We need to look at less obvious paths, things like the wind in the jet stream, which is very high up. The material science of what type of kite string you would need to connect up to that. That's still at the basic research level.

I've been very lucky, and therefore I owe it to try and reduce the inequity in the world. And that's kind of a religious belief. I mean, it's at least a moral belief.

With nuclear weapons, you'd think you would probably stop after killing 100million. Smallpox won't stop. Because the population is naïve, and there are no real preparations. That, if it got out and spread, would be a larger number.

The next big invention that will change the way we live should be things like ways of generating energy like electricity.

The moral systems of religion, I think, are super important.

The interview process tests not what the applicant knows, but how well they can process tricky questions: If you wanted to figure out how many times on average you would have to flip the pages of the Manhattan phone book to find a specific name, how would you approach the problem? If a spider fell to the bottom of a 50-foot well, and each day climbed up 3 feet and slipped back 2, how many days would it take the spider to get out of the well? .

Cutting through complexity to find a solution runs through four predictable stages: determine a goal, find the highest-leverage approach, discover the ideal technology for that approach, and in the meantime, make the smartest application of the technology that you already have - whether it's something sophisticated, like a drug, or something simpler, like a bednet.