was sitting there thinking, like, "I wonder what the properties of clay are-"

   18. LFLex Fridman21:08

       (laughs) Right.

   19. GSGrant Sanderson21:08

       "... if I add some arbitrary rules about what, when I can't cut it and when I can't glue it." Instead it's, there's a ton of pieces of math that, um, can actually be equivalent to, uh, like, these very general structures that's like geometry, except you don't have exact distances, you just want to maintain a notion of closeness. And once you get into those general structures, constructing mappings between them translate into non-trivial facts about other parts of math. And that, I just, I don't think that's actually pop- like, popularized. Um, I don't even think it's emphasized well enough when you're starting to take a topology class. 'Cause you kind of have these two problems. It's like either it's too squishy, you're just talking about coffee mugs and donuts, or it's a little bit too rigor first-

   20. LFLex Fridman21:49

       Mm-hmm.

   21. GSGrant Sanderson21:49

       ... and you're talking about, um, the axiom systems with open sets, and an open set is not the opposite of closed set, so sorry about that everyone, we have a notion of clo-open sets-

   22. LFLex Fridman21:59

       (laughs)

   23. GSGrant Sanderson21:59

       ... for ones that are both at the same time.

   24. LFLex Fridman22:01

       Yeah.

   25. GSGrant Sanderson22:01

       Um, and just, it's not, it's not an intuitive axiom system in comparison to other fields of math. So you as the student, like, really have to walk through mud to get there. And you're constantly confused about how this relates to the beautiful things about coffee mugs and Mobius strips and such. And it takes a really long time to actually see math, like see topology in the way that mathematicians see topology. But I don't think it needs to take that time. I think there's, um... This is making me feel like I need to make more videos on the topic, 'cause I think I've only done two.

   26. LFLex Fridman22:28

       Yeah, 100% you do.

   27. GSGrant Sanderson22:29

       (laughs)

   28. LFLex Fridman22:29

       Uh, but, you know, I've also seen it in my narrow view of, uh, like, um, I find game theory very beautiful. And I know topology has been used, uh, elegantly to prove things in game theory.

   29. GSGrant Sanderson22:41

       Yeah, you have, like, facts that seem very strange. Like, I could tell you, you stir your coffee. And, um, after you stir it, and like, let's say all the molecules settle to, like, not moving again, one of the molecules will be basically in the same position it was before. Um, you have all sorts of fixed point theorems like this, right? That kind of fixed point theorem, directly relevant to Nash equilibriums.

   30. LFLex Fridman23:00

       Mm-hmm.
6. 23:52 – 32:28

   Intuition about exponential growth

   1. GSGrant Sanderson23:52

   2. LFLex Fridman23:52

      Okay. So you mentioned the SIR model. I think, uh, there are certain ideas there of growth, of exponential growth. What maybe have you learned about, um, pandemics from, from making that video? Because it was kind of exploratory, you were kind of building up an intuition. And it's, again, people should watch the video, it's kind of an abstract view. It's not really modeling in detail the whole field of epidemiology. Those, those people, it's (laughs) , they go really far in terms of modeling, like how people move about. I don't know if you've seen it, but like, there is r- their mobility patterns, like...... how, like, the tr- like, how many people you encounter in, in a certain situations, when you go to a school, when you go to a mall. They, like, model every aspect of that for a particular city. Like, they have maps of actual city streets. They model it really well, and natural patterns of the people have. It's crazy. So you don't do any of that? You're just doing an abstract model-

   3. GSGrant Sanderson24:56

      (laughs)

   4. LFLex Fridman24:57

      ... to explore different ideas of, uh-

   5. GSGrant Sanderson24:58

      Simple peda- ... Well, because I, I don't want to pretend like an epide- I'm an epidemiologist. Like, we have a ton of armchair epidemiologists-

   6. LFLex Fridman25:04

      Yeah.

   7. GSGrant Sanderson25:06

      ... and the spirit of that was more, like, uh, can we, through a little bit of play, uh, draw, like, reasonable-ish conclusions, um, and also just, like, uh, get ourselves in a position where we can judge the validity of a model. Like, I, I think people should look at that and they should criticize it. They should point to all the ways that it's wrong, 'cause it's definitely naive-

   8. LFLex Fridman25:24

      Yeah.

   9. GSGrant Sanderson25:24

      ... right? In the way that it's set up. Um, but to say, like, what, what lessons from that hold? Like, thinking about the R naught value and what that represents and what it can imply. Um-

   10. LFLex Fridman25:34

       What's R naught?

   11. GSGrant Sanderson25:35

       So R naught is, if you are infectious and you're in a population which is, um, completely susceptible, uh, what's the average number of people that you're gonna infect during your infectiousness? Um, so certainly during the beginning of an epidemic, this basically gives you, kind of, the, um, the exponential growth rate. Like, if every person infects two others, you've got that one, two, four, eight, uh, exponential growth pattern. Um, as it goes on, and, uh, let's say it's something, um, uh, endemic, where you've got, like, a ton of people who have had it, uh, and are recovered, then, uh, you, you would ... The R naught value doesn't tell you that as directly, because a lot of the people you interact with aren't susceptible, but in the early phases, it does. Um, and this is, like, the fundamental constant that it seems like epidemiologists look at, and, you know, the whole goal is to get that down. If you can get it below one, then it's no longer epidemic. If it's equal to one, then it's endemic, um, and it's above one, then you're epidemic. So, uh, like, just teaching what that value is and giving some intuitions on how do certain changes in behavior change that value, and then what does that imply for exponential growth? I think those are, um, general enough lessons, and they're, like, resilient to all of the chaoses of the world, um, that i- i- it's still, like, valid to take from the video.

