Stephen asks Paul Goldberger why America can't take our existing skyscrapers and stack them to make the tallest building in the world. Stephen asks Neil deGrasse Tyson what dark matter is because he doesn't see the color of matter.

Stephen asks Lama Surya Das if it would be hard for Barack Obama to convert from a secret Muslim to a Buddhist. Daniel C. Esty believes the free market can solve the environmental problem. Stephen's been saying that for years.