Randall Munroe answers your wildest questions (Transcript)

[00:00:00] Steven Johnson:
Welcome to the TED Interview. I'm your host, Steven Johnson. Now, this is a show where we wrestle with big, profound questions like, where is the artificial intelligence revolution going to take us? Or how can we reinvent our work routines in the post-Covid age? This week's guest happens to be a world-renowned expert in answering questions.

Questions that revolve around the fundamental laws of physics and the nature of reality itself. In fact, his question-answering skill is so celebrated that people all over the world have been sending him questions over the internet for more than a decade, now.

Questions like: what would happen if you shrunk Jupiter down to the size of a house and placed it in a neighborhood? What would happen if you microwaved a smaller microwave oven? If you put a million hungry ants in a glass cube with a human, who’s more likely to walk out alive? Now, what I love about our guest, Randall Munroe, is not just the fact that he actually does the work to figure out the answers to these improbable queries in best-selling books—like What If? and his latest, What If? 2. But he also manages to craft those answers into genius illustrated essays that are both hilarious and surprisingly enlight. Originally a robotics engineer, Munroe is the creator of the classic Hugo Award-winning internet comic XKCD. In addition to his two What If? books, he’s also the author of How to.

In this conversation, Randall and I explored some of the most intriguing scenarios from the new What If? volume. And we discussed how contemplating these absurdist thought experiments actually helps us understand the world. That's next on the TED interview.

[BREAK]

[00:02:03] Steven Johnson:
Randall Munroe, welcome to the TED Interview.

[00:02:06] Randall Munroe:
Hey, no, thanks so much for having me.

[00:02:08] Steven Johnson:
First off, congratulations on the new book. It is a delight, as all your work is.

[00:02:14] Randall Munroe:
Oh, thank you.

[00:02:15] Steven Johnson:
I wanted to start by taking a step back and, and talking about the, the arc of your career. I mean, one way to describe what you do for a living, at least with the What If? project is that people from all around the world send you crazy hypothetical scenarios, and you spend your time figuring out how they would actually work in practice. And that is, to put it mildly, not a traditional career path. How did you get to that?

[00:02:48] Randall Munroe:
Well, so I started drawing comics originally about a bunch of sort of sciencey topics.

So I would draw comics about whatever I was interested in. And I started posting them online and then was kind of surprised to discover that there were a bunch of other people out there who thought the same stuff was funny that I did and, and, uh, were into the same sort of, uh, niche science topics, et cetera.

And so that was really fun. But one of the unexpected consequences was that people would start sending me questions that they had. Often, like, you know, something they'd been debating with their friends or, or they'd been wondering about, and there was always a little bit of a subtext to those emails that was like, “We have this question, but we think it's like not a good or important enough question to bother a real scientist who has important stuff to do. But we talked about it. We agreed you would… you seemed like you'd be a great person to answer it.”

And, and I wasn't sure if I should be a little bit offended, like, you know, what are you saying? I don't have anything better to do than sit around and research questions? You know? But they were also 100% right. I, So I would get these emails and I would like, immediately, like it would derail my whole day. Because I would be like, “Well now I want to know this, the answer to this question too.” And I would start, uh, “Okay, well I bet I could look it up this way. No, I can't figure it out there. Okay. Maybe I can calculate it this way. Uh, first, I just need to dig up the textbook where I had that information.”

And then, like, six hours have gone by and I'm like surrounded by like papers. I have a hundred tabs open to my browser of PDFs, and then I'm like, “This is more effort than I maybe should have put into any email.” Um, but you know, I was really proud of myself and, and, and then I was, after doing several of these, I was like, “Hey, maybe I should post these somewhere.”

Like maybe other people would wanna read the, this like enormous amount of research. ‘Cause I don't imagine the person who sent it sort of got it like a one-line question to me, and then they get back this essay, and they're like, “Oh, thanks. Cool. I will, I will mark this to read,” you know?

[00:04:48] Steven Johnson:
So there was something in the original XKCD comic series that suggested to your audience that you would be a good answerer of crazy questions about how the world works?