   12. LFLex Fridman26:52

       I mean, one of the interesting aspects of that is just the exponential growth-

   13. GSGrant Sanderson26:55

       Mm-hmm.

   14. LFLex Fridman26:55

       ... and the way we think about growth. Is that one of the first times you've done a video on, on, uh ... No, of course not, the, the whole (laughs) uh, Euler's identity? Okay, so-

   15. GSGrant Sanderson27:08

       Sure.

   16. LFLex Fridman27:08

       (laughs)

   17. GSGrant Sanderson27:09

       I guess I've done a lot of videos about exponential growth in the circular direction.

   18. LFLex Fridman27:12

       Yeah.

   19. GSGrant Sanderson27:12

       Uh, (laughs) only minimal in the normal direction.

   20. LFLex Fridman27:15

       I mean, another, another way to ask, like, do you think we're able to reason intuitively about exponential growth?

   21. GSGrant Sanderson27:24

       It's- it's funny. I think it's, um, I think it's extremely intuitive to humans, and then we train it out of ourselves such that it's then really not intuitive, and then I think it can become intuitive again when you study a technical field. Uh, so what I mean by that is, um, uh, have you ever heard of these studies where in a, uh, like, anthropological setting where you're studying a group that has been disassociated from a lot of, like, modern society, and you ask, "What number is between one and nine?" And maybe you would ask it, you, you've got, like, one rock and you've got nine rocks, you're like, "What pile is halfway in between these?" And our instinct is usually to say, "Five," that's the number that sits right between one and nine. Um, but sometimes when, uh, numeracy and, uh, the kind of just basic arithmetic that we have isn't in a society, the natural instinct is three.

   22. LFLex Fridman28:10

       Mm-hmm.

   23. GSGrant Sanderson28:10

       Because it's, uh, in between, in an exponential sense, in a geometric sense, that, uh, one is three times bigger and then the next one is three times bigger than that. So it's like, what's ... You know, if you have one friend versus 100 friends, what's in between that? Yeah, 10 friends seems-

   24. LFLex Fridman28:24

       Mm-hmm.

   25. GSGrant Sanderson28:24

       ... like the social status in between those two states. So that's, like, deeply intuitive to us to think logarithmically like that, um, and for some reason we kind of train it out of ourselves to start thinking linearly about things.

   26. LFLex Fridman28:35

       So in the sense, yeah, the early, early basic math is, uh, yeah, it forces us to take a step back. It's- it's the same criticism, if there's any, of science, is the lessons of science make us, like, see the world in a slightly narrow sense to where we s- we have an over-exaggerated confidence that we understand everything-

   27. GSGrant Sanderson28:59

       (laughs)

   28. LFLex Fridman29:00

       ... as, as opposed to just understanding a small slice of it.

   29. GSGrant Sanderson29:03

       But I think that probably only really goes for small numbers, 'cause the real counterintuitive thing about exponential growth is, like, as the numbers start to get big.

   30. LFLex Fridman29:10

       Yeah.
7. 32:28 – 40:09

   Elon Musk's exponential view of the world

   1. GSGrant Sanderson32:28

   2. LFLex Fridman32:28

      Are you wearing a SpaceX shirt? So let me ask you-

   3. GSGrant Sanderson32:30

      (laughs) Sure.

   4. LFLex Fridman32:31

      Let me ask you, one, one person, uh, who talks about exponential, you know, just the miracle of the exponential function in general is Elon Musk. So, he kind of advocates the idea of exponential thinking, you know, realizing that technological development can, at least in the short term, follow exponential improvement, which breaks apart our intuition. Our ability to reason about what is and isn't impossible. So he's a big... One, it's a good leadership kinda style of saying like, "Look, the thing that everyone thinks is impossible is actually possible, because exponentials." But what- what's your sense about, um, about that kind of way to see the world?

   5. GSGrant Sanderson33:19

      Well, so I think it's, um, it's g- it can be very inspiring to note when something... Like Moore's law is another great example where you have this exponential pattern that holds shockingly well, um, and it ena- en- enables, um, just better lives to be led. I think the people who took Moore's law seriously in the '60s were seeing that, wow, it's not gonna be too long before like these giant computers that are either batch processing or time-shared, you could actually have one small enough to put on your desk, on top of your desk, and you could do things. And if they took it seriously, like you have people predicting smartphones like a long time ago. Um, and it's only out of like kind of this, I don't wanna say faith in exponentials, but an understanding that that's what's happening. What's more interesting, I think, is to, um, really understand why exponential growth happens, and that the mechanism behind it is when the rate of change is proportional to the thing in and of itself. So the reason that technology would grow exponentially is only gonna be if, um, the rate of progress is proportional to the amount that you have. So, that the software you write enables you to write more software. Um, and I think we s- we see this with the internet. Like, the advent of the internet makes it faster to learn things, which makes it faster to, uh, create new things. Um, I think this is, uh, oftentimes why like investment will grow exponentially, that the more resources a company has, if it knows how to use them well, the more, uh, the more it can actually grow. So I mean, you know, you referenced Elon Musk. I think he seems to really be into vertically integrating his companies. I think a big part of that is 'cause you have this sense, what you want is to make sure that the things that you develop, you have ownership of, and that they enable further development of the adjacent parts, right? So it's not just this you, you see a curve and you're blindly drawing a line through it. What's much more interesting is to ask, when do you have this proportional growth property? Um, because then you can also recognize when it breaks down. Like in an epidemic.

