David Christian on A Big History of Everything

We think things that hold us back and dampen our spirit. But it's not just about thinking. Our actions matter. It takes conscious, consistent and creative effort to make a life worth living. This podcast is about how other people keep themselves moving in the right direction, how they feed their good wolf. Hi friends, if you're looking for a free and easy gift, consider sharing this show with someone you know. It's a gift to them, and it's a big gift

to us. Happy Holidays to you from the One you feed. Thanks for joining us. Our guest on this episode is David Christian, a distinguished professor of History at Macquarie University and director of the school's Big History Institute. He co founded the Big History Project with Bill Gates. David has delivered keynotes at conferences around the world, including the Davos World Economic Forum, and his TED talk has been viewed

more than seven million times. He's the author of numerous books and articles, including the one we discussed on this episode, Origin Story, A Big History of Everything. I David, Welcome to the show. Hi. Yes, I am very happy to have you on. Your book is called Origin Story, A Big History of Everything, and it is a wonderful and fascinating book and I loved reading it so much, and we're going to get into a lot of mind blowing details from it here soon. But let's start like we

always do with the parable. There's a grandfather who's talking with his grandson. He says, in life, there are two wolves inside of us that are always a battle. One is a good wolf, which represents things like kindness and bravery and love, and the other is a bad wolf, which represents things like greed and hatred and fear. And the grandson stops and he thinks about it for a second, and he looks up at his grandfather and he says, well, grandfather,

which one wins? And the grandfather says the one you feed. So I'd like to start off by asking you what that parable means to you in your life and in the work that you do. It's parable, of course I agree with it, But I also think, like whenever we think in dualities, we actually need to look for a balance somewhere, And the bad wolf is not something I think that we need to eliminate entirely from our lives.

There are times we need the bad wolf. So I might be inclined to agree that perhaps you should give the good wolf a bit more food than the bad wolf. He seems remarkably resilient. Yes, and I agree with you. I don't think starving the bad wolf is really the idea. It's not a very kind thing to do, I think, No, No, it's certainly not. So let's talk about your book. It's called origin story, a big history of everything. So what is an origin story to you? In what way are

you using that phrase? I'm acutely aware of using the phrase in a particular sense, and it's it's like all these phrases. It carries baggage, and it carries different baggage for different people. But for me, what it means is the idea of unifying knowledge, the idea that in all human societies we know of And I think this was probably true a hundred thousand years ago or forty thousand years ago in Late Mungo in Australia, which is where

I begin the book, people told origin stories. That is to say, older people, people who had accumulated some wisdom and knowledge, put all of that knowledge together, and they put it together in a sort of story like form that made it accessible to young people. Now, I remember, as a kid, I grew up in Britain in a Christian culture. So as a kid I learned the Christian origin story in kindergarten, and as I got older, I learned to understand it in more and more sophisticated ways.

And now it's not the only story that I believe in at all. In fact, I'm much more committed to a sort of scientific story. But my argument is that origin stories are immensely powerful. We need them. They help us place ourselves in the universe. They tell us what we're part of, what thing it is that we belong to, and that is a profound way of Biden guidance, telling us what we need to do where we are what our relationships are, what our networks are, what our places

and everything. And my argument is that what what basically happened is that in the last hundred years, modern societies abandoned the project of telling origin stories. We abandoned it so decisively we're more or less forgotten. We don't even notice that we don't tell origin stories in our schools. We teach knowledge in bits and pieces, and in fact, nowhere in a school curriculum, and very rarely even in a university curriculum do you find courses that try to

link all forms of knowledge. And many people think that's a naive and impossible project. So we've lost all the virtues of origin stories because of the way we teach and we research and we organized knowledge in modern society. Right. I think some of that speaks right to the level of specialization. Things get into each of these fields. And that's what I find remarkable about this book and about

the type of science or history you're part of. It's called big history, right, which is, like you said, trying to sort of put it all into some sort of context. And in order to do that, you obviously have to move a few levels up from going as deep as a specialist would go. However, what I found really impressive about the book is you're still going into more detail about how a lot of things happen than most people even know. So it's not like we have to sacrifice

accuracy in order to have an origin story. I'm not attacking specialization at all. Specialization has been hugely successful in the twentieth century. The amount we know about our world and our universe and our planet is staggering. What what I think is the real problem is that the other side of knowledge, which is linking things together, that's what's

