In energy, you have to plan and do research way in advance, sometimes decades in advance to get a new system that's safer, doesn't require us to go around the world to get all our oil.

We always overestimate the change that will occur in the next two years and underestimate the change that will occur in the next ten. Don't let yourself be lulled into inaction.

But the improvements will happen faster and last longer if we can channel market forces, including innovation that's tailored to the needs of the poorest, to complement what governments and nonprofits do. We need a system that draws in innovators and businesses in a far better way than we do today.

America's high schools are obsolete. By obsolete, I don't just mean that they're broken, flawed, or underfunded, though a case could be made for every one of those points. By obsolete, I mean our high schools-even when they're working as designed-cannot teach all our students what they need to know today.

I watched the piles of feces go up the conveyor belt... They made their way through the machine... A few minutes later I took a long taste of the end result: a glass of delicious drinking water.

We believe the world changes when the boldest thinking is directed at the toughest problems

The advance of technology is based on making it fit in so that you don't really even notice it, so it's part of everyday life.