   6. LFLex Fridman35:09

      Mm-hmm.

   7. GSGrant Sanderson35:09

      As you approach saturation, that would break down. Um, as you do anything that, uh, skews what that proportionality constant is, um, you can make it, maybe not break down as being an exponential, but it can seriously slow what that exponential rate is.

   8. LFLex Fridman35:22

      So the opposite of a, a pandemic is you want w- in terms of ideas, you want to minimize barriers that, uh, prevent the spread. You wanna maximize the spread of impact. So like you want it to, to grow when you're doing technological development, is so that you do hold up, that rate holds up. And that's almo- that's almost like a, like an operational challenge of like how you run a company, how you run a group of people, is that any one invention has a ripple that's unstopped. And that ripple effect then has its own ripple effects and so on. And that continues. Yeah, like Moore's law is fascinating in the, like on a psychological level, on a human level, 'cause it's not exponential, it's- it's just a consistent set of like what you would call like S-curves, which is like it's constantly like breakthrough innovations nonstop.

   9. GSGrant Sanderson36:18

      That's a good point. Like it might not actually be an example of an exponentials, because of something which grows in proportion to itself. But instead, it's almost like a, a benchmark that was set out that everyone's been pressured to meet. (laughs) And it's like all these innovations and micro, uh, inventions along the way, rather than some consistent sit back and just let the lily pad grow across the lake phenomenon.

   10. LFLex Fridman36:38

       And it's also the, there's a human psychological level for sure of like the four-minute mile, like it's-

   11. GSGrant Sanderson36:43

       Mm-hmm.

   12. LFLex Fridman36:43

       ... there's something about it, like saying that, look, there is, um...... you know, Moore's law, it's a law. (laughs) So, like, it's, uh, it's certainly th- an achievable thing. You know, we achieved it for the last decade, for the last two decades, for the last three decades, you just keep going, uh, and it somehow makes it happen. I mean, it makes people... I'm continuously surprised in this world how few people do the best work in the world. Like, in that particular... whatever that field is. Like, it's very often that, like, the genius... (sighs) I mean, you could argue that community matters, but it's certain, like, I've been in groups of engineers where, like, one person is clearly, like, doing an incredible amount of work and just is the genius. And it's fascinating to see... Basically, it's kind of the Steve Jobs idea, is maybe the whole point (laughs) is, uh, to create an atmosphere where the genius can d- discover themselves. Like, like, have the opportunity to do the best work of their life. And... yeah. And that, the exponential is just milking that. It's like rippling the idea that it's possible, and that idea that it's possible finds the right people. For the four-minute mile, the idea that it's possible finds the right runners to run it, and then explodes the number of people who can run faster than four minutes. It's kind of interesting to... I don't know. Basically, the positive way to see that is most of us are way more intelligent, have m- way more potential than we ever realize. I guess that's kind of depressing. But I mean, like, the ceiling for most of us is much higher than we ever realize.

   13. GSGrant Sanderson38:28

       That is true. Uh, uh, a good book to read if you want that sense is Peak, uh, which essentially talks about peak performance in a lot of different ways like, you know, chess, uh, London cab drivers, uh, how many pushups people can do, short-term memory tasks. Um, and if there's one... it's- it's meant to be like a concrete manifesto about deliberate practice and such, but (laughs) the- the one sensation you come out with is, "Wow, no matter how good people are at something, they can get better, and like way better than we think they could." I don't know if that's actually related to exponential growth, but I do think it's a true phenomenon that's interesting.

   14. LFLex Fridman39:01

       (laughs) Yeah, I mean, there's certainly no law of exponential growth in human innovation. M- well, I don't know. (laughs)

   15. GSGrant Sanderson39:09

       Well, kind of, there is. Like, th- there's... I think it's really interesting to see when innovations in one field allow for innovations in another.

   16. LFLex Fridman39:16

       Yeah, sure.

   17. GSGrant Sanderson39:16

       Like the advent of computing seems like a prerequisite for the advent of chaos theory. You have this truth about physics and the world that, in theory, could be known. You could find Lorenz's equations without computers. Um, but in practice, it was just never gonna be analyzed that way unless you were doing, like, a bunch of simulations and that you could computationally see these models. So it's like physics allowed for computers, computers allowed for better physics, and, you know, wash, rinse, and repeat. That self-proportionality, that's exponential. So I think... I wouldn't... it's-

   18. LFLex Fridman39:48

       I don't think it's too far to say that that's a law of some kind. (sighs) Yeah. A fundamental law of the universe is that, uh, these descendants of apes will exponentially improve their technology and one day take, be taken over by the AGI. That's some- that's built in the simulation. That would make the video game fun, whoever created this thing.

8. 40:09 – 45:28

   SpaceX and space exploration

   1. LFLex Fridman40:09

      Uh, so, I mean, since you're wearing a SpaceX shirt, let me, let me ask. Uh, so does it-

   2. GSGrant Sanderson40:13

      I didn't realize I was wearing that shirt.

   3. LFLex Fridman40:15

      (laughs) I apologize to-

   4. GSGrant Sanderson40:16

      No, it's, it's, it's on point.

   5. LFLex Fridman40:16

      ... call you out.

   6. GSGrant Sanderson40:17

      So it's on topic.

   7. LFLex Fridman40:17

      Yeah.

   8. GSGrant Sanderson40:17

      I'll take it.

