 Thank you very much. We have a welcome to the first session in Plenary Hall for this year's annual meeting. The concert last night was unbelievable. I hope you enjoyed it as much as I did. It was amazing. We're in for a real treat in this first session. David Christian is director of the Big History Institute at Macquarie University and co-founder with Bill Gates of the Big History Project. He has an amazing presentation. I'm very pleased and honored to introduce David Christian. Thank you very much, Al. In the last 200 years, we humans have created a global world of staggering complexity. It's a huge achievement, and with it come great opportunities, but also significant dangers. Now, if we're to avoid the dangers and take the opportunities, if we're to create a world that will be good for my grandson Daniel and his cohort, we're going to need a lot of guidance, we're going to need perspective, we're going to need insight, and we're going to need leadership and a significant degree of global unity. In the past, human communities have sought this sort of guidance in what we call origin stories. Origin stories are sort of huge, ramshackle accounts of how things came to be the way they are. They're always best based on the best available knowledge in that society, and they provide guidance. Now, we today also have an origin story. It's been constructed over several centuries of fantastic science, not just in the hard sciences but also in the humanities. And it's also got guidance, plenty of guidance about the challenges we face, but we don't teach it in our schools. We don't teach it to the young people who need to know this story in order to face the challenges of the next 50 years. In the Big History Project and through the Big History Institute at Macquarie University, we're trying to tease out this story and make it available to high school students throughout the world, because we believe it's a story they seriously need to know. And that's information about the Big History Project. Already we're teaching this in several hundred schools, mostly in the US and Australia but also in several other parts of the world. Now what I want to do in this talk is give you just a taster for the story we tell, the modern origin story which we call Big History. And I hope that'll give you a sense of the way it may suggest important perspectives and insights about today's world. So let's go back to the beginning. I'm going to use this timeline. On the top, we have absolute dates for events in the history of the universe. Although I've divided all those dates by a billion, so you can imagine the universe began 14 years ago, I found that dividing it by a billion makes it easier to see the proportions of this story. So let's go back to the beginning. 13.8 billion years ago, there's now a huge amount of science that makes it very clear that all the energy, all the matter in today's universe was scrunched up into something smaller than an atom. So not surprisingly, that tiny thing was busting with energy. It was incredibly hot. It was expanding incredibly fast and it was cooling as it was expanding. And that process of expansion is still continuing today as the universe keeps growing. But we also know that the early universe was very simple. This is a diagram taken about half a million years after the Big Bang. It's an iconic image from the WMAP satellite and what it shows is temperature differences in the early universe. And it shows that they were tiny. The differences between the blue areas and the red areas are about a thousandth of a degree. Very homogenous. It was also simple chemically. Most of the early universe consisted of a sort of thin mist of hydrogen and helium atoms. You've got the proportions over there. 75% hydrogen, probably more than 23% helium and a tiny smattering of lithium and beryllium. There was also dark matter, which we don't understand as well, but it was a bit clumpier and we'll see that unevennesses, clumpiness, gradients are crucial to the Big History story. But we also know that simplicity is the default state of the universe. Today, most of the universe is still remarkably simple. Most of it is cold, empty vacuum. And we also know that the second law of thermodynamics guarantees that the tendency of the universe is towards simplicity rather than complexity. And yet, over 13.8 billion years in pockets in the universe where the Goldilocks conditions are just right, we see the appearance of more complex things. Now we don't know of any drivers of complexity. We may discover them, but at the moment it looks just as if these fluctuations in special conditions create slightly more complex things like whirlpools in a stream or like whirlpools in galaxies and complexity builds on complexity in this way. And in the Big History project, in our Big History courses, we talk about eight thresholds of increasing complexity, beginning with the Big Bang, the creation of stars, the creation of new chemical elements, the creation of planetary systems, then the creation of life, and finally, these three last stages concern modern human society. So this process of building, increasing complexity is the core of what we're talking about. And every time this happens, it depends on Goldilocks conditions, we find somewhere in the universe where the conditions were just right to create something slightly more complex. Now there's one other thing is needed in the story, and that is flows of energy. Because the tendency of the universe is to wind down, complex things need flows of energy, and they need to be able to manage those flows of energy. So to understand complex things, you need to understand the energy flows that they deal with. This is a graph from the work of the astronomer Eric Shason, who's also taught Big History courses. And what he's showing is the density of energy flowing through different things. Can we go back? The density of energy flowing through different things. That is to say the amount of energy in a gram per second that's flowing through different entities. And what he's showing is that the amount of the density of energy through the sun is maybe a million times less than the density of energy flowing through modern human society. Now, that is a measure of complexity, but it's also a measure of fragility, because it means that to maintain these complex structures, we need to manage these huge flows of energy. So to understand this story of increasing complexity, we need to keep track of the energy at every point. Now let's go back. The first threshold is the creation of the universe itself at the Big Bang. The second is the creation of stars. Gravity's the main player here. Gravity seizes on tiny differences in density, and it creates clouds of matter. It breaks the universe into billions of clouds of matter like this. And eventually those clouds heat up, and at their center, when the temperature's high enough, protons start to fuse together. This is the same reaction you get in a hydrogen bomb. This huge release of energy is what maintains the structures of stars. So stars depend on fusion at their center, and we know the first stars probably appeared about 200 million years after the Big Bang. A universe with stars is already a much more interesting place. There are hotspots. There are gradients of energy in density. There are huge flows of energy. There are structured entities such as stars and also galaxies. But stars also create the gold