[00:05:02] Randall Munroe:
Yeah, I, I think probably a combination of like, I would talk about science topics now and then where I would, you know, mention some fairly obscure detail, and it, and it would make people assume that I knew everything about all of the fields I was writing about, which is, which is absolutely not true. Um, but I also often drew comics about, like, my tendency to really overthink things, and to, like, dive into pointless questions.

Like, “Hey, what's the most optimal way to walk from this side of campus to the… You know, where there's this place where you can walk across the grass and this place where the, there's this angle of, of pathway. Okay, you have to do trigonometry, you know.” Um, and people are like, “Oh, I guess he, he seems to enjoy overthinking this stuff.”

[00:05:54] Steven Johnson:
So, let's get into some of these scenarios from, from the new book, from What If? 2. Um, I picked a few out here, um, that I thought were particularly entertaining. So the first one is near the beginning of the book. Uh, and I'm just gonna read. This is the question that came into you. Um, “if one were to stand on top of the old faithful geyser in Yellowstone National Park, at what speed would you be launched upward by the water, and what injuries would you likely sustain?”

Don't, don't try this at home, on your family vacation. Obviously, we start with that caveat, but beyond that, what is, what is the answer to this?

[00:06:29] Randall Munroe:
Well, this is really my favorite, my favorite kind of question is one where like, I think I know the answer when I hear it, but I'm not sure cuz like when I heard this I was like, “Well of course you'd, you'd, you'd die probably.”

Like you’d definitely get burned, right? But then I start second-guessing myself. Cause I'm like, wait a minute, is the jet that comes out of Yellowstone—I know it's caused by heat underground—but is it actually hot water when it comes out? I realize there are all these questions, you know, like, how dense is it? Is it like a jet of water or is it just like steam?

And I realize this is, this is a tricky problem. Well, could it lift a person out off the ground? I don't know. Yeah. And so, I did a bunch of calculations. The first thing I learned is, yes, it would be very bad. It is very hot. It's very fast-moving. Um, if it hit you right, it could certainly fling you into the air, possibly higher than the geyser itself if you managed to like, catch enough of it, you know, with maybe you were holding an umbrella or something.

Um, and what I also learned though, was, sort of, to my surprise, no one has been killed by the geyser at Old Faithful. Um, I found this great book by a, a park historian. It was like Death in Yellowstone, and all the different dangers and deaths that people encounter when they're there. So I, I was surprised.

No one has been, no one has, uh, died from the Geyser at Yellowstone. Um, lots of people have been severely burned by leaning over and trying to look into it and having it erupt. Um, but most of them have just sort of gotten a, you know, you, you see the steam starting to come up and you probably flinch, uh, right.

At least one person, I think in the 20s, the 1920s did fall into the, the, uh, crevice where the, the steam comes out. There's sort of a bathtub size depression there. Um, but I think he managed to get out, uh, and relatively, uh, you know, alive at least. But what I learned was they're really strict about having people. They’ve gotten better about, you know, making sure people don't go walking up to the geyser.

And the big reason not to walk up to the geyser. The area around it, which is much more deadly ‘cause you'll get these boiling pools with a thin mineral crust over them. So it's sort of like a creme brulee, and you're walking and it just looks like solid ground, solid ground and suddenly, you know, crack and you like plunge through into boiling water.

So I came out of that chapter with a real respect for like when they put up signs that are like, stay on the boardwalk as you're walking around here? Really stay on the boardwalk.

[00:08:59] Steven Johnson:
Just answer the original question, how high up in the air you would potentially get higher than the actual geyser if you, if you positioned yourself exactly right?

[00:09:07] Randall Munroe:
Yeah. Yeah, I think, I think because the geyser, it comes out at, at a really high speed, so you know, not, not the speed of sound, but certainly fast. Yeah. And the, the geyser, I think, tops out, you know, it depends on the, the specific eruption, but it might get, you know, 50, 50 meters. Uh, something like that, but it slows down because of the drag of the air.

It's like if you spray a spray bottle, it's very fast when it comes out of the nozzle, but it slows down right away when it hits the air. Um, but a person who's small and dense, if you got kicked up to speed by the initial impact of the water, uh, you could get flung much higher.

