The Evolution Of The Butthole

It's my object today. I brought I'm actually going to save it. I'm going to I'm going to save telling you what it is, but it's it's something to do with the human body. And it starts off with the straw. We'll get to it in a bit. You got you got you know, you got to wait for that kind of joy. I'll wait. But as always, you come first. We've got questions you guys have submitted. Thank you for doing that, by the way. They're a blast to read. I don't know how we're going to ever cover all of them. They're also good. They are. Here's one that's come in from Kevin. I think this one's for you, Michael. I often hear scientists complaining on documentaries about maths not working or breaking. This tends to happen when maths encounters zeros. So my question is, rather than moaning about maths not working, shouldn't scientists busy themselves making a new maths that doesn't have a zero? That's what I say every day. Just let's go back to not having zero and nothing will ever break. Which is not very long ago, actually. This episode is brought to you by Cancer Research UK. So when most people think of naked mole rats, their unusual relationship to cancer probably isn't the first thing that comes to mind. But maybe it should be because it is incredibly rare for them to develop cancer, which could be partly down to their unique immune system, or it might be the way that their cells respond to damage. So scientists are studying their biology for its cancer-fighting secrets. It's a reminder that discoveries can sometimes come from places you don't expect. Cancer Research UK is the world's largest charitable funder of cancer research. Thousands of scientists, of doctors and nurses, work across more than 20 countries to help turn discoveries in the lab into new tests, new treatments and new innovations. And the impact is clear. Over the past 50 years, the charity's pioneering work has helped double cancer survival in the UK, meaning more people living longer, better lives free from the fear of cancer. For more information about Cancer Research UK, their research, their breakthroughs, and how you can support them, visit cancerresearchuk.org forward slash rest is science. when was zero introduced as a numeral so it goes back to i think it's brahmagupta it's in indian mathematicians anyway uh i mean they had it for a very long time and i think that the idea is that it's about sort of the the the idea of a zero having that shape that secular state is is sort of you're following eternity, right? So sort of the state of nothingness. But getting to Europe, it took it a really, really long time. It came through the Islamic world, really adopted it, sort of came up through Spain. But people were really reluctant, really reluctant to adopt it. I think Shakespeare was walking the earth before zero was commonly used in Britain. In like mathematics, because clearly he knew about the concept of nothing, emptiness, not having any. So the reason I wanted to look at this question today was because I've got you here, Hannah. And I wanted to see how you felt, too, because that whole that whole phrase mathematics is broken. It doesn't work. We've discovered a place where if you divide by zero math breaks, it feels so histrionic, like it's not breaking. And look, as we all enjoyed, I don't know when this is going to happen. I originally picked this question for my zero limericks, but now I did the limericks already. So that's why I was scrambling to find a different question. But division by zero or, you know, physical singularities causing science and math to break because you hear that all the time. But it feels like clickbait. I mean, generally, people say maths breaks when you're dividing by zero, which I guess happens, you know, in the high school when you're just presented with it as an equation. But in, you know, much higher level mathematics and physics, there are situations where in the Navier-Stokes equations, for instance, which model how fluids flow, where you end up with what's known as singularities, where you get some denominator. I mean, usually it is basically boils down to the fact that you're eventually divided by zero. You get some denominator that goes really, really small. You get a term that becomes really, really big and just blows up the whole equation. Everything else becomes it shrinks, sort of pales in comparison to this one particular term and the equations no longer work. So it seems like we don't need to make a new maths that doesn't have a zero. We just need to deal with zero better. like what is the solution to a singularity in fluid dynamics uh i mean the equations break you just can't use them anymore they break yeah i mean they literally break yeah a correspondence between the math and reality ceases to exist exactly exactly yeah okay so what do we need to do um to overcome that do we i feel like getting rid of zero is the wrong answer because it's useful in a lot of other circumstances. It seems like we just need a better way of making reality correspond to it. Reality certainly isn't going, oh my gosh, there's a zero in the equation that we're all following. Time to, what, create a rip in space-time? No, the fluid keeps flowing. I think that a lot of the time when you're using equations like the ones that you find in physics, for gravity, for instance, they tend to work really well at certain scales. So Newton's laws of gravity work really well if you and I are chucking a ball between each other but when you zoom out further they just they don't quite fit as well they sort of they aren't powerful enough to deal with things in that scale and likewise when you shrink down really small the thing that works on the scale of humans down at the quantum level doesn't it just doesn't work anymore so I think the thing about equations breaking essentially that's what you're describing you're trying to like you've got an equation that works at a certain scale works in a certain set of assumptions and you are like pushing the boundaries you're right up against the very limit of what those