missing from modern education. Um So in tell a modern origin story, it's it's it's more of us as if I'm asking a question that I think has been asked since the Enlightenment. Can we construct an account of how everything came to be that is as coherent as the accounts we find in traditional religions or traditional indigenous stories, But that's based on the knowledge of modern science. That's the challenge, and it's it's very difficult, and getting the

balance right is very very difficult. Indeed, so sometimes in origin story, I suspect I've gone a bit too deep on some things, but that's the project. Can we tell the equivalent of an ancient origin story using the staggering information that has been generated by modern science? And I like what you say about it being a way to construct either meaning or some sense of orientation to where we fit within everything, because we know that a lot

of people are rootless and untethered. Tell me how knowing this story makes you feel more a part of the world, or how it helps you to have a sense of meaning. As a school kid, I lost my faith that Christianity would tell me everything I needed to know. And like a lot of people, I felt there are other forms of knowledge I need to acquire. But but of course

I got them in bits and pieces. So my world it was as if my world got pixelated, you know, when I was in my teens and as a scholar, and then I realized that this pixelated world of knowledge, where you have lots of bits of knowledge, it's it's a bit like looking at the world through a broken glass. You can't ever see what unifies everything. That I think

can be dangerous, and it can be dangerous psychologically. The great French sociologist and he will do a kind began his career writing a book about suicide and his argument was that many people commit suicide because of what he called anomy, a sense of rootlessness or not knowing what it is your part of. They don't know what they're connected to, they don't know who they are. And I feel this, this modern knowledge doesn't help young people get

a sense of what is the universe? They are part of, what is the planet, they are part of what does it mean to be a human being? All of these things. And I think it's profoundly important of the psychological as well as an intellectual level. And it's a sort of mapping. In fact, my first book on big history was called Maps of Time. You'll have seen those maps of the Milky Way where there's an arrow that says you are here. Well, that's map I'm thinking about, you know, the map of

the universe that says you are here. This is your place in space and time. So once you understand that place in space and time, then you know who you are, you know where you are, and you're beginning to get a sense of what are the challenges you face uh and and what is your task? Right? I think the other thing that for me an origin story or understanding where we come from and how we get here is it?

It brings out the sense of mystery and awe. And I'm going to quote a Jewish mystic, Abraham Joshua Heschel about all, because I think it ties this stuff together a little bit. He says, all is an intuition for the dignity of all things, a realization that things not only are what they are, but also stand, however remotely, for something supreme. And I love that idea, that it gives us an intuition for the dignity of all things. Yes,

that's a lovely idea, right. I don't know that quote, but certainly I think you know all really good scientists understand that sense of awe. If you learn about you know, how how does single celled organisms operate? Millions of cells? How do those cells collaborate? Once you begin to get into that, it is absolutely awe inspiring. Or when you start trying to imagine how big the universe really is, it's impossible to avoid a sense of awe. What does

the big bang mean? I don't think we really understand. We can sort of tell a story, but telling a story is not quite the same as really understanding what's going on. So the story itself I think is full of awe and mystery, and then you can eventually stand that, stand back and say, well, so this huge, awe inspiring whatever it is, I am part of, and I think that is powerful. I agree completely. I think that's the next step of it is like I belong here, I

am part of this, This is my home. That's what dor Kin was talking about. He was saying, you know, many particularly young people commit suicide because they have no sense of a home psychologically speaking, their street people. And what an origin story can do is give you a sense of your home. Perfect. So one of the things you say very early on is it that the heart of the modern origin story is the idea of increasing complexity. So let's start there with that part of the story. Yeah.

When I first began teaching, I'm still not quite sure why I did it. I think, really I began teaching this because I wanted to get a sense of the history of humanity as a whole. In a globalized world, seven billion humans are sort of stuck together on a raft and we have to see the unity of humanity. But as I did that, I found myself pushing back and back and back and thinking, well, where did humans come from, and that forces you to talk about evolution

and what is this planet we evolved on. So these questions pushed me back and back and back until I began to think that to really understand my place in the universe, I have to tell a history of the universe. So when I began teaching in nine that the truth was, I had no idea how to do that, because it's it's not a thing that many people do these days. Um So what I did is I invited people from many different disciplines, from astronomy, from geology, from ancient history,

from archaeology, and they all gave great lectures. I'm so grateful to them, but the story didn't quite hang together. So it took me several years to try to see the storyline behind all of this. And the storyline of increasing complexity really comes from the work, or at least I learned it from the work of Eric Chasson, who's an astronomer who's taught forms of big history. He calls it cosmic evolution at Harvard in Boston for many, many years.