[00:09:44] Steven Johnson:
This next one I thought was interesting on a couple levels. It involves a story that I had not heard about, which was kind of bizarre in, in the first place, but I also loved where you took it in terms of answering the question. Um, and so the, the actual question, and hopefully you can explain the backstory to this, is what if Au Bon Pain, the chain of, um, kind of upscale fast food restaurants, I guess you would say, um, what if they lost their 2014 lawsuit and had to pay the plaintiff two undecillion dollars? That was the question. Am I pronouncing it right? Undecillion?

[00:10:25] Randall Munroe:
I, I have never run into a person in real life who's used that word. So your guess is as good as mine.

[00:10:30] Steven Johnson:
For all intents and purposes, it’s how we pronounce it. So that is a, a number that has, uh, just a massive number of zeroes behind it.

[00:10:38] Randall Munroe:
Yeah. It's a 2 with, I think, 36 zeroes after it.

[00:10:41] Steven Johnson:
Right. I like, by the way, that they asked for two undecillion.

[00:10:45] Randall Munroe:
Yeah, I'm not sure. Maybe it was one for like the one time they got their order wrong and then they're like, “Oh, but then they got it wrong a second time. That's another undecillion.”

[00:10:53] Steven Johnson:
What the heck is going on with this, with this story?

[00:10:55] Randall Munroe:
Well, this, this sort of highlights a, a maybe underappreciated aspect about our legal system, which is that anyone can file a lawsuit about anything. Uh, it doesn't have to be reasonable or, or even involve numbers that are remotely connected to reality. So you can, you can file a lawsuit for this, which might have just been like the largest number the plaintiff could look up.

The lawsuit was pretty quickly thrown out by a judge, uh, but a lawyer who wrote about it wrote to me and was like, “So what if, what if they actually did have to pay this?” And what's funny is that the amount of money being sued for here is much bigger than the amount of money in the world. And sometimes when we talk about really big numbers, it can sort of blur together.

Like people will frequently mix up a million and a billion. I do this, I have trouble with the words sometimes. Um, but they're very different. They're like different by a factor of a thousand. And these big numbers all kind of blur together. Like, Oh, it's a million trillion. Is that really that much bigger than a thousand billion? You know?

But so what I sometimes like to do is instead of using scientific notation, just like write out the whole number, and if you write out the amount of money with all the zeros that they're being sued for. Uh, you know, it, it might take up most of the page.

[00:12:19] Steven Johnson:
I think it, it’s a wonderful exercise though, in just trying to calculate what these kinds of numbers would really mean in practice. And you ran through a couple of exercises trying to explain how much money exactly that would be. Can you walk us through where, where you ended up with that?

[00:12:31] Randall Munroe:
Yeah. So you write out this number with 30 odd zeros after. On the paper, you can then write other numbers under it and just be like, “How wide is this number?”

You know, how many zeroes are there? Which sort of feels like a, a like fake way to do math, but it, it sort of makes sense. It's sort of equivalent to working on logarithmic scales. And so I wrote out, like, the total amount, the value of all goods and services in the world, which was an estimate I had calculated a while ago for a chart I made.

And then the value of all goods and services produced by humanity since we first evolved. Uh, and that's also, the number isn't even half as many zeros. You know, it's not even half as long. And so I worked out that like even if Au Bon Pain conquered the planet and put everyone to work from now until the death of the last stars, they would not make a dent in the bill in terms of the value.

And so, I tried to figure out all these things like, what if you sold the whole planet for scrap? Which parts of the earth are most valuable, if you like, could shred it? Um, weirdly the potassium and calcium ended up being, uh, the most valuable parts just cause there's so much of them. Of course, you pretty quickly like crashed the market for potassium and calcium, but, but look, there's, we don't have a lot of options here if we need this much money.

And so what I eventually just concluded, like paying this settlement is, like, impossible and not just, you know, practically impossible. It's like impossible in almost any sense of the word you can come up with.

[00:14:01] Steven Johnson:
This next one actually is one of my favorite questions. It may be my favorite question in the book actually, because it, um, I think it's a great reminder of the, the crazy run of technological progress and kind of Moore's law that we've been on with computers over the last 70, 80 years or so.