assumptions uh can tell you and and and that's the point when a zero gets sort of a rogue zero appears it's where exactly as you described your your description of reality departs from the real reality itself i mean the other place you get singularities is in black holes right yeah obviously the physics that we know well that you can sort of move around in doesn't apply once you get to something that's as dense as a black hole same with like plonk volumes and plonk distances it's like well it seems significant because physics as we have constructed it today doesn't really help us there or when we start trying to describe a time closer and closer to the big bang we can only get so close to time zero before mathematics breaks and i don't know why i don't like that phrase i think it just goes back to the fact that it feels clickbaity i think it implies that like uh all of math has been wrong the whole time when in reality what we're just we're we're modeling reality really well with math but there's some fundamental like small scale in the universe where the universe does something different i mean do maybe we just need to discover zero in real life not emptiness but a mathematical zero in real life a mathematical zero in real life what would that look like well, it would look like what happens in the singularity of a black hole. We don't know how reality deals with it. And our equations certainly don't. But when it comes to the grade school stuff about division by zero, my opinion is that division by zero is just not division. Because one way to think of division is that it's repeated subtraction until nothing is left. But if you're subtracting zero over and over again, you're not actually subtracting. It's like saying, what's two plus tuna fish? Well, one of those isn't a number. So there's no mathematical breakage happening. You've just made a joke. But zeros that we find in our equations describing reality aren't jokes. So, Kevin, I don't think the answer is a mass without zero. I think the answer is understanding real zero. Can I tell you my favorite thing about that answer? Please. that uh the way you i've never heard uh plank pronounced plonk before i really enjoyed it plank i don't know i get it's wrong all the time someone sent me a message the other day we were talking about um air dosh the other day and someone sent me a message saying it's air dish right saying it wrong apparently there's a there's um euler was how i thought his name was pronounced but apparently it's euler um so i don't know maybe it is plonk but from now on i'm going to call it plonk's constant because i think that sounds much cuter it always just felt a bit more european plonk plank sounds like a trend from 2007 and i've i've heard it both ways i guess you know whenever i'm gonna say something in a script that i've prepared i look up how it's said and i look up what how other people have said it yeah you can't always trust the like what google says the pronunciation is or what um youtube videos do i will look at like the oed or merriam webster and i'm like look if they say it's that way then i can i'll blame them um but yeah i i for the longest time have always said the plonk distance but plank distance is that what you say i say i say plank but you know who knows who knows who knows one thing i will say is that um as well as marion webster the oxford english dictionary those pronunciation guides when you work for the bbc they actually have a pronunciation unit where there's a phone number that you can call you call up that number and you ask how to pronounce a particular a particular word it's especially useful when you're making science documentaries yeah anyway one of my favorite games is to call them up and say hello is that the pronunciation unit oh my god they buy every single time anyway there's an interesting story about what happened once there was um a very good friend of mine uh jim al-khalili who is a uh physicist a british physicist who makes amazing documentaries in the uk for the pbc anyway he was out on a shoot and there was a particular word that came up that nobody on the shoot knew how to pronounce and he said oh you know what i'm i'm not sure i think it might be this but i'm not completely sure let's call the pronunciation units they call up the pronunciation unit they get an answer half an hour later they call them back have an answer so they record that on tape that's what goes out on air anyway the next day Jim is in his office in Surrey University and he's still wondering about this word so he goes next door goes next door to one of the businesses down the corridor and he says oh you don't know how to pronounce this word do you and his colleague says funny you should ask yesterday i got a call from the pronunciation unit of the pvc and they asked me how to pronounce it i didn't know so i went on wikipedia and took a guess look once you get down to it it's all duct tape it's duct tape with wd4c you're right it's all duct tape together and we're all just kind of feeling around in the dark um when i lived in london and i worked at google that was jackpot city because i i sat on the floor with all the partner managers at youtube for all of europe middle east and africa so if i saw a name or a word um say in italian i would just go to the italian youtube partner representative and i would say how do you pronounce this and he'd be like basically a spaghetti and meatballs i'm really good at italian uh accents by the way not cultural There were Germans. There were people from Iran, from Egypt. It was amazing. It was so much more helpful than going on the Internet and trying to find what to say. All right. So let's let me find out what to say next. I'm going to pull out a question for you, Hannah. How about this one? This one's from Tom. What are some assumptions about the universe that scientists rely on that might someday turn out to be wrong? and what false assumption would be the most devastating to the scientific community? Okay, so, I mean, we've already one assumption that it's that it's plank, not