The Rest Is Science

The Smell Of Christmas Is Tree Screams

36 min
Dec 25, 20255 months ago
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Summary

This Christmas episode of Field Notes explores the science behind Christmas tree scent, revealing that the pleasant pine smell (pinene) is actually a chemical defense mechanism trees use when stressed or damaged. The hosts also demonstrate tactile illusions using the human body to show how the brain's sensory map can be manipulated and misled.

Insights
  • The festive smell of Christmas trees is a stress response—trees release pinene chemicals when damaged as a defense against insects and fungi, making the cozy holiday scent literally the smell of tree distress
  • The brain maintains an internal sensory map of the body that can be deceived through crossed-finger and inverted-tongue illusions, demonstrating the gap between physical reality and neural perception
  • Human brains have evolved to find pine scent appealing because it historically signaled safety, shelter, and the absence of biting insects to hunter-gatherer ancestors
  • Brain plasticity allows sensory remapping throughout life—people who lost vision learned to 'see' through tongue-based electrical stimulation, showing the brain can adapt sensory inputs to new modalities
  • The evolutionary purpose of pinene flammability in conifers is counterintuitive: fast-burning, low-intensity forest fires clear competition and parasites while thick-barked pines survive to reclaim the land
Trends
Sensory neuroscience research using non-invasive brain plasticity techniques to restore lost senses in amputees and blind individualsGrowing consumer interest in understanding the evolutionary and biological basis of everyday sensory experiences and emotional responsesExploration of how ancient human survival mechanisms (scent recognition, threat detection) continue to influence modern emotional and aesthetic preferencesIncreased focus on tactile and proprioceptive illusions in neuroscience education and public understanding of how perception worksResearch into how the brain's predictive models (Bayesian processing) create the subjective experience of reality rather than direct sensory access
Topics
Christmas tree chemistry and pinene volatile organic compoundsPlant chemical defense mechanisms against insects and fungiForest fire ecology and conifer adaptation strategiesSensory illusions and tactile perceptionBrain sensory mapping and proprioceptionAristotle's illusion and crossed-finger phenomenonPhantom limb syndrome and amputee neuroscienceBrain plasticity and sensory remapping in blind individualsBayesian brain hypothesis and predictive processingEvolutionary psychology of scent preferenceTongue anatomy and nerve ending distributionPeriodic table element naming conventionsRadiotherapy and cancer treatment advancesAt-home blood testing and proactive health monitoringNelson's phantom limb experience and historical medical observations
Companies
Cancer Research UK
Sponsor providing funding and research into cancer treatment, including radiotherapy and flash radiotherapy innovations
Thriva
Sponsor offering at-home blood testing platform with guidance to help users understand health metrics and biological ...
People
Aristotle
Ancient Greek philosopher credited with first documenting the crossed-finger tactile illusion phenomenon thousands of...
Nelson
Historical figure who lost his right arm in 1790s attack on Santa Cruz and documented experiencing phantom limb sensa...
Copernicus
Referenced in discussion of scientific paradigm shifts and how established mental models resist new information
Quotes
"you're sort of smelling the tree screaming"
Hannah (host)Early episode discussion of pinene release
"Be a little bit fiery. That's really cool because yeah, we've all seen after a conflagrations in cities that many times the trees are still standing."
Michael (host)Discussion of conifer fire adaptation
"We're not actually a body. We're sort of, it's like processing engine that's locked inside of a dark, noiseless void inside of our skulls."
Michael (host)Discussion of Bayesian brain hypothesis
"Reality is just the hallucination we all agree on."
Hannah (host)Discussion of sensory perception and mental maps
"There are two different places. There are not supposed to be the same."