He was teaching it long before I was, and his argument was that the early universe is very, very simple, and that as you watch the history of the universe, what you see is the appearance of increasingly complex things. Now that put like that, it sounds very abstract, but the global society we all live in today is staggering le complex. So this is really a story about us. How, step by step from a universe that began very simple, do you build up to the staggering complexity of our

world today? How do you get that? How does the universe create something as complicated as my brain or your brain or the internet? That story held everything together, and eventually I started focusing on some of those moments when something new appears. Now it's a bit arbitrary, but I focus on eight in my teaching, which works pretty well from a storytelling point of view, And you can show step by step how more complex things appeared in the

universe until eventually you get to today's society. So it's a way of placing today's global society in the history of the universe. So basically, what you're doing is you're describing what you're calling thresholds. We can think of as key transition points where the universe seems to have taken another leap of complexity, right, and so threshold one is the Big Bang thirteen point eight billion years ago or so,

we think. The other thing that you do in the book that I really like is you break thirteen point eight billion years ago down to thirteen years eight months ago, because it gives a sense of things and it's kind of interesting if you say, well, the universe started thirteen years eight months ago, Well, we started burning fossil fuels six seconds ago, you know, billions of years. It is hard to wrap your head around. That's a little bit easier to wrap your head around. And I like the

way you did that. But let's start with the Big Bang, because in a sense you alluded to this in the earlier part of the conversation. But we have a pretty good idea of what happened really shortly after the Big Bang, but we don't really understand what on earth happened at the Big Bang, or what was there before that, or what caused it to happen. Yes, I think that's true, um, and I think most cosmologists would probably agree that the actual moment of the Big Bang we don't have hard

evidence about. We have hard evidence for things that were happening within a you know, a billionth of a second after the Big Bang, and this, this is this is staggering. But but astronomers can actually measure um fluctuations in energy in the universe just two and eighty thousand years after the Big Bang, and in the next decade or two they will be able to look at events much closer to the Big Bang, probably using gravitational waves, which is a new sort of technology. But we don't know what

happened at the beginning. And one of my arguments is that actually this is true of all origin stories. If you look flee at them at the very beginning of the story, no storyteller knows quite how to begin it. Do you begin with nothing? If so, how do you get something out of nothing? Do you begin with something in which case there was no beginning, something existed forever.

Is that satisfactory, you know? Or then there's a kind of mushy in between position which you find in things like that, you know, the great Hindu religious texts, you punishers and the vaders, the idea of Earth world which wasn't quite in existence, but wasn't quite not in existence. It's a sort of sort of mushy world of potential.

And then something happened so that the potential turned into reality, and that, strangely is very close to the sort of thinking of modern quantum physics, which often you have to heade your bets on whether something exists or not, and then there comes a moment when you can say, okay, now it exists. Yeah. It's fascinating because along with the Hindu origin story. As I'm a I'm a practicing Zen Buddhist, and we talk a lot about emptiness, emptiness is form.

Form is emptiness, right, and it's that idea that what is emptiness? You know, what is nothing? Well, one of the ways that someone in Zen might describe it is full of pregnant possibility, is what it is. It's really crazy. But it's what's so insane is that everything we see and can see or will see was all there in this tiny beginning that was so infinitesimally small. That's where

everything came from. And you make a great point you say that it was a point smaller than an atom, and an atom is so small you could fit a million of them into the period at the end of this sentence. So something a million times smaller than a period at the end of a sentence contained everything that is or will be at least as far as we know now, and that's staggering if you're looking for all

there's a good place to stop. The thing is that, as weird as that sounds if you're unfamiliar with it, the amount of evidence that points towards that conclusion is now colossal. And the main piece of evidence is just the realization. Well actually astronomers began to realize it in the nineteen thirties, but they didn't take it seriously really until the nineteen sixties. Was the idea that our universe is expanding. Um, it seems to be expanding in four dimensions.