   9. LFLex Fridman40:18

      So Crew Dragon, the first, uh, crewed mission out into space since the, the space shuttle, and just by first time ever by a commercial company. I mean, it's an incredible accomplishment, I think, but it's also just an incredible... and it, and it inspires imagination amongst people that this is the first step in a long, like, vibrant journey of humans into space.

   10. GSGrant Sanderson40:50

       Oh, yeah.

   11. LFLex Fridman40:50

       So what are, what are your- how do you feel? Is this as ex- you know, is this exciting to you?

   12. GSGrant Sanderson40:55

       Yeah, it is. I think it's great. The idea of seeing it basically done by smaller entities instead of by governments. I mean, it's a, it's a heavy collaboration between SpaceX and NASA in this case, but moving in the direction of not necessarily requiring an entire country and its government to make it happen, but that you can have, um, uh, something closer to a single company doing it. We're not there yet, 'cause it's, it's not like they're unilaterally saying (laughs) like, "We're just shooting people off into space." Um, it's just a sign that we're able to do more powerful things with smaller groups of people. Uh, I find that inspiring.

   13. LFLex Fridman41:26

       Innovate quickly.

   14. GSGrant Sanderson41:28

       I hope we see people land on Mars in my lifetime, right? Like-

   15. LFLex Fridman41:31

       Do you think we will?

   16. GSGrant Sanderson41:32

       I think so. I mean, I think there's a ton of challenges there, right? Like radiation being kind of the biggest one. And I think there's a ton of people who (laughs) , uh, look at that and say, "Why? Why would you want to do that? Let's let the robots do the science for us." But I think there's an- enough people who are, like, genuinely inspired about broadening, like, the worlds that we've touched.

   17. LFLex Fridman41:51

       Yeah.

   18. GSGrant Sanderson41:51

       Um, or people who think about things like backing up the light of consciousness with like super long-term versions of terraforming. Like, as long as there's a-

   19. LFLex Fridman41:59

       Sorry, backing up the light of consciousness?

   20. GSGrant Sanderson42:01

       Ye- yeah, the thought that, uh, you know, if we, if Earth goes to hell-

   21. LFLex Fridman42:04

       Ah.

   22. GSGrant Sanderson42:04

       ... we gotta have a backup somewhere. Um, a lot of people see that as pretty out there, and it's, like, not in the short-term future, but I think that's an inspiring thought. I think that's a reason to, like, get up in the morning, and I feel like most employees at SpaceX feel that way too.

   23. LFLex Fridman42:18

       Do you think we'll colonize Mars one day?

   24. GSGrant Sanderson42:21

       No idea. Like either AGI kills us first, or if we're, like, allowed, I don't know if it'll take an century.

   25. LFLex Fridman42:26

       If we're allowed? (laughs)

   26. GSGrant Sanderson42:27

       Well, like, honestly, it's- it takes, it would take such a long time. Like, okay, you might have a small colony, right? Um, something like what you see in, um, The Martian, but not, like, people living comfortably there. Um, but if you wanna talk about actual, like, second Earth kind of stuff, that would- that's just, like, way far out there, and the future moves so fast that-

   27. LFLex Fridman42:49

       It gets hard to predict.

   28. GSGrant Sanderson42:50

       ... it's like we might just kill ourselves before that even becomes viable.

   29. LFLex Fridman42:54

       Uh, yeah. I mean, there's- there's a lot of possibilities where it could be just... It doesn't have to be on a planet. We could be floating out in space. Have- have, uh- have a- have a space-faring backup solution.

   30. GSGrant Sanderson43:05

       (laughs) Yeah.
9. 45:28 – 49:50

   Origins of the Internet

   1. LFLex Fridman45:29

      This is what people... Like, the internet didn't get created because people sat down and tried to figure out, "How do I, uh, f- you know, uh, send TikTok videos of myself dancing to people?" They... You know, it was... There was an application. I mean, actually, I don't even know how-

   2. GSGrant Sanderson45:46

      What do you think the application for the internet was when it was-

   3. LFLex Fridman45:49

      It must've been very low-level, basic network communication within DARPA. Like, military-based, like, "How do I send..." Like a networking, "How do I send information securely between two places?" Maybe it was an encryption. I'm totally speaking totally outside of my knowledge, but like, it- it was probably intended for a very narrow, small group of people.

   4. GSGrant Sanderson46:10

      Well, so, I mean, it was... There was, like, this small community of people who were really interested in time-sharing computing and, like, interactive computing-

   5. LFLex Fridman46:16

      Ah, yeah.

   6. GSGrant Sanderson46:16

      ... in contrast with, uh, batch processing. And then the idea that as you set up, like, a time-sharing center, uh, basically meaning you can have multiple people, like, logged in and using that, like, central computer, um, why not make it accessible to others?

   7. LFLex Fridman46:30

      Yeah.

   8. GSGrant Sanderson46:30

      And this was kind of what I had always thought. Like, oh, it was this, like, fringe group that was interested in this new kind of computing and they all, like, got themselves together. But the thing is, like, DARPA wouldn't act-... You wouldn't have the US government funding that just for the funds of it, right? What... In some sense, that's what ARPA was all about, was, uh, like just really advanced research for the sake of having advanced research, and it doesn't have to pay out with utility soon. But, uh, the core parts of its development were happening, like, in the middle of the Vietnam War when there was budgetary constraints all over the place. Uh, I only learned this recently actually. Like, if you look at the documents basically justifying the, um, budget for the ARPANET as they were developing it, um, and not just keeping it where it was but actively growing it while all sorts of other departments were having their funding cut, uh, 'cause of the war, um, a big part of it was national defense in terms of having, like, a more robust communication system.

