Science is fun. Science is curiosity. We all have natural curiosity. Science is a process of investigating. It's posing questions and coming up with a method. It's delving in.

Nature is not simply a technical or economical resource, and human beings are not mere numbers. To suggest that one can somehow align all the squabbling institutions of science, environmental management, government and diplomacy in an alliance of convenience to regulate the global climate seems to me optimistic.

Humanity has experienced many revolutionary changes over the course of history: revolutions in agriculture, in science, industrial production, as well as numerous political revolutions. But these have all been limited to the external aspects of our individual and collective lives.

The most important thing we can do is inspire young minds and to advance the kind of science, math and technology education that will help youngsters take us to the next phase of space travel.

Science always uses metaphor.