plonk. That's one. And I'm devastated that we don't know. Okay, I mean, there's a few of them. There's a few of them. I going to go a bit bigger than the university I going to go for science in general I think that there are lots of situations where people have theories that then end up forming the basis of I mean, the central basis of a lot of people's careers. Right. So dark matter is one example of this, where when you make a calculation about how much gravity there should be to hold the galaxy together, there's sort of there's loads of stuff missing this this matter that you can't see hence dark matter um and so it sort of it began to to really fill a hole in an equation and now there are people who spend their entire careers studying analyzing trying to decipher what dark matter is no one's ever found it but i mean there is sort of quite good evidence that something like that exists um but there is this rival theory that says well what if einstein was just wrong like what if you know we were talking about scales earlier what if what if einstein works at the scale of the solar system but doesn't work at the scale of the galaxy what if there is something else that's missing so there are some other people who are working on this this this rival theory which is called modified newtonian dynamics um that says you know actually kick einstein out the whole phrase of like oh what are you einstein's not going to work anymore because they're just going to disprove everything that he ever came up with um i mean that's that's one really big fundamental thing that would be pretty devastating to the entire scientific community. But I hope that they can get past that devastation because that's the only way you make progress. I mean, how exciting of an idea. I've never heard of this before. Modified Newtonian dynamics. Yeah. So the idea is that Einstein is once again just an approximation that's not good for big stuff. It's good for medium sized stuff. And then we've got the quantum realm on one side and the galactic transgalactic world on the other. how interesting yeah because you we already know that einstein isn't a complete picture exactly as you described right it doesn't it doesn't capture things down at the small scale so who's to say there's not another big scale above it i always assumed look we've got the top half figured out it's the it's the bottom half that that we still need to marry to the big and yet maybe we're still just eating the filling of the sandwich and we don't know what two slices of bread are doing where is the bread michael that's that's the question i mean there's other things like okay so at our scale we make and actually the scale of galaxies and solar systems we really make the assumption that time goes forwards only you can't like smash a glass in reverse right that's sort of this unwritten rule um but the thing is is that at the quantum realm i think that they're slightly less comfortable with that as a as a baseline assumption i mean why should that be and that i think is one that would really tear everything apart um there's also all the constants you know like like like plonk's constant well you know hey i've heard of that before i've said that before um there's other constants about for example um the way that electrons orbit an atom and the sort of strength of those um of those forces who's to say that those constants have been constant throughout the entire history of the universe right maybe actually they're just we're seeing one snapshot in time of the way that they look or one corner of the universe in which they look and look that way all of these are fundamental assumptions that actually you know you still have to question right like you can't um you can't just accept them as fact and move on and and i think that everything would fall apart there but i think actually um the reason why i wanted to go beyond just the universe on this is that i had um one thought there's this really brilliant piece in the sunday times that was about scientific publishing and i think that this assumption that actually scientists rely on a lot is that the peer review process is great that the way that scientists publish papers means that we end up with facts right and uh sometimes that looks on slightly shaky ground right um i think that's been an assumption for a long time that scientific papers are have been through such a rigorous process of peer review of other scientists checking the numbers checking that they work you can trust every single scientific paper um and i think that there are a few little cracks in that there's a few there's quite a lot of duct tape down there as well a lot of scientific retractions um because the system isn't necessarily built for true stuff to come to the top you know new stuff too has a big barrier because again it's not god reviewed it's peer reviewed it's other people who have their own community expectations and and paradigms that are shared here's the thing right if you're a scientist of course you're contributing to this great big body of knowledge of course you're advancing human understanding of the universe of course you are but you're also trying to get a job you're also like you know trying to get a research grant and the thing is is that uh to do this the the things that are you know fundamentally and understandably selfish sometimes they run counter to the things that serve that wide range you know you need to publish papers you need to like get a reputation you need to be noticed internationally you need to like have people cite your work and all of that is um you know you do best in that situation when you are like pumping out papers when you've got got amazing data when you're like coming up with incredible results and so there are basically incentives in the system for people to just like you know fudge a little bit around the corners like just sort of like maybe just tweak the data a tiny bit here and there maybe publish the most interesting results that they're getting and not the boring ones right um and i'm not talking about necessarily