Um, and the, so the question is what if my phone—presumably a, you know, smartphone, android phone, iPhone—was based on vacuum tubes? Um, you know, the earlier technology that, that the first computers in the forties and fifties were based on. Uh, how big would the phone be?

[00:14:36] Randall Munroe:
I love this question too. It's fun to think about. It is, in a sense, possible. One of the, one of the really neat and fundamental things about electronics is like, uh, and about computing, is that once you have a minimal set of operations, like, uh, you have a, a circuit or a, a set of switches that can do some basic pieces of math.

Then, with that, you can build a computer that can solve any problem that any other computer can. It just might take more time or memory. And so using vacuum tubes, You can build the same fundamental circuits that we build nowadays in our phones with chips that have these, uh, uh, you know, billions of transistors on them.

It's just gonna be much bigger, take much more power, and be much slower. So I worked out, I looked at like the vacuum tubes they used in ENaC and Univac, some of those early room-sized computers, and figured out if you were, if you tried to do a modern iPhone, it would take up a couple of city blocks.

Um, and it would, it depends on whether you assume you can use all the other modern stuff for like the, you know, power and, and uh, the other components that they had. But the problem you would have would be heat, because the vacuum tubes take a lot of power, and they produce a lot of heat. And so if you put that many of them together in one place, you wouldn't be able to get the heat away from them, uh, quickly.

The phone is gonna heat up to the point where it's glowing and like melting its way through the earth's surface. So you need a protective case for your phone, but like, not to protect the phone. To protect the ground if you drop it.

[00:16:19] Steven Johnson:
It is a, it's, it's a great reminder of like how important heat management is in, in the modern tech world.

[00:16:25] Randall Munroe:
And still is! The other thing that, that I did while I was working on this is I, I thought, “Oh, well what about the reverse problem? How small could you make Univac, now?” You know, it used to be this big, you know, thing that took up most of a room, and I realized you could, you could make, if you just scale it down in the same way, you know, assume you're making it the same shape, but it has transistors in place of vacuum tubes.

You could make a Univac that's embedded in a grain of salt, and I love that mental image of like salt fortified with Univac.

[00:16:56] Steven Johnson:
The, the vacuum tube question actually reminded me of of a story you told in a TED talk you did a few years ago that I think is based on a, on a scenario from the first version of What If?, um, which involves Google and, and punch cards.

[00:17:14] Randall Munroe:
Yeah. So the question was if Google, sort of similar to the vacuum tube question, you know, if Google wanted to use punch cards, which is what they used to use to store digital information, to store their, all the stuff they currently have in their data centers on hard drives, magnetic tape and so on, uh, how much space they would need?

And, and the answer again is like, you know, more space than, than anyone has. You know, it would, like, cover the whole country up to a fairly deep depth of punch cards. But in order to answer that question, I had to sort of estimate how much data Google has and that turned out to be something they did not publish.

So, I tried a bunch of different ways of estimating it. Um, and, you know, I looked at like, okay, what's the global hard drive market? What percentage of that do we think Google could conceivably be, uh, you know, make up? How many data centers do they have? How much room is there in them? How much power do they typically use?

And I eventually came up with, uh, uh, an estimate that I felt like, okay, this is good enough. I stand by this. Uh, I think it's at least, you know, within an order of magnitude of the correct answer. So I put it in, in my answer. Google of, of course, you know, refuses to, to share any of this information. But in response, they did send me a series of punch cards, uh, that I thought, “Oh, that's a nice souvenir.”

Of course, they wouldn't tell me anything. Um, but I'm like, “Oh, but they have these punch cards. Uh, hey, I should try to read these. And I read them and there was a code on them. And you know, I got some friends to help. We, like, worked through the punch cards. You had to put them all together, overlay them, do these, these clever things.”

And I finally decoded it to get the secret message Google was gonna share with me. Uh, and the message was, “No comment.” But, but I, I stand by my estimate. I think it was about right at the time I did it.

[00:18:59] Steven Johnson:
Secretive, but with a sense of humor.