deluxe conditions for threshold 3, which is the creation of increasing chemical complexity. When very large stars run out of fuel, they collapse gravitationally. That collapse generates temperatures so high that protons start to fuse into heavier elements, oxygen, carbon, up to iron. And eventually if the star is big enough, it will explode in a supernova, and in just a few seconds it will create all the elements of the periodic table and it will scatter them like confetti in intervening space. And that is threshold 3. And now in the space between stars we get dust clouds. We get atoms combining as a result of gentle flows of electromagnetic energy and now chemistry is happening. We get shards of ice. We get motes of dust. And around young stars, gravity combines these new materials into balls of matter, into sort of snowballs, eventually into meteorites, into asteroids, and eventually into planets. And that's how planetary systems are formed and that's threshold 4. We now know that planetary systems are remarkably common. This, by the way, shows the distribution of chemical elements in today's world, still mostly hydrogen, mostly helium, but it's that tiny layer at the top that's going to allow increasing chemical complexity. Now here are some images of our solar system. We know there are billions of solar systems. Ours appeared about 4.5 billion years ago. Rocky planets like our Earth, and this is an image of what our early Earth may have looked like, are peculiarly interesting because in our solar system, at least, most of the hydrogen and helium was driven away so that we get a much more interesting mix of chemicals. So this is a chemically rich environment and a great environment for chemical experiments. This image here, by the way, was created by a former student of mine. I love it. It captures very well the early Earth. It captures gentle flows of energy from inside the Earth, from the Sun. Chemical richness. You've got a great diversity of materials here, and there's also water which allows for chemical experimentation. And finally, we've got stromatolites. We've crossed our fifth threshold. We have life, living organisms. Now, we know life exists on our planet. It appeared at least by 3.5 billion years ago. It probably exists on billions of planets. It was bacterial. You couldn't see them. They're tiny, but fantastically complex organisms. Living things get their energy from metabolism. They extract energy from energy flows through the biosphere, often by eating other organisms. But very early on, some bacteria learnt the trick of extracting energy directly from the Sun through photosynthesis. And ever since then, energy from the Sun created by fusion of the Sun, captured by photosynthesis, has driven the biosphere. That energy allowed a buildup of increasing evolutionary complexity. Multicellular organisms appear in the last billion years. We get huge towering monsters. We get fish. We get amphibia. Eventually, we get dinosaurs. 100 million years ago, dinosaurs dominated the land. Unfortunately for the dinosaurs, an asteroid landed 67 million years ago, created a sort of nuclear winter which wiped out large organisms, which was great news for our mammalian ancestors here, who were sort of mouse-like organisms that now flourished in the intervening spaces left empty by the dinosaurs. We humans are part of this mammalian radiation. We appeared about 200,000 years ago. You can see it's right at the end of the graph there. That's about an hour ago on the 14-year timeline. And we regard the appearance of humans as threshold six. It really made a difference. We're the first species in 4 billion years that can communicate so efficiently that ideas accumulate within communities. So we're a species that over time gathers more and more information. More information means you can control more energy, more resources. And that allowed our paleolithic ancestors to spread to every continent on Earth. Then 10,000 years ago, this mechanism of collective learning, as we call it, allowed a new suite of technologies that we call agriculture. Farmers manipulate their environments, the plants and animals around them, so as to divert more of the flows of energy through the biosphere to their own use. And with more energy, human numbers grow. You get villages, you get towns, you get cities, you get civilizations. You get with more people, you have more ideas being shared, you get new innovations. And the whole history of civilization, this whole speed up, depends on these increasing energy flows. And then just 200 years ago, we cross our eighth threshold with fossil fuels and our entry into the Anthropocene. Under the agrarian regime, if you burnt a piece of wood, you were tapping into energy probably created in the sun 30 or 40 years ago. If you burn a piece of oil or coal, you're tapping into energy created and stored over 300 million years. That's a staggering increase in energy. And it's that energy bonanza that created today's very complex world. That's the world we live in. Will this process of increasing complexity continue? Surely it will. There will surely be creatures that can tap much more efficiently than we can into the energy of their stars. But eventually, gazillions of years in the future, kilometers beyond the end of that timeline, energy flows will thin out as the universe keeps expanding. There won't be enough energy to create living things, planets, complex molecules, even atoms. They'll all eventually vanish and there will be zilch. Now what this means is that we live in a sort of springtime of the universe. We're very privileged. A time when there were flows of energy that allowed the creation of complex things. And we live quite high up the mountain of complexity. Now I've just given you a sort of taste of this story. This is just a bare taster of a very complex story. What can we learn from it? Well, what I learned from it is that we live in an astonishing moment in the planet's history. Never before in four billion years has a single species controlled such huge flows of energy that it dominates the biosphere. Never before has a single species created such staggeringly complex structures. And that's fantastic, but it also means we have to manage these huge and potentially dangerous energy flows. Over the next few days, there are going to be three panels which try to tease out some more of the insights from this story as we look at innovation, as we look at global collaboration and as we look at global growth. In the meantime, we need to look for the insights from this story. We need this story. We need to teach it around the world in order to make sure that we preserve the Goldilocks conditions that will give my grandson Daniel and his generation a good life. I thank you for your attention. David, that was absolutely brilliant. Thank you so much. What is the future of the Big History Project? Well, we want to bring big history courses into every school in every country in the world. And we also, through our Big History Institute, would love to create research agendas around big history because most of the interesting research problems today, I think, now lie between disciplines rather than within disciplines. And we hope Big History can contribute to that research agenda. Well, thank you and good luck. And you're fortunate to have Bill Gates as your co-founder and partner. Absolutely, absolutely. Thank you very much, David. Thank you. Well, I often...