It's getting bigger. And if it's getting bigger, then you know, in our in our minds, we can wind it backwards. In the past it must have been smaller, and if we keep going, it must have been infinitesimally small. So the logic behind that is very powerful, but it's very hard to get your minds around it. We've got a lot of complexity to go through. But this is the threshold. One the universe appears right, and then the next threshold

is we get stars. So maybe give us a couple of minutes on how we get from a universe that is initially just pure energy two stars. Let me go back a bit and talk about thresholds, because there are certain things that seem to happen at all thresholds, and I think the best way of describing a threshold is to say that it's not something that happens to the whole universe. Most of the universe is incredibly simple today.

It happens in special goldilocks environments in the universe. Suddenly, in a particular part of the universe, you find that things that already exist recombine in new ways, and suddenly they combine in ways that have new qualities. And that's what we see over and over again in emergence. Is the word. It's not magical, because the components of the new thing we're already there. It's just that they're arranged

in new ways. And that's true of course, you and me as well, all the atoms in our body have been around for a long time. It's just they're arranged in a very particular configuration. So there are sort of rules about thresholds. And the second rule that Derik Chason pointed out is that whenever you get these new structures emerging, you're probably going to find that there's a lot of

energy maintaining those structures and flowing through them. So to understand the structures, you can look at the flows of energy today. We can look at the flows of fossil fuels to understand modern society, for example. So back to what the Big Bang gave us threshold one. It gave us time, it gave us an expanding space, It gave us energy, all the energy in today's universe because the amount of energy doesn't change, and it gave us something else, which is a number of rules. So this this energy

was not completely random. There were a number of rules. The rules said things like one of the forms that energy will take his gravity, and gravity is a force that pulls everything together. So there were rules at the beginning, and they explain why the universe was not complete random.

There was always a bit of structure. So that's all about thresholds in general, the second threshold, and it's a really good threshold to understand to get a sense of how thresholds work, and I can tell the story sort of very very quickly. Actually, there's a lot of technicalities there, most of which I don't understand. About two hundred or three hundred thousand years after the Big Bang, the universe

is cooling down. It begins incredibly hot, but as it expands, it cools, and there comes a point where atoms can form, electrons can blong onto protons and form atoms. And we know quite a lot about the universe at that point, and the main thing we know is that it consisted of hydrogen and helium, tiny smattering of one or two other chemicals, but basically just those two elements, and it

was incredibly smooth. So you can think of the universe, the early universe, as a sort of thin mist of hydrogen and helium atoms, and the whole thing was almost exactly the same temperature. So this is very, very simple. This is what I mean by saying the early universe was simple. There's nothing complex here, So how do you get something more complex? Well, gravity is the crucial actor of this threshold. What gravity does is it clumps matter together.

So if there's an area where the hydrogen and helium atoms are slightly closer together than that means the gravitational pull between them is slightly greater. So gravity breaks this homogeneous universe into billions and billions and billions of clumps, sort of clouds of hydrogen and helium atoms, and as they get clumpy, gravity gets more powerful and pulls them together.

And inside these clumps you find atoms banging into each other more and more and more as they get denser, until eventually the clouds of matter start heating up again while the rest of the universe is cooling. So now you can imagine these clouds of hydrogen and helium atoms getting denser and denser and denser. Eventually the atoms break up and then at a certain point, protons start fusing together,

and that's what happens in an h BOD. So when that happens, when you reach that temperature at the center of each cloud, you suddenly have a huge release of energy as some batter is turned back into energy because matter is really a sort of congealed form of energy. So now at the center of each clump, you've got a huge furnace pushing back against gravity. So these two

forces sort of stabilize, and you have a star. And if you think about it, universe with stars trillions and trillions and trillions of them is very different from that simple early universe. You now have huge differences in temperature. You've got these these hot spots and stars while most of the universe is cold. You've got areas where matter is very concentrated, very dense, and areas where it's very empty. You've got flows of energy now from the stars out

into empty space. So this is a much more interesting universe than the early universe, and the flows of energy that are now created create the possibility of new and

more interesting developments. It's totally fascinating the way we go from, like you said, this thin mist two stars, and the next thing that happens is we go from largely hydrogen and helium to lots of other elements, and we're going to go through this threshold very quickly, because essentially that happens as a star dies and explodes at an even

harder level. That's right, because in dying stars, what you need to create higher elements is colossal temperatures so that protons can bang together and come together in groups of ten, six, sixteen or ninety protons to form new new elements. And that happens in dying stars. And what you see is that each threshold creates the preconditions for the next threshold, and so our next threshold, which happened about four point

five billion years ago. So going back to our analogy of the universe being thirteen years eight months ago, well four years six months ago, we got something that's pretty important to us, which is our son and our solar system. Yeah, well, I mean actually that threshold happened much earlier in some parts of the universe. We now know there are billions

and billions and billions of sort of solar system. Just that our solar system appeared four and a half billion years ago, about four years and eight months on at that sort of shorter timeline um, and from that point on we have to focus on our planet and our solar system because we know very little about other solar systems.