[BREAK]

[00:19:16] Steven Johnson:
So, I, I wanna take a step back and think about these questions in, in, in general. Um, the, there was one that struck me as indicative of something that I think is really interesting about the questions that you receive. Um, and it was more, it was less about the question. It was more about the comment about it.

So someone wrote in and said, “Can all the world's bananas fit inside all of the world's churches?” And then they followed up by saying, “My friends have had this argument for a little over 10 years now.”

So there's this friend group that has been sitting there debating this, you know, presumably like predating, you know, the, the original publication of What If? So this is not a Randall Munroe kind of question that, that they, they gravitated to. They somehow got to this question on their own, and they've been debating it for this, this much time.

And that to me, is kind of lovely, um, that people stumble onto these thought experiments and spend so much time, but are, are you surprised at the amount of cognitive labor that people are putting into these kinds of questions?

[00:20:21] Randall Munroe:
No, I, I mean, I, I think people in general are, are. You know, they like asking questions. They’re curious about things. Um, I find that sometimes the best questions come from little kids and occasionally people will suggest, “Oh yeah, it's ‘cause little kids are innately curious, and adults have lost their curiosity.” And I don't really think that's it. Um, I think maybe adults feel more like they're supposed to know. And if they don't know, it's, there's some reason they don't know.

And so like it makes them, like, nervous about asking or feel like they don't know who to ask. Um, and so I, I really enjoy getting these questions and enjoy showing like, “Here's how, here's how these tools of calculation can help to answer them.” Just to try to encourage people to be like, “No, no, no, this is, these are ans—these are answerable questions. It's okay to… It’s okay that you wonder about these. You can talk to other people.”

Like, I'm really glad this person had a friend group where they were comfortable going back and forth and talking about this. I, I really enjoy that.

[00:21:26] Steven Johnson:
It just, you know, it suggests to me that before you came along, the world was filled with people who were having these kinds of debates with their friends and they didn't have anywhere to, to pose these questions officially.

I mean, presumably that, you know, if this isn’t… this kind of curiosity was always there latent in the population, but there just was not a place to kind of think out loud in public about these kinds of questions. And so you've, you have satisfied a, a long unmet need in the population with this series. I think it's a really important service.

[00:21:59] Randall Munroe:
Yeah, and I, and I, and I do think it's really helpful because you know, if the question is important to something, then eventually you'll find, you know, someone will find a venue where it's appropriate. Like if it's a question about how to build a better car, someone in the car company will eventually ask it, you know?

But what I like is the same tools that you use to answer serious, important questions, uh, can be used, uh, on these kinds of silly questions and vice versa. And so I like using these questions that everyone has, that there's no clear answer to out there, um, to illustrate how we, we can use the tools of science and math to, to actually get answers and not just have to argue with our friends forever.

[00:22:43] Steven Johnson:
Have you discerned kind of patterns in the kinds of questions you get over time? You know, is there a kind of typology of, uh, of what if questions that, that you think about?

[00:22:54] Randall Munroe:
Yeah, I think one thing that stands out is it can be fun when a question that sounds kind of, uh, straightforward and mundane ends up having, like, these catastrophic consequences.

If you ask about anything moving at the speed of light or, you know, what, if you gathered some astronomical thing on some human scale, often you end up with like, well, that would destroy the earth, or that would, you know, demolish your city, or that would, you know, have some consequence like that. And so I found sometimes people ask questions where they're clearly like trying to come up with a scenario that will be as destructive and catastrophic as possible. But what's funny to me is that often those end up being less catastrophic and destructive than, like, very straightforward questions from little kids.

One of my favorites that's in the new book is there was a, a little girl who asked—her father sent it in—uh, because she said she wanted to build a billion story building. And like, I think I got that, you know, that same day I read through a bunch of questions about like, what have you put a nuclear bomb on a train going at, you know, 90% of the speed of light and then crashed into a volcano. And it, like, sounds very destructive. And the billion-story building is like a better question ‘cause it's a real straightforward, simple question that is also ultimately, like, a lot more destructive because if you build something a billion stories tall in earth's gravity, it will not be stable. And when it, uh, when it breaks apart and collapses, it will not be great for people on earth. Like the volcano at least would only be bad for the people in its vicinity.

