How is science fiction like a cultural research and development lab. Will we someday have AI agents that live inside robot bodies? And will we be liable if they commit murder? What happens when reality itself is no longer verifiable? How do we create AI agents that guide us towards survival and self actualization, not just profit or distraction? And what is
the Young Lady's Illustrated Primer? This week we talk with researcher Bethany Maples about science fiction and how it might prepare us to wrestle with the deepest human questions about AI and identity and the future of humanity. Welcome to Innercosmos with me David Eagleman. I'm a neuroscientist and author at Stanford and in these episodes we sail deeply into our three pound universe to understand the hidden forces that shape our lives. Today, we're going to talk about science fiction.
So imagine this. It's nineteen sixty six and you're watching Star Trek on the television, one of those cathode ray tube televisions with a bubble screen. Anyway, what you're looking at is Captain Kirk and Spock, and they're interacting with a cool looking machine. It's a thin slab of glass and metal that can display anything, including a person at a distance talking to a camera. It's like a telephone call,
but you can actually see the other person. Now, for the audience in nineteen sixty six, this is science fiction. It's pure fantasy. But for a generation of engineers and inventors who are just growing up and tuning in, it was a blueprint. Fast forward a few decades and we all have tablets in our hands every day, and even smaller tablets called smartphones, and we never stop to think how fantastical this would have seemed to our great grandparents.
So that's the thing I want to explore today, because quite commonly science fiction anticipates the future, or more specifically, it lays down the tracks for it. Now, if you're a regular listener, you know that I am a lover of literature more generally, because literature expands how we see ourselves,
but science fiction in particular often prototypes futures. We often think about sci fi as escapism or entertainment, but when we look more closely, we can sometimes see it as a testing ground for society's biggest hopes and deepest fears. It's the stage where we get to rehearse what might be, and sometimes we end up waking up inside worlds that
novelists and filmmakers imagined a long time before. For example, today we'll talk about Neil Stevenson's Diamond Age, which features an intelligent self writing book that can raise the child, or we'll talk about Spike Jones's movie Her, where a lonely man falls in love with his AI operating system. So science fiction gives us a lens into the future and whether or not it's a reliable oracle, which it sometimes is and sometimes isn't. It always lets us ask
what if? What if your AI companion wasn't just a distraction but an advocate for your very best self? What if technolog didn't just change our tools, but changed what it means to be human. It allows us to stretch our brain's internal models. So that brings me to my guest today. My colleague Bethany Maples runs an education company
called Atypical AI. I first met her when she was a researcher in education at Stanford, where she studied the rise of personalized AI agents like AI tutors or learning companions or lovers and how these things are changing us. She recently published a paper in Nature on loneliness and suicide mitigation using GPT chatbots. In other words, can having an AI friend actually save a life? The answer was yes.
Check that out in episode ninety eight now, when Bethany first started talking about a world where a billion people might form indispensable relationships with AI agents, that certainly seemed like far off science fiction. But it's not. It's actually the present moment. And that's exactly what science fiction does. It normalizes the impossible so that when it finally arrives, we recognize it. So I got Bethany here again today
because she is a giant fan of science fiction. She and I both feel that science fiction is where society's write down their deepest dreams and hopes, like our longing for immortality or companionship, or invisibility or mind reading or flight. These are all very ancient human fantasies. They show up in myths and in fairy tales. Then they get retold in futuristic novels, and sooner or later they inspire the labs and the startups that try to make this stuff real.
So today we pick up that thread because if you zoom out. Science fiction has always been less about rayguns and aliens and more about testing the questions of who we are and who we might become. Here's my conversation with Bethany Maples. You're a fan of science fiction. Tell us about how you think about science fiction and how it can be used in our current world for the planning we're doing now.
You know, science fiction catches a lot of flack.
People don't think it's a deep medium, and I think it's just like light entertainment, and that is trashy. But I deeply believe that science fiction tells us about the deepest dreams and hopes of society. So operating with that, let's think about what science fiction tells us, and let's look at history and see how much science fiction has guided and predicted and created the technological magic that we see today.
That's right. What's an example of that? For example, the tablets and star Trek that became the iPad precisely.
So think about that, and think about you know, the Young Ladies illustrated primer from from the Diamond Age.
Great, so I've read that, But for the audience, tell us about that.