direct manipulative behavior always here i think sometimes it's sort of overlooking there's like confirmation bias all of that kind of stuff and the thing about the peer review system is that you're handing these papers that you're writing and you're handing them to volunteer scientists who've got their own stuff going on who maybe don't have time or the expertise to go through and check every single number and like quite a lot of stuff slips through so this article in the in the times was was really talking about the number of retractions that have happened in the scientific literature is increasing and i think that with ai contributing um to this landscape of like just you know making it a tiny bit easier to make your paper sound amazing just making it a tiny bit easier to like you know play with your data in a particular way right the number of attractions is increasing because ai as a as like an llm specifically is going to be able to write things that sound right but this is what peer-reviewed papers tend to sound like and so here's one and it passes peer review because it's been engineered by an algorithm to sound like it should and we don't wind up making any progress we certainly don't do anything novel or revolutionary I also wanted to say that I think we might discover that there are limits to what we can know that we don't currently know about. I think we could prove in some like Godelian mathematical way, for example, that we will never know what consciousness is and whether one thing is conscious or not. That might actually be for some really clever reason beyond the ability of a fellow conscious being. And we're just going to be left in the dark having to accept it on faith. And I think that I could see a far future where science is more about making people feel OK with what we cannot know. And it kind of takes the place of religion. You're such an optimist. I mean, I definitely agree with you about the limits of human knowledge and about accepting the limits. I don't think we're there yet, though. I do not think we're there yet. No. All right. Here's one for you, Michael. I know you're going to like this one. OK. This is from Jacob. When hanging a post from my office, why do I feel compelled to hang it at the centre? I could hang it anywhere. But why does it look best if equally between two endpoints? Is there an evolutionary reason for this? I've attached a photo of it hanging in my dingy office. OK, let's show that photo and then let's judge whether it's centered enough. Let me tell you what we're looking at here. So we've got this. It looks like one of those it's been taken inside one of those sort of temporary buildings that you get on on construction sites. That's sort of what it looks like. It's got a it's a corner of a room. It's got sort of cream paneled walls. It has a window to one side and then symmetrically between one of the wall panels hangs a glass framed photograph of a man with a guitar and a cowboy hat. Looks a bit like Bruce Springsteen from afar. First of all, I love that Jacob submitted a photo with his question as though we would read his question and go, what do you mean centering a poster? I've never seen such a thing. I need a visual here. Oh, a poster. Now I know what you're talking about. Thank you for that picture, Jacob. I mean, I would say that aesthetically, there's a bit of headroom there to go, isn't there? Look, we don't need to judge Jacob's decoration. okay he's asking about a psychological evolutionary phenomenon yeah i don't think i don't remember coming across bruce springsteen posters in the history of evolution but maybe i missed that lecture regardless of who it is i think this is a really important question because i think it gets at like one of those like what is a human kind of things and why are we still here why did we not go extinct i think that we um really enjoy stuff that's difficult stuff that is unnatural i think we are a a high skill based species where we don't hunt with the claws we're all born with we have to like come up with strategies to hunt and the only food sources available to these like little hairless naked apes that had no protection was the high skill stuff. Like, let's get a mastodon or let's hunt an elephant. And that's going to require traps and cooperation and tools and spears and things that other animals just couldn't put together. And so humans that enjoyed things like, hey, look, this is symmetric or this is centered, did better when it came to surviving with such soft, fleshy bodies. So now we are their children, right? We also really enjoy when things are unnecessarily rule following, when they're centered, when they're symmetric. And this has been our story forever. One of my favorite mysteries is why so many ancient stone axes are symmetric when they didn't need to be. And it's been shown that making these, you know, what do you call it? When you nap stone to make a sharp point, making it symmetric or bifaced or giving it the shape that they seemingly all have took a lot more time than necessary to do the job of killing an animal or ripping the skin off the bone or the meat off the bone. And so the only explanation seems to be that we just thought it was cool looking, that it showed a level of skill that meant that we were good potential mates, that we were going to be good at other things that humans needed to be good at, like cooperation, planning, thinking ahead, imagining. So, yeah, we want our posters to be centered because if we didn't, we would have gone extinct. It's like I often think about about the number of right angles that are in our lives. Yeah, because nature does not have right angles. Then you don't find them. I mean, maybe very occasionally as a fluke, but in every room, in every building you ever walk into and every object that you own in every space that you encounter, we are surrounded by them, surrounded by this thing that is the most unnatural of human inventions. And I totally agree with you. It's like, why are we so obsessed with right angles? It's because they're symmetrical. You