But having pieces of a building enter the Earth's atmosphere, uh, all around the planet can be pretty bad for a lot of people.

[00:24:39] Steven Johnson:
Amazing. There’s another question that I thought was striking in the way you began your answer to it, which is, the question was, “Has humanity produced enough paint to cover the entire land area of the earth?”

But what I, I thought was striking about it was you, you begin your answer by talking about, um, what's called Fermi estimation, which is after the physicist Enrico Fermi, Um, which is something that, that, as I recall, that Carl Sagan was really interested in as well, which is kind of performing rough order of magnitude calculations almost, almost off the top of your head.

Um, you talk about how important that is as a, as a kind of mental module to have. Um, tell us, tell us a little bit more about that.

[00:25:26] Randall Munroe:
Yeah. This is, this is a sort of, it's a skill that, or like, you know, it's a, it's a tool that it doesn't fit neatly into any one area of, of science, but it's like really useful in all of them, which is like trying to get a very rough idea of the scale of numbers involved in something.

There's a quote from, uh, the statistician John Tukey that I really like. Uh, it's something like, “It's far better to have an approximate answer to the right question, which might be vague, than an exact answer to the wrong question, which can always be made precise.”

So it's like, often when people get questions, they'll try to rephrase the question into something that can be precisely answered or looked up, and then look up that answer and then, you know, say, “Okay, well here's the answer.” But that step where you rephrase it into something that can be looked up might be like, where you're losing all of the, what's important. And, and sometimes you'll get that answer and then you'll be like, “Wait. But if we apply that answer to the original question, it clearly can't be, you know, it doesn't make sense.”

And so I like, I like trying to get approximate answers. Uh, I think that's really useful. You know, and this applies to, for example, the painting the Earth. Like, the way I started with that one was supposing: “Uh, well, okay, I live in a room. I have another room. Let's just assume everyone in the world has two rooms and they need to cover them both with paint.”

Well, that's like if a room is about 50 square meters of area, the two rooms is a hundred. Um, you know, you've got 8 billion people, a hundred square meters per person that's like, you know, a little under a trillion square meters, and that's much smaller than the earth. So, if that's how much paint we have, enough for everyone to paint two rooms, then that suggests it's, there's not nearly enough.

Um, you can come at it from another direction though. ‘Cause that's not certain. Maybe there's enough paint for every person to paint, like, 20 rooms. ‘Cause you have to paint outsides, you have to paint cars, you have to paint other stuff. Like other stuff I'm probably not thinking of or maybe there doesn't exist that much paint in the world.

And if we all suddenly tried to repaint our rooms, the world would run out of paint, but then we can try coming at it from other directions. Okay. What about how much paint do they stock at stores? Like if I went in and wanted to paint my house, maybe you need about 20 gallons of paint? Sounds about right.

Um, and if you do math out, figuring out how many houses there are, how many gallons of paint that would be, you come up with an estimate that's sort of similar to the first one. It says there's not enough paint. And so I finally found a global paint industry report and figured out how much paint they produce, how quickly is the paint market growing?

And came up with an estimate of like the total amount of paint that's been produced in the world. And it came up with, it was sort of in between all of those, those three Fermi estimates I came up with. It was like, there's not enough to cover the earth, but there's enough to cover—I came up with roughly the area of like the US or Canada—those first estimates.

There were a whole bunch of like numbers in there that are probably wrong. You know, my idea of how long it takes to paint a house might be wrong, or you know, how many cans of paint it takes to cover a room or whatever, but, but they don't need to be that right to tell you, like, if the number is a hundred times bigger than the area of the Earth, then there probably is enough paint.

And if it's a hundred times smaller, there probably isn’t, because like on average, your mistakes kind of tend to cancel out. Like maybe one estimate is too big, but the other estimate is too small. And then when you multiply 'em together, you come up with something that’s, if not exactly right, at least sort of in the neighborhood.

