The Scale of the Universe

The scale of the universe stretches from the Planck length, the smallest scale physics can describe, to the observable universe, the largest thing we can see. Travel inward from one and outward from the other by powers of ten and they meet at something astonishingly familiar: the size of a human egg cell. Michael Stevens (VSauce) takes Professor Hannah Fry on a journey through powers of ten, from quarks and protons and DNA to bananas and pyramids and on to planets and galaxies, to explore where we sit in the scale of the universe. Along the way they ask whether the Planck length could be the universe's smallest pixel, whether reality might be a computer simulation and just how empty space really is. Plus, your questions: why our best ideas arrive in the shower, Wikipedia's strangest rabbit holes and Hannah corrects the record on whether Saint Augustine and Thomas Aquinas believed curiosity was a sin. ------------------- You can find the Reddit thread for scale of the universe here: https://www.reddit.com/r/TheRestIsScience/comments/1uycf3l/i_visualized_michael_scale_comparison_from_the And The Power Of 10 documentary here: https://www.youtube.com/watch?v=0fKBhvDjuy0 See some of Hannah & Michael's favourite Wikipedia pages here: - Osama Bin Laden The Elephant - https://en.wikipedia.org/wiki/Osama_bin_Laden_(elephant) - Death From Laughter - https://en.wikipedia.org/wiki/Death_from_laughter - Order Of Magnitude - https://en.wikipedia.org/wiki/Order_of_magnitude - Amedeo Avogadro - https://en.wikipedia.org/wiki/Amedeo_Avogadro - Guy Standing (Economist) - https://en.wikipedia.org/wiki/Guy_Standing_(economist) -Guy Standing (Actor) - https://en.wikipedia.org/wiki/Guy_Standing_(actor) ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠https://www.cancerresearchuk.org/our-research/rest-is-science Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley + Jack Meek Animator: Sam Benson Video & Social: Bex Tyrrell Assistant Producer: Lucy Lipscombe Producer: Simona Rata Senior Producer: Lauren Armstrong-Carter Chief Digital Officer: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

• 0:00Speaker 00

  Hello, welcome to The Best Is Science. This is Hannah Fry.

• 0:03Speaker 01

  And this is Michael Stevens. Wow, that was a pretty good radio voice.

• 0:08Speaker 00

  That was, I think I sort of doubted myself halfway through. Anyway, this is Field Notes, which is basically a grown-up version of show and tell.

• 0:15Speaker 01

  That's right. And today, I'm showing and telling something that I did not make, but you and I inspired, Hannah.

• 0:21Speaker 00

  Oh.

• 0:22Speaker 01

  Yeah, it's pretty cool. In fact, it almost makes me feel guilty. It's so cool. So if you remember, many episodes ago, we were talking about weird coincidences.

• 0:31Speaker 00

  Uh huh.

• 0:31Speaker 01

  And we mentioned that human cells are like exactly halfway between the smallest size possible and the largest size possible. We are right in the smack middle. What does that mean? I don't know. Well, on our subreddit, a user named Burrow or Beru.

• 0:53Speaker 00

  Buru.

• 0:54Speaker 01

  Beru.

• 0:55Speaker 00

  Gru.

• 0:57Speaker 01

  What matters is that it's really cool. I'm going to send you in our chat, the Reddit thread, and we'll put this in the description and the episode notes for everyone to visit. There's like, and read the comments, because there's like multiple versions of it. This visualization shows an incredible journey that I'm going to take you through. And for those of you listening, going visualization, uh, whoa, problem. Don't worry, I'm going to walk you through it. What we're going to do is we're going to imagine a little game that you play with your friend. Okay? This is just giving a lot more color to this fact. So imagine that you start at the size of the Planck length, which is what? It's the

• 1:38Speaker 01

  smallest size physics as we understand it today can describe. Anything smaller than that, literally, we don't know. Is it even possible? It's up for debate. It's almost a philosophical question. Can you observe something as small as the Planck length? No. If you got light, or any kind of information out of something that's small, or you tried to, it would turn into a black hole. Okay? And exactly why is a discussion we've had before, we can have again, but it's the smallest point. Now imagine your friend is as large as the observable universe. Okay? The largest thing we can observe, the entire observable

• 2:19Speaker 01

  universe. And you both agree to start shrinking and growing until you meet in the middle. So every second, you get 10 times bigger, and every second, your friend gets 10 times smaller. This is what you're going to see. Okay, so you begin this little game, and you start growing, your friend starts shrinking. For the first 10 seconds, you getting bigger are like super lonely. There's like nothing between a Planck length and then a neutrino. Okay?

• 2:49Speaker 00

  Oh, yeah.

• 2:50Speaker 01

  There's like nothing, nothing's going on. Meanwhile, your friend, who's getting 10 times smaller every second, is passing the size of, you know, the great voids in the universe, super clusters like Laniacaya, where we are, our local group, galaxies Andromeda, the Milky Way. Eventually, after 10 seconds of this game, you are now as large as a neutrino, which is 2.8 yadometers across. And your friend is the size of the Ring Nebula, which is 1.3 light years across.

• 3:29Speaker 00

  This episode is brought to you by Cancer Research UK.

• 3:32Speaker 01

  Do you remember when we discussed why feet are so weird? Well, one particular foot bone holds an even stranger surprise. It's helping shape our understanding of cancer timelines.

• 3:43Speaker 00

  And for that, we're going to need to go all the way back, before Neanderthals even existed, to a 1.7 million-year-old foot bone. Researchers have identified a tumor in it, in the oldest known example of cancer in people.

• 3:58Speaker 01

  Which really shows that cancer is far from a modern disease. Beating a disease so deeply rooted in our biology won't happen overnight.

• 4:07Speaker 00

  But today, Cancer Research UK scientists are discovering incredible ways to turn our biology against cancer.

• 4:14Speaker 01

  In fact, Cancer Research UK has helped double UK cancer survival over the past 50 years. And their world-class research is driving even more discoveries to tackle over 200 types of cancer.