   9. LFLex Fridman47:23

      Mm-hmm.

   10. GSGrant Sanderson47:23

       Um, like the idea of packet switching versus circuit switching. You could kind of make this case that in some calamitous circumstance where, you know, a central location gets nuked, uh, this is a- this is a much more resilient way to still have your communication lines that, like, traditional, um, telephone lines weren't as resilient to, which I just found very interesting-

   11. LFLex Fridman47:43

       Yeah.

   12. GSGrant Sanderson47:43

       ... is that that, um... Even something that we see as so happy-go-lucky as just a bunch of computer nerds trying to get, like, interactive computing out there. The actual, like, thing that made it, uh, funded and thing that made it advance, uh, when it did was because of this direct national security question and concern.

   13. LFLex Fridman48:01

       I don't know if y- you've read it, I haven't read it, I've been meaning to read it, but Neil deGrasse Tyson actually came out with a book that talks about, like, science in the context of the military. Like, basically saying all the great science we've done in the- in the 20th century was, like, because of the military. I mean, he paints a positive... It's not like a critical... It's not... You know, a lot of people say, like, military-industrial complex and so on. Another way to see the military and national security is like a source of, like you said, deadlines and, like, hard things you can't move. Like almost, you know, almost like scaring ourself into being (laughs) productive. (laughs)

   14. GSGrant Sanderson48:38

       It is that.

   15. LFLex Fridman48:39

       Yeah.

   16. GSGrant Sanderson48:39

       I mean, Manhattan Project is a perfect example-

   17. LFLex Fridman48:41

       Yeah.

   18. GSGrant Sanderson48:41

       ... probably the quintessential example. That one, uh, is a little bit more macabre than others because of, like, what they were building. But in terms of how many focused smart hours of human intelligence get pointed towards, um, a topic per day, you're just maxing it out with that sense of worry. In that context, everyone there was saying like, "We've gotta get the bomb before Hitler does." And that...... like, that just lights a fire under you that I... Again, like, the circumstance is macabre, but I think that's actually pretty healthy, especially for researchers that are otherwise going to be really theoretical. To take these, like, theorizers and say, "Make this real, physical thing happen." Um, meaning, a lot of it is going to be unsexy. A lot of it's going to be, like, young Feynman sitting there kind of inventing, uh, a, a notion of computation in order to, like, compute what they needed to compute more quickly with, like, the rudimentary automated tools that they had available. Um, I think you see this with Bell Labs also, where you've got otherwise very theorizing minds in very pragmatic contexts, that I think is, like, really helpful for the theory as well as for the applications. Uh, so I, I think that stuff can be positive for progress.

10. 49:50 – 54:31

    Does teaching on YouTube get lonely?

    1. GSGrant Sanderson49:50

    2. LFLex Fridman49:50

       You mentioned Bell Labs and Manhattan Project. This kind of makes me curious, um, for the things you've create, which are quite singular, like if you look at all YouTube, or just not YouTube, it doesn't matter what it is, it's just teaching, content, art, doesn't matter. It's like, yep, that's, that's Grant, right? That's unique, uh, in, uh, your teaching style and everything. Does it... Manhattan Project and Bell Labs was, like, famously a lot of brilliant people, but there's a lot of them. They play off of each other. So, like, my question for you is that does it get lonely?

    3. GSGrant Sanderson50:28

       Honestly, that right there, I think is the biggest part of my life that I would like to change in some way, that, uh, I, I look at a Bell Labs type situation, and I'm like, "Goddamn, I love that whole situation and I'm so jealous of it." And you're, like, reading about Hamming, and then you see that he also shared an off- with, with Shannon, and you're like, "Of course he did. Of course they shared an office." That's how these ideas get, like, uh-

    4. LFLex Fridman50:50

       And they actually-

    5. GSGrant Sanderson50:51

       ...

    6. NANarrator50:51

       in each other.

    7. LFLex Fridman50:51

       ... probably, very likely worked separately-

    8. GSGrant Sanderson50:53

       Yeah, totally-

    9. LFLex Fridman50:54

       ... most of the time.

    10. GSGrant Sanderson50:54

        ... totally separate.

    11. LFLex Fridman50:55

        But there's a literally, and sorry to interrupt, there's a literally magic that happens when you run into each other, like, on the way to, like, get- getting a snack or something, uh-

    12. GSGrant Sanderson51:06

        Conversations you overhear, it's other projects you're pulled into, it's, like, puzzles that colleagues are sharing, like, all of that. Um, I, I have some extent of it just because I just try to stay well-connected in communities of, uh, people who think in similar ways. But it's not, it's not in the day-to-day in the same way, which I would like to fix somehow.

    13. LFLex Fridman51:25

        That's one of the, I would say, uh, one of the biggest, well, uh, one of the many, um, drawbacks, negative things about this current pandemic is that, uh, whatever the term is, but, like, chance collisions-

    14. GSGrant Sanderson51:42

        Yep.

    15. LFLex Fridman51:42

        ... are significantly reduced.

    16. GSGrant Sanderson51:44

        I, I saw, um, I don't know why I saw this, but on my, on my brother's work calendar, uh, he had a scheduled slot with someone, um, that he scheduled a meeting, and the, the title of the whole meeting was, "No specific agenda, I just miss the happenchance, serendipitous conversations that we used to have, which the pandemic and remote work has so cruelly taken away from us." (laughs)

    17. LFLex Fridman52:05

        (laughs) Brilliant.

    18. GSGrant Sanderson52:06

        (laughs) That was the long title of the meeting.

