210 | Randall Munroe on Imagining What If…?

0:00:00.0 Sean Carroll: Hello everyone, and welcome to The Mindscape Podcast. I'm your host, Sean Carroll. In certain corners of the Internet, certainly ones that I find myself in all the time, there's a saying that goes, there's an xkcd for everything. Xkcd, of course, is the wildly popular web comic started in 2005 by today's guest, Randall Munroe. And xkcd is famous for many things. It has a very austere, minimalist art style, featuring more or less stick figures doing things and very often just talking to each other, but there's also a spirit about it that is very, very resonant with people who care about science and technology and building things and numbers and lists and words, but also who understand that these things are connected to humanity and love and emotions and things like that.

0:00:50.2 SC: It's also remarkably good at finding those little things that you've been thinking about and turning them into web comic form, thus the idea that there really is an xkcd out there for everything. One of the very popular features of the blog that Randall runs associated with xkcd is the What If? Section, where he started a few years ago taking questions from readers about "What if this crazy hypothetical scenario was going on?" Something that he himself is very fond of doing. This is the origin of probably many of the comics. And the great thing about the What If? Questions is that, it's not just a yes or no answer, and you have to really think sometimes. You know, the questions being asked, the famous, the iconic What If? Question is, what if someone pushed a baseball at 99.999% the speed of light, what would it do when you tried to hit it? You have to take that seriously, right? Okay, what would it mean to move at that speed through the atmosphere?

0:01:50.0 SC: And you have to ignore the problems, like you cannot throw a baseball that fast and take seriously the consequences. And what Randall has subsequently done is to collect some of the best answers to the What If? Questions into a book, first called What If?: Serious Scientific Answers to Absurd Hypothetical Questions, and now just very recently, : What If? 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions. And what I love about the book is that you really learn a lot by reading it, not just because he gives you the answers, but because he walks you through the methodology for answering these questions. And of course, it's sprinkled with humour and cute little cartoons along the way. Randall really has an amazing capacity to think about things in a new and enlightening, illuminating way, and so, it's been great to talk to him.

0:02:42.2 SC: We're gonna talk a little bit about some crazy hypothetical questions and a little bit about the general strategy for addressing such questions and why it's so interesting to do so. So, let's go.

[music]

0:03:10.5 SC: Randall Munroe, welcome to The Mindscape Podcast.

0:03:13.2 Randall Munroe: Thanks, it's so great to be here.

0:03:15.1 SC: So you have a famous comic strip, obviously, famous web comic, but the immediate reason that I was able to get you on the show here is 'cause you have a new book coming out, so I do wanna talk about the book, because the more I think about it, it's just a kind of a fascinating concept and you're clearly having a lot of fun with it. So why don't you tell the audience about What If? And its successor What If? 2, and why this is a good thing to do and buy a book about?

0:03:39.1 RM: Well, I originally started off drawing comics about science, and... You know, because I touched on these subjects of like, weird science ideas, I found people would often write to me with questions to answer, which I was not expecting. And often it wouldn't just be that they had their question, they thought I was the best person to answer it, there was sort of an undertone of like... It was like a back-handed compliment. They were like, me and my friend have been arguing over this science question, but we don't think it's a good enough question, like important enough question to bother a real scientist with. But we all agreed, you seemed like a good person to talk to.

0:04:11.6 SC: Yeah. You have nothing else to do.

[laughter]

0:04:16.1 RM: Yeah, he probably... That guy who does the comics, he is not a real scientist, we can bother him. And so, I... But the thing is, they were right. I... So I would spend... I would get an email with some question about Superman or building tall skyscrapers or dropping things off of other things, or lava, and I would see the question and like... It's like, one of the things where you briefly black out and like six hours have passed [chuckle] and you're... I would have 500 tabs open and like, 80 PDFs and like...

0:04:51.1 SC: Right.

0:04:53.9 RM: Books that I dug out of the closet or... And because I'm just determined to know like, alright, once I've seen the question, I wanna know the answer.

0:05:01.2 SC: Yeah.

0:05:02.5 RM: And so, I would send them all this work I had done. And at some point I was like, I'm putting a lot of work into these emails, which are probably half of them getting spam filtered. Like, I should share some of this research 'cause I'm learning all the cool stuff. And so I started posting them online and eventually publishing them as a book, first, What If? And then that... The problem with publishing those is it only leads to more questions.

0:05:25.8 SC: Of course. Just asking for it now.

0:05:27.5 RM: And so then... And so now, What If? 2, and it's like my compiled answers to these questions that random people have sent me.

0:05:34.4 SC: So to give the audience who unfortunately has not read What If? 1, a flavor for what's going on here, just tell us one or two of your favourite questions that you've answered.

0:05:46.5 RM: Well, I mean, the one that I... That it sort of all started with was, what would happen if you tried to hit a baseball that was pitched at 90% of the speed of light? And it's fun, because the... I like questions where you're like, Well, right away, I know nothing good is gonna happen there.

[chuckle]

0:06:06.3 SC: It's not good, right.

[chuckle]

0:06:07.8 RM: But I'm not actually sure what would happen, and that was the case, you know, I ended up having to spend six hours just going through sort of the particle physics of like the ball would start crashing into the air in front of it, and might undergo nuclear fusion. How many of the air molecules would pass directly through the ball, how many would fuse? What would they release? And you end up with this sort of millisecond or nanosecond by nanosecond picture of the ball disintegrating into an expanding cloud of radiation and destroying the playing field.

0:06:40.8 SC: Presumably, yeah, the kinetic energy is large enough that the explosion is gonna be pretty big, or is it mostly from... 'Cause there's no anti-matter [0:06:47.5] ____ it's running into, there wouldn't be a lot of conversion into actual pure energy, it's just kinetic energy, right?

0:06:53.2 RM: Yeah, it's... Well, it's the kinetic energy. You do get quite a bit from fusion, though.

0:07:00.3 SC: For fusion, okay.

0:07:00.4 RM: Because the ball is going fast and it's actually going fast enough, I got a great... Got some folks from an MIT High Energy laboratory after I published the first book who said, "Hey, we saw your question and we love this, so we ran the... I ran the simulation of those impacts, and here's how the actual energy distribution worked out," which was cool. And I got the software and I got to run it myself. But it's fun, because like... It's fun to get specific. My favourite thing about that scenario is that the ball is approaching the batter, but it's moving at near the speed of light, which means the batter doesn't have any sign that it's coming until the first wave of radiation hits, and once it does, the speed at which signals move down the optic nerve is slower than the rate at which the actual cloud...

0:08:02.7 SC: Sure.

0:08:03.7 RM: Of the ball approaches and starts disintegrating, so you would literally not see what hit you.

