GUY RAZ, HOST:
Later in the show, Spencer Wells returns to explain how, in a very short period of time, we left Africa and spread out across the planet. But first...
DAVID CHRISTIAN: My name is David Christian and since 1989 I've been teaching courses on the history of the universe and the place of humans inside that story, and I call them Big History.
RAZ: David Christian is a historian and his idea - Big History - is really about our place in the universe and how small our part of the story actually is.
CHRISTIAN: Here you are. You exist around this star. You exist on this planet. You are a member of this species, and all of these are part of knowing what you. And eventually, of course, you'll get to say that you were brought up in Australia or in America. All of those stories we need but we also need this big story. And as long as we don't have this big story, it's going to be very hard, I think, for us to understand ourselves as humans.
RAZ: So the story David Christian tells begins 13.8 billion years ago, pitch black darkness. Here's David on the TED stage.
(SOUNDBITE OF TED TALK)
CHRISTIAN: Around us there's nothing. There's not even time or space. Imagine the darkest emptiest thing you can and cube it a gazillion times and that's where we are. And then suddenly, bam, a universe appears, an entire universe, and we've crossed our first threshold. The universe is tiny. It's smaller than an atom. It's incredibly hot. It contains everything that's in today's universe. It's busting and it's expanding at incredible speed. And at first, it's just a blur but very quickly distinct things begin to appear in that blur. Within the first second, energy itself shatters into distinct forces, including electromagnetism and gravity. And energy does something else quite magical. It congeals to form matter. Quarks that'll create protons and leptons that include electrons. And all of that happens the first second. Now we move forward 380,000 years. That's twice as long as humans have been on this planet and now simple atoms appeared of hydrogen and helium. Gravity is more powerful where there's more stuff. So where you get slightly denser areas, gravity starts compacting clouds of hydrogen and helium atoms. So we can imagine the early universe breaking up into a billion clouds. And each cloud is compacted. Gravity gets more powerful as density increases. The temperature begins to rise at the center of each cloud and then at the center of each cloud, the temperature crosses the threshold temperature of 10 million degrees. Protons start to fuse. There's a huge release of energy and bam. We have our first stars. From about 200 million years after the Big Bang, stars begin to appear all through the universe - billions of them. And the universe is now significantly more interesting and more complex.
RAZ: And all of that wasn't even half a billion years after the Big Bang. It would take another eight or nine billion years for our solar system and our planet to form, and nearly another billion before the first signs of life.
(SOUNDBITE OF TED TALK)
CHRISTIAN: For most of that time of life on earth, living organisms have been relatively simple single cells but they had great diversity and, inside, great complexity. Then from about 600 to 800 million years ago, multi-cell organisms appear. You get fungi. You get fish. You get plants. You get amphibian. You get reptiles and then, of course, you get the dinosaurs. And occasionally, there are disasters. Sixty-five million years ago, an asteroid landed on earth, near the Yucatan Peninsula, creating conditions equivalent to those of a nuclear war. And the dinosaurs are wiped out. Terrible news for the dinosaurs but great news for our mammalian ancestors who flourished in the niches left empty by the dinosaurs. And we human beings are part of that creative evolutionary pulse that began 65 million years ago with the landing of an asteroid.
RAZ: Why do you think we need to know this story? Why do we need to know about our origins?
CHRISTIAN: Well, if I were to turn the question around and say why do we need to know about American history, what would the answer be? I think it would be that we need to be able to place our self in a story. Isn't that right? One example of this, one wonderful example about this, is my friend Walter Alverez, the geologist. He's the person who more or less proved that it was an asteroid that wiped out the dinosaurs. Now, if that asteroid had been on a trajectory five minutes earlier or five minutes later, it wouldn't have wiped out the dinosaurs and the dinosaurs would almost certainly still rule the planet and we wouldn't be here. It's as simple as that. So it's a story that, in one sense, makes us feel very small and very little. We inhabit an obscure planet, in an obscure galaxy, around an obscure sun but on the other hand, modern human society represents one of the most complex things we know. And that's the other side of the story. That makes us look pretty interesting.
(SOUNDBITE OF TED TALK)
CHRISTIAN: Humans appeared about 200,000 years ago. Now, what makes humans different is human language. We are blessed with a language, a system of communication, so powerful and so precise that we can share what we've learned with such precision, that it can accumulate in the collective memory. And that means it can outlast the individuals who learned that information and it can accumulate from generation to generation, and that's why, as a species, we're so creative and so powerful and that's why we have a history. We seem to be the only species in 4 billion years to have this gift.
RAZ: I mean, I know sounds like a little bit new-agey but, I mean, it is a mystery. Where we come from is a mystery. We really don't entirely now.
CHRISTIAN: Look, it's a wonderful - it is a mystery indeed but, having said that, the astonishing thing is that modern science can open many doors on that mystery - not all of them, there are still doors we can't open. We don't know what to do with consciousness, for example. We don't know what happened before the Big Bang but we can tell a remarkably good story about many parts of that mystery and that story's gotten better and better and better in the last 50 years.
(SOUNDBITE OF TED TALK)
CHRISTIAN: So I hope you'll agree this is a powerful story and it's a story in which humans play an astonishing and creative role. But it also contains warnings. I remember very vividly as a child, growing up in England living through the Cuban Missile Crisis, for a few days, the entire biosphere seemed to be on the verge of destruction. And the same weapons are still here and they're still armed. If we avoid that trap, others are waiting for us. We're burning fossil fuels at such a rate that we seem to be undermining the Goldilocks conditions that made it possible for human civilizations to flourish over the last 10,000 years. So what big history can do is show us the nature of our complexity and fragility and the dangers that face us but it can also show us our power with collective learning.
RAZ: When you think about our origins and you think about this idea of a unified history of the universe, it places, like, our whole very brief history into a context in which I can't help but think, god, not only are we less relevant than we think but we've wasted so much time focusing on ourselves and on our differences when, in fact, we are a tiny piece of this huge story.
CHRISTIAN: I agree. I agree and that's one of the reasons why I think this story is so powerful because it makes the differences between humans seem rather irrelevant. So if in schools we keep teaching that history is divided into American history and Chinese history and Russian history and Australian history, we're teaching kids that they are divided into tribes. And we're failing to teach them that we also, as human beings, share problems that we need to work together with.
RAZ: David Christian teaches a course called Big History. To find out more about it and to see David's entire talk about the story of us, go to ted.com. Our show today, How It All Began, our origins. I'm Guy Raz and this is the TED Radio Hour from NPR.
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