• 4:28Speaker 00

  For more information about Cancer Research UK, their research, breakthroughs, and how you can support them, visit cancerresearchuk.org/restiscience.

• 4:38Speaker 02

  Observe the North American dad. 50s, great polo collection. He enters his vehicle information on Carvana. An offer appears in minutes. Remarkable. He squints, reads it again, smiles and says, dang, that's a good offer. The highest form of approval. No haggling, no hassle, no one called him boss. He's still on the couch. Astonishing. Sell your car today on carvana.com. Pickup fees may apply.

• 5:09Speaker 03

  This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome, that's new. It can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration block, or finally break down that long article you've had open for weeks. Gemini and Chrome is here for it. Ready to make anything online make sense? There's no place like Chrome. Check responses. Setup required. Compatibility and availability varies. 18 plus.

• 5:42Speaker 01

  And now let's keep going.

• 5:43Speaker 00

  It feels like your friend is having a better time than you are.

• 5:47Speaker 01

  Yeah, my, your friend has had a lot more to see. They've had a lot more on their journey. Keep in mind, should I, I mean, this is a bit of a spoiler, but I think that it's important to keep in mind where we're going. You are both going to meet in the exact middle, and in that middle is the human egg cell, the cell we all come from. Okay? So the human egg cell is not only exactly in between the Planck length and the observable universe, it's also exactly in between the size of a neutrino and the size of the Ring Nebula.

• 6:21Speaker 00

  Okay, because those are the same distance in from the ends on the scale. Yeah.

• 6:27Speaker 01

  That's right. There are 10 powers of 10 smaller and bigger than the edges of our knowledge. Okay, after 17 seconds, you are now the size of a quark, and your friend is now the size of Earth's orbital diameter.

• 6:43Speaker 00

  What?

• 6:44Speaker 01

  Yes.

• 6:45Speaker 00

  What?

• 6:46Speaker 01

  Yes.

• 6:47Speaker 00

  You're a quark? You're not even up to a proton yet, and it's that you've come down to the Earth's orbital diameter?

• 6:54Speaker 01

  Isn't that incredible? It's very lopsided, isn't it?

• 6:57Speaker 00

  Wow. So your friend is like, it skipped out, the whole universe is just down to just the ring that the Earth?

• 7:06Speaker 01

  Yeah, two astronomical units.

• 7:08Speaker 00

  No.

• 7:09Speaker 01

  93 million miles times two. That shows you just how small the Planck length is compared to like actual stuff and matter, right?

• 7:17Speaker 00

  Wow. And by the way, we are still way, way, way, way, way, way, way smaller than anything that observable light would sort of, that light would give color to, by the way. We are below color.

• 7:31Speaker 01

  We're going to reach color also in a lopsided way, because after 20 seconds, you are now the size of a proton.

• 7:39Speaker 00

  Okay.

• 7:39Speaker 01

  And your friend is the size of the moon.

• 7:43Speaker 00

  Ah!

• 7:44Speaker 01

  Yeah. So your friend is now the right size for there to have color. Well, I mean, your friend has been able to have color for a long time, but you still aren't.

• 7:54Speaker 00

  What on earth? I am genuinely astonished. Okay, keep going, keep going. This is amazing.

• 8:00Speaker 01

  Yeah, isn't that weird? So again, keep this in mind. The human egg cell is exactly in between the sizes of a proton and the moon. All right. After 24 seconds, you are now the size of an oxygen atom, and your friend is the size of the Great Pyramid of Giza.

• 8:19Speaker 00

  Wow, I didn't realize the small stuff was that small. I didn't realize.

• 8:23Speaker 01

  Isn't that incredible? One second later, one second later, and remember, every second, you get 10 times bigger, your friend gets 10 times smaller. After 25 seconds, you are now the size of a carbon atom, and your friend is the size of the Statue of Liberty.

• 8:39Speaker 00

  One single carbon atom?

• 8:42Speaker 01

  Yeah.

• 8:43Speaker 00

  Okay, aside from anything else, I didn't know carbon atoms were 10 times bigger than an oxygen atom.

• 8:48Speaker 01

  Let's, let me give you the actual numbers here. So an oxygen atom is about 10 to the negative 10 meters across, and a carbon atom diameter in meters, well, it's still 10 to the negative 10, but the, you're almost a power of 10 different.

• 9:07Speaker 00

  Okay, got you. I'm with you. I'm with you.

• 9:10Speaker 01

  After 26 seconds, you are now as wide across as a DNA molecule, and your friend is as wide across as a stegosaurus.

• 9:24Speaker 00

  Right, from the entire universe down. Okay, yeah.

• 9:27Speaker 01

  All right. Two seconds later, 28 seconds into this game, you are the width of the COVID-19 virus.

• 9:35Speaker 00

  Right.

• 9:35Speaker 01

  And your friend is the size of a banana.

• 9:39Speaker 00

  Still too small for color.

• 9:40Speaker 01

  Still too small for color. 30 seconds into the game, you are the size of a white blood cell, and your friend is the size of a grain of sand.

• 9:51Speaker 00

  What? Hold on. What?

• 9:54Speaker 01

  Yeah.

• 9:55Speaker 00

  A white blood cell to a human cell?

• 9:58Speaker 01

  To a grain of sand.

• 10:00Speaker 00

  Wow.

• 10:01Speaker 01

  On both sides. A human egg cell.

• 10:03Speaker 00

  It is the biggest cell, right?

• 10:05Speaker 01

  It's the biggest cell. It's bigger, it's biggest by a lot. In fact,

• 10:09Speaker 00

  Yeah.

• 10:09Speaker 01

  You can, you could almost see a human egg cell with your naked eye. Now, I think, I think it's important to point out that like that difference makes the human egg cell

• 10:19Speaker 01

  different than if the answer, if the very middle of this scale was a typical human cell.

• 10:24Speaker 00

  Sure, like a skin cell.