0:08:07.9 SC: It's interesting to me because there's a lot of steps in the thought process at which many people might say, "Well, no, this is just not gonna happen, so I'm not gonna follow it up." Like, I could say, "No, you can't throw a ball at the 0.9 of the speed of light," or, you know, "What would happen is it would go by the person so quickly." But taking into account exactly the right level of detail seems to be part of the art form here, right? Like, just say it's going 0.9% of the speed of light, but don't ignore air resistance, right? These are very explicit choices along the way.

0:08:42.7 RM: Yeah, yeah. And the way I usually think about these is like, We're not gonna worry about how the situation got set up exactly, like the premise is What If? Like, what if somehow this situation occurred? And then you press play on it and let normal physics take over. [chuckle] And so often people would kind of design questions trying to elicit really destructive results. So I found that people who liked the questions in the first book would send in things like, "Well, what if I put a nuclear bomb on a train that was going at relativistic speeds, but through a tunnel so that it doesn't interact with the air? And then it's going toward a volcano or something." And this is where I found that little kids asked some of the best questions. Because little kids aren't trying to come up with something weird, they're just asking an actual question that they're curious about.

0:09:38.6 SC: Right.

0:09:41.1 RM: And that... Like, one of my favourite ones in What If? 2 is a little girl who asked, What if I wanted a billion storey building? And she asked her dad and he couldn't answer it, so he sent it to me. He was like, "I don't really know what gets in your way if you do that." And what's fun is, it's like it's a much more concrete question, it's like a straightforward, real question, and the answer turns out to actually be more destructive than the train thing.

0:10:03.9 SC: Oh, really? Well, go ahead. Tell us the answer, don't hold us in suspense.

0:10:08.0 RM: Well, like, a billion storeys is really, really, really tall. There's a... The upper limit on skyscrapers isn't really engineering, it's more money. You can build a skyscraper up into the... At least, you know... Much further up into the atmosphere than we've successfully built them. It just gets rapidly more expensive, and there's just not a lot of economic incentive to do that. Most of the really tall skyscrapers are build for bragging rights as much as anything.

0:10:33.1 SC: Right.

0:10:35.0 RM: But a billion storeys is just orders of magnitude bigger than that, and so you'd end up with a skyscraper that is far enough out that as the earth is rotating, it's being flung outward by centrifugal force harder than gravity is pulling it down. So you end up with a sort of space elevator situation where suddenly your problem is not making it strong against compression, it's keeping it from being flung apart. And you would also with a billion storeys, that's enough that you would have a problem where the end of the skyscraper would be in danger of swatting against the moon.

[chuckle]

0:11:11.0 SC: Not the sun, but the moon.

0:11:12.6 RM: So you'd end up with a... Yeah, with these fragments of skyscraper falling and even if it's not that big a building, the amount of energy in a billion... Half a billion floors of a building entering the atmosphere all at once, you're gonna get some [chuckle] pretty significant destruction here on earth when the thing finally falls apart.

0:11:33.9 SC: So clearly one of the skills you have to develop, or maybe you just had this all along, is the research aspect of this, right? You're not sitting down with pencil and paper. I mean, when you say things like the limitation on skyscrapers is more money than engineering, how do you find that out? I mean, do you have secrets or is it just like, fire up the Google like everybody else?

0:11:55.4 RM: I think at some point I've... A useful skill in this kind of thing is being able to skim a lot of different things until you find something that's promising and then dig into it. And usually what I'll do is either skim until I just look through Google libraries, like the Internet archive has a lot of cool weird old reports on it, but really some of the best resources are just PDFs on some defunct government website where the link is broken, but you can find an archive copy and it was like, "Oh, this was briefly posted in 2004," and it happens to be like a report on someone in the '60s who did this exact thing.

0:12:37.5 RM: I really do like the very practical questions that don't... Even like, one of the ones that didn't really require all that much in the way of fancy physics was someone who asked, she wanted to know what would happen if she walked over... Stood over the geyser at Old Faithful in Yellowstone when it erupted.

0:13:00.4 SC: Sure. [chuckle]

0:13:03.2 RM: And that's a great question. And it has my favourite quality, which is like I hear it and I'm like, "Oh, well, I mean, of course you... " [chuckle] I mean, nothing good, but... Like, would you get flung into the air?

0:13:19.3 SC: Right.

0:13:19.4 RM: Or would it just burn you or what? And so, one of the first things I did, I did some back of the envelope calculations about how much liquid actually comes out of there, in what form is it, what's the flow rate, what's the speed, what's everything? But also like, has anyone done that? And so I was looking at records of injuries around Old Faithful, the Park Service is very clear about how you should not try to do this. And what I learned sort of surprisingly was as far as... So I found this wonderful book, Death in Yellowstone by the Yellowstone Park historian, that just kind of catalogues all the different natural hazards there, of which there are a lot, everything from exposure to rock slides to falls, to lightning, quite a bit of that, people who try to feed bears or take picture with them. Bison, surprisingly dangerous.

0:14:10.4 SC: Lots of ways to die. Yeah.

0:14:13.0 RM: And also some regular human murderers. They've got a few of those there, you know, like many places. But what was interesting going... And so, when I'm looking through research, part of it is, try to find something that has the answer.

0:14:28.2 SC: Sure.

0:14:28.3 RM: And this book did indeed have the answer, which is that surprisingly no one has, as far as I can tell, been killed by the geyser itself erupting. But it's also, you find a book cataloguing all of the different injuries that happen to people in Yellowstone, and that's gonna... Like, even if I don't see the answer I'm looking for there, I'm like, "Wait, okay, I wanna stop and read this," like the chapter indices or like, all these different kinds of injuries, and some of them are things that never even occurred to me.

0:14:55.9 SC: Right.

0:14:58.5 RM: And so what I learned is, not a lot of people who have been killed there, a huge number of people have been badly burned, many of them by leaning over and trying to look into the geyser when it erupts.

0:15:11.4 SC: When it erupts.

0:15:12.4 RM: It's like, exactly the thing you'd think. There's even... I think there was a German doctor tourist who fell in in the 1920s, who fell into the little crevice where it erupts and managed to get out as it was erupting and was scalded, but survived.

0:15:31.6 SC: So is that because the water is hot? I don't know much about Old Faithful, or it's just the velocity?

0:15:36.1 RM: Yeah. So the geysers, they're erupting water that's, it's really super heated, it's under extreme pressure. It's coming out, going on the order of 50-100 meters per second, I think. The amount of momentum carried by the stream, it has pretty low density. It's like one of those cotton candy type fluffy pillow, but it's like getting hit by a pillow going at the speed of a car on the highway.

0:16:01.2 SC: Right.

0:16:03.1 RM: If you took a direct hit from the stream or if you stood over it with an umbrella or something, it could absolutely fling you very high into the air.