But planets were created in a universe that was now chemically complex because dying stars had created new elements, all the elements of the periodic table, and they scattered them through space. So you now have a universe in which you can create new kinds of stuff like water and ice or dust particles, and that's the stuff that makes our planets. So planets are particularly rocky. Planets like Earth are chemically much more complex than stars. Jupiter is much

more like a star. Jupiter and Satin are basically gassy

and they're mostly hydrogen and helium. But rocky planets like the Earth or Mars or Venus are chemically incredibly complex and interesting and so then relatively quickly, given the time frames, we're talking about three point eight billion years ago or three years nine months ago, so we're about seven tenths of a billion years seven million years, which is which is a long time, but in the times we've been talking about is pretty short, something remarkable happens, and that

is we get something that we call life. Yes, at this point in telling the story, I always have to remind my students that, you know, the thresholds we're focusing on. I think they're pretty important, but there could be other thresholds. But this is one of the most important of all, the emergence of life, and I think most astrobiologists today would say there's a very good chance that life has popped up all over the universe, but as yet we

can only study it on our own planet. Maybe in the next decade or two we'll get good evidence that life exists elsewhere, but so from now on we really have to focus on planet Earth and what we know about planet Earth, but we know that on this planet, as you say, life popped up pretty quickly, pretty soon after the planet was created. So it's as if this planet created the ideal Goldilocks conditions for extraordinarily rich chemistry.

Because life really is molecules forming in more and more complex ways and into reacting in more and more complex ways. But you go on to talk about life, you say something I think is really important, and we're going to skip over how we define life because you know there's a little bit of debate there, but your book has some great stuff on it. But I just want to read something you say about life because I think this

is really, to me pretty fundamental. And you say, the spooky thing about life is that whole cells give the impression of acting with purpose. Something inside each cell seems to drive it as if it was working its way through a to do list. The to do list is simple, one stay alive despite entropy and unpredictable surroundings, and to make copies of itself that can do the same thing. But all of a sudden, we have this new thing.

And you say, here in the seeking out of some outcomes and the avoidance of others, are the origins of desire, caring, purpose, ethics, even love, perhaps even the beginnings of meaning. If that means the ability to discriminate between the significance of different events and signs. Organisms are different, because it's as if they prefer some futures to others, and the future they

prefer is one in which they survive long enough to reproduce. Again, that sounds kind of mechanical, but we know that must be true because you and I are the heirs. We belong to a lineage that goes back four billion years. Every single one of our ancestors survived long enough to reproduce, Otherwise you and I wouldn't be here. So what that means is that we are the heirs of organisms that

were good at surviving and eventually good at reproducing. Right, And this is another one of those thresholds to me that seems to contain a certain amount of mystery despite the explanations of it. This seems to hold a little bit of mystery in that we go from strictly chemical reactions increasingly complex chemical reactions to like you said, something that actually cares about something. There are several points in this story where we have to be honest and say

we don't have a good grip on this. One is the Big Bang. The second is the origin of life. Origin of life. Biologists know a huge amount now about the chemistry of the early Earth, but we still can't quite explain how you get from purposeless chemicals to something that acts with what looks like of us. And of course, the third great mystery is consciousness, which we don't know how to explain how to deal with it. So there are really, I think three great areas of mystery where

we're really uncertain. There are many more, of course, but one is the Big Bang. The second is the actual origin of life. I think biologists are very close to cracking this one. But the third great mystery is consciousness. You know, the fact that I experience things, I'm aware of things. We don't know how to explain that. Um As I said, that doesn't mean we won't eventually come up with an explanation. We've managed to explain many things

we couldn't explain in the past. But at the moment these are areas of mystery in the precise sense that we don't really understand them. I want to read something you wrote about early life because we we tend to say, all right, single celled organisms were around a long time before anything else happened, and we might go, well, you know, okay, that's kind of pretty simple a single cell organism, but a cell itself is pretty amazing. And you say this,