• 10:27Speaker 01

  Maybe there's, there's more or less poetry to it. Like, is it, is it the cells we're made of? Is it the cell that living things are made of? Not quite. It's, it's the egg cell size. So what does that mean? I don't know. But that, we've reached the end of the game now. After 31 seconds, 31 powers of 10 bigger, 31 powers of 10 smaller, you are both the same size you've met in the middle, and you are both the size of a human egg cell. The cell we all come from.

• 10:56Speaker 00

  Phenomenal. Do you know, okay, I, I like, I didn't play it because I wanted to hear it from you, but I'm just looking at it now. This is the, honestly, this is one of the best things I've ever seen. This is absolutely phenomenal. It reminds me of, do you remember the Powers of 10 video that was done in like the 1970s? This very famous sort of science communication video? It was amazing. It took a human, a picnic, it zoomed out powers of 10 every second, and then did the same going smaller. But at no point in that was it making this direct comparison from one to the other. He anchors it in so much more of a, of a real way when you are, because I mean, I don't know how big the universe is, but I know how big it looks. I know how big it looks through a telescope even.

• 11:41Speaker 01

  I think this also shows how small the Planck length is. It's, it's, it's not like, oh, you get neutrinos and then, you know, beyond them, it's, it's the smallest we can do. No, it's way beyond them.

• 11:53Speaker 00

  Way beyond them.

• 11:55Speaker 01

  Okay, it's 10 powers of 10 beyond them.

• 11:58Speaker 00

  Yeah.

• 11:58Speaker 01

  And, right, if you, if you have some time, please, guys, go watch the Powers of 10 documentary. It's a short, it's on YouTube for free. And I remember watching that as a kid, and it just kind of put everything in its place.

• 12:16Speaker 00

  Right.

• 12:16Speaker 01

  And it was beautiful. And the, the people in the, in the middle are having a picnic in Chicago. And then I wound up going to university in Chicago. And I like thought about that a lot. I was so proud to be in the city where those people were in the Powers of 10 documentary. Like, it just, it meant a lot to me.

• 12:35Speaker 00

  Did you go, did you go find the exact park?

• 12:37Speaker 01

  Yeah, I did. I did. And I laid in the park, and I had to show everyone the video first because they had all seen it. But I, I even have the, like, the scientific library book version of it, where each page is zoomed out. I don't know if they went by powers of 10, or or, or 1,000, 10 to the 3. But anyway, it's very cool. And Burrow, you have just added a cherry on top of a wonderful and important human endeavor.

• 13:04Speaker 00

  Honestly, that is the best version of it that I have ever heard of. That is so good. That has come alive for me in a really profound way. Burrow, that was, thank you. Thank you so much. Can I just say one thing about Planck length?

• 13:18Speaker 01

  Yeah.

• 13:19Speaker 00

  So I have spoken to some of the, I don't know how much they really believed it, but you know this idea about like the fact that we're living inside of a computer simulation? They sort of use Planck length as, Planck length as, as evidence of it, that like Planck length is like the pixel of the universe.

• 13:39Speaker 01

  Yeah.

• 13:40Speaker 00

  Just sort of throw that in.

• 13:41Speaker 01

  I don't know, I feel this like gut urge to not believe we're in a simulation.

• 13:47Speaker 00

  Me too, but I don't have any evidence for it.

• 13:49Speaker 01

  But there, I know. And in fact, like when people talk about it, or when I look into it to try to like prove it wrong, I'm always like, ah, shoot. For example, if you can simulate a universe, it could probably be simulated a lot more simply than like a real one can be made. Like, if you can run an entire universe on some special advanced alien computer, then you could probably run a trillion of them simultaneously. In which case statistically, we are much more likely to be in one of those simulations than in the actual universe where the simulations are running. Just, it's just a numbers game. So if you, if you're open to the possibility that something with the resolution of our universe could be simulated

• 14:33Speaker 01

  as, as we experience it, then you kind of have to conclude that it's more likely than not that we're in one of those simulations.

• 14:41Speaker 00

  Yeah, I, I remember hearing, the first time I ever heard that argument was Elon Musk giving a talk in about, I don't know, 2005 or something. No, maybe it was later than that, actually. But, but I remember hearing that. And

• 14:56Speaker 00

  I agree with you. I just, I just emotionally reject it.

• 14:59Speaker 01

  Yeah. Well, and it's, and it's easy to reject it and just say, well, you know what? I, I don't believe that the Planck length is the pixel. We just don't know enough about physics to, to go beyond it.

• 15:12Speaker 00

  Right.

• 15:13Speaker 01

  But here, here's my question. I don't know if, if you can answer it for me, but how do you, how do you explain irrational numbers in a simulation? Like, pi is, is in the, in the simulation as a way to calculate the ratio between the circumference and diameter of a circle. But that number has, it can have infinite precision. Is there a point at which they said, okay, look, we only need the first, you know, 12 Google digits, and that'll be enough? Because if so, then we should reach a point where we're like, ooh.

• 15:47Speaker 00

  There it is.

• 15:48Speaker 01

  There it is. There's the end of pi, meaning we are in a simulation, because it couldn't hold the exact, exact, exact, exact, exact, never-ending precision of pi.

• 15:59Speaker 00

  Exactly. You're absolutely right. Because, because this is the thing, you know, the, the way that we've built computers, they are fundamentally discrete machines, right? They're not continuous machines. You know, if you draw a circle on a computer and you zoom in far enough, you will see that there are these pixelated edges, there are corners, there is no, there's no, there's no, there's not even diagonal lines, right? It's, it's sort of like a grid, a stepped grid. And so the whole kind of basis of this idea that we're inside of a simulation is that if you zoom in far enough, it's discrete. And it just so turns out that with physics, it is discrete. People know the word discrete. I sometimes forget what words are, what words are real words and what words are just mass words.

• 16:38Speaker 01

  I'd say like with, with something continuous, every value in between is available. Okay, like, like a vinyl record is a, an analog, it is a not digital, it is a not quantized, it's a, a continuous medium. Like, the bumps in the groove can literally be, well, again, we get down to physics, though, but they could have any size. You could make it as small as possible of a difference, and that exists. But with digital music, it's got to be a one or a zero.

