Many of the first-day talks focused on education. Among them were:

• Stuart Firestein, a neuroscientist at Columbia University who stressed that science isn't about accumulating facts but about learning enough so that we can expose our ignorance and ask the right questions.

• Freeman Hrabowski, the longtime president of the University of Maryland, Baltimore County, who has won acclaim for innovative approaches to education and research and for strengthening scientific and engineering education for minority students.

• And in perhaps the best example of self-organized learning, Richard Turere, a 13-year-old from Kenya, who figured out how to save his family's cows from marauding lions by inventing a system of lights to ward off the lions.