know, it's because they're neat. It's because there's sort of there's this precision to them that we are completely drawn to. I totally agree. That's right. There's an unnatural precision that shows a mastery of something that requires more skill than any other animal would require. And that's us. The only way we could survive was by having that high skill. So there you go, actually. I started off by slagging off your Bruce Springsteen poster, but actually now, now you've got the, you know, the line of your window. You got the really sad foam panels in the ceiling You got right angles and symmetry all over the place Jacob You are demonstrating yourself as uniquely human I'm trying to make this picture bigger. Ah, okay, so it's not Bruce Springsteen. It's a guy in a cowboy hat. Maybe it's Jacob himself. Oh, wouldn't that be cool? And we're sitting here not admiring it enough. Oh, hold on a second. Now that we've zoomed in, it's not Bruce Springsteen at all. it's a clint black okay this is a signed poster actually he says it in his email a signed poster from 1990 i don't know who clint black is but i know what he looks like now thanks to this image i think at that point maybe we'll go to a break shall we this episode is brought to you by cancer research uk radiotherapy is over a century old but it is still changing cancer research uk helped lay the foundations of radiotherapy in the early 20th century and has driven progress ever since. Radiotherapy remains one of the cornerstones of cancer treatment today. Every year, millions of people worldwide benefit from Cancer Research UK's work to make it more precise. Scientists are still refining how radiotherapy is delivered. And one example is an experimental treatment called flash radiotherapy, which delivers radiation in fractions of a second, up to a thousand times faster than standard radiotherapy. And early studies suggest that speed could make a real difference. Flash radiotherapy may cause up to 50% less damage to healthy cells. But scientists don't yet know why healthy cells seem to be spared, so Cancer Research UK are working to answer that. Understanding it could be key to reducing side effects in the future. For more information about Cancer Research UK, their research and breakthroughs, and how you can support them, visit cancerresearchuk.org forward slash the rest is science. This episode is brought to you by Thriver. Most of us tend to think of blood as something slightly clinical, linked to illness or bad news. But in reality, it has been quietly keeping a record of what's going on inside our bodies, almost like a biological diary. It holds clues about how everyday choices shape our health, sleep, stress, food, movement. And without access to that information, staying healthy can feel more complicated than it needs to be. 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We'll be doing a different book each time and digging into all the stories behind them. And we are going to be talking about the historical contexts behind some of the greatest and most famous books of all time. We're going to be digging into the remarkable people behind them, the unexpected stories behind the stories, and also unravelling the plot of each book a bit and delving into the depths of the story. Now, you don't have to have read the books to listen to the show, but we hope that by the end of each episode, you will be able to pretend to people that you've read them. That is the key thing. And either way, whether you read them or not, we hope that you'll learn lots of fascinating facts. You'll do lots of great stories and maybe, Tabby, the odd laugh. We will be looking at thrilling Gothic bodice rippers like Wuthering Heights and Frankenstein, as well as iconic stories like The Great Gatsby or Little Women. and then also some more modern stuff. So Game of Thrones, Normal People, The Hunger Games, Hamnet, all manner of exciting stories. So please join us on our journey into all things books wherever you get your podcasts. Just search for The Book Club every Tuesday and hopefully we will see you there. all right we're back and uh this time i've got another question for you michael how many how many holes does a straw have one are you sure yeah i'm sure i mean if we're talking about topological holes holes that cannot be removed by gluing or ripping one this is a topic of much debate on the internet you know of how many holes does a straw have because as you say some people say one it's just you know you look through it it's a hole done um other people um say that there's two because there's one on this end and there's one on the other end and um in many ways both both groups of people i think have a point sort of they have a point i mean you know i did a video on how many holes a human has and i think the bottom line is that here's what a hole is, it's a word. We made it up and it can mean whatever we want. And most of these debates are around what the word should mean. Should it mean like an individual entrance or is there some better definition? So look, by using a mathematical definition of a hole, the straw has one. You can imagine taking one end of the straw and stretching it open so that you wind up with a plate with a hole in the middle. Then it's really obvious that you've got one hole. I mean, of course, you are absolutely right i uh i'm going to come to your video on the on how many holes a human has in a moment if i may i'm really curious about what object you've brought because we're jumping right into holes oh yeah which we've established matters a lot to me it does evidently okay but really what i want to talk about here is topology which is it's basically the alice in wonderland of uh of mathematical ideas it's where it's where you take a shape and the rules are that you can bend it and stretch it and deform it as much as you like but you cannot cut it right you cannot cut it you cannot rip it you cannot crease it um and then people um have these arguments extensively about um how many holes things like straws or t-shirts or trousers um have now okay while