David Deutsch: What is our place in the cosmos?

Legendary physicist David Deutsch back-burners the work for which he's best known -- quantum physics, quantum computing, the many-worlds theory -- to discuss a more basic topic: how to think about our species' significance in the universe. Far from being simply "chemical scum," we have the ability to gain knowledge, the importance of which he illustrates in spectacular manner. As a result, he says, we are always equipped to solve problems (including global warming). The brain contains the tools we need: knowledge, reason and creativity. It's a thrilling, and profoundly optimistic argument.