Lots of countries, like Israel, live with terrorism every day, and it doesn't impact their integrity. The big threat to America is the way we react to terrorism by throwing away what everybody values about our country - a commitment to human rights. America is a great nation because we are a good nation.

When my father started talking about strip mining in the Appalachia back in the '60s, I remember a conversation I had with him where he said, you know, this is the richest state in the country if you look at the resources and the land, but the poorest people after the state of Mississippi: the 49th poorest people in the country.

When I was 7 years old, I announced that I was going to write a book about pollution. I didn't get around to it until I was 29, but I always recognized that pollution was a theft. That it was a way of stealing something from the public - the common earth.

At the time of the Civil War, there were six democracies in the face of the planet. Today, there's 120 and they've been inspired by the American exceptionalism.

Scientific education is by far the best training for all walks of life because it teaches us how to assess situations critically and react accordingly. It gives us an understanding based on reverence for life-enhancing technologies as well as for life itself.

Big History's not going to replace existing educational courses. It's not an attack on specialisation. It is simply the argument that specialisation needs to be complemented with an overview, which I think is scientific commonsense.

Though neglectful of their responsibility to protect science, scientists are increasingly aware of their responsibility to society.

Representation is so important because it's hard for kids to want to be what they can't see. Little girls and boys need to know that it's natural for girls to love science and tech.