0:16:09.5 SC: Okay.

0:16:11.4 RM: So the... Probably the fall would get you before the burns if that happened. But people do get very badly burned, including... So the reason that they tell you not to do this is... And they tell you not to go near the geyser is that it is extremely dangerous, of course, to get scalded by the geyser, but what the real danger there is around the geyser, there are all these boiling mineral pools that are just barely on the edge of boiling water with a mineral crust over the surface. [chuckle] And so, if you are walking around there, you could step on what looks like rock and just plunge through into boiling water.

0:16:50.1 SC: Wow, okay. Good safety tip.

0:16:52.8 RM: And that... There are some very harrowing accounts of accidents that are kind of... That I... At some point I'm like, "Alright, I've read enough of these, I don't wanna... " But, you know... So really what we get you would be trying to walk toward the geyser, that's where the real danger is. And so, my big takeaway from reading this is like, if you ever go to Yellowstone, they've got railings, just stay behind the railings. That is good advice. It's there for a reason. There's a whole book cataloguing why.

0:17:28.1 SC: Well, and this is a great reminder of why I'm not very good at exactly the kinds of questions that you're devoted to answering here. I mean, I'm a theoretical physicist, I think about where the universe came from and how quantum mechanics works. And the whole art form there is simplifying away all of the complications. And almost every question that you answer in the book is about, there's this complication you didn't think about, [chuckle] and that changes what you might have guessed.

0:17:53.4 RM: Yeah. Well, and I think, it's sort of an interesting question, because when we talk about simplifying away the complications, we're doing it in the service of answering a question, you know? Like, the reason you assume a spherical cow in a vacuum, as the physicist expression goes. They never say, what is it you're trying to find out about the cow? You know? Like, you're doing this in the process of trying to figure out what would the cow's orbital path be? Or, you know, how much would its mass increase if you did this to it? Places where the vacuum and the shape don't matter.

0:18:31.2 SC: Right.

0:18:31.8 RM: But you do have a question you're trying to answer. And so a lot of the What If? Questions, the question is just kind of broadly, what would happen?

0:18:39.2 SC: Yeah.

0:18:40.8 RM: Sometimes it's like, would this work? Would you be able to do this? But in every case, the simplifications you're making are guided by that question you're trying to answer, you know? So I feel like you're doing the same process, I think, you know, the... Like, when you're... I don't know, when you're building an inflationary model of the early universe, like, you could just simplify away everything, you could just be like, well, at this time there was the universe, we won't worry about the details, but you're done. I think you're selling yourself short by saying you don't address the complications.

0:19:18.4 SC: Well, I guess...

0:19:19.9 RM: It's all complications.

0:19:20.0 SC: Sure.

0:19:21.7 RM: Just choosing which ones you're gonna focus on.

0:19:23.3 SC: I guess the everyday world, dinosaurs and baseball and geysers, to the extent that they're the everyday world, this is deep within a regime where the dynamics are complex and non-linear and strongly coupled to each other, and it becomes hard to figure out exactly what matters and what doesn't. Have you ever answered a question and then had some expert come along and say, "No, no, no. You missed the most important thing?"

0:19:52.2 RM: I would say I have been lucky to mostly avoid that level of having someone say, "Oh, you've got this all wrong." I also will often tackle things where I'm like, "Well, I'm pretty sure no one's gonna be able to test this." So who's to say whether I'm wrong about what would happen if you threw a battleship into the sun or whatever it is.

0:20:17.6 SC: Fair enough.

0:20:19.3 RM: But... And I really... I think I have an instinct to hedge on things, I really... I'm not just trying to give a good answer; I'm trying to find an answer that satisfies me. And so there are a lot of things where it's like, "Well, I don't know what would happen. Here's a reasonable guess, here's why." And I'll try to be upfront about that when I'm really not sure about something. It is fun when I have a question that I don't think is gonna be easy to test and then someone comes along and tests it. In my first What If book, I had... Someone had asked about if you threw a steak into the Earth's atmosphere from very high up, when it fell in at hypersonic speed, how high should you drop it if you want it to be perfectly cooked when it lands? And I did a bunch of theoretical calculations about...

0:21:16.1 RM: So at first, I came into this... I have an undergraduate physics degree. And so my instinct was, okay, I know about stagnation temperatures, meaning if you have something flying through the air, it compresses the air in front of it and the center point reaches a certain temperature, and you can figure out what's the temperature of the steak gonna be at different points in its descent. And then I start looking up, okay, how quickly does heat propagate through meat... Like these materials, like a steak or water, how do you approximate it? And if you apply this much heat at this temperature, how much will the back of the steak heat up? How much will the center heat up? And I was really struggling to find good articles on heat propagation through flesh, through... And then at some point I had a moment where I sat back and I was like, wait a minute, and then I closed all the physics tabs and just opened a cookbook.

0:22:07.8 SC: Yeah, I was gonna say, there are people who are devoted to this. [laughter]

0:22:10.0 RM: It's like, oh wait, there's a different regime, a different domain of expertise where they know a lot about what happens if you apply different amounts of heat to a steak, and then it turned out it was very easy to answer. And the answer is that your steak would be a style called Pittsburgh rare where it has a seared very edge, but the inside is still raw. But what was interesting, so I put up my explanation, I said, okay, the steak is gonna probably tumble, and I don't know how a steak would tumble in hypersonic winds, you... There are some shapes where there's... There are models for this, but sort of large kind of floppy piece of meat that's roughly the size and shape of a steak, I couldn't find anything specific on. And I said, "As far as I know, no one's put one of these in a hypersonic wind tunnel, but if you do, let me know." And I had my theory about how it would heat up and some of it would ablate and break up and be blasted off. I got a letter some years later from a couple of physicists who said, "Hey, we had a hypersonic wind tunnel and we finished all our experiments," so we went out to the shop and got some steak and we decided to try it, and it was really cool.

0:23:28.8 RM: And I would say that quantitatively, I feel like I had it about right, I had the temperatures, I had the heating, the surface, it would heat the surface, not propagate to the interior, the surface would blacken and eventually be vaporized away. I think I didn't appreciate quite how grizzly it would be. [laughter] I saw some pictures that they sent, they have the cool diagrams and everything, but boy, a steak that has been heated in this manner does not look as appetizing as...

0:24:05.2 SC: No, no.

0:24:06.2 RM: I was still imagining a steak with a nice crisp crust. It looked more like the edge of a carpet when it's been worn away, just frayed bits sticking off. I didn't quite appreciate how much it would fragment in an irregular way.

0:24:24.3 SC: Not gonna replace the cast iron skill that is a way of making the steaks.

0:24:25.6 RM: No, which... But of course, then that raises all these new questions like, the inside of the wind tunnel after this experiment, did they get yelled at? How did it smell? [laughter]

0:24:37.2 SC: Yeah [0:24:38.4] ____.

