We in astrophysics we think of the universe all the time. So to us, Earth is just another planet. From a distance, it's a speck. And I'm convinced that if everyone had a cosmic perspective you wouldn't have legions of armies waging war on other people because someone would say, "Stop, look at the universe."

Darwin's theory of evolution is a framework by which we understand the diversity of life on Earth. But there is no equation sitting there in Darwin's 'Origin of Species' that you apply and say, 'What is this species going to look like in 100 years or 1,000 years?' Biology isn't there yet with that kind of predictive precision.

Nothing is a thing: it's nothing. So I can imagine a place where there's not even nothing.

The chunks of comet Shoemaker-Levy 9 were so large, and were moving so fast, that each hit Jupiter with at least the equivalent energy of the dinosaur-killing collision between Earth and an asteroid 65 million years ago. Whatever damage Jupiter sustained, one thing is for sure: it's got no dinosaurs left.

I have found that when calculating what no one has calculated before, like my observing sessions on the mountain, my mental acuity peaks. Ironically, these are the times that I would flunk the reality check normally reserved for mental patients and dazed boxers: What is your name? What day is it? Who is the president of the United States?... I do not know, and I do not care. I am at peace with my equations as I connect to the cosmic engines that drive our universe.

With one linear centimeter of your lower colon there lives and works more bacteria (about 100 billion) that all humans who have ever been born. Yet many people continue to assert that it is we who are in charge of the world

I don't have specific television ambitions in the sense that I remain fundamentally and academic, and so, my innermost ambitions are what's the next discovery I can make; that's in my direct center.