    19. LFLex Fridman52:07

        That's brilliant.

    20. GSGrant Sanderson52:08

        I'm like, "That's the way to do it. You just schedule those things."

    21. LFLex Fridman52:11

        Schedule it.

    22. GSGrant Sanderson52:11

        You schedule the serendipitous interaction.

    23. LFLex Fridman52:13

        It's, like, I mean, you can't do it in an academic setting, but it's basically like going to a bar and sitting there just for the strangers you might meet, just the strangers or striking up a conversation with strangers on the train. E- harder to do, um, when you're deeply (clears throat) , like, maybe myself or maybe a lot of academic types who are, like, introverted and avoid (laughs) human contact as much as possible. So, it's nice when it's forced, those chance collisions, but maybe scheduling it is a possibility. But for the most part, do you work alone? Like, I'm sure you struggle, like, a lot, like, d- like, this, like, this, you probably hit moments when you, it, you look at this and you say, like, "This is the wrong way to show it. This is the wrong way to visualize it. I'm making it too hard for myself. I'm going down the wrong direction. This is too long, this is too short." All those self-doubt that's, like, could be paralyzing. Okay, what do you do in those moments?

    24. GSGrant Sanderson53:12

        Honestly, for, I actually much prefer, like, work to be a solitary affair for me. That's, like, a personality quirk. I, I would like it to be in an environment with others and, like, collaborative in the sense of ideas exchanged. But those phenomena you're describing when you say, "This is too long, this is too short, this visualization sucks," it's way easier to say that to yourself than it is to say to a collaborator. Um, and I know that's just a thing that I'm not good at. So, uh, in that way, it's, it's very easy to just throw away a script because the script isn't working. It's hard to tell someone else they should do the same.

    25. LFLex Fridman53:43

        Actually, last time we talked, I think it was, like, very close to me talking Don Knuth. It was kind of cool, like, two people that you guys-

    26. GSGrant Sanderson53:50

        I can't believe you got that interview.

    27. LFLex Fridman53:50

        (laughs) Yeah. It's, it's a hard hit. Uh, no. Can I brag about something?

    28. GSGrant Sanderson53:54

        Please.

    29. LFLex Fridman53:55

        Uh, my (laughs) my favorite thing is Don Knuth, after I did the interview, he offered to go out to hot dogs with me.

    30. GSGrant Sanderson54:02

        (laughs)
11. 54:31 – 1:00:20

    Daily routine

    1. LFLex Fridman54:31

       You know, writers like Stephen King, you know, often talk about, like, their process of, you know, what they do, like, what they eat when they wake up. Like, uh, when they sit down, like, how they like their desk, if... You know, on a, on a perfectly productive day, like, what they like to do, how long they like to work for, what enables them to think deeply, all that kind of stuff. Um, Hunter S. Thompson did a lot of drugs. Uh, you know-

    2. GSGrant Sanderson55:00

       (laughs)

    3. LFLex Fridman55:00

       ... everybody (laughs) has their own thing. Uh, what's... Do you have a thing? Do- is there... If you were to lay out a perfect, productive day, what would that schedule look like, do you think?

    4. GSGrant Sanderson55:13

       ... part of that's hard to answer because I, like, um, the mode of work I do changes a lot from day to day. Like, some days I'm writing. The thing I have to do is write a script. Some days I'm animating, the thing I have to do is animate. Some days I'm, like, working on the animation library. The thing I have to do is, like, a little, um, not a software engineer, but something in the direction of software engineering. Some days it's, like, a variant of research. It's like, learn this topic well and try to learn it differently. So, those is like four very different modes of what it (laughs) some days is, like, get through the email backlog of people I've been, (laughs) tasks I've been putting off. Um.

    5. LFLex Fridman55:46

       It goes research, scripting, like the idea starts with research and then, and there's scripting, and then there's programming, and then there's the, uh, showtime.

    6. GSGrant Sanderson55:56

       And the research side, by the way, I, like what's I think a problematic way to do it is to say, "I'm starting this project and therefore I'm starting the research." Instead it should be that you're like ambiently learning a ton of things just in the background, and then once you feel like you have the understanding for one, you put it on the list of things that there can be a video for. Otherwise, um, either you're gonna end up roadblocked forever, or you're just not gonna, like, have a good way of talking about it. Um, but still some of the days it's, like, the thing to do is learn new things.

    7. LFLex Fridman56:25

       So what's the most painful one? I think you mentioned scripting.

    8. GSGrant Sanderson56:28

       Scripting is, yeah, that's the worst. Yeah, write- writing is the worst.

    9. LFLex Fridman56:31

       So what's your, on a perfectly, so let's take the hardest one. What's a perfectly productive day?

    10. GSGrant Sanderson56:37

        (laughs)

    11. LFLex Fridman56:37

        You, you wake up and it's like, "Damn it, this is the day I need to do some scripting." And like you didn't do anything the last two days, so you came up with excuses to procrastinate, so today must be the day.

    12. GSGrant Sanderson56:47

        Yeah. I, uh, I wake up early. I, uh, I guess I exercise. Um, and then, uh, I turn the internet off. (laughs)

    13. LFLex Fridman56:56

        (laughs)

    14. GSGrant Sanderson56:56

        If, if we're writing, yeah, that's, that's what's required, um, is having the internet off. And then maybe you keep notes on the things that you wanna google when you're allowed to have the internet again. I'm not great about doing that, but when I do, uh, it makes it happen. And then when I hit writer's block, like the solution to writer's block is to read. It doesn't even have to be related. Just read something different, uh, just for like 15 minutes, half an hour, and then go back to writing. Um, that, when it's a nice cycle, I think can work very well.