0:24:41.6 RM: They did apparently finish getting their degrees that they were there, their... They were there for their PhD work, and so they did apparently get to keep using the wind tunnel.

0:24:48.4 SC: Well, it is one of the things... I was gonna get to this later, but you're bringing it up right now, which is that, you're not aiming, I guess, at the middle of the population distribution in terms of your audience, but because of the internet, etcetera, because of the way you can reach tiny minorities of people, you can aim at those kind of people, the geeky inquisitive physicists who are gonna say like, "Yes, this does sound like fun," and you found enough of them to build up quite a big audience.

0:25:22.6 RM: Yeah, and I mean, it's really cool to be able to come up with my answers and then find out like, "Oh, this expert is able to answer it better, has some data that I didn't have." I think that the neatest effect of that has been that it's made me feel like, "Oh, now I have a book I'm writing, it's reaching a real audience, I can feel justified in going and bothering someone who... "

[chuckle]

0:25:54.0 SC: Oh yeah.

0:25:56.4 RM: Like the people sending me questions when I started out, who I just sort of assume, "Oh, they have something important to do. I shouldn't bother them about this." And what I found is, reaching out to scientists, is like, they're really nice.

[laughter]

0:26:10.1 SC: Some of them.

0:26:13.2 RM: And even if they aren't familiar with my books or comics or whatever, it's like people are just excited to talk about the things they work on.

0:26:17.9 SC: That's true.

0:26:18.5 RM: And so like these silly questions, they'll be like, "Oh yeah, I've wondered about that too. Here's the answer." Or sometimes it's like, that's a ridiculous question, but they're like, "Oh, it's a ridiculous question because of this cool thing you don't know about." And so I feel like it's always a really fun conversation, I've always had... It's just been really cool to reach out to people who know stuff directly as sort of a supplement to reading all the stuff they've written and published.

0:26:47.2 SC: It's why I started a podcast, I completely agree. Now I have a license to talk to whoever I want to about all this cool stuff.

0:26:53.0 RM: It's so much fun. Well, and I... I don't know, and it's cool writing a book and then getting to talk to people who do cool science stuff, and then podcasts, who... It's everything I can do always in these situations, not to turn the interview around and be like, "Okay, but listen. Tell me more about the early universe. [laughter] Tell me more... "

0:27:13.6 SC: Well, look, I was talking to Daryl Morey, who is an executive for the Philadelphia 76ers, and one of the leaders of the analytics and statistics in basketball movement, he was a guest on my podcast. And you could tell at the end, we were reaching end of the conversation, he had to go make a trade or whatever, he was getting a little antsy, and then I said, "You didn't even ask me about dark matter yet," and then we went off for another 20 minutes where he was asking me questions about dark matter. So you're very empowered to do that, if that's what you wanna do. But first, I do wanna ask about the... There's a certain skill set in picking out the questions that are asked, there's certainly skills involved in answering them, but then of course... Sorry, in doing the research to get the right answer, but then there's a third skill set in presenting the answer in a compelling way. And obviously, humour comes in, but also it's a wonderful education in problem solving. How explicit is your intent to walk people through exactly what you were thinking to get these kind of answers? 'Cause you're very good about giving the answer right away and then explaining how you got there.

0:28:19.6 RM: Yeah, I think the way I usually approach it is not... When people are trying to simplify things, and I think this is especially something that people with a scientific or academic background struggle with, is they're like, "Well, do you want me to talk to my audience like they're really slow? Do you want me to... " And they sort of will... If you try to tell them to simplify things, they'll really start condescending to people. And so I try not to do that. The way I kind of approach this stuff is to imagine... I've just spent six hours researching with all these dead ends and random side paths, and I have 50 tabs of PDFs open, and I've got an answer, and then I think, okay, if I went back in time, and I was gonna tell myself, "Hey, I figured it out, I'm gonna save you all that time," what would my CliffNotes summary be? What would my, "Okay, here's the stuff that you need to understand to understand the answer. Here's the answer. Here's cool stuff that I found on the way that you're not gonna wanna miss."

0:29:33.8 RM: And I try to take that approach, it's just like, assume the person is interested in the question 'cause I was interested in the question. Now, how do I get it across to... All the cool stuff that I found in the minimum time? And I try to assume that the person I'm talking to has a lot of other stuff going on in their life, they're busy, they're interested, but they don't have infinite time to follow me on all of my little blind alleys and stuff. And so I'm just like, What's the cool stuff? What are the interesting parts?

0:30:13.8 SC: Yeah, so you give a little bit of a flavour of the exploration in there, you might think this, but then we have to do that, without... Like if you're really doing a scientific research problem, there are a lot of dead ends, [chuckle] you don't need to necessarily bring everyone down all of your dead ends.

0:30:27.4 RM: Yeah, and that's... I think maybe the reason for some of that showing the process, some of it is because it's cool to show how this stuff works, and it's important to bring people into science and show them how you can use these tools to solve a problem. But I think also another part of it, and I never really thought about this before, but is that, an explanation that doesn't show some amount of how you got there and why you think that's satisfactory, just raises more questions.

0:31:04.4 SC: Sure.

0:31:05.0 RM: Like if you answer a question of, why is the speed of light what it is? And you're like, "Oh well, it's because it's this over the permittivity of free space times the permeability of free space." You're like, "Okay, well, wait, now I have two new questions." And what are those two things? So you have to explain why did you think that was helpful? Why did you know to go there? What does that concept mean? How did it connect up? You need to give a little bit of... You figure out if the person isn't gonna know what that word means, that answer is not gonna satisfy them.

0:31:41.0 SC: Well, it makes me think of answers to math problems that always include a step, like, now change variables so that X equals the hyperbolic cosine of theta. And you're like, "Well, [chuckle] why did I do that? How did I get there?" And that little bit of insight into problem solving. And I think it's maybe the most valuable aspect of the book, we don't really need to know what happens when a baseball goes to 0.9 the speed of light, but the process of getting there is just fascinating.

0:32:08.1 RM: Yeah, yeah. And the secret is, one of these questions might be completely ridiculous, but the math that you're using is the same as math that you'd use to answer a very practical and important question, and so there are... The thing about the geyser and getting launched up into the air is like, no one's gonna go and read this book, and I certainly hope, get themselves scalded to death by going in Yellowstone. No one has ever been launched into the air by Yellowstone as far as... By Old Faithful, as far as we know. But the equations for the way that the gas flows out of the mouth of the geyser, is it involves these really cool choked flow equations that come up almost everywhere when you do any kind of fluid dynamic problems. The momentum coming out is like the mass flow, you can just use the rocket equation to figure out what momentum's being transferred there, and all of those are extremely common, extremely practical, extremely useful mathematical tools.