For the audience, there's this book around this really strong AI agent that's embodied in a book that is able to take anybody, the poorous street, urchin, anybody and make them not only you know, maybe.
Wealthy and rich, but the best possible version of.
Themselves because it tutors them, it leads into life lessons, all.
Of it, and it does it in this beautifully intelligent way. It's not just mechanical and wrote. It interacts with the real problems that's happening in their life. It's able to intercede. It brings in characters, it brings in fairy tales. It uses all of the things that humans use to create meaning and teach and just using them beautifully. And of course there's a human in the loop. It's not just an AI agent. It's like combining people they actually care.
So that's an example of you know, the precursor book to all of these AI tutors. Like the number of people in Silicon Valley that have been thinking about building the Primer and building the primer versions of it over the last decade are many.
I didn't realize anyone was building something like this. I mean, obviously the technology that we have with AI, we can squint and see how it could become something like this. You're saying, people are actually working on the Ladies Illustrated Primer, well.
Versions of it, right, I mean you know, I I started thinking about this actually when I was studying neuroscience as Stanford back and my masters.
I was like, what would it actually take, Like, what's.
The learning science theory, what are the sensing mechanisms, what actual algorithms and like modules which you need?
And I mapped it up and then one of.
The most senior people Google called and said, Hey, I've always wanted to build.
This, Come build this with me.
And five years later at Google AI things happened.
Wow, and remind me the Ladi's Illustrated Primer was a book that she carries around it physical and she opens it up. But remind me that the text always changes the illustrations.
Yeah, it's a dynamic narrative, but it also has like you know, an accelerometer and aultimeter, like had all these sensing mechanisms so that it could actually like interact with the world around you. So look, a book might not be
the exact like right embodiment. Up until now, education has been, in fact, this incredibly thin slice of learning, right you go to a room and you learn, and you're not able to connect the variety of inputs that actually makes a life right, all the informal learning, all the social stuff, all the peer things, like all the hormones. And imagine that you were actually able to bring that all together and have an agent that cared deeply for you and
loved you, that was guiding you through. I mean, that is like the height that we're trying.
To get to. That's right and remembers everything you said and doesn't have any other concerns and let your personal best exactly.
And I think that's what is tough is we think about AI companions, is that a lot of these AI girlfriends and companions, they're there for entertainment. They're not there for your personal bests. And so there's this Nirvana's day or this thing that we all know that we want, which is an agent that actually wants us to be the best possible version of what we can be. But the disconnect or the question is how do we get
that into everybody's hands. Because people are going through so much shit, they're just trying to survive, they're poor, they're hungry, like they don't have power, so how do you help get them to a place where they can learn? And at first that book that the primer just helped what's her name, lil just help the protagonists survive. So as we think about, you know, AI helping each of us individually, it's not just like, hey, I'm going to be a tutor, it's like AI that's going to help me survive.
So why are there more companies doing that? Right now? We're saying we want to build an AI that is your advocate, that just cares about you, that makes everything about you the best that you can be. Are their companies doing this?
The reason that there's not more is it's both an incredibly challenging build and people don't always want to be the best version of what they can be. They don't know it right, as we said before, they're just trying to get through the day. And this is what makes AI companions such an interesting entry factor because everybody needs a friend, and if you can have an agent that starts as your friend, it ends up being your tutor
and your advocate for your higher self. That's beautiful. But the issue from a commercial perspective is how do you monetize that?
Oh interesting? Oh right? Because people won't pay in advance or something like that.
Yeah, and frankly, you get into a VC like kind of rat hole where you know, they're like, oh, like monetize now, monetize now, and you're like, no, it's a trillion dollar opportunity. Let's just get people to engage. So I think that more and more people are thinking about this.
I wonder if somebody in the distant future, along with having universal basic income, the government would pay for your advocate to make you the best you could be.
I think that they should.
But the only way that works is if the government has none of that data, none of that data's tied to your insurance or your healthcare or anything like that, you feel completely safe. So I know that companies are thinking about this. All the big tech companies are thinking about it, and a lot of the AI labs are thinking about it. But again, you know, there's a lot of commercial forces at play, so doing the right thing in the end kind of gets muddied by needing to sell in the five year time frame.
So let's trace the thread back to the beginning about science fiction. What are other examples the way that the science fiction that you've read influences the way you think about what we can do now.
