NASA is increasingly not the future of space exploration. I love the fact that we have private sector folks devoting a lot of money to stimulate innovation in space technology.

I think graffiti is part of Berlin culture. You think about what the Berlin wall meant and how visible that was in everyone's life. How it was a part of their very identity.

In the nearer term, the likeliest source of risk is a conflict between China and the U.S. These are now the two largest economies in the world, and the combination of their economic interdependence, the sharp differences in their political and economic values, and the growing divergence in their interests makes this relationship potentially dangerous for everyone who might be affected by it - which means pretty much everyone.

I think it's fantastically narcissistic to believe that in the entire universe, with all of the planetary systems that we've already discovered and the countless others that are out there, that we are the only forms of life.

I think that the environment is very a complicated question. I am very sympathetic to people who support the environment who live in the United States. I am very sympathetic to people who don't support the environment who live in a very poor country.

There is always the risk that a conflagration in the Middle East becomes larger and more dangerous. In this scenario, we discover that the Arab Spring was merely the prelude to a deeper and much farther-reaching upheaval in the region that has greater impact on countries like Iran and Saudi Arabia.

An emerging market is a country where politics matters at least as much as economics to the market.