0:33:23.5 SC: Sure. And I also think of the question that you got about, how big would Google's data centers be if they were all on punch cards? And instantly, if you're me, your brain goes, "Well, that's not hard to figure out how much data is on a punched card and how big they are, and then multiply it by the size of Google's data center. But you don't know what the size of Google's data center is, and that was a fascinating detective story, right?

0:33:46.7 RM: Yeah, it's fun. We still don't. They're not...

0:33:50.0 SC: We're not being told.

0:33:51.2 RM: Very public about that. But yeah, it's surprising which pieces of information turn out to be hard to come by. And in that case, it was actually really hard to even get an order of magnitude estimate. You had to be like, "Okay, well, they can only have so many buildings, they don't occupy a majority of the earth's surface, but they could have enough room to fit... Okay, how many hard drives does earth manufacture? They can't be buying all of them, so like, that puts a bound on it.

0:34:30.2 SC: There's a bound.

0:34:30.2 RM: You can put bounds from different directions, you can say, "Well, how much power are they using?" In some places, they have to contract with municipalities and have public records of what power they're consuming, so you can learn something that way and then you can be like, "Okay, how much power does it take to run a server? How many drives would be attached to a server, etcetera? And you just kind of keep coming at it from different directions until you find kind of something that hems in the answer to be like, "Oh, it's probably in this range." To this day, Google, they did send me a whole puzzle with punch cards that I had to decode. And when I finally did, the coded message was, "No comment." But I think...

0:35:16.6 SC: If you could've guessed...

0:35:17.1 RM: I think at the time that I did that, I feel like I got it pretty...

0:35:21.7 SC: You probably got it right, yeah, they wouldn't let you know, but they were interested enough to respond in some way. And the other part of the process that I really, really like is... And I think you've mentioned this, but it's not just the most direct question you could try to answer, they're always tangible, they're always something you can touch and visualize and then put into absurd situations. And even though, like you say, maybe the equations or the principles that are involved are common to other kinds of questions, there's something visceral and really connecting about that way of exploring the physics and the engineering behind them.

0:36:04.3 RM: Yeah, I think... Yeah, I like the really practical questions that I don't know the answer to, that someone... One of the ones in the book, someone asked about what happens... Your tyres get smaller as you drive them. So, the rubber on the treads, why aren't our roads getting thicker as a layer of rubber builds up? Where is all that rubber going? And that, it turns out it's going everywhere, and it may be a huge problem and no one knows how to solve it. So I was like, "This is an unexpectedly good, important, and alarming question." But then, I don't know, I think some of what's really exciting about this, like with the baseball question and with some of the other ones I got to tackle in this book, is taking something really extreme and imagining touching it. I think maybe my favourite question in What If 2, if we can... Now that we're however many minutes into this podcast, I can sneak out that tidbit. I think there's someone who asked about... They said, "Okay, the sun, it's getting hotter over time, as it ages. At some point, it's going to explode/collapse into a white dwarf, which will be extremely hot, and then it'll thermally cool over... Through a couple of processes, for billions of years. So at what point will it be room temperature, and can I touch it?"

[laughter]

0:37:48.3 RM: And that was one where I was like, I knew in principle that the white dwarf stars in our universe are cooling down over time, all of them are still hotter than the surface of the sun is now. They're all in the tens of thousands of degrees, I think, because the universe is not old enough for them to have cooled. But until I thought about someone saying, "Okay, so I'm gonna go touch one, when is it safe?" I hadn't really thought about the idea of a room temperature star. But that's gonna happen and it's gonna happen in not that many billion years. I was surprised that it's more than the current age of the universe, but not that much more, it's like in that order of magnitude is when we'll start getting room temperature stars.

0:38:42.4 SC: Interesting.

0:38:42.5 RM: And then it immediately raises all these new questions of like, so you have a ball that's the size of the earth, really strong gravity, but so you couldn't visit the surface because it would crush a person, but it's not like a neutron star. It's not gravity so much that no structure can survive on the surface. You could, in principle, come up with some kind of a solid state probe. And then I got to think about, how would you land?

0:39:18.0 SC: Okay.

0:39:20.7 RM: And I try in the book to come up with a plan and I can see right now you've just gotten this look as you're like...

0:39:24.9 SC: I'm thinking. [laughter]

0:39:27.4 RM: Well, I mean, okay, could you...

[overlapping conversation]

0:39:32.2 RM: It's like getting a song stuck in your head. Once you hear the question it's like your brain will never be fully engaged in what you're talking about 'cause in the back of your mind, you're still thinking, well, okay, could you... With a nuclear... No. What if you orbit? Okay, what are the tidal forces?

0:39:45.8 SC: Yeah, no, I'm thinking like how big could a cube of iron be and still maintain the structural integrity in that gravitational field, things like that.

0:39:52.9 RM: Yeah, you can have a person-sized one, you can build some structures on roughly a human scale of sturdy materials.

0:40:03.6 SC: What is the atmosphere like on a room temperature neutron star? There's probably a solid surface, but then there's something on top.

0:40:10.2 RM: Yeah, and this is all hypothetical. There's a couple of papers on this. You don't get the... You get some amount of sort of sorting at the surface from the gravity pulling the heavier elements toward the middle. Because of the extreme gravity, you don't have a wispy gas kind of... At that low temperature, it's not gonna be a free floating atmosphere for the most part because it's...

0:40:36.3 SC: Makes sense.

0:40:39.0 RM: The individual molecules don't have enough kinetic energy to keep themselves up in the air, they stick down to the surface. You might have a little bit of a hydrogen haze over it depending on... But right now, the sun has the corona around it, which is extremely hot.

0:40:57.7 SC: Sure.

0:40:58.6 RM: For reasons that have never been totally clear to me.

0:41:00.9 SC: Or to anyone else for that matter. It's an ongoing problem. Yeah.

0:41:03.0 RM: Yeah. And so, I don't know, maybe there would be something weird going on with the... There are gonna be some intense magnetic fields here, I think. I'm not totally sure, but who knows what... It's possible you'll get a bit of a haze, but then thinking about the haze, I realized... It wasn't until I sat down to try to draw this scenario, I'm thinking about this, I'm picturing a room temperature star, picturing landing on it, picturing what would you experience, like what would you encounter? But it was in... Until I drew it, I draw a circle, I draw a space, I draw the spaceship. I'm like, I'll make space black, the background, and now I've gotta draw the star, and normally when you draw a star, you're like, well, this is bright. But then I realize that it's not. It's not emitting light. So the spaceship will need headlights.

[laughter]

0:41:57.9 SC: Yeah.