    15. LFLex Fridman57:22

        And when you're, when you're writing the script you don't know where it ends. Right? Like, you haven't, uh, like-

    16. GSGrant Sanderson57:27

        Problem-solving videos I know where it ends. Expositional videos I don't know where it ends.

    17. LFLex Fridman57:32

        Like coming up with, uh, with the magical thing that makes this whole story, like ties this whole story together. Is that, when does that happen?

    18. GSGrant Sanderson57:41

        On, uh, that's, that's the thing that makes it such that a topic gets put on the list of, like, videos to actually make.

    19. LFLex Fridman57:45

        Oh, that's an issue.

    20. GSGrant Sanderson57:46

        Yeah, yeah.

    21. LFLex Fridman57:46

        There isn't a hot thing.

    22. GSGrant Sanderson57:46

        You, you shouldn't start the project unless there's one of those. Uh-

    23. LFLex Fridman57:49

        Uh-huh. And you have, you have so many nice bag, that you have such a big bag of ah-ha moments already-

    24. GSGrant Sanderson57:54

        (laughs)

    25. LFLex Fridman57:54

        ... that you could just pull at it. Uh, that's one of the things, and one of the sad things about time and that ev- nothing lasts forever (laughs) and that we're all mortal. Let's not get into that, um, (laughs)

    26. GSGrant Sanderson58:07

        (laughs)

    27. LFLex Fridman58:08

        ... discussion. Uh, is, you know, if I see like even when I ask for people to ask, like ask, I did a call for questions if people want to ask you questions, and so many requests from people about like certain videos they would love you to do. It's such a pile, and I, I think that's uh, that's a sign of, like, admiration from people for sure. But it's like it makes me sad because like whenever I see them g- people give ideas, they're all like very often really good ideas.

    28. GSGrant Sanderson58:38

        (laughs)

    29. LFLex Fridman58:38

        And it's like, it's such a, makes me sad in the same kind of way when I go through a library or through a bookstore, you see all these amazing books that you'll never get to open. (laughs) So, so yeah, so, so you did, yeah.

    30. GSGrant Sanderson58:55

        You got to enjoy the ones that you have.
12. 1:00:20 – 1:10:38

    Social media

    1. LFLex Fridman1:00:20

       I try to check social media once a day.

    2. GSGrant Sanderson1:00:22

       Mm.

    3. LFLex Fridman1:00:22

       But I'm like only, so I post and that's it. I, when I post, I check the previous days. That's like my, what I try to do. Uh, that's what I do like 90% of the days. But then I'll go, I'll have like a two-week period where it's just like I'm checking the internet like I mean it's some, probably some scary number of times. And that-

    4. GSGrant Sanderson1:00:43

       I think a lot of people can resonate with that. I think it's a legitimate addiction. It's like-

    5. LFLex Fridman1:00:47

       Man.

    6. GSGrant Sanderson1:00:47

       It's a dopamine addiction. And it, I don't know if it's a problem because as long as it's a kind of socializing, like if you're actually engaging with friends and engaging with other people's ideas, uh, I think it can be really useful.

    7. LFLex Fridman1:01:00

       Well, I don't know. So like for sure I agree with you. But I'm, it's, uh, it's definitely an addiction because for me, I think it's true for a lot of people, I am very cognizant of the fact I just don't feel that happy-If, if I look at a day where I've checked social media a lot, like if I just aggregate, I did a self-report, I'm sure I would find that I'm just like literally un... Like less happy with my life and myself after I've done that check. When I check it once a day, I'm very, like I'm happy.

    8. GSGrant Sanderson1:01:33

       Hmm.

    9. LFLex Fridman1:01:34

       I, even like, 'cause I've seen it. Okay, one way to measure that is when somebody says something not nice to you on the internet, is like when I check it once a day, I'm able to just like, like I smile, like, like I virtually, I think about them positively, empathetically. I send them love. I don't, don't ever respond, but I just feel positively about the whole thing. If I check it, if I check like more than that, it starts eating at me. Like-

    10. GSGrant Sanderson1:02:01

        Mm-hmm.

    11. LFLex Fridman1:02:02

        ... it start, uh, there, there's an eating thing that, that happens, like anxiety, um, it occupies a part of your mind that's not, doesn't seem to be healthy. Same with, um, I mean, you, you put stuff out on YouTube. I think it's important, I think you have a million dimensions that are interesting to you. But yeah, one, one of the interesting ones is the study of education and the psychological aspect of putting stuff up on YouTube. I, like now, have completely stopped checking statistics of any kind.

    12. GSGrant Sanderson1:02:33

        Mm-hmm.

    13. LFLex Fridman1:02:34

        I've released an episode, uh, 100 with my dad, conversation with my dad. He checks, he's probably listening to this, stop. (laughs) Uh, he checks the number of views on his, on his video.

    14. GSGrant Sanderson1:02:48

        Mm-hmm.

    15. LFLex Fridman1:02:48

        On his conversation. So he discovered like a reason, he's new to this whole addiction, and he just checks. And he like, he'll text me or write to me, "I just passed Dawkins."

    16. GSGrant Sanderson1:02:57

        (laughs)

    17. LFLex Fridman1:02:58

        In the top... (laughs)

    18. GSGrant Sanderson1:03:01

        (laughs)

    19. LFLex Fridman1:03:02

        And so that, that kind-

    20. GSGrant Sanderson1:03:02

        Oh my God. I love that so much.