• 17:04Speaker 00

  Totally. That was such a beautiful explanation. And so, so the thing is, is that in our, in our physical world, it feels as though things are continuous, you know? I can, I can move my hand from here to there, and there's no value, it's not jumping in between these values. But when you're doing something on a computer, even if I was simulating that movement, actually zoom in far enough, and it would be, it would be making discrete jumps. Any animation, any, any mathematical model is ultimately discrete. It has, it has these jumps in it. You know what? Well, maybe we should save this and do a whole episode on simulation hypothesis. Because I think it's really interesting.

• 17:39Speaker 01

  Yeah, I think we should, because there's a lot more I want to learn, and there's a lot more to say.

• 17:43Speaker 00

  Yeah.

• 17:44Speaker 01

  About this.

• 17:45Speaker 00

  I also just realized that me trying to explain how collapsing the wave function is evidence of the simulation hypothesis is far too ambitious for this time on, on an evening as we're recording this.

• 17:56Speaker 01

  Yeah, so let's, so let's revisit it. But the point is that, guys, we just don't know. You might be real listeners, or you might just be NPCs in the simulation that we are also NPCs running in. Is there, is there someone playing? Is there like one person or one creature in this universe that's actually like, hey, I am an avatar of like a real person in the real universe? And if so, who are they? That's a question we'll leave for you. Leave your answers in the comments below.

• 18:29Speaker 00

  I've got a suggestion. We'll definitely do a simulation episode where we'll go really into it. All the evidence for, all the evidence against. One of them's going to be longer than the other, but nonetheless, I know which way my conclusion.

• 18:40Speaker 01

  It could be two episodes. You're right. It could be we live in a simulation, and then a week later, we don't live in a simulation.

• 18:48Speaker 00

  Okay, should we go to people's questions? But let's have a break first.

• 18:50Speaker 01

  Yes, we're going to do that. So after the break, we will come and, and we'll read comments you've left in the past and respond to, answer them, and enjoy them. So, see you soon.

• 19:13Speaker 01

  This episode is brought to you by Cancer Research UK.

• 19:15Speaker 00

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• 19:27Speaker 01

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• 19:40Speaker 00

  Today, Cancer Research UK is backing innovations that could transform the future of screening. Picture a smart bra that could one day detect breast changes as it's worn, making screening more accessible.

• 19:53Speaker 01

  And AI trained on a database of over 10 million mammograms that helps doctors spot early signs of cancer.

• 20:00Speaker 00

  Research like this saves and improves lives.

• 20:02Speaker 01

  For more information about Cancer Research UK, their research and breakthroughs, and how you can support them, visit cancerresearchuk.org/restisscience.

• 20:15Speaker 01

  This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome, that's new. It can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration blog, or finally break down that long article you've had open for weeks. Gemini and Chrome is here for it. Ready to make anything online make sense? There's no place like Chrome. Check responses set up required compatibility and availability varies 18 plus.

• 20:48Speaker 00

  And we're back. First question, Michael, this one's for you. Another Reddit one here. RemoteIsland underscore 7798. You spoke about Osama bin Laden, the elephant, being one of your favorite Wikipedia articles. I feel I now need to know everyone on the list. Thank you for your attention to this matter. I've got a couple of favorites as well, you know.

• 21:08Speaker 01

  I want to know, I want to know your favorites. Throw them at me.

• 21:12Speaker 00

  Okay, I don't know, there's enough. One, one that I really love is dying while laughing, which is just a list of famous people who died while laughing.

• 21:23Speaker 01

  Oh, how nice for them.

• 21:25Speaker 00

  And the circumstances in which, which their death was brought about during laughter. I really enjoyed that. That one's very good.

• 21:33Speaker 01

  Yeah, it's something to aspire to. So, I mean, there, there are so many good Wikipedia articles, and I feel like it's hard to compete with what you can get by just Googling best Wikipedia articles and reading every Reddit thread about them. There's even a Wikipedia page that just lists their most unusual articles. Like, just start there, you know? But, um, so, so I'm trying to think of things that I enjoy that maybe aren't already pretty well-known. And I think I really like the orders of magnitude pages that Wikipedia has. I refer to those quite a lot. And there's, there's one for like almost every unit of measurement. You can, you can look up orders of magnitude length, and it goes, okay, here's

• 22:15Speaker 01

  every length in order, and something that is about that size. So, um, there's also one for mass. And that's how I learned that I think every second, the sun converts an amount of mass equivalent to the Great Pyramid of Giza into pure energy, every second. And that's, yeah. And that was just on the orders of magnitude page for mass. And it's like, here's this amount of mass. It happens to be what the sun burns through in a second. It's also how much the Pyramid of Giza weighs. And you look at this, and you go, this is amazing. I read those. There's one for, you know, time. There's one for sound. There's one for torque. There's even one for different orders of magnitude of torque. Like, here's this amount of torque. 10 times stronger would be this boat engine. 10 times stronger

• 22:58Speaker 01

  would be if you tied a string to the moon. You know, and it's just like, it's really neat. But what I want to also throw into the mix are just people who have the most hilarious or weird photos.

• 23:12Speaker 00

  Right.

• 23:13Speaker 01

  As the picture of them for, for their Wikipedia page. And there are some that just look really funny. It feels a bit mean spirited, but like, go look at Avogadro's Wikipedia page. Look at that guy's face, okay? Look at his head.

• 23:27Speaker 00

  As in Avogadro of constant fame?

• 23:29Speaker 01

  Of the constant.

• 23:30Speaker 00

  You worked out how many molecules there were in a mole, right?

• 23:34Speaker 01

  Yes, that guy.

• 23:36Speaker 00

  Oh, gosh. No human has ever looked like that. No human has ever looked like that.

• 23:41Speaker 01

  I kind of don't believe it. It's just a drawing. Um, but it looks like a comic drawing. I don't know.