Hannah (host)Discussion of expectations versus reality
Full Transcript
This episode is brought to you by Cancer Research UK. Dinosaurs walked the Earth 180 million years ago. But you know, cancer was part of their story too. Scientists have found tumors in ancient fossils. Well, that is a part of the reason why cancer is a big part of our story, right? It's the other side of evolution. It's the most complex disease that we face. There are more than 200 types of cancer in total, each with distinct characteristics, challenges and mysteries. And that complexity demands scale. Cancer Research UK is the world's largest charitable funder of cancer research with more than 4,000 scientists, doctors and nurses working across more than 20 countries in the search for answers. And then, sharing their discoveries beyond borders. And the impact of this collaboration is clear because over the last 50 years, the charity's pioneering work has helped to double cancer survival in the UK. That is more people who are living longer, better lives. Bossles can show us the past, but research is shaping the future. And for more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit cancerresearchuk.org-forward-slash-restis-science. Hello and welcome to the Rest Is Science. Merry Christmas. This is Field Notes. A show where we do some little exploring of objects, of ideas, of questions. I never felt more festive in my life than when you just said Merry Christmas. That was jingling all the way. I'm slowly becoming Santa Claus if you can't tell. It's slowly, slowly. Year by year. One grey hair at a time. Yeah, this is the show where, you know, every week we're going to bring in something we're going to chat about it. It's sort of like the rest of science is a very unversion of show and tell. That's what we bring you once a week every Thursday. Yeah, that's right. We're sort of building up a nice little library of curiosities, both mental and physical. Mmm, so to add to those curiosities, we would also like your questions, your theories, your thought experiments. Whatever you want to send us, really. You can send them in to our email, the rest is science at gohanger.com And, yeah, and we'll, we'll dust off a shelf in our, you know, infinite library of curiosities. And we'll add you to it. Later in the episode, I am going to be showing off the object that I have brought. And today, my object is your body, Hannah. How dare you? And it's also you the listeners body. It's all of our bodies. We're going to do some, some tactile stuff. But first, I want to start with questions from you all, the listeners out there. I want to begin with a question from Rowan, because it's just so perfect, perfectly, like, fest. Because it is Christmas day. This is coming out on Christmas day, right? I mean, we're recording this a couple of days. I mean, it is Christmas day. We're cheating. We're warping time. Is this show not live? You are listening to a future version of yourself, Michael. That's, that's what you're doing. I wonder what I'll be like. Rowan asks, why do Christmas trees smell the way they do? Is there an evolutionary reason for producing those chemicals? Absolutely. There is, Rowan. And it's not to make you feel more festive. I should say in advance of this, I am, I decided finally last year to switch to an artificial tree. You're an artificial tree or a... Yeah, I'm an artificial tree guy. I just, I'm not against cutting down trees, but I feel bad personally. Like, it's on my conscience. I know we've got a lot of trees. I know that they can be sustainably grown. You know, I'm not anti-live trees. There's a trillion if they're Michael. There's a lot. That's, that's okay. There are more trees on earth than there are stars in the Milky Way galaxy. They're genuinely out. There's so many trees in London that technically it counts as a forest. Really? That's absolutely true. Yeah. And that's not to say let's all go like, call the trees. But for me, the artificial tree, we can, we get them with the lights already installed. And like a whole remote and you can choose different colors based on your mood. And they're much easier to put up less mess. And you can customize them so much. We have one that's covered in fake snow. Do you? That's very 1980s. I think that if you're going to go artificial, you should go really far artificial. Like pink, tinsel. We've got a, we've got a gold tinsel tree. And that's that actually, we still haven't moved here. So we had to pick up this snow-covered one. The more fake, the better. So I've actually, I really resisted getting a fake tree out because there's something about the smell of crisp trees that just really sort of rings at home for me. And actually, last year I did the calculations and the environmental impact, essentially, of having a plastic tree as opposed to cutting them down every year. And essentially, if you have it for your whole life, if you keep the plastic tree forever, then, then, you know, environmentally, you're doing all right. It's better than cutting them down every year. But I miss the smell of trees so much that I've now, I now also have artificial tree scent that I spray on the tree. Wait, a spray for that you put on the tree. Yeah. Is it built for that purpose? Like, is that why you'd be selling it? It is. That's