0:41:58.9 RM: And so I drew the star being... And then I drew a little spaceship, and then I drew headlights illuminating the star because you'd need to be able to see it.

0:42:05.7 SC: Yeah.

0:42:05.9 RM: It's out in the middle of space.

0:42:06.7 SC: Yeah, it's a super heavy rock at that point.

0:42:09.1 RM: And that, somehow that idea of just having to shine a flashlight at a star to see it really just, I cannot quite get that picture out of my head. That's just so strange and it would never have occurred to me until I sat down to try to draw it.

0:42:22.3 SC: But like you said, it's not a neutron star. It's the gravitational field is not so strong that you had to worry about the bending of light from the headlights.

0:42:28.9 RM: Yeah, yeah. It's pretty... The light's moving pretty normally, but you're still gonna be getting up to non-survivable speeds as you plunge toward it.

[laughter]

0:42:43.8 RM: The speed's where it's like you're gonna start measuring these speeds in C instead of meters per second.

0:42:51.9 SC: Good. We're getting a lot of good safety tips here from this podcast conversation. It's very practical... [laughter] help.

0:42:58.1 RM: Yeah, yeah. You definitely... If you approach the star to within the distance of the sun's current surface, that's around the point at which you're now too late to turn around and escape not because of black hole style, like there's nothing that can physically escape, but that's the point at which the acceleration it's gonna take is gonna flatten you to the floor of your spaceship.

0:43:23.5 SC: Good to know.

0:43:23.8 RM: So now at that point, you'd better have figured out the... If you're gonna try to do this, you gotta figure out the landing plan before you get to that point, because at that point you're committed.

[laughter]

0:43:34.2 SC: So this leads me into something that is a common question to both the book and other books you've written and xkcd, the comic, which is, there's sort of a... It's quirky, right? Your comic is not the same as Doonesbury or Peanuts or whatever, there's something different about it. And sometimes there's not even a punchline. Oftentimes, there's not even a punchline, it's just pure, here's something cool, or here's something to think about. How explicit is the balance that you have there? Do you have to remind yourself, well, I need to throw some jokes in to keep the audience happy? Or is it just like you go with what is cool to you and hope the audience comes along?

0:44:15.8 RM: I think it's definitely go with what's cool to me. Part of it is like... If I'm gonna post a comic, if I'm gonna write something... I think that you can only go so far analyzing this stuff before you kind of... If you think about tying your shoes too hard, you stop being able to do it.

0:44:44.0 SC: Sure.

0:44:45.7 RM: So I never... I don't know. I think that to the extent that I try to balance it, it's mostly I just think I'm gonna show this to someone so I wanna make it worth their time, either there's a good punchline at the end or there's something so cool and interesting that they're not worried about a punchline. I just don't want them to be finished and be like, "Okay, why did I read that?"

0:45:06.9 SC: Sure. Did you...

0:45:08.2 RM: So that's why I just try to think like, if I have a really cool way to visualize something, I feel like that'll speak for itself. And then sometimes you can put in some jokes here and there too just to make it clear people don't have to be studying this. But I think sometimes the punchline isn't even the destination, it's just the thing that reassures you that we're all just hanging out here. This is fun.

0:45:32.0 SC: Yeah, but there's definitely... Sometimes it is like just purely a really cool infographic. I think of like the Lord of the Rings characters talking to each other or the Money Plot or whatever. It's just there's... Like you say, there's little jokes in there, but it's just thinking about things in a slightly different way.

0:45:54.1 RM: Yeah. Yeah. That's one of the things that's the most fun about this job is being able to just decide what it is I'm gonna be doing today with each comic. It's just it has to be something I think is good and I think people will like, and I get to explore if I'm really interested in this particular idea or this particular thing. But a lot of those really big charts and that kind of comic where I'm like visualizing something or cataloguing something, it's like, it started off as just my notes to myself. I'm just trying to understand this thing and I'm like, okay, wait, there are too many different numbers here, I need to write them all down. I need to put them in some visual form so I can make sense of them. And then I'll do that and I'll be like, oh, I wonder how this other thing compares to that and I'll go add that in. And then before I know it, it's become this sprawling catalogue.

0:46:48.9 SC: At what point in this process, 'cause you originally or at some point you were just working for NASA before you started xkcd, at what point did you realize, it dawned to you like, I'm an artist? That is my job. [laughter]

0:47:03.9 RM: I don't know. I always feel a little... It's always a little bit strange when people... People will get really weird about titles or defining whether or not something is art or defining whether or not you count as an author or if you're a... And I can see sometimes if you are trying to establish your legitimacy and that you have a right to be taken seriously. I would say I get called Dr. Munroe with surprising frequency and I don't worry about what name people are using for me, but that one does bother me just because of how many women I know do not get called doctor even when they do have a PhD.

0:48:08.3 SC: Who have the opposite issue. Right.

0:48:09.6 RM: And so that makes me wanna be picky about that.

0:48:11.1 SC: Sure.

0:48:14.9 RM: But that's just... People are like, oh, is this art or not? Are these comics or not? Are you an artist? And I know that's not quite what you're asking there, but it is something like, I know that when... There's another comic, Dinosaur Comics, that started around at the same time I did where it's the same six panels every day, just new dialogue, same six pictures of dinosaurs and it's clip art. And people spend a lot of time trying to decide, is this really a comic or not? And I'm like, I don't know.

0:48:49.2 SC: No. So who cares about that?

0:48:50.1 RM: But it's all semantics.

0:48:51.4 SC: Exactly. But I guess... But nevertheless, since you're not just using clip art, you do whatever the labels are, whatever legitimacy is, you need to make artistic decisions, right?

0:49:01.7 RM: Yeah.

0:49:03.0 SC: Like you're using stick figures. There are questions about how expressive you can make stick figures. Is it a limitation? How do you... Do you... I'm not quite even sure what the question to ask is, but how do you approach the craft of, you're trying to say something funny or illustrate something cool, but you're also drawing it, right? And that has to come into the best way to do it.

0:49:31.1 RM: Yeah. I don't know. I don't know if I have a satisfying answer to that. It's I guess a lot of trial and error. I read a lot of comics growing up.

0:49:42.0 SC: Okay.

0:49:43.9 RM: One thing I found surprisingly helpful as someone might guess if they were inclined to be judgemental, I haven't taken any art classes. I did take a technical drafting class at one point.

0:49:56.4 SC: All right.

0:49:57.3 RM: And that ended up being really helpful. And I think one of my small opinions is I feel like anyone who does physics should have to take a class in perspective drawing just for the part on where you're drawing on the board, okay, you've got the plane of the so and... You've got the particle moving in this plane and then perpendicular to it you have this force, and now you have another surface here. And I just have so many memories of my physics professors drawing... Draw the front face of a cube and then the back face with a different angle and then they've got this Picasso construct and I'm like, okay, I... This is the one thing where it would be so helpful. It's really helpful to be able to take a picture and just figure out like, "Where do these lines roughly go?"