• 23:50Speaker 00

  It does, it does. It looks like, um, Spitting Image, those puppets that you used to, you used to get on BBC, where they do an extremely exaggerated version of, for example, Margaret Thatcher.

• 24:01Speaker 01

  So, so my question is, is that really what he looked like? Or did he look better? And this is unfortunate. Or did he look worse? And the illustrator was trying to be flattering to him?

• 24:12Speaker 00

  I've seen, there's another drawing of him that I have found, and he does not look anywhere near as strange. I think you're right, that it's an exaggerated version of what he looked like.

• 24:19Speaker 01

  Oh, it is. That's disappointing. I was hoping that he really was like the funniest looking dude in the world. And I just wanted to, I just looked up his birth date. He was actually, he was born in the 1700s, 1776, just about a month after America was born. But he did most of his work in the 1800s. The, the best one, though, I've saved my favorite thing. I actually, I actually laugh when I look at this, and it improves my day. There are two humans named Guy Standing. Okay, first name Guy, last name Standing. So one is an economist at SOAS, University of London. His name is Guy Standing, but his

• 24:57Speaker 01

  picture is of a guy sitting. You've got, that's gotta be intentional. The Wikipedia editors surely said, the photo of Guy Standing must be a photo of him sitting. And it is.

• 25:13Speaker 00

  Oh, man, I love Wikipedia so much. I love Wikipedia so much.

• 25:17Speaker 01

  Isn't that wonderful?

• 25:18Speaker 00

  They are so deliciously nerdy, right? This whole community. So amazingly brilliantly nerdy. And this is, what a gift for humanity this thing was.

• 25:28Speaker 01

  It's a gift. But I said there were two people named Guy Standing. The second one is an actor. And if you look up the Guy Standing actor page, there's a photo, kind of, this isn't like his profile photo or whatever, but there's a picture of him sitting down with two other, with two women.

• 25:45Speaker 00

  Yeah, it says Guy Standing Sitting. Guy Standing Sitting Next to Jimmy Wales.

• 25:49Speaker 01

  That's what it is. Guy Standing Sitting Next, yes.

• 25:54Speaker 00

  Amazing. Absolutely love it. I remember the other one that I really like, actually, which is inventors killed by their own inventions. That one is great. It's quite gruesome, though, I'll be honest.

• 26:05Speaker 01

  That's a, see, that's a famous one. Yes, I, yes, I love that one. Um, there are so many articles where you're like, this topic is incredible. I'm going to read all of them. And I mean, I'll spend multiple nights going through the like, missing people Wikipedia article, and just reading everything about them. Um, like, if there's a name or an event or something, and, and on the article, it's, it's a blue link, you know I'm clicking on that. It just, it keeps going deeper and deeper.

• 26:37Speaker 00

  Do you know about the philosophy thing?

• 26:39Speaker 01

  Yes, I do.

• 26:40Speaker 00

  The game that you can play. I love this so much. So, and I, basically, sometimes I give a talk and include this in there. But if you start on any Wikipedia page, and you follow the first blue link on that page, and carry on clicking through, first blue link, first blue link. You know what? I'm going to do it for you, Michael. Let's do it for you.

• 26:59Speaker 01

  Yeah, and walk us through what you're clicking. What is the first link? I mean, the reason, what she's saying is that you always wind up back at the philosophy page because, of course, like, the first word in someone's, in any Wikipedia page tends to be like more general. Like, it is a planet, is a person, is an American, or whatever. And you just keep becoming more and more general until it becomes so big that all you can really say is philosophy.

• 27:24Speaker 00

  Philosophy. It's like, it's like the wine game, you know? Karen asking why eventually you get to.

• 27:30Speaker 01

  Philosophy. So, yeah, do it with my page and walk us through.

• 27:34Speaker 00

  Okay. Michael David Stevens. You're an American educator. So I go to educator.

• 27:40Speaker 01

  Okay.

• 27:40Speaker 00

  And then it says, a person who helps students. A student is in a school. School is an educational institution. Uh, an education institution is about education, which is the transmission of knowledge, which is about, um, facts, uh, into, um, into characterized as a true belief, a propositional knowledge is a version of belief. Then we've got attitude. Then we go to psychology, which point we go to the mind. Gosh, it's quite long, actually. You're quite far away from philosophy, Michael. Then you've got thinks, you've got think or thinking is a cognitive process, which goes to mental processes. Goodness me, human brain, organ.

• 28:20Speaker 01

  Oh, whoa, we're leaving. We're getting further away.

• 28:23Speaker 00

  Organism, living matter, physical science, uh, natural science, science, um, knowledge. We're going back. You're in a loop. You don't go to philosophy.

• 28:35Speaker 01

  I'm in a loop. We loop around knowledge.

• 28:37Speaker 00

  You don't go to philosophy. You're one of the rare ones.

• 28:40Speaker 01

  I don't go to philosophy. I'm an exception to the philosophy rule.

• 28:43Speaker 00

  You're an exception. Oh, my gosh.

• 28:45Speaker 01

  But that would also mean that anything that gets to knowledge is going to get trapped in that loop.

• 28:51Speaker 00

  It is. Hang on, guys, I'm going to have to check myself here. Starts, they've changed my picture. I don't like that. Can I contact Jimmy Wales about that? I also go to knowledge.

• 28:59Speaker 01

  Uh-oh. Uh-oh. So, do you think we might need to update this fact? And, and someone may have already noticed this before us, right now, but.

• 29:07Speaker 00

  Michael, it's broken.

• 29:08Speaker 01

  Is philosophy not the endpoint of the funnel? Is it, is it basically a knowledge loop now?

• 29:14Speaker 00

  You know what? The thing is, is that, oh, no, it is. Knowledge is a loop. Someone needs to, someone needs to immediately update the knowledge, the knowledge Wikipedia page. They've, they've broken it. I'm, I'm calling Jimmy Wales immediately. Right. Well, thanks. That's sort of end of the talk I can give on that then, isn't it? Um, should we move on to the next question?