What we can do or also like what's happening right now. So you know, an issue that we're having in education is deep fakes. You know, both porn deep fakes, which is really disturbing. Students are making deep fakes of each other and it's really disturbing for the victim, and also deep fakes of teachers or deep fakes of kind of any authority figure.
And you see this issue.
Was taken up like decades ago in Player of Games, right, so you know, in this world, deep fakes are you know, prevalent. Everything can be fake, and so the only way to get around it is to have like certified humans that are there in the room able to see what's going on.
And so you know what we're going to see, for example, in education, as everybody wants to start taking these high stakes exams online but you have all this like you know, ability to deep fake, and you know, we're going to go through an arc where they're going to try to create these ubiquitous global, worldwide assessments and everybody's just going
to be like faking in. Everybody's going to be cheating, and we're going to have to go back to small format in the room, like one proctor is looking over your shoulder in order to verify who's there and what's going on.
By the way, is a side note. The thing that's intrigued me about deep fakes is I've been very interest in the legal system, the intersection of science and the legal system, and everyone was worried that people would be introducing deep fakes into the system and saying, look, I see the guy who's holding the gun whatever. But in fact, exactly the opposite has happened, which is that everyone who's caught on camera now goes into the court and says it's a fake. It wasn't actually me, even though it
actually was. By the way, it's intrigued to me that a science fiction writer, let's say, who ever wrote a player of games, could foresee a world of deep fakes, because it seemed so unlikely even ten years ago that you could make a convincing photograph or video of somebody, and now it's so trivial.
But I mean it's been in the collective consciousness for decades. I mean, think about the Holidacks on Star Trek, like we've always dreamt of having completely immersive magical environments.
Yeah, that's right. But faking it and being able to replicate a human and have them do something bad on the camera, that's really unusual. In fact, I was just thinking about the movie Total Recall, which I haven't seen since it was in the theaters a million years ago. What I'm going to try to do this without giving anything away if someone hasn't seen it. But the protagonist thinks he's one person, and eventually he's shown a video of himself doing these other acts and he realizes that
his memory has been essentially wiped and manipulated. And I thought, wow, that movie wouldn't work now, because if you saw a video of yourself doing something, you'd think, well, that's a deep fake. That's not actually me. But in the movie, that was the turning point where he realized, oh my gosh, I used to be someone else. Yeah. So it strikes me that not all authors have foreseen the possibility of deep fakes, and a lot of plot points get thrown out now that that exists.
It's true.
I mean, hearing you talk made me just think about, you know, the issues of AI and self awareness and kind of sovereignty.
So gosh, Blade runner.
Yeah.
Right, Well, everybody's worried that we're nearing actual AGI.
But even if we're not, even if we're just coming to.
A point where we're going to have really strong AI companions and they're gonna have a ton of data and they're going to persist apart from a human And I mean next step, like next year, we're going to have you know, covered in flesh AI robots.
I mean we're already seeing stuff come o.
I mean both from Asia and here where it's you know, it's not just extra skeletons. Yeah, yeah, yeah, you've got soft exteriors, right, So it is it's very Westworld so to speak, right, and they're going to be armed, not just with these you know, task based systems or goals of service. Like it's so easy to put in a companion that you know wants to be your friend or wants to be a doctor, wants to be a therapist, or just wants to be you out in the world. And so you know, it seems far fetched, but I
tell you next year. You know, certainly within five years, issues of you know, liability, agent sovereignty and like web, they're not it's murder is going to be.
In the public eye. But think about this.
If you were to program your dead loved ones memories into you know, an agent, you know, maybe it's just software, and then you put it into an actual body and you're able to interact with it. Think of the emotional distress that will cause you some more to destroy that thing.
Yes, exactly.
You know, as soon as there was emotional distress in the USA, you've got a libel suit.
Yes, quite right, although although in that case, as long as you have a backup, you can just reboot it. Right.
Sure again, okay, this isn't no, this is blade Runner. Well, if you don't have a backup, what do you have to take it with you? What if you can't afford the backup?
Oh right right, yeah, what if it cost an ungodly amount by some vicious company that's trying to profit from it?
And so this is all science fiction. I mean, it seemed far fetched and it's here now.
I know. That's the surprising part. Okay, So what else, Because you're such a fan of science fiction, what else have you read that seems to reflect on what's happening in this in this fast moment in time.
