Speech Summary: The history of our world in 18 minutes — David Christian

Eric Lee
3 min readJun 30, 2022


“So here’s a great puzzle: in a universe ruled by the second law of thermodynamics, how is it possible to generate the sort of complexity that we have today?”(David Christian: The history of our world in 18 minutes: TED 2011) We have many different types of materials, plants, animals, planets, solar systems, and the category goes on. It is really hard to think about all these things were originally the same. What I meant is that they are all made up of the same energy after the Big Bang. The origin of the universe was relatively simple than we have today. “The answer seems to be, the universe can create complexity, but with great difficulty.”

We refer to these moments, like the Big Bang, as the threshold moment. Threshold moments are utter new things that appear almost out of nowhere in the universe. Here are the six threshold moments in the speech.

From The Big History Project, Khan Academy
  1. The Big Bang (only hydrogen & helium)
  2. Stars light up (Gravity)
  3. New chemicals get created when a star dies (new atoms)
  4. Solid planets and moon
  5. Living organism
    When molecules get combined to a point that they are too big to keep in the same shape. A new trick gets introduced. “You don’t stabilize the individual; you stabilize the template, the thing that carries information, and you allow the template to copy itself. DNA, of course, is the beautiful molecule that contains that.” “The real beauty of DNA though is in its imperfection.” “As it copies itself, once in every billion rungs, there tends to be an error. What that means is that DNA is learning. It’s accumulating new ways of making living organisms because some of those errors work. So DNA’s learning and it’s building greater diversity and greater complexity.”
Red mean the error (From TED Talks, 11:00)

6. Human
What’s so special about humans is that even someone without a kid can pass an individual’s information to the next generation because we have human languages. Unlike animals 200,000 years ago, when an individual dies, the information dies with them. And that’s why, as a species, we’re so creative and powerful, and that’s why we have history.

Humans learn things faster (From TED Talks, 13:27)

Complexity also means vulnerability and fragility. Although we have such a powerful tool, it’s not clear that we humans are in charge of it. “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 are still armed. If we avoid this trap, others are waiting for us. We’re burning fossil fuels at such a rate that we seem to be undermining the Goldilock condition that made it possible for human civilization to flourish over the past 10,000 years. “

“We believe that big history will be a vital intellectual tool for us to face the huge challenges and also the huge opportunity ahead of us at this threshold moment in the history of our beautiful planet.”