• 29:34Speaker 01

  Yeah, let's move on to the next question. This one, uh, came from Margot on Reddit, who asks, shower thought? Is the reason that shower thoughts exist at all due to the increased blood flow to your brain in the hot water?

• 29:48Speaker 00

  Okay, this is great. First things first, you're definitely not imagining it. You, people genuinely do have better thoughts in the shower. I know that I do. I'm sure you do as well. Um, there is a few reasons for this, but basically, they come down to...

• 30:07Speaker 00

  Uh, you know the Chinese finger trap? Where like the more that you, the more that you kind of pull at something, the harder it is to get.

• 30:14Speaker 01

  Yeah.

• 30:15Speaker 00

  Um, your brain actually works a lot like that. So you, you have, uh, when you are working and you're really intensely concentrating on something, whether it's like a, a school problem or, you know, work problem, when you're really thinking really hard, your brain is using all of its executive control networks. Um, but when you switch over to a, a sort of autopilot task, so something you know how to do, it doesn't really require your brain to think very hard or deeply, but you are doing something like washing your hair, you know.

• 30:47Speaker 01

  Yeah, going for a walk, going for a walk, right?

• 30:49Speaker 00

  Well, going for a walk is ever so slightly different actually, but when you're doing something, um, kind of repetitive that you don't need to think about, your, your brain stops its intense focus. And instead it's the default mode network that takes over instead of your, your executive control networks. And, and the, the default mode network, this is like your, your brain's mind wandering state. When you're sort of like allowed to kind of think about different things, your, your, your subconscious is able to freely associate with stuff. You can dig up old memories, you can, you can connect seemingly unrelated concepts. Uh, while your focus, the stuff that your focus brain would have filtered out because your focus brain is like, no, this is the thing in front of me.

• 31:27Speaker 01

  Right.

• 31:28Speaker 00

  But actually sometimes to solve a problem, what you need is the free association that comes from, from your default mode network. Um, so it's just much better for that. There's also, uh, actually creativity is really heavily linked to dopamine. Um, you know, sort of the neurotransmitter that, that feels pleasurable. And taking a really warm, nice relaxing shower, it's sort of, it feels nice, right? It feels good. So your, your body and brain is in like this better state already. You've got a bit more dopamine release, um, which then goes on to help your, your creative drive. Um, but you're also bluntly, you're not doing anything else. You can't look at screens. You can't like distract yourself.

• 32:13Speaker 00

  It's one of the very, very few moments of an entire day when you are not locked to a screen in front of you. Um, and so all of those things together, when, when you go for a walk, on the other hand, actually you are, um, you're increasing the oxygen to your brain. You're, you're sort of, you're, and glucose actually, your, your, your, your, your heart be pumping more. You're kind of feeding your brain loads and it's as well as all of these other elements as well.

• 32:40Speaker 01

  Interesting.

• 32:41Speaker 00

  But it's totally real, totally real.

• 32:42Speaker 01

  I definitely have found that, like in the shower, for some reason, maybe because I'm so focused on my body. I don't have as great thoughts in the shower.

• 32:50Speaker 00

  Who wouldn't be Michael if they looked like you?

• 32:53Speaker 01

  Driving in the car or watching something kind of mindless.

• 32:59Speaker 00

  Yeah.

• 32:59Speaker 01

  Actually kind of like brings forward better new ideas. And I, I need to, I don't know, I, I experienced this so often, I don't know why I don't do it more often. That I'll, I'll be working on a problem with such focus all day and I won't get anywhere. And I'll be so frustrated, but then what happens is two weeks, I'll give up. And two weeks later, I'll suddenly be like, oh, wait a second.

• 33:21Speaker 00

  Of course.

• 33:22Speaker 01

  It just kind of happened because I'm allowing my, my non-conscious activities to, to associate things and put something together. And, um, I've definitely found that when I, when I need to write something, it's better for me to take a few days off and not think about it at all. And then boom, it happens.

• 33:40Speaker 00

  Wow. Uh, yeah, yeah. So, so the example I always think about with this is when I was doing my PhD, I at one point was stuck, so stuck on this unbelievably annoying problem. And I was stuck in it for honestly six months. And, and I, and I, it just could not get this code to work. I'd written this, this bit of software and for a mathematical model, basically, and I just could not get it to work. And I would like go into the, to, to the kind of office and I would sit there and I would try from the beginning of the day and work all the way through and nothing would happen. And then the next day and the next day and the next day, and I would rewrite it and rewrite it and rewrite it.

• 34:23Speaker 00

  And then the day that I solved it, it's like the clearest moment ever. After six months of this, I was like, I got up from my desk, I was so frustrated. It'd been six months of this stuff and I walked to the toilet. And as I put my hand on the door to the toilet, literally as I'd like pushed the door open, I was like, oh my God, I completely know what the problem was. And everything was immediately solved.

• 34:46Speaker 01

  Exactly.

• 34:46Speaker 00

  It's like, it's, it's unbelievable, unbelievable that you guys spent that many hours sitting at a desk. And it was when I wasn't at the desk that I, that I managed to solve it.

• 35:01Speaker 00

  This segment is brought to you by Cancer Research UK. Our bodies, they're very clever. You've got all of these mechanisms that are in place to help protect us from parasites, from viruses, basically anything that's bad.

• 35:12Speaker 01

  But sometimes they can be a little overprotective and start freaking out over something that's not actually harmful.

• 35:17Speaker 00

  This is the type of situation when your tongue starts itching just because you've eaten a pineapple tart or hay fever season that triggers a massive sneezing fit.

• 35:26Speaker 01

  Allergies are our bodies turning what was once an evolutionary advantage into a problem. But what if we could harness that defense system to do something useful?

• 35:35Speaker 00

  So today we are asking, can we turn our hay fever mechanisms on tumors? Starting from the beginning here, there are hundreds of species of parasitic worms and creatures that will quite happily crawl inside your bodies and make us sick. But these things, they're too big for our immune system to engulf and destroy. So instead our immune systems evolve this special security system that will help keep these bigger things out. You get these antibodies called immunoglobulin E or IgE. And they have learned how to recognize a parasite. And then IgE antibodies go in and will bind to specific patterns that appear on the surface of parasites. Kind of a bit like how a key fits into a lock.