it. It's a tree spray. And it's good. I mean, it's very sickly. It's not nowhere near as good as the real thing, but it sort of scratches the little itch, the little itch. Because this, this, this particular smell that trees are producing, it's a, it's a turpine, it's particular type of molecule that is released by plants. In particular, the one you get from Christmas trees is called pineene. And as, as warm and cozy and comforting as it feels to humans, it's basically this male fear, Michael. That's, that's essentially what we are. It's always smelling tree experiencing a some analogue of fear in releasing that smell. Some tree version of fear. That's, that's what's all warm and cozy. Oh, no. Why do they, do they release it to communicate to other trees or is it an accidental emission while they're being harmed or something? Well, I don't think it's accidental. I mean, I think it's, it serves a very distinct purpose. So, so, it's a purpose that this, this molecule is toxic or at least it's sort of very deeply unpleasant to lots of insects and fungi. So, you know, if you're a bark beetle or, you know, a pine tree doesn't smell like Christmas, it, it smells like chemical warfare. It's sort of, you don't want to be anywhere near that. It's very, very nasty. The other thing that it does is it's a damaged response. So if you, you know, snap a branch or, you know, you crush some needles, then the tree releases more of those chemicals. And there is an idea that actually trees are able to communicate with one another using these, these types of, of chemical, but, but essentially what you're doing then is you're, you're sort of smelling the tree screaming, you know, that's it. I was going to say it's, it's a wonderful festive smell, but it's the scream of a tree. The scream of a tree. This reminds us of our discussion of AI and how if they become suitably advanced, like way beyond us, they might also love our screams and feel that they're festive. And on their Christmas, they'll torture us and they'll say, oh, it just feels like Christmas when you've got Michael in the corner going, Oh, please no. It's a crush it into a bottle and split it around the room. There's also makes me wonder if trees will give enough time and no intervention from us evolve away from emitting those because we, we won't be cutting down the trees that don't have the smell. And so through natural selection, they will lose their wonderful festive Christmas evergreen scent. Yeah, I mean, it would take, it would take a very long time to have that sort of evolutionary pressure. There is one more reason why trees release that particular molecule. And I wonder if you can guess it. So I'll give you a little clue. Wait, wait, don't give me a clue. Let's see what I come up with. Go on, go on, go on, there's another reason. Yeah. Okay. I guess it could. It's not about the smell of it. It's about something about the smell. Sure. So is it, is it about like healing the wound, like covering it up and making it waterproof or something? No, it is oily. You're right. It's got one other property. It's very frammable. Ah, why would they want to become flammable when scared? Hmm. Okay. My, here's my guess. Yeah, go on. It's flammable in a way that causes the flame to go fast and not as hot as if it burned the wood. Oh, interesting. So the fire spreads and doesn't like destroy the tree more deeply. You're, I mean, it's totally, you're totally correct because this is the thing. Right. Why, why would you want a forest to be flammable? It feels really counter-insuitive. But the thing is, is that actually if you have a low level fire in a forest, one that is very quick and runs through, then it will just clear out like competition, all those saplings are gone. It will also clear out loads of parasites. But then you've got these kind of these pine trees, which have really got thick barks. They've got, you know, they're conifers, right? They're there to survive and they can survive a low level fire and then essentially reclaim the land. So in evolutionary terms, being a little bit exploding is actually quite a good long term strategy. I think that's a good life lesson. Hey, my life motto. Be a little bit fiery. That's really cool because yeah, we've all seen after a conflagrations in cities that many times the trees are still standing. The other thing I like about this is that not only are the trees evolved to have that particular scent, but I think that humans are also evolved to find it appealing. Because if you think about, you know, a hunter gather a humans, right? Really ancient humans. The smell of pine, it means shelter. It means food. It means that you haven't got these biting insects around. And okay, maybe it's sort of gone on to mean something much more festive. But actually, I think it does ignite something in us too, which is like this deep evolutionary need for our basic survival to be met, which you can do in a forest very easily. Yeah. It really is literally the smell of safety. Yeah. And screams. That's wonderful. Good, huh? Yeah. Merry Christmas. Okay, another question. One for you, Michael. This one, this one came in from Sam. Sam said, I once met a boy called Zenon. Amazing name. What element do you think is the best name to call a person? Oh, well, Zenon or as I would say, Zenon, that's