Well, as I said before, I'm a huge advocate of some company hopefully soon changing the dynamics around users privacy and data and giving everybody basically their own data and
like letting the code come to them. And so my favorite example of that heir the e Butler's from Pandora Star right where so everybody has this incredibly strong agent that's kind of a defense mechanism where it stores all your data kind of locally, and then if any system or service wants to interact with you, the code comes to you and it is, you know, making sure that all of that compute and all that service happens locally. And I think it's so powerful and it would be
so wonderful. And of course then you've got like how strong is your agent and it can I preprotect you properly and all that. But to me, that's the best example of what we really want that we're not getting right now.
Fascinating. Do you see a business path to that?
I think that one of the biggest companies in the world will eventually see the writing on the wall and they will up in the market and upend their investors and make the leap.
Yeah, but it will.
Probably be somebody that thinks that they're about to lose. Yeah, you know, so a key player that's like, Okay, we don't have the computer or we haven't you know, we see the other guys or like, you know, leaping ahead because of whatever functionality or investors.
Yeah, so I have a question for you, because you're such a fan of science fiction. I'm a fan of literature more generally. I haven't read that much science fiction, as it turns out. But for example, I heard an interview with Isaac Asimov on Jonah Lerer, which was the show on PBS a million years ago, and asm off this was probably the eighties. He said, Look, I foresee a day when every household is connected to a central
mainframe computer. Everyone has a dumb terminal in their house, and this computer knows all of humankind's knowledge and you can ask it any question you want, you can get the answer. And so he essentially foresaw the Internet. But what's interesting is the technical He didn't get the technology right. I mean, it doesn't matter, but you know, you imagine these cables all going to a mainframe and so I'm fascinated by the way that thinkers can foresee the direction
that things are going. But of course we're always limited by the technology that we have in thinking about it. Yeah, So if you thought about your science fiction bookshelf and how many of the predictions were spot on versus sort of kind of off but mostly right versus totally off, what would you say?
I would say that the why and the what is almost always correct, but the how is often wrong.
Beautiful as you said, Yeah, and so what does it mean about the why and the what? Does it mean that the trajectory of where we're going as a species is is clear enough? If you really sit and squint into the future, you can sort of see the direction.
You can. You can just read any fantasy novel or any fairy tale, like we want to fly, we want to live forever. We want to be to read people's thoughts, we want to be able to be invisible.
We want to you know, like.
All of these superpowers we are directly heading towards.
Yeah.
So, like think about it as an example, you know, spells and the Internet of things. You know, now, through bioauthentication, we're able to get differential access to different places and different functionality and systems.
So I walk down this hallway and the door open, you.
You know, but you say abricateab and it opens. That is a spell. We're going to just see more of them.
Yes, what's the most far fetched thing that you've read in a book that you're seeing evidence for? Now?
Okay, this is going to be a weird one, but hold with me. Whether or not you believe in reincarnation, the desire to live forever.
Is core to who we are.
And there's this amazing book by Kim Stanley Robinson called The Years of Rice and Salt and again without read you know, revealing everything. Guys, you might want to mute if you haven't read it, but it explores what would it mean if we were able to sense our reincarnation and what would happen if we could track our soul like coming back, And when you think about it, there's huge incentives, especially for the ultra wealthy, to be able
to do this. So you're already like, I'm hearing whispers about companies where they're like, okay, you know we're starting now with really crude house. Right, We're like, I'm going to what was that company that was like I'm going to freeze you at the point of death, So yeah, yeah, right, So people are already pursuing very brutal kind of early ways of living forever or being able to reconstitute themselves
or come back to life. But there's this fantasy, and if science fiction and the progression of technology is any indicator, you know, we will move to a point where we might be able to track our soul's reincarnation. And there is so much economic benefit to that. Imagine being able to leave your billions of dollars to yourself.
I mean it sounds crazy, but like people are thinking about it.
Wait, hold on, this requires the existence.
Of a soul, wait, which we can argue about.
We can argue about, but the chance is enough to make people obsessed with the question.
Oh fascinating. But so you might get all sorts of predatory companies coming in here and saying, hey, pay me a lot of money, I'll track your soul, which may be a preposterous thing.
Okay, But then the question is like how much of you has to exist for it to be your soul?
Right?