• 36:19Speaker 00

  And what that does is it causes your immune cells to just wake up, at which point they just release this massive onslaught of chemicals like histamines that cause things like coughing and sneezing, but will help to weaken and then expel the parasites from the body. So allergic reactions, I mean, they are this mechanism going wrong. They happen when your body mistakes pollen or peanuts or whatever it might be for a parasite. In other words, essentially allergies that are a misdirected immune response.

• 36:51Speaker 01

  So if your immune response can be misdirected, can it be redirected in ways that would be helpful? Well, that was the idea that came from a Cancer Research UK scientist, Professor Sophia Karagianis. And she was studying allergies for her PhD. And her boss said, hey, I want you to be in charge of this experiment where we're going to look at allergic responses as a cancer treatment. Okay, imagine that, imagine being like, oh, I'm allergic to cancer. Uh, if I have it, my body gets into fight mode and attacks it. So their idea was to take those IgE antibodies, the ones that attach and cause allergic reactions.

• 37:30Speaker 01

  But what if, what if we re-engineered them to bind to molecules on cancer cells instead of onto pollen or food? Well, then those antibodies would start releasing inflammatory chemicals. And that local reaction would alert all the other immune cells and they would join in the fight. This idea has a lot of potential because these allergy causing antibodies can launch a powerful and persistent attack against a threat. If you turn them on cancer, our bodies could rapidly destroy the disease.

• 37:57Speaker 00

  So how close are we? This sounds amazing. This is like a big, bold idea. But of course it's one that comes with risk because this proposed treatment that Sophia had come up with, look, it's based on an allergic reaction. And if you are provoking an allergic reaction in the body, you want to make sure that you're, you're not having side effects like anaphylaxis. Anaphylaxis is a life threatening allergic reaction that, that can happen really quickly. It's when you get this sudden flood of chemicals in the body that narrows your airways and can stop you from breathing. Because of that risk, you know, the industry was a bit reluctant to invest. But then Sophia, she pitched her idea to Cancer Research UK. Digging into her biology, she managed to alleviate the safety fears to win their vital backing.

• 38:39Speaker 00

  And then after years of hard work, her team, they managed to launch this early stage clinical trial, testing the first ever IgE antibody drug in people with advanced cancer. Look, this is designed at this stage to test safety at low doses. That's what an early stage clinical trial does. Uh, the treatment still managed to show promise though, it shrank one woman's tumor. So the idea now is that they're on the next stage of these trials. They're trying to bring this treatment one step closer to the clinic with the hope that in the future IgE antibodies could be this widespread treatment approach that can actually save lives.

• 39:19Speaker 01

  I mean, it turns out that itchy eyes and a runny nose and odd rash, it's a sign that your body is working overtime to shield us from harm. And our immune system is already doing the heavy lifting. We just need to teach it that the target is tumors, not tree pollen.

• 39:33Speaker 00

  Right, which sounds simple, but it all started as Sophia's radical idea. By backing these kind of ideas though, Cancer Research UK, they deliver breakthroughs that can help people affected by cancer.

• 39:45Speaker 01

  In fact, eight in 10 people who receive a cancer drug in the UK, receive one developed by or with Cancer Research UK.

• 39:53Speaker 00

  And this impact is felt globally too. Over half of the world's essential cancer drugs have been developed by Cancer Research UK or with them.

• 40:03Speaker 01

  And for more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit cancerresearchuk.org/RestIsScience.

• 40:21Speaker 00

  All right, let's do the next question. This is one from Ben who came in on email. Ben asked a simple question. How dirty is space?

• 40:29Speaker 01

  How dirty is space? It depends on what you mean by dirty, right? Like, just full of debris is how I'm taking it. And the universe is famously, like, basically empty. There's, there's nothing here. I think despite the fact that, you know, in our daily lives, we're surrounded by stuff, by matter, by atoms. We've got statues and books and food and people and trees and ground and buildings. In between all of that and the next big clump of stuff, like Venus or Mars, there's, there's like basically nothing. Not, not totally nothing. But if you took all the matter in the observable universe and compared it to how much space there is,

• 41:13Speaker 01

  it's, it evens out to about maybe an atom or two per, like, three cubic meters.

• 41:20Speaker 00

  What?

• 41:21Speaker 01

  Yeah, it's like, and so imagine a clothes dryer, like, three of those volumes. On average, you'll be able to find in our universe, like, one atom in that space, and that's it.

• 41:34Speaker 00

  Hold on. Are we talking about American clothes dryers or British ones? Because...

• 41:37Speaker 01

  American ones, for sure. The, the, the British clothes dryer is just like a weird foldy ladder thing that you put clothes on and it makes your room all humid and it makes the clothes smell. It's, it's great. I, no, I, I do think that they can work really well. Like, like here in Colorado, they work great. But in New Zealand, in the winter, like, the wettest time of the, it's, they don't dry.

• 42:06Speaker 00

  No.

• 42:07Speaker 01

  It's, it's more of like an algae farm is what those things are.

• 42:10Speaker 00

  This is this way here about Americans who moved to, moved to the UK. And they're like, what are you doing with your clothes? Anyway.

• 42:17Speaker 01

  You don't just put them in a big hot box that blasts them until they're bone dry.

• 42:22Speaker 00

  Yeah. Climate change, what climate change? Okay, so that's, I would say not dirty. If you had, like, three massive washer dryers and one atom in it, now that we know how small an atom is, especially given the first half of this episode.

• 42:39Speaker 01

  Yeah, I know, I know. We think, we think atom and we think like, oh, okay, so three cubic meters and there's like a little dot in it. No, it's not a little dot. It is an invisible dot, okay?

• 42:49Speaker 00

  Yeah.

• 42:50Speaker 01

  It doesn't have a color. Light cannot interact with it in a way that we can see with our eyes. It's not a mote of dust. It is a septillionth of that.

