Legendary skeptic James Randi takes a fatal dose of homeopathic sleeping pills onstage, kicking off a searing 18-minute indictment of irrational beliefs. He throws out a challenge to the world’s psychics: Prove what you do is real, and I’ll give you a million dollars. (No takers yet.)

As E.O. Wilson accepts his 2007 TED Prize, he makes a plea on behalf of all creatures that we learn more about our biosphere.

Richard Dawkins urges all atheists to openly state their position — and to fight the incursion of the church into politics and science.

Richard Dawkins makes a case for “thinking the improbable” by looking at how the human frame of reference limits our understanding of the universe.

Hawking asks some Big Questions about our universe — and discusses how we might go about answering them.

Wright explain(s) why we appreciate the Golden Rule, why we… ignore it and why there’s hope that, in the future, we might all have the compassion to follow it.

Jared Diamond talks about the signs that collapse is near, and how — if we see it in time — we can prevent it.