[00:29:01] Steven Johnson:
One of the things I noticed as a parent, um, when my kids, particularly when they were kind of in middle, middle school, was that the, the, that differed from the kind of education that I had in, particularly in math, was that they were specifically taught, uh, techniques for making guesstimates at things. So instead of being like, “Okay, this is how you calculate the exact answer down to nine decimal places”, they would be taught, in addition to that, “This is how you can quickly in your head come up with a rough estimate of, of what this is. You know, that's not exactly precise, but probably pretty accurate.”

And I thought that’s an amazing advance because that's what you need most of the time. Most of the time you're just sitting there trying to do a rough calculation of something like, “Well, if I did this, had this many hours, it'd be roughly 800 bucks, you know? Okay. Give or take.” Um, and so teaching those skills is really important, I think.

[00:29:53] Randall Munroe:
Yeah. And a lot of the time I feel like even an approximate answer, you don't necessarily need to know the answer. You just need to know, is it definitely smaller than this other number? If it is, I don't care what the answer is, you know, like, how much will this cost?

I don't know, but if it's definitely way more than the amount of money I have, I don't need to figure out if it's a billion dollars or a trillion dollars. I know it's outside my budget. And so yeah, that kind of approximation is really useful and I'm really happy to hear when, uh, you know that, that it's being taugh.

[00:30:22] Steven Johnson:
Beyond those Fermi estimations, what do you think people are getting kind of cognitively or intellectually out of these exercises?

[00:30:31] Randall Munroe:
I don't know. It was neat to see that when I started posting them, people started sending me more questions. I also saw people who would mention that a question came up and one of them suggested, you know, “Oh, hey, let's send it to the, the ‘What If?’ guy.”

And, and I found that really encouraging because it, I think it made people feel more like, “This might be answerable.” And that's really what I, I, I like encouraging, uh, is people to understand that like, it's okay if you don't know the answers to things. Um, it's possible to figure them out, and I really like kind of the distinction between, there's stuff you can argue about forever that doesn't really have an answer, like how many angels can dance on the head of a pin? Is a hot dog a sandwich?

You know, there are… these questions you might be able to come up with answers in one way or another. Like the hot dog sandwich thing has been… There, there was at least one, uh, lawsuit that, that rested on whether a taco was a sandwich, I think.

Um, but, but like, you'll get the answer that's like that person's answer. But there's something like less satisfying about that like, whereas there are other questions that really do have answers. Like, we might not know what they are. We might not be able to figure them out easily, but you really can get an answer and be like, “This is what would happen”, and then you can try it and see if it's right, you know?

[00:31:58] Steven Johnson:
Right.

[00:31:59] Randall Munroe:
And I, and I've really like moving some things from the realm of like, “Oh, well, I've always wondered about this, and I'm sure different people would give different answers, who knows?” to like, “No, I can be sort of confident that like, this is, this is the correct answer. This is, this is what would happen.”

Um, and so like, moving more stuff from the realm of frustrating semantic arguments to, like, cool facts about the universe is something that I find really satisfying and I’m… sort of hope other people do too.

[00:32:30] Steven Johnson:
Well, Randall Munroe, thank you so much for joining us. I, I, you know, it's been great to hear your answers to some of these questions, and I'm sure our listeners have now come up with their own long list of questions that they're gonna bombard you with, and so look out in your inbox. Oh, uh, we really appreciate it.

[00:32:44] Randall Munroe:
Oh, no, thank you. It, it's been, it's great to chat with you.

[00:32:50] Steven Johnson:
That's it for the show today. The TED interview is part of the TED Audio Collective. This episode was produced by our managing producer, Wilson Sayre and mixed by Erica Huang. Jimmy Gutierrez is our story editor. Fact-checking by Hana Matsudaira. Farrah Desgranges is our project manager, and Dan O'Donnell is our executive producer.

Special thanks to Constanza Gallardo, Michelle Quint, and Anna Phelan. I'm your host, Steven Johnson. For more info about my other projects, including my latest book, which is about to come out in a young reader edition, Extra Life, you can follow me on Twitter at @stevenbjohnson or sign up for my Substack newsletter: Adjacent Possible.