you're describing a cell. Billions of molecules swim through a thick chemical slurry, being nudged and pulled by other molecules thousands of times each second. Rather like a tourist in a crowded market full of traders, touts and pickpockets. If you were injected into one of these molecules, you would find this a terrifying world. Enzymes will try and glom onto you and change you, perhaps hook you up with other molecules to form a new team that can cruise

the markets looking for new opportunities. Imagine millions of these interactions going on inside every cell every second, and you have some idea of the frenetic activity that powers even the simplest of cells in the early biosphere. Yes, as I was writing the book, I should confess I went deeper into molecular biology than I have ever before. And well, you began this interview Eric by talking about all and my sense of awe for what happens inside single cell

bacteria increased massively. This messy, murky environment inside the cells, with molecules sort of jostling into each other and bumping into each other and vibrating somehow or other. From all of those relationships between complex molecules, you get cells that act with a sense of purpose. It's as if, for all what's going on in this complicated world is sort of compute tational. It is computing something. And in fact, recently I've been reading about how e Coli bacteria in

our stomachs are full of them. They're single celled organisms. How do they predict the future? Because in effect they do. All living organisms have to kind of relate themselves to their environment in such a way as to avoid bad things happening and increase the chances of good things happening. So it means they all have to think about the future. They all have to make bets on the future. It's as if they're all at the horse races, and most of the time they bet well. So how do they

do it? And we sort of know some of the mechanisms involved, but they work very very well. Because these things survive and they navigate. So an e coliself, for example. It has these kind of flagella. It can wave around, and it has two types of movement. It can move forward. So if things look good, you keep moving forward. If things start looking bad, you there are proteins in your membrane that detects something bad. Then what you do is you go to plan B, and plan B is to tumble.

You just spin around randomly and head off in another direction. That is future thinking. It's staggering, it really is. It's funny. My Buddhist background, right, we talk a lot about how part of the human condition and one of the things that becomes a problem is when we are trying too hard to get more of what we want and trying to get away from what we don't want. And I agree with that as a truism. I also often say to people like, take it easy on yourself, because that

mechanism is embedded in every cell in your body. It's inherent to life. It's wired in. It is it is, but it doesn't guarantee selfishness in the crudest sense. It does mean that all of us live in this world from a particular point of view. You know, I'm in Australia, You're in Columbus, so so you know what I'm going to do in the next hour or two. It's gonna be very different from what you do. So we all

have our personal perspective. But there are so many environments in which collaboration is the successful strategy that to say this is not to say that every living organism is selfish in the narrowest possible sense, and their collaboration is about what's to take us to our next threshold here and so earliest life on Earth three point eight billion years ago and then about three point two billion years go by until you don't mark this as a threshold.

But it's another big event, which is we get our first large organisms on Earth about six hundred million years ago. We probably got large multi cell organisms earlier than that, but they really take off about six hundred million years ago. And this is, by the way, a very good reminder of of of the fact that the idea of thresholds is not a kind of rigid scientific concept. It's more

like chapter headings. Because I think many biologists would say that that the creation of multi celled organisms ought to be a threshold. It's a profound change in the nature of life. But what it means is it's it's all the it's lots of cells collaborating and specializing. Um they they certain types of cells you Carryotic cells learned to switch on and off the genes in their DNA so

that they could become specialists. So some could become muscle cells, some could become nerve cells, and so on and so on and so on. In multi celled organisms, a lot of the work of the cell is not devoted just to surviving. It's devoted to maintaining relationships with other cells and with the rest of the organism you're a part of. I can't help but think that this is the situation we live in today's world. I could not survive as as a single person without fitting myself into colossal networks

of other people. I think in today's world we're slowly turning into sort of a complex, global, seven billion person, large multi cellulttle organism. I agree. I think it's a really useful analogy that I do think holds true to a certain degree. So we've got big organisms, and now the next big threshold is done to done us two hundred thousand years ago or in our story that started thirteen years eight months ago, about a hundred minutes ago, so a little over an hour and a half ago

we showed up. Yeah, the thresholds are great touristics. There are a great sort of ways of raising questions. So the big question around this one is, say the appearance of human's counts as a threshold in this story. Is that simply a sort of species bragging. Isn't just because I'm human that I think humans are so great? Or is there in an objective sense in which the appear of humans is a transformative event, at least on planet Earth.