    21. LFLex Fridman1:03:04

        Yeah, so he's, um-

    22. GSGrant Sanderson1:03:05

        Oh, can I tell you a funny story in that effect of like-

    23. LFLex Fridman1:03:08

        Sure.

    24. GSGrant Sanderson1:03:08

        ... parental use of YouTube? Uh, early on in the channel, uh, my mom would like text me. She's like, uh, "The chann- the channel has had 990,000 views. The channel's had 991,000 views." I'm like, "Oh, that's cute." She's going to the little part on the About Page where you see the total number of channel views. No, uh, she didn't know about that. She had been going every day through all the videos and then adding them up.

    25. LFLex Fridman1:03:31

        Adding them up, wow.

    26. GSGrant Sanderson1:03:32

        And she thought she was like doing me this favor of providing me this like global analytic that, uh, otherwise wouldn't be visible.

    27. LFLex Fridman1:03:39

        (laughs) That's awesome.

    28. GSGrant Sanderson1:03:39

        But it's just like this addiction where you have some number you wanna follow. And then like, yeah, it's funny that your dad had this, that I think-

    29. LFLex Fridman1:03:45

        Well, the, the-

    30. GSGrant Sanderson1:03:45

        ... a lot of people have it.
13. 1:10:38 – 1:27:03

    Online education in a time of COVID

    1. LFLex Fridman1:10:38

       So on that topic, uh, you've done a series of live streams called Lockdown Math, and you, you know, you went live, which is different than you usually do. Maybe, one, can you talk about how'd that feel? What's that experience like? Like, i- in your own when you look back, like, is that an effective way, did you find, of being able to teach? And if so, is there lessons for this world where all of these educators are now trying to figure out how the heck do I teach remotely?

    2. GSGrant Sanderson1:11:11

       For me, it was very different, as different as you can get. I'm on camera, which I'm usually not. I'm doing it live, which is nerve-wracking. Um, it was a slightly different, like, level of topics, although realistically I'm just talking about things I'm interested in no matter what. I think the reason I did that was this thought that a ton of people are looking to learn remotely. The rate at which I usually put out content is too slow to be actively helpful. Let me just do some biweekly lectures that if you're looking for a place to point your students, if you're a student looking for a place to be edified about math, just tune in at these times. Um, and in that sense, I think it was, you know, a success for those who followed with it. It was, um, a really rewarding experience for me to see how people engaged with it. Um, part of the fun of the live interaction was to actually, like I'd do these live quizzes and see how people would answer and try to shape the lesson based on that, or see what questions people were asking in the audience. I would love to, if I did more things like that in the future, kind of tighten that feedback loop even more. Um, I think for, you know, you ask about like if this can be relevant to educators. Like, 100%. Online teaching is basically a form of live streaming now. Um, and usually it happens through Zoom. I think if teachers view what they're doing as a kind of performance and a kind of live stream performance, um, that would probably be pretty healthy because Zoom can be kind of awkward. Um, and I wrote up this little blog post actually just on like just what our setup looked like if you want to adopt it yourself and how to integrate, um, like the broadcasting software OBS with Zoom or things like that.

    3. LFLex Fridman1:12:39

       It was really ... Sorry to pause on that. I mean, yeah, maybe we could look at the blog post. But it looked really nice.

    4. GSGrant Sanderson1:12:45

       The thing is, I knew nothing about any of that stuff before I started. I had a friend who knew a fair bit, um, and so he kind of helped show me the ropes. One other thing that I realized is that you could- as a teacher, like it doesn't take that much to make things look and feel pretty professional. Um, like one component of it is as soon as you hook things up with a broadcasting software rather than just doing like screen sharing, you can set up different scenes, and then you can, like, have keyboard shortcuts to transition between those te- scenes. So you don't need a production studio with a director calling like, "Go to camera three, go to camera two," like, "Onto the screen capture."

    5. LFLex Fridman1:13:16

       Screen capture.

    6. GSGrant Sanderson1:13:16

       Instead, you can have control of that. And it took a little bit of practice, and I would mess it ups now and then. But I think I had it decently smooth such that, you know, I'm talking to the camera, and then we're doing something on the paper. Then we're doing like a- um, playing with a Desmos graph or something. And something that I think in the past would have required a production team, you can actually do as a solo operation, um, and in particular as a teacher. And I think it's worth it to try to do that because, uh...... two reasons. One, you might get more engagement from the students. But the biggest reason, I think one of the, like, best things that can come out of this pandemic education-wise, is if we turn a bunch of teachers into content creators, and if we take lessons that are usually done in these one-off settings and, like, start to get in the habit of, um, sometimes I'll use the phrase "commoditizing explanation" where what you want is, whatever a thing a student wants to learn, it just seems inefficient to me that that lesson is taught millions of times over in parallel across many different classrooms in the, uh, world. Like, year-to-year, you've got a given Algebra 1 lesson that's just taught, like, literally millions of times, um, by different people. What should happen is that there's the small handful of explanations online, uh, that exist, so that when someone needs that explanation, they can go to it. That the time in classroom is spent on all of the parts of teaching and education that aren't explanation, which is most of it, right? Um, and the way to get there is to basically have more people who are already explaining publish their explanations, and have it in a publicized forum. So, if during a pandemic, you can have people automatically creating online content, 'cause it has to be online, but getting in the habit of doing it in a, um, in a way that doesn't just feel like a Zoom call that happened to be recorded, but it actually feels like a- a- a piece that was always gonna be publicized to more people than just your students, that can be really powerful. Uh-

Episode duration: 2:08:25