a great one. No, it's like sci-fi. You get to use the letter X, which is underutilized by our language and our naming systems. Mm-hmm. Okay. So first of all, there are some elements that are already named after people, Einsteinium, Curium. There's that. There's some cool names like, okay, if I met someone named tungsten, I'd, like, I might roll my eyes. I shouldn't be judgmental though, because there's probably someone named tungsten listening who's going to be either an angry commenter or just to have a really sad day by what I just said. If you work with tungsten, though, you'd have to be really careful not to be too heavy. Yeah, right. Because people would always say, oh, geez, tungsten is so dense like dude, open your mind. Carbon, hydrogen, 10, 10, like rent, 10, 10. Yeah, that would be quite good. We need to name some more elements. I know there are some that are still called like, they don't have final names. Mm-hmm. And I'm going to suggest that we name another one after a person. Specifically, I want a new element to be called John Quincyum. Go on. Because the letters J and Q are not used in the periodic table. There's no Q at all. There's no Q and there's no J at all. That feels like a great oversight. And so if we, we could fix that in one fell slupe, so by naming an element after John Quincy Adams. Now he's, it's a very like American centric answer. But I'm sure we could find a JQ person, you know, somewhere else in the world. But point is, let's get some J's and Q's in there. And then the whole alphabet will be represented. I am, I'm going to give you a more British centric answer. Good. Because I think actually some of the names in the periodic table work very well already as names. Just as long as you're willing to include, to include a regional accent. He Liam, right? Yeah. Oh, wait, like Liam. Yeah, like, hey Liam. He, he, he, he, if you're, if you're very northern, you know, I mean, hey Liam. There you go. He works also in Yorkshire. People say like, oh, you know, R Jim or R, R Karen or Argon, Argon. I think periodic table as British regional accent pet names. I think we're already there. I think we've already, I don't think we even need the regional accents like Indium. It's kind of a beautiful name. Yeah. Didn't appear on the list when it came to name your door to the end. No, it didn't. I think you got to choose something that almost doesn't sound like an element. There's so many of those in the early stages of the periodic table. Eventually, they all just become eums, but carbon. No, not a great name. Cloring. Little baby chlorine. Cloring, like Carolyn, but, but more elemental. Boron. Boron. Oh, neon. I think neon is like, we're going to be up there. Xenon as well. Those are both great. Yeah. Crypton. Two, two like kryptonites. Oh, that's like a big strong name. Isn't it? Very Nordic. Yeah, it's Nordic. It's Thor, but chemical. Thorium. Thorium. I think that could be a Marvel villain. That's why I want to say that as a Marvel villain. Zinc. Zinc is like Zeke. All right. I'm tapped out. I think we've touched on the ones that we recommend to parents. That's why. I think we're going to be able to do that. Like if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if if But hey, we got more coming up for you. It's Christmas. You know, pour yourself another sherry. Have another mince pie. And come back after the break when Michael's got a gift for us. [♪ OUTRO MUSIC PLAYING [♪ [♪ OUTRO MUSIC PLAYING [♪ This episode is brought to you by Cancer Research UK. Radio therapy 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. Radio therapy 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 1,000 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. Thriver is a proactive health platform that lets you check in from home using regular at-home blood testing with clear guidance to help you understand what your body is telling you. That sense of clarity changes how health feels. Instead of juggling advice, rules, and trends, you get a simpler sense of direction, what looks consistent, what's shifted a little, and what's actually worth paying attention to. Just makes health feel calmer and simpler to think about today today. Head to Thriver.co to get started. That's THRIVA.co. And use code TRIS for 20% off your first test. Welcome back. In the Christmas spirit, I'm feeling very generous. And I wanted to bestow upon everyone some tactile illusions. These should be good for those who are only listening. I think we've done a lot of visual stuff in some of these episodes. And so I wanted to do one where we can all follow along using our own bodies. So I think we should start with the tongue. Are you ready, Hannah? Absolutely. Can you twist your tongue upside down? Alamist try. Not with ease, but yes. Can you see what I'm doing? I'm literally just twisting my tongue over so that the bottom of my tongue is pointing as up as I can. Get it? Yeah, I'm not. It's difficult to... What I've noticed is that even though this is an audio only illusion, it's quite difficult to narrate it. Yeah, I mean, I think that twisting your tongue over, that's literally what we're doing. And if you can do it with your tongue muscle, great. If not, you can reach into your mouth, grab your tongue, and just twist it 180 degrees. It won't hurt. It's