i agree with you that fundamentally i think that a straw has one hole you could say well hold on a second if i cover up one end here if i pinch one end of the straw now how many holes does it have because it's sort of you could say that it sort of does still does still have a hole it's sort of a hole on the end no right okay so i mean i would say that first of all you have pinched a hole shut all right so you you have you're no longer talking about topology because you've committed a heteromorphism it's now a different shape you have glued one end shut and you don't have a hole anymore you have a blind hole which is a hole that you cannot go all the way through but those can be removed by just you know moving the thing around like clay okay sure but then hold on a second what about this glass does this glass have a hole in it no why not what are you talking about it's got a hole right there yeah but i can get rid of that hole without needing to use any glue or scissors i can just if we imagine that the glass is made of clay i can open its orifice larger and larger until the whole thing is flat and it's a plate. Okay, so this is, I think, the fundamental key point. The two ways that you can look at this straw. One is that you can say that the surface is two-dimensional, that the paper around the outside is 2D, and you can imagine blowing up this straw until it's the size of a balloon, okay? So it's like this big round balloon. Oh, uh-huh. At which point then there are these two circles that are cut into it. Those are boundaries, right? So I think that exactly as you pointed out at the beginning, the problem is that the word hole means two different things. Sometimes it means tunnel and sometimes it means a boundary. So you could say that this straw, if it was the shape of a balloon blown up to the shape of a balloon, would have two circles cut in it, two boundaries, essentially. And so that is like the argument in favor of the people who say that a straw has two holes, one at each end. What field of mathematics worries about holes as boundaries? Because I do appreciate the difference between these two conceptions. A topologist would say this shape still has just one hole. I think it's still a topologist. It's just a topologist is looking at the surface rather than a three-dimensional object, no? I'm not sure. I think you're right. I don't know if I would say to apologize, but maybe I'm wrong. The other way to look at this straw is to say, OK, well, imagine it was made of plasticine, at which point you could. Well, you could also cut off a tiny bit of it, make it shorter and shorter and shorter and shorter and shorter until you had just a little ring that was left over. At which point you're like, that's definitely got one hole. I mean, you're kind of crazy to imagine anything else. It's the same shape as a donut. A donut obviously has one hole. Right. so those are the two different ways to look at it right as though that the the surface is paper two-dimensional or the surface is a sort of physical object itself a three-dimensional object itself if we blow the straw up to a balloon i like this way of thinking about it because now we've got seemingly two boundaries though a topologist would say but i could put my fingers into one of those boundaries and pull it and stretch the balloon until it was just a circle with a hole in the middle, one hole. Right. So this is exactly it, right? Is that it's like you've got two boundaries on the surface. But if you consider that the whole object is like solid, then it's one tunnel. So there's a difference between boundaries and tunnels, which is where the confusion comes in. So, OK, it's all right. It's not so bad on a straw. But what about a T-shirt? How many holes does a T-shirt have? Well, it has three holes, right? It's got four openings, the head hole and the torso hole top and bottom are like one hole but then it's got two more openings that join the central cavity of that hole the arm holes so you can imagine shuffling them around and creating three very distinct through holes in a t-shirt i really think the blowing it up into the balloon thing is really helpful here because if you imagine taking a t-shirt and blowing up into a balloon then you've got four circles cut on on the balloon that's right Exactly. But you're right that if it was if if the T-shirt itself is like made of plasticine, then essentially you have one tunnel, one central tunnel from top to bottom and then two additional tunnels that join that tunnel. so three holes in total okay so mathematicians love playing around with these ideas of like taking really kind of crazy intricate shapes manipulating them asking whether a sphere can pass through itself asking whether you can like invert a donut all of these kind of things um but the reason why this is fun and the reason why this matters i think is because of what happened with early life in the universe because it was basically playing this topological game um so uh the earliest earliest organisms they try to uh digest food in a sort of as as though they're a sack right so sort of imagine you know jellyfish here or anemones okay so they're they're they eat with the same hole that kind of goes into their stomach they digest it and then they sort of basically spit this waste out the same hole which is inefficient pooping and eating out of the same hole is not a good idea i would say yeah don't i don't need to be told that and then around about 550 million years ago right like uh i mean quite a long time ago there was this worm-like creature that did the i mean it was the first one that did this really incredibly revolutionary thing it essentially evolved a second hole second boundary but in effect made the hole into a tunnel so it started stopped being like a poke into the into the body of the creature and actually became a tunnel a tunnel all the way through so this creature how long ago did it emerge uh 550 million years ago that doesn seem that long ago to be honest for the first butthole for the first living donut the first butthole that