And I increasingly take the second view. I think our appearance was transformative for the history of planet Earth and is proving to be transformative for the history of planet Earth because we humans do something that no other organisms did in the four billion years that preceded us, which is we share information about our environment. So we do it so precisely and in such massive volume that over time groups of humans acquire more and more information, not

just as individuals but as groups. So were the first species in four billion years in which information accumulates across generations, and if you add that for a living organism, information is crucial. Knowing what's happening in your environment is absolutely crucial, and the more you know about the environment, the better

your chances of surviving and controlling that environment. So if you have a species in which knowledge of your surroundings is growing from generation to generation, then you have a species that's going to get more and more and more powerful, faster and faster. And today we live at the culmination of that story where we as a species dominate change on planet Earth. What we do in the next fifty years will determine the future of millions of other species.

It will determine the future of the Earth's climate, of its oceans for millions of years. We have become a planet changing species. So in a sense, our appearance really is a turning point for planet Earth. Certainly is for better and worse, you know, for better and worse. And what staggering is when you talk about the next fifty years is going to side a whole lot of things

related to climate. It's amazing that again, if you take this entire story and you go, okay, about thirteen years eight months ago, this whole thing the universe started, and now we're fouling up Planet Earth, right we're messing with some pretty big forces, right, and that started in essence about six seconds ago. We need to keep balance on this because, yeah, what's happening is very sudden. Indeed, when we talked about thresholds, we saw that there are energy

flows associated with each of these thresholds. So when humans first appear, because they share information, they get better and better at controlling energy. So about ten thousand years ago, humans are controlling flows of energy and resources all around the earth. Then they learn agriculture that gives them more energy, more control over the energy flowing through the environment. And what what makes today's world so different is we're tapping

into fossil fuels. And fossil fuels are stores of energy that was laid down over three hundred million years, mostly in the form of carbon. So as we use that staggering store of energy, it allows us to build the very complex societies of today. It allows us to build societies in which most people are much wealthier than they they've ever been before, so most of us enjoy quite

high living standards. But the other thing is with throwing back into the atmosphere carbon dioxide that was buried over three hundred million years and we're doing so at a

faster rate than you've seen for millions of years. So we're changing the climate because the crucial factor that determines how hot the Earth is is the mix of greenhouse gases, and what we're doing is we're pouring greenhouse gases back into the atmosphere, and that is dangerous, right, And you know, I think it's the hope of people who are wanting

to see a change here. And I think is that work, like the type of work you're doing, will give us a greater appreciation for what we're doing and how quickly we're doing it and how sudden this is. I very much hope so. And this is one of the reasons why I'm passionate about big history. I think young people today need this wide division. I mean, let me just give you one quicker illustration of what I mean. To understand climate change, basically, you need to understand how climates

have evolved over four billion years. And the crucial point is Carl's Sagan pointed this out forty years ago. The Sun has been emitting more and more energy over four billion years, and yet the surface of the Earth has remained at a temperature between roughly nought and a hundred degrees the temperature of which you can have liquid water. How is that possible, Well, the answer is that the

Earth's atmosphere has slowly changed over four billion years. The amount of carbon dioxide, the amount of greenhouse asses, which was very high when the Earth was cooler, and that was a good thing because it kept the Earth warm, has slowly diminished as the Sun has become more powerful. To some beautiful thermostatic mechanisms have functioned, and we know quite a lot about them. The dangerous thing is that

we humans, we're messing with the thermostats. And what those thermostats did was keep planet Earth life friendly for four billion years, and that's not an easy thing to do. Mars lost life, Venus lost life, our neighbors lost life. So this is a really tricky thing. We are messing with those thermostats, and the first thing we'll do is just make life more and more uncomfortable for human beings.

The cockroaches will survived fine, um, But but what we're really damaging is the future for our children and grandchildren and great grandchildren. And that is the great problem that we face. I think in the next fifty years can we avoid degrading the future of our children and grandchildren. I could not agree more and I think that is a good place for us to wrap up. Thank you

so much. I did love the book. It was such an enjoyable read, and I just feel like my appreciation for the big story or big history is so greatly enhanced. So thank you so much for the book and the work that you're doing. Well. Thank you so much. I'm delighted that you enjoyed the board. All right, take care, okay, bye, and thank you very much. Indeed, thank you. If what you just heard was helpful to you, please consider making a donation to the One you Feed podcast best head

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