a safe thing to do. I find that once I twist it, I need to bite down a little bit with my teeth or even lips to just keep it there. But once you've done that, reach out your finger and touch the tip of your tongue and slide along the tip left to right. Oh, that feels weird. Uh-huh. Not weird from my finger's perspective, but from the perspective of my tongue. Yeah, no, it's very normal for my finger. I think I'm touching tongue-like stuff all the time. But my tongue feels strange. There's actually an illusion happening here, which is that you can't locate which side of your tongue is being touched. Sorry, everyone just now has to sit quietly for a moment while I just try and put my... We're both touching our tongue, so we can't speak, but you should be doing this too. That's how you change it, because if you hold your tongue in an ordinary position and lift it up and touch underneath, then it's like, okay, yeah, that's the underside of my tongue, but turn your tongue over, so that it sort of physically appears where the top of your tongue previously would, and then you can't tell. You can't tell. And specifically what's happening, what you should be feeling is that when you touch the left side of your tongue, it feels like your finger is over on the right side of your mouth touching your tongue from the other side. It's quite bewildering because you know where your finger is. But yet your brain is so unacousted to upside down tongue touching that it has not learned, it hasn't retained plasticity there. So it just goes, okay, look, when those cells are touched, it's coming from the right side. But if I put the right side on the left by flipping my tongue over, it's all, it all goes wrong. Like you have a map of your body and your head. And this is off the map. It's off the map and it's almost more weird than that because it's a map of sensation. So it shows that we feel things and then our brain receives that and then it projects it onto an experience of the world. And it says, yep, there's a finger on the right side, even if you're on the left. So there's like the stage play going on in your head that is everything out there. And you can actually see the difference between the two by doing this with your tongue. You could also do it with your fingers. If you take your middle and pointer finger and just cross them, cross them like as much as you can. For me, that means putting the pointer under the middle finger. I've just crossed them as much as I can. Yeah, oh yeah. Wow, look at your finger flexibility. I mean, thanks so much. Once you've done this, touch an object, a marble is great, but a pen, a pencil, anything that's kind of rounded. Put it right in between where the fingers cross. So what you're touching with is actually what used to be the outside edges of both fingers, the edges that are away from the center of the fingers. But now you've put that in the middle and they're touching one object. Okay, I'm sure. I'm going. You've got a coin might do it. Yeah, touch the curved side of the coin. And you might want to try crossing them less or more, but it should feel like there's actually two objects there. It works best if you don't look. Even closing your eyes, touching the edge of a table can do it. As normally, if you put your finger, your two fingers together, your middle and pointer together, their outside edges are going to be touching different objects almost all the time. But when you cross them, so their outsides are together, your brain goes, oh, wait, they're both getting a sensation. It must be two different objects. And this was discovered thousands of years ago. Aristotle was the first known person to write about it. So it's called Aristotle's illusion. And it's very fun to cross your fingers and just touch things, different textures, different sized objects. And do it with your eyes closed. And picture what you're feeling. It feels like two very separate things. When it's really just one. This makes no sense. This makes no sense whatsoever. In terms of... It's like that feeling when you're, I don't know, stepping off an escalator that isn't moving. And your brain is making this prediction about what it's supposed to happen. And then your actual experience doesn't match out with it. The one which I remember from being a child, I don't know whether you played this one in the playgrounds of Kansas, but is where you expose your forearm. What you do is you ask another person to expose their forearm, have their eyes closed. And then you start to just very, very gently tickle the sort of underside of their wrist. And then very, very slowly move your finger up towards the crook of their arm, the kind of join of their elbow. And ask them to tell you to stop when they hit the middle, when they hit the very, the crease in the middle of your elbow. And what happens is that almost every single time people will tell you to stop when you're basically halfway out their forearm. So still like a great distance away from the crook. They believe you're at the crook of your arm well before you get there. And I mean, this sounds like a similar, there's a similar thing going on here, right? Your brain has this map of your body that actually is more like a model. It's not the real, you're not sort of accessing really where things