great that good the first butthole michael i love working with you you so right that is the italician of the butthole is that what we call this video we haven't even been around for a billion years anyway the the butthole as an innovation was genius okay so so much of life on the planet i mean basically every creature that you can imagine that that eats at one end and then ejects waste at the other is like following this this same moment of revolution and this is the thing now you can eat continuously right you've got you what you've done is you've You've turned yourself topologically into a different shape. And now you can have this like assembly line of food. And that is what allowed animals to get way bigger, way more complex. It's a miracle. That's why I think eating on the toilet is almost a religious experience. It's a celebration of the fundamental donutness of my body. Yeah, right. Because we are. We are like squish us down. We are all these donut shapes. it's also though the reason why our brains and our eyes and our nose and our mouth are all in the same place because think of us as though we are just a tube that's existing through through the world that's like continually looking for food sort of imagine us worm shaped right and we are all of our senses packed up um towards the like entrance to our to our to our like fundamental tube. Yeah, that's right. It creates a bit of a problem, though, because you need the tube, the kind of the esophagus to like go through the middle, right? You want the brain to kind of exist all the way around the tube. You don't want the brain on one side and nothing on the other. So there are some very simple animals, even antropods, I think, where the esophagus literally goes through the middle of their brain. So if they swallow a chunk of food that is too big, they can give themselves brain damage which is not great i'm glad that's not us do you know how humans worked out our way around it well not humans but i mean mammals more generally no no how um so if you think we have like uh are kind of you're eating through your mouth you have your uh you're breathing through your nose which is above above your mouth but then once it gets to your throat they have to swap over your you have to go to your lungs the nose goes into the sinuses yeah and they all connect in the throat the mouth hole and the nose hole but then there is a division between the esophagus and the trachea for air and food and for humans that's a dangerous connection it's much easier for us to choke than like a dog or a bear you know i thought i understood this and now i'm thinking about it i'm not sure i completely do this little bit oh there we go look at this yeah so here you can see the mouth opens up and comes down this way into the throat but the nose goes into this big open area called the sinuses and this connects back into throat to the throat as well they come down and here we have this division between the esophagus and the trachea so air that we breathe comes down here to the lungs and food is squeezed by the muscles in the esophagus to get to the stomach so here's the problem is that you need the stomach to go in the middle of the body right but at the nose it's like the airway is on top it's sort of it's kind of at the back as it were and then they switch over they cross over in that section where the air supply starts to come to the front right so originally it's at the back and now it comes to the front you've got this crossover the switch over and it's the topological solution to the fact that we need our brains to be around our whole body you need the tube to be in the center and how do you sort of how do you do it yeah are you with me i'm with you and it makes me appreciate the existential quality of choking that it's fundamentally because of this crossover that has to happen the crossover has to happen exactly the brain's on top the nerve cord is on the bottom you've got to have your connecting nerves physically to to wrap around the esophagus to link up so the brain can act around the entire body. And so what you end up with is this like switch over. All right. So we're all these tubes munching along, eyes and ears and stuff all at the top. But then we also, of course, have breathing apparatus attached, right? Our noses. Now, I know that you have done a video on this. Tell me how many holes are there in the human body in topological terms. Okay. To make it brief, I'll say that we need to define how big something has to be to be a hole. Like if a single blood cell can pass through it, then the body has millions of holes, right? The urethra is a hole because you can get up into the bladder, through the ureters, to the kidneys, blah, blah, blah, blah, blah. So I think we need to go bigger than that. If we go 60 microns, all right, the thickness of a human hair, if it can come in one hole and come out another we've got ourselves a through hole and as it turns out humans have eight entrances meaning we have seven topological holes seven topological holes ears don't count pores don't count female reproductive organs don't count that's right the ears don't count because the eardrum blocks uh any continuous passage from the ear into anything else at the scale of a human hair, right? A neutrino can pass right through the eardrum. A neutrino can pass right through reproductive organs and go wherever it wants. But a little spaceship 60 microns wide, it's going to be like, guys, we're stuck. We've got eight ways in and out. And that means we've got seven holes. There was a program that I was doing a few years ago about evolution. And we were talking about how all creatures were tubes and i mentioned the fact that you had done this seven hold human thing and uh was extremely excited about it just absolutely loved it and so i also by the way um at the time was quite obsessed with wood turning videos on the internet which i'd also mentioned on the show anyway someone made me wood turned me a topological model of a human body Oh, it's beautiful. Isn't that gorgeous? You know, it looks like the