• 43:00Speaker 00

  Yeah. I, I do like the idea that you could create a chamber, say a sort of glass chamber of this amount of space, have one atom in there and someone going to be like, it's so dirty.

• 43:10Speaker 01

  It's so, it's so dirty, yeah.

• 43:12Speaker 00

  This place is a pigsty.

• 43:14Speaker 01

  But there isn't much stuff. I mean, I, in a way, it does feel like a lot. Because if you think of outer space as being like a vacuum, then, you know, that's averaging out not too badly. But there is a little bit of material in between planets, in between stars, in between galaxies. But again, we're talking about, like, even less than, than the analogy we just gave, like, maybe, maybe a, a tenth of an atom per cubic meter. I mean, it's very small. There, there are different calculations. Different numbers have been arrived at here. But the, the universe is spick and span and it's nice and clean. But that also should make us feel very special to be part of the matter. It's very rare to be matter.

• 43:59Speaker 01

  If you have, happen to be any, any volume in the universe, to be one filled with matter is quite, quite rare.

• 44:06Speaker 00

  And even rarer to be biological matter, where you are, you are basically locally resisting the pull of entropy towards disorder.

• 44:15Speaker 01

  It makes me feel very special.

• 44:17Speaker 00

  We are very special, Michael. We are extremely special.

• 44:20Speaker 01

  I mean, why me, though? You know, it makes me feel guilty. I'm like, why do I get to enjoy all of this? Oh, brother.

• 44:26Speaker 00

  Why, why these atoms? Why not, why not, why me? Why not, why not other atoms instead?

• 44:32Speaker 01

  And then I look at a cheeseburger and I'm like, you're going to be, it's your turn next, guys. And then they get to be a part of me for a while and experience consciousness and life. But they always got to be matter, you know? But one of these days, they'll become energy, right? Like, my body is warm. I'm a mammal. That's, that's waste heat that's leaving and, and that's just energy. So eventually, they will get turned into not matter.

• 44:56Speaker 00

  Eventually, we all will. Eventually, we all will. Okay, that kind of brings us to the end of our episode. But you know what? There's one thing I wanted to say, actually, before.

• 45:05Speaker 01

  Oh, good.

• 45:06Speaker 00

  Before we go, because, right, this is The Rest of Science, and I take a scientific approach, which also means that inevitably, sometimes we are going to make mistakes. That's just, that's like, that's just a fact of life. And so I am extremely grateful when listeners and viewers point out the mistakes that we have made. And I made a mistake on our curiosity episode, Michael, and I would like...

• 45:30Speaker 01

  Oh, you did?

• 45:30Speaker 00

  Correct it, yes. Because Kevin Carnahan, Professor Kevin Carnahan, no less, who is a professor of philosophy and religion at the Central Methodist University, he made a little video. He clipped up some of the curiosity episodes that we had. And where we were talking about Augustine and Aquinas. And I was saying that they were a bit anti-curiosity, right? That they were sort of, they were, that, that, they thought curiosity as a whole was kind of considered a sin. And I was a bit snobby about it. And I was saying, well, it's kind of quite useful if curiosity is a sin, if you're sort of trying to persuade an entire population of people to...

• 46:13Speaker 01

  To not question something.

• 46:14Speaker 00

  To do as you say, yeah.

• 46:15Speaker 01

  Yeah.

• 46:15Speaker 00

  Anyway, it turns out, I got it wrong. I misread, I misread the history and I was a bit too broad in, in my, my dismissal of Augustine and Aquinas. They actually weren't against asking questions or curiosity, full stop. What they condemned was a particular type of curiosity. They were, they were condemning prying, morbid gawking, or sort of seeking knowledge just to show off, like a vanity thing. So, so when they called curiosity a sin, they really meant a lesser kind of curiosity, is that there were different types of curiosity. So my bad, I take it back.

• 46:50Speaker 01

  It's good to know and it's good for all of us to know. They, they weren't against curiosity. They were just buzzkills.

• 46:57Speaker 01

  But, but yeah, no, I love that. I love that. And so please let us know meticulously. I want every detail. Let us know everything we get wrong or could have said better down in the comments below.

• 47:08Speaker 00

  Absolutely. One hundred, like, for real, for real, not just saying that. You know, Michael and I, we've got a team of researchers who help us with these episodes, this amazing team of producers behind us. But it's inevitable, right? That we, we're not going to get everything absolutely right. And, you know, we are extremely grateful when people point out mistakes. I really, really, honestly mean that. That's what science is, right? That's what science is, is, is, it's the march towards progress collectively. And that's, that's always been my attitude to it. So thank you for pointing that out. We really appreciate it.

• 47:40Speaker 01

  Yeah, yeah. So keep it coming. Yeah, keep, keep the questions coming. Keep the questioning coming. We are not always right. We are just along for the ride. I don't even consider myself a Sherpa. I consider myself a fellow traveler in this journey of thought.

• 47:54Speaker 00

  A fellow morbid gawker.

• 47:57Speaker 01

  And, and keep morbidly gawking, okay? I don't care what Augustine said. Like, if you want to know about, I'm trying to think of something.

• 48:06Speaker 00

  Do you want to know about inventors who have been killed by their own inventors? You go look at that Wikipedia page, my friend.

• 48:10Speaker 01

  Please, dude, there's a reason that page exists and there's a reason it has the page numbers, the page views that it has, okay?

• 48:17Speaker 00

  Absolutely. Okay, we will be back next week. But in the meantime, please do send us your questions, [email protected]. And leave comments on the video, leave comments on Reddit. Among us, we read all of them. So, yeah, we will, we'll see you next week.

• 48:33Speaker 01

  Later.

• 48:45Speaker 04

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• 49:46Speaker 06

  Everyone's got a hard question about AI. Your job, your kids, where it's going. Anthropic was built to surface those questions and share what it finds along the way. Because there's hope in hard questions. Ask yours at claud.ai/spotify and keep thinking. That's claud.ai/spotify.