If we're already saying that we can externalize our intelligence and pass that along, then does it have to be actual flesh or could it be a sufficient amount of our intelligence.
Like an upload?
Yeah?
Yeah, oh totally. Now that's a good idea, and I think uploading the intrigant. There are, of course, all these questions about it that people have filosters have been asking for a long time, which is, you know, if I could upload myself into a computer. And so this other thing wakes up. Is that actually me? It certainly thinks it was me. It says, wow, it's just sitting in this chair a moment ago. But as far as I'm concerned, I'm still going to drop dead.
And there's so much science fiction in that grapples with this ghost on the shell, right, like how much how much flesh or how much essence? Or like, you know, is your entire intelligence equal to even a spark of your natural matter?
You know?
Is the ship of Theseus?
Yes?
The question?
Yes? Well okay, so just for the listener, of the Ship of Theseus is thesis. Ship pulls into the dock, plank rots, it gets replaced, Another plank rots, it gets replaced. Eventually all the planks of the ship have been replaced, every piece of wood that was on it. Is it still the ship of Theseus? In ancient Athens? I look this up recently. About half the philosophers said yes. Half lost said no on this, But it's a deep question
about identity. The modern neuroscience version is if I took a neuron out of your head and replaced it with a metal neuron that did exactly the same function, and then replaced another neud on another and eighty six billion neurons later, sort of a metal robot, is it's still you exactly? Yes, this is the question. I do think that might be a separate question, though, from the upload question, which is, now I start the version of Bethany and a computer over here, do you still feel like you're
having a heart attack and dying? And this other thing is but it doesn't do you any good. It's happy that it's there, but you're not. You don't feel anything about it. You don't feel any continuity.
Yeah. So, the question of what it means to be human and how much our intelligence defines us versus our bodies defining us, is it's happening right now, right, and it's going to happen again more and more and quickly, as we think about liability, as we think about agents that act on our behalf, and as we form and grow these deep relationships with agents that are the ghosts of our loved ones or versions of ourselves.
You know, in a previous podcast that you and I did together, you were talking about this idea of a mirror of oneself, and a lot of young people are doing this, which seems to be very foresighted and mature of them to do this so they can learn about themselves. But yes, as you make a richer and richer digital twin, in a sense, you don't even have to imagine this upload thing where you scan your brain to do it, because in a sense, by the end of your life, you've got a really rich digital twin.
Correct.
Or there's a really great science fiction book about this, the whole the Last Emperor series, I tell you the Emperor with an X. So the emperors or the ruling family in this series implants kind of like a spinal tap, so that everybody in the family is not only having their memories be recorded, but their full like body functionality be recorded, which has typically been the missing piece, right, because we know that our cognition isn't just in our brain,
that it's you know, tied with our gut, and there's you know, chemicals involved, and so the idea was that you know, because they were able to completely track through lives. That then every new impro can have a conversation with their entire family going back through millennia.
Ooh oh oh. Interesting because there's a replica of their.
Very grandfather, and it's able to say exactly how that person not only thought but felt in every moment of their life.
Interesting, you know what I find interesting about that? So it just so happens that I'm my family's genealogist. I've studied the family tree for years, and no one else seems to be that interested. I try to show them the thing, and to them, it's just some names on the page and so on. I do wonder, though, if I said, look, I've got this great replica of your great great grandfather, would they care or would they rather hang out with their friends and play Fortnite? That's it's
an interesting question. If you had all of your ancestry, you know, thirty two sixty four hundred and twenty eight people, would you sit and talk to them or do you think, oh boy, I got more relatives to deal with.
Now I'm also my family's genealogist, and I think about this as well, And my conclusion is that people care less about facts, but they really want to know how their ancestors felt. If you could find out that your great great grandfather like also felt this driving need to you know, look beyond the horizon and was never like happy in one spot for long, that would give you great understanding about kind of what it means to live
as a human today. It doesn't really matter what the fact is, but that like chemical experience, would really change people's understandings of who they are.
We're really going off track here.