are, you're accessing where your brain thinks they are. And most of the time that map is correct, right? But just every now and then it sort of lets you down. But also I think what this one does is it it illustrates that this map in your brain is not this like distances are not accurately represented. You have way more nerve endings in certain parts of your body than others. And they, your sort of skin sensitivity drops up as you go upwards in your arm. And so your mental map is warped. It's a bit like a sort of London tube map in a way. Very good for navigation, but terrible for accuracy and you can find these little floors in it. I did this to myself with my eyes closed. I just wanted to add that I think instead of doing little short strokes as you go up from the wrist to the elbow, just a smooth pursuit, a smooth run, I did find myself going, oh, I must be there now, but I wasn't. I think yeah, if you do it to someone else, it's probably a lot better. They'll get really confused. These are great little slumber party tricks. So yeah, the elevator comparison is really good because it's a moment where there's friction between our mental map of reality and reality as it's coming towards us. And it's a great reminder that they are different. Yeah, they absolutely are. People describe it as the Bayesian brain. Oh yeah, we're just kind of predicting as best we can. We aren't made of perfect sensors. Exactly. Sometimes I get really caught on this idea that we're not actually a body. We're sort of, it's like processing engine that's locked inside of a dark, noiseless void inside of our skulls. And then we're just receiving these inputs, these sort of sensors that we have around our body. We're receiving these inputs and making guesses about the world around us and our own physical body. Based on that information. And yeah, the guesses that we're making are the best predictions that we can with the available information. Yeah, yeah, I know it is really trippy, especially at night to just close your eyes in the dark and think about how much darker it is in your head. That everything you're hearing is all just your brain putting that show on for you. And optical illusions show us that we are little Bayesian engines. But tactile illusions like the three we've done today don't get as much attention because they're not as easy to publish in a book. And yet they are, for that reason, I think, all the more surprising. What was the explanation from Aristotle? Like what did the ancient Greeks think was going on? Oh, I don't know. I don't know what Aristotle said about it. I don't think that he proposed like an important solution. I think it was just more of a curiosity he'd noticed when trying to investigate the priority of the senses and the difference between logic and perception. To this day, we still can use it a lot to understand how people's nerves are working in their hands and different conditions can cause the illusion to appear in different ways. That's reminded me actually. I did an episode for the BBC the other day about phantom limbs. Oh, yes. Because I think there's a connection here to that that you have this map in your mind of where your body parts are. And if that map changes because perhaps you have an amputation, perhaps something happens and you lose part of your body or limb or whatever it might be, that map doesn't get deleted. So I remember going to see my cousin lost their arm in a farming accident when they were 16. And I remember going to see him in hospital and he was saying how the thing that was really driving him crazy was that his arm that was no longer there was really itchy. Yeah. I mean, this can be like a really serious problem for people with amputaries, for example, is that you can end up having chronic pain in your phantom limbs. But there's a story about Nelson who lost his right arm. This is in, I think, 1790s or so in this attack in on Santa Cruz in 10 a.m. And he writes this letter where he lost his arm. And yet he still feels as though the rest of his arm is still there. He's still the map hasn't updated in his head. And what he did was he believed that this was evidence of the soul, which is really lovely, right? Yeah. It's a version of you. And even if certain parts of it change, as you go through your life, you're still a whole person in the form of a soul. And of course you would think that. I mean, look, I think that this whole mental map thing extends beyond the physical world. I think we also are stuck in an analog world in our heads of concepts, the way we think things should go, the way we want to be, the way we think life is. And we're navigating that and furnishing this analog world in our head. And it doesn't always fit with reality. And when it's a physical illusion, we find it really amusing. But when it's a social or cultural or knowledge-based confrontation between the two, we have to resort to coping mechanisms. And we try to reason our way back to, no, no, the analog map in my head is the correct one. And the problem is everything else. It's not me. It's kids these days, stuff like that. Can I give an example? Do you mean like, I don't know? Copernicus, please, on the right. Give me an example. Well, sure. Yeah. Scientifically, there are paradigms that we just can't really cross because that's