cylinder of a revolver. That's right. There's a central hole that it could pivot around. And then there are six holes for the six bullets. And that's the human body. Topologically, that's the same thing. We haven't discussed what these other six holes are. Like we know that there's this hole from the mouth to the anus. but there are six more tunnels that all join into that same tube two of them are the nostrils you've got your left and your right nostril they meet together in the sinuses and then they connect up with the throat and then you have on both eyes you have two holes that are called your lacrimal punctum and they absorb your tears if you're actually crying they they can't keep up and so the the tears come down on your face but normally the wetness of your eyes is it's like squirt it on the eye and then it drains through these two holes we have at the corners of our eyes and that goes into the sinuses as well the back of your throat that's why when you get really teary your nose runs a lot of that crying nose runny liquid is actually tears that are in your nose now so you've got those four punta two in each eye two nostrils that's the six holes that all join up and they are greater than 60 microns across so they fit my definition of a hole that you know you could travel through you stick a hair through and pull it out somewhere else so that's all seven of them you've got the here you go mouth to bum right here in the middle it's the middle one let's say yeah and then you've got the two nostrils nostril nostril right there and then you've got the four lacrimal puncta left eye right eye human yep and they all connect but you can and this is hard to do if you're just listening but you can imagine all of those tunnels being morphed and continuously deformed away from each other to form exactly the shape hannah is holding that's us that's us right there just um just that really loving right angles as well this is us us and right this and right angles that's the whole description of humanity that you ever need you know what forget about the arecibo message this is what we should have sent yeah they would have gotten it like in general this is us i mean be better than the other one they sent frankly we could have sent a board of wood with two holes drilled in it and said this is our pants drill a third hole it's a shirt yeah yeah unless unless it's a button-up shirt in which case the first one would do oh yes yes and by the way like we all in general have seven holes but if you've got piercings those add additional holes oh gosh oh they do you're absolutely right i need to put in a teeny tiny especially a nose piercing i need to put in a teeny tiny one in there and not to get too into the weeds but some people have additional holes through their sinuses i forget what the medical term is for it but we don't really know if we have them unless we've had like scans or like nasal problems but you can live your whole life not knowing that you've got an eighth hole hidden inside your head or someone with two buttholes there aren't many of them but i've met some people that i've been suspicious i'm like you've got two down there don't you you're talking out of your second butthole yeah it requires a whole different language but it's possible now that we've done an evolutionary history of the butthole i think uh i think we put this episode to bed michael that was uh that was an enjoyable an enjoyable romp let's flush all of it all right guys thanks for joining us i'm glad you've got your seven plus holes and um we hope you bring them back next time certainly do if you have any questions you'd like us to answer anything uh you want to send us in you can send us uh anything you like the rest is science at goalhanger.com and you can join our newsletter at therestis.com slash science. We're going to be back next Thursday with another edition of Field Notes and on Tuesday with our usual normal episode where we will not be talking about buttholes. Stay there. Probably not. But until then, stay curious. Troy, the Odyssey, the Iliad, all of these great ancient epics depict a monumental collapse that destroyed the interconnected empires of 3000 years ago. And to understand the Bronze Age apocalypse that Homer wrote about 400 years after it happened, subscribe to Empire World History. a fellow goal hanger podcast where we are deep diving into the biggest imperial collapse in ancient history. To get a flavour of the series, here is a clip from our episode with none other than Stephen Fry. It is one of my favourite subjects, the story of the Greeks and the siege of Troy and Odysseus' return home, of course. I say Greeks, Homer called them the Achaeans, the Danaeans, the Argives. The word Greeks is a much later one, but it refers really to the Mycenaeans, a warrior aristocracy, essentially, obsessed with honor and reputation that would give them an eternal glory, a kleos, as they called it. It's the kleos that's in the name of so many Greeks, you know, Cleopatra and all the Socrates, you know, all the Heracles, who's Hercules, you know, Hera's glory. He was actually named Heracles because she hated him because he was a love child of Zeus and she never liked Zeus's love child, her husband, her errant husband. And so as an attempt to placate her, Tiresias, because he was born in Thebes, suggested that he change his name, as a baby this was, to Heracles, the glory of Hera. But it didn't help much. It didn't help at all. Athena even put her on Hera's breast when Hera was asleep, because it would bond them if he suckled her milk. But she woke and saw it and tossed him away, and her breast milk spread across the sky to form the Milky Way. I didn't know that story. Because galaxy, of course, is from the Greek for milk. Galactic, as in lactic. Right. So the chocolate makers are right. Anyway, this is completely separate. Lovely. Keep going. Don't stop. Well, we really hope you enjoyed that clip. To hear more on the Bronze Age apocalypse and how it shaped the ancient Greek epics. Just subscribe to Empire wherever you get your podcasts.