I've always been amazed by Da Vinci, because he worked out science on his own. He would work by drawing things and writing down his ideas. Of course, he designed all sorts of flying machines way before you could actually build something like that.

If you think of global public goods like polio eradication, the kind of risk-taking new approach, philanthropy really does have a role to play there, because government doesn't do R&D about new things naturally as much as it probably should, and so philanthropy's there.

R&D generally has been a bipartisan thing, because in the IT space, in the medical space, the U.S., the benefits to ourselves and the world and our economy have been very, very clear. I'm hopeful we can make a very strong case there. Energy is actually harder; it takes more time to get a product, but if you do it's a very, very big market and the constraints of doing that in a clean way are more obvious all the time.

Lectures should go from being like the family singing around the piano to high-quality concerts.

You always overestimate what you can get done in a year and underestimate what you can get done in 10 years.

The United States has a huge budget deficit so taxes are going to have to go up and I certainly agree they should go up more on the rich than everyone else. That - that's just justice.

Digital technology has several features that can make it much easier for teachers to pay special attention to all their students.