0:50:49.8 SC: Yeah. That's useful.

0:50:51.3 RM: And I think that's helpful outside of comics, it's helpful in physics, it's one of those places where I think the art can in a very small kind of [0:51:01.0] ____ communicationist way inform the actual process of science.

0:51:07.8 SC: Well, and also we seem to be... I guess I should phrase this as a question. Are we still in a dynamical discovery phase in the history of web-comics? They're clearly a different thing. You can use them in different ways. Dinosaur Comics is something that probably would never have gotten a lot of daily strip use in newspapers back in the day, and then also you can use the technology in fun ways, which you've done in a couple of xkcd strips. So have we tapped that out or is there a whole new frontier we haven't explored yet?

0:51:47.3 RM: I don't know. I feel like it almost turns into a little bit of a categorization question again. In all these different mediums, we mess around with getting things across visually with pictures that are grouped together with words, and there are different conventions and then you lean on the conventions and use that to say things and you subvert the expectations. And I think there are always new ways to do that with new mediums and it all kinda bleeds into itself. When I started doing comics, memes were around, but a very different thing, and then they slowly evolved and you now get things like the distracted boyfriend meme is just the one that came to mind first just now, like that, it's similar to comics. You're like, you're taking this picture and assigning things to it, it's like a political... It's a very political cartoon. It's very much in that mould. Is it a web-comic? I don't know, I don't... That's one of those things, like I don't really care that much, and it's all... You can call it... You can decide how you wanna group it and categorize it, but it's like it's a cool way to get across a point using these tools and...

0:53:30.8 SC: Yeah, I think...

0:53:31.6 RM: I think that's... I think that's neat and fun.

0:53:33.2 SC: And that's exactly the way that I would go. Forgetting about the categorization ahead of time, let's let the thing be what it is and see how it evolves into and maybe we'll discover some new things. I would imagine that you do more programming and scripting than the typical cartoonist. [chuckle]

0:53:53.5 RM: Yeah, yeah, I think that's probably a safe bet.

0:53:57.2 SC: Maybe...

0:53:58.2 RM: Although, a surprising amount of it is part of the writing process. Most of the interactive stuff, almost anything that you interact with in code, I've worked with someone who does JavaScript, who handles that better, anything that's gonna be public-facing like that, what I'll do is programming like for... There was a comic I did a while ago that was Wikipedia article titles that you can sing to the tune of Teenage Mutant Ninja Turtles.

[laughter]

0:54:29.2 SC: Okay.

0:54:30.7 RM: Ace Ventura Pet Detective, single payer health insurance. You can sing it to the Ace Ventura Pet Detective, like the Teenage Mutant Ninja Turtles theme. And so I made a whole list of these, but it's not just any word with the right number of...

0:54:49.3 SC: No, the accents matter.

0:54:50.3 RM: Syllables, any eight syllable [0:54:51.1] ____ table. You have to have the right patterns of stress and that's actually tricky. So I got a language processing library, figured out how to use it, figured out how to get... Extract syllable patterns from words and stress patterns, which meant I had to learn how to interpret those. They have a whole system for this. And then get some... Download all of Wikipedia's articles, run them through this, generate a list of candidates, filter through it. Most of the work there was just the programming, most of the work there was learning how to use that software, and it was just 'cause I wanted to make this joke about... 'Cause I had noticed one or two articles that you could sing to that.

0:55:34.9 SC: How many titles are there?

0:55:41.1 RM: I ended up publishing a comic that was mostly just a list of them, which had a few dozen, maybe 100. The total number of articles that technically qualify is probably in the maybe tens of thousands, maybe thousands.

0:55:54.8 SC: Okay. So you picked out your favorites for the comic, yeah.

0:55:56.7 RM: Yeah, so I could skim through and find the ones that worked the best.

0:56:01.2 SC: There is something about the... Again, this is a very vague kinda question, which maybe there's no answer to, but there's something about the style of xkcd, where you put your fingers on things that are pretty familiar to a certain segment of people. There's a reason why people say there's an xkcd for everything, and a lot of scientists and engineers have XKCDs on their doors and so forth, so the impossible to answer question is, how do you distill these little bits of truth down to a comic? Or how do you put your finger on these things that everyone goes, "Oh yes, right. Someone is wrong on the internet. [chuckle] I have spent that night."

0:56:48.0 RM: Man, I don't, I... That's another, I don't know. I think about the stuff that I have strong feelings about and, or that I notice, and then I think, you know what? Is this a common thing? But like, it's not always about just like, I'm gonna try to find something relatable or I'm gonna gonna, I wonder if this is a universal experience, some of the... The comic that you just mentioned about someone is wrong on the internet where I did this comic about this phenomenon of not being able to drop something because there's someone out there who has a wrong opinion and you need to correct it, they're wrong about something. I partly drew that one, just trying to call myself out. [chuckle] Like...

0:57:28.5 SC: Of course.

0:57:29.6 RM: It's like, I catch myself doing this. Okay. I'm gonna do a whole comic about it. And that will both serve to just drawing it and making it explicit. Like it's a reminder to myself like, oh yeah, this is a thing that it's easy to get sucked into. And I should back off, I should remember not to get too caught up in wanting to correct someone. But also it worked extra well because, let me tell you, nothing takes the wind out of your sails than you thinking you're making a really good point and then someone else quoting your own comic back at you.

[chuckle]

0:58:00.5 SC: Oh yeah. Okay.

0:58:01.6 RM: So now I have to be careful not to go too overboard and correcting people because they'll just reply with a link to my own comic.

0:58:08.9 SC: Do you to index all the comics you've ever done just to make sure that you're not telling the same joke multiple times?

0:58:15.8 RM: Definitely. I mean, but I have that problem in real life. Like, I'll tell a story, I'll have a really good little story.

0:58:20.1 SC: Of course.

0:58:20.8 RM: You forget which, it's like you have to keep a table of which of your friends you've told the cool microwave story to.

0:58:26.6 SC: It's terrible.

0:58:27.6 RM: And otherwise you start into it and they're like, "Yes, we know this one. You told us last winter and also at the party before that."

0:58:36.1 SC: Do you feel different like when you're doing the comic versus a book, like What If? I mean the comic is supposed to be presumably mostly entertaining and the book maybe is mostly informative, or is it just whatever is working in the moment?

0:58:54.6 RM: I think when I'm writing What If? I have a goal, which is, I wanna get the answer. And with the comic, it's a lot more like, I have to show why I introduced this topic. Like you can have a, any kind of a sketch or a movie or a show, you open with a, something happening and you start watching and you're like, alright, I trust you're going somewhere with that. And so you have to then have something to make it worth their while. With What If? It's like, I open with the question, now we're all on the same page about where this is supposed to end, like we wanna know the answer. Now the question is like, what's the route to get there, and what's the weird stuff along the way?