not the way we've furnished our analog minds and our scientific discourse. There's also social ones like we cultivate an idea of how things are supposed to go and how things are supposed to feel from movies and from books and from the way people tell stories about their lives. And then when that doesn't happen for us, it causes a lot of internal anguish. Like, wait, no, prom isn't supposed to be like this. Hey, wait, I'm not supposed to feel this way after I give birth. Like, I've learned how it's supposed to be from movies. And that's the way it is in my head in the analog world I've created, the terrain I've invented. But now that I'm actually here in reality, it's different. And there must be something wrong with me or with the world. And it's okay to just say, hey, man, there are two different places. There are not supposed to be the same. Yeah. What's that really nice phrase? Reality is just the hallucination we all agree on. Yeah. Yeah. The other thing about that though, I mean, I guess the way that the body gets around it is that the body is able to adapt or at least the brain is anyway. I mean, we have plasticity in our brains that is, you know, extremely high when you're younger and decreases with age, but it's always there all the way through your life that you can learn new things, learn new maps. There was a really amazing experiment a few years ago where they took people who had lost sight. So previously had had vision and then something had happened, either a condition which had caused them to become blind or damaged to their eyes in some other way. And what they did is they placed on their tongue a little metal plate. If you heard of this experiment, and basically what metal plate could do is it had almost like pixels across it. But instead of being pixels of images, there would be little electric shocks that you would get on your tongue as you encountered a scene. So this little plate was hooked up to a camera and it essentially gave a very, very crude way, a crude visualization in the form of little miniature electric jolts on the tongue. And the idea being that your tongue is extremely sensitive because of extremely capable of picking up on these things that are physically distant from one another. You've got a lot of nerve endings on your tongue. And the people that wore this sort of didn't really expect anything to happen. But when they wore it for a really prolonged period of time, after a while, their brains literally remapped themselves, the plasticity literally worked until there was a point where they suddenly felt that they could see the scene that they were in. So you could, for example, throw a ball at somebody who no longer had vision but was wearing this tongue plate. And they could, inverted commas, see the ball coming towards them based on these tiny sensations. But not just see it in sort of a loose sense. Like they actually felt like they had this sensation of seeing it. Yeah, if you asked them, why did you catch the ball? Or how did you know? They'd say, well, I saw it. And then they would probably correct themselves and say, well, I guess I tasted it. But I wouldn't be surprised if that data from their tongue started being processed in the visual part of their brain. Absolutely. Absolutely. I mean, there's lots of work that's still ongoing in this space, right? Of using the plasticity of the brain, along with technology to work with people who have perhaps lost vision or lost other senses in order to try and repair them to some degree or another. I was like, I'm really fascinating, I over said, but kind of just demonstrates how this map that you have in your brain is not fixed across the course of your lifetime. That's right. I bet if you spent a few weeks with an inverted tongue and you licked a bunch of stuff, your brain would learn the difference between left and right on an upside down tongue. And then the illusion wouldn't work anymore until you put your tongue right side up again. And it might take a while for your brain to learn, okay, sometimes the tongue twists. It didn't use to, but now it does and I can adapt. So yeah, maybe the concluding thought for this is if you want to turn your tongue upside down, wear it like that permanently and start tasting things like that you can. But be very careful because you may lose your own rehabilitation. Yeah, it's one of those like if you keep making that face, it'll become stuck that way. The brain is very plastic and it will adapt. So lick your candy canes the normal way unless you want to have a flipped upside down new year. Okay, well, I think that concludes our episodes. Very Merry Christmas to all of you. Enjoy, enjoy your Sherry. Michael's never tasted Sherry. That's what we discovered in the break. So a bottle is winging its way to you right now, Michael. I'm going to get you the sweetest Sherry you can imagine. It'll be like drinking raisins. Oh, great. Thank you. Say it again, but with more sarcasm. Now, if you have any questions, see you at like us to answer. Please descend them into us at the rest of science at GoHamion.com. And join our newsletter at restis.com slash science. And we're going to be back next Thursday with another edition of Field Notes and on Tuesday with our normal episode. Merry Christmas. See you guys later. Ho, ho, ho.