I like it. This is great because so the class that I'm teaching, it stands for this quarter is literature and the brain. And there's a lot involved in this. The starting point is my fascination with the fact that the way we study the brain is looking at Okay, here's how the visual system works, heres out, audition works, here, touch arks, and but what is never talked about is how easy it is for the brain to completely go
off track and be someone else. So I open Game of Thrones and I am John Snow or the next chapter, I am Denaros Targarian, and so on. We can just slip into other shoes so readily, and the story of neuroscience and every textbook that we read is you know, it's all about in mutual information and finding out exactly what you're hearing and seeing, but it's not somehow we're so easily able to slip on other identities. So that's
fascinating to me. But one of the jobs of literature is that it allows us to experience broader worlds or be in situations that we would never be in, and we get to learn from those situations. And so what's interesting about science fiction is really stretching that out and really trying things out at a very different place, at
a different scale. And you'd get the same thing if you met your grea great grandfather who got to tell you about something that was really meaningful in this is era which is totally removed from yours, but you'd get to really experience something, oh.
And understand how he made meaning because, as you know, your upload download rate doesn't really matter. We create memories through meaning and through narrative, and that's kind of inherent kind of how our memory works. So I have this debate with my friends at neuralink where I'm like, really, will the upload download rate really like make us superhuman?
Or will a brain computer interface much more likely be one in which we have an agent in our head which we are conversing with because in fact, that's how we process information better we create meaning we're dilgic, we ask questions, and that that will be the memory augmentation versus some kind of I just learned Kung Fust the situation.
Oh, I love that. Are there any other science fiction books that you've read that you feel like this really shines an interesting light on where we are right now in twenty twenty five.
Dune is an epic book and an epic series, and of course Denny made an epic set of movies around it. But I think one of the reasons that it is capturing the public imagination right now is because it is all about that tension between kind of physical and social striving and being your higher self, you know, like can you actually become like an evolve into being better humans?
And there's a lot of oil politics in there, and I'm going to show those aside for a second, But to me, the core theme of Doom is around human evolution and using meditation and using all of the different skills that we have from all the different you know, veins of knowledge throughout the world to naturally evolve ourselves. That's what the been a guess er it did, right.
So if anyone who hasn't seen the movie or read the book or read the book, give us the quick stuff.
Okay, So the quick summary is, in this wonderful space opera far funk future, they've outlawed thinking machines because they had some bad running with killer machines, and so they
focused on natural human evolution and augmentation. And there are some specific groups that have started to use basically yoga, meditation, memory techniques, somatic dreaming like you know, hyper awareness, as well as you know, psychedelic substances to dramatically expand and increase the scope of their capabilities.
And you see people's doing it now.
I mean this has frankly been something that we've done in you know groups around the world forever, but there hasn't necessarily been a you know, a an effort around it for intelligence augmentation.
Oh you see echoes of that.
Well, Dune is very important right now as we have new technology coming online, an awareness of how different techniques around what we eat and how we meditate, how we use our memory can produce you know, longer life can slow aging can inc intelligence, And there's this tension right now around are we going to be able to do any of that naturally or are we going to have to hand it off to machines.
That was my conversation with Bethany Maples. So let's come back to where we began. In nineteen sixty six, Star Trek put glowing tablets into the hands of its characters, and decades later, engineers turned that fiction into fact. That's just one example of what we've been circling today, the way that science fiction becomes a rehearsal for the future. Now, it would be too simple to say that science fiction
is prediction or prophecy, because it often gets things wrong. Instead, I think it makes sense to say that it's the place where we write down our collective hopes and fears, our dreams of flying, of reading minds, of living forever, of building companions who will never leave us. And by committing these things to the page, these ideas have a chance to blossom. They plant seeds in the minds of young people, and they go on to build the technology
of tomorrow. And when that technology finally arrives, whether it's AI tutors or digital twins, or companions that blur the line between friendship and therapy whatever, we often feel a sense of deja vus. Haven't we been here before? Yes, but only in the pages of a novel or in the flicker of a movie screen. So as we wrap up, I'll leave you with this thought. Sometimes the stories we tell are more than just entertainment. Every once in a while, the novels on your shelf and the shows on your
screen are a way to move ideas forward. And so the next question becomes, what stories do we want to tell now? Because if science fiction has a way of becoming real life, then all of us, all the writers, the readers, the engineers, the visionaries, we all share some responsibility. We are all collaborators in building the future. Go to Eagleman dot com slash podcasts for more information and to
find further reading. Send me an email at podcasts at eagleman dot com with questions or discussion, and check out and subscribe to Inner Cosmos on YouTube for videos of each episode and to leave comments until next time. I'm David Eagleman, and this is Inner Cosmos.