0:59:36.9 SC: So I guess it's almost like an episodic versus long arc kind of storytelling. Like, you have the buy in from the audience. Presumably if they bought a book called, What If, they know what they're expecting, but in the comic every week, is it that you put up a new comic?

0:59:52.2 RM: It's three times a week.

0:59:53.3 SC: Three times a week. Yeah. So that, yeah. So you have to sort of re-establish a premise and get to the punchline in a very short number of words, right?

1:00:02.7 RM: Yeah. Yeah. It's, man, nothing will make you edit yourself down, like, especially, I mean, that's, I hand write the text in my comics and, yeah, nothing... Having to actually write out all those words really makes you realize how much, how many words you've written. That's one way to keep your word count down.

1:00:25.8 SC: But your handwriting is very good. I wonder if that's possibly part of the drafting class you took, 'cause I also took a drafting class and the only thing it did was improve my printing.

1:00:36.3 RM: Yeah, no, I think handwriting was the first class I got a bad grade in.

1:00:39.5 SC: Yeah.

1:00:40.5 RM: Like you reach the point at which they start giving you grades or marks and then a year into that I think I got my first C or D or something in the handwriting class. And I was like, okay, well, I'll just accept that handwriting isn't my strong suit. And then I went on to get many other C's and D's. But I... It is funny that that's then the career I ended up in, was I do more hand lettering than almost any other job nowadays.

1:01:06.5 SC: But maybe this is, I mean, a good place to wind up because you know, joking about not getting good grades in school, but look, there's no super strong correlation between getting good grades in school and being good at things. [chuckle] There's a kind of thing you can be good at that requires that you get good grades in school, but you have been able to find a niche for doing something that you're very, very good at even though the whole job you have literally didn't exist when you were born, right? You didn't grow up wanting to be a [chuckle] web cartoonist. So, is there any lesson here that we could get? Is there anything that you can think about, about finding a way to get your talents into useful channels for the vast listenership out there?

1:01:57.0 RM: I don't know. I feel like it's always tough to ask someone who's like, you know, if you get someone who's successful at something and you're like, "Okay, what advice do you have?" It's like, you're really sampling from a pool of people that's selected here.

1:02:12.6 SC: Highly selected.

1:02:13.5 RM: It's like if you interview, if you only interview lottery winners and you're like, "What's the secret?" And they're just like, "You gotta buy a lot of tickets. You just gotta keep buying tickets, don't worry, it'll pay off in the end. I'm living proof of that." You know? So it's like, I don't know. I mean, I know what worked for me, but I don't know how likely it was to work. You know? I know what, and I think that... I don't know, I think that I was lucky in that I just kind of put stuff out there and paid attention to what was working, what people, you know, like when I originally posted my comics, I wasn't really thinking about... I didn't think that there would be an audience for it. And then I was surprised when people started sending some of them around, and I was like, "Oh, this is connecting with people. Cool. I can do more of these." You know? And I don't know. I think there's an amount of like a combination of being really confident about like, hey, maybe someone is interested in this. Maybe someone wants to do this. I'm gonna just plough ahead with this.

1:03:14.2 SC: Right.

1:03:15.2 RM: I think there's a combination of being confident about the things you're interested in and the things you think are cool, you know, the things that you're excited about and trust that, like there are other, that other people probably share those feelings, and also like being aware of whether or not the way you're communicating with other people is working right or not, and kind of accept that. Like, I think this is advice that goes way beyond comics or even creative work or careers, is just like communicating with people is hard, and so... And like fundamentally the only measure of whether you're doing it right, is if other people are getting the message that you want them to. And so you kind of have to go into it with this humility of like, "If I say this and people are taking the wrong thing from it, I can't control everything about how they feel, or I can't take responsibility for all of that, but also, if I'm not getting the response that I was going for, then what am I doing?"

1:04:20.9 SC: Right.

1:04:21.1 RM: Like, I should try something different, you know? If, like, we're all just trying to connect with each other and get on the same page with each other about all these things. And I think it's good to have sort of a humility about like, if I use this word and people are understanding me wrong, I can be like, "Well, it's because they don't understand this word. It really means this." And I can just be angry all the time or I can be like, "Okay, what words would get this across?" You know? And I think that going into things with a little bit of kind of humility and willingness to self-correct about that kind of thing is really helpful because otherwise you just get more and more angry and lonely.

1:04:57.5 SC: Yeah. Look, I'm actually quite skeptical about advice as a genre in many ways, 'cause people's situations are always very different from each other, but that kind of sort of general thing to keep in mind can be useful. I mean maybe to end on something more concrete but along the same veins, am I crazy to draw a connection between things that NASA does and things that you do? [chuckle] I know that you worked for NASA, but in some ways NASA is an example of a bunch of people who are faced with these real world versions of what if questions. What if we needed to land a Rover on Mars without it crashing? Right? I mean, there is some, the what if questions are great because they're absurd, but there are... The lessons that we learn from them are actually kind of important.

1:05:48.3 RM: Yeah. I think something that I really... Something that I think is really unique about NASA compared to a lot of the other big places where there's a lot of interesting technical stuff going on is that they are tasked with doing things for no reason except that we think it's a good idea, like collectively as a society to do this to learn more. It's like very, like there are benefits from the things NASA does and a lot of the stuff they do teaches us about the world, which is important because the world is where we live and might destroy us at any moment. So it's important to study it, it's self-interested in that way, but like finding out was there life on Mars? Is there life on Mars? It's something we want to do. We don't wanna do it for a reason. We just wanna know, like people are curious.

1:06:42.9 RM: And NASA is just like, they are going to... They are working on these problems because they want to know and they are acting as our representatives, you know, my representative is... In my country to go out there and work with these other space agencies and solve these, and solve problems that there's not necessarily an economic incentive to solve. Or that there's not someone who's gonna pay for it. It's just like, we've all decided we wanna know what's up there on those moons. Let's pick some people and have them go figure it out. And I think that's really cool. It's just answering a question because we wanna know the answer and that's, I think that's a good thing to do sometimes.

1:07:23.6 SC: And I bet that there's some young people out there who will read your books and be inspired to do exactly that. So, I hope that they do by them.

1:07:30.9 RM: Yeah, I hope so. Thank you.

1:07:32.2 SC: Randall Munroe. Thanks very much for being on the Mindscape Podcast.

1:07:33.9 RM: Hey, thanks so much for having me on. It was so much fun to talk to you.

1:07:36.1 SC: Great. Take care.

1:07:37.9 RM: You too.