I [do not know] when the end of science will come. ... What I do know is that our species is dumber than we normally admit to ourselves. This limit of our mental faculties, and not necessarily of science itself, ensures to me that we have only just begun to figure out the universe.

There was a transition going on - Baghdad being the intellectual capital of the world where major advances were made in agriculture and mathematics and engineering and medicine and astronomy, and then that all sort of collapsed. And I was trying to understand how such a intellectually fertile environment can lose its compass bearing. Because I think about the creative centers today - countries, or even regions. Will Silicon Valley always be as innovative? Will the United States be innovative, or will we become complacent?

I have a multivolume history of the world from the 19th century that begins with Noah's flood as though it's as historical a fact as the rise and fall of Rome.

I see all this talk about jobs going overseas as a symptom of the absence of innovation. And the absence of innovation is a symptom of there being no major national priority to advance a frontier.

But my vote for Venus's most peculiar feature is the presence of craters that are all relatively young and uniformly distributed over its surface. This innocuous-sounding feature implicates a single planetwide catastrophe that reset the cratering clock... turning Venus's entire surface into the American automotive dream-a totally paved planet.

The value of the space program is beyond science, it's beyond military; it's a cultural shift in how we think of our place in the universe.

Rational thoughts never drive people's creativity the way emotions do.