Science is a philosophy of discovery. Intelligent design is a philosophy of ignorance. You cannot build a program of discovery on the assumption that nobody is smart enough to figure out the answer to a problem.

When I grew up I assembled my role models à la cart. I wanted to be an astrophysicist. If I tried to find a role model who grew up in the Bronx with my skin color who was an astrophysicist, I would never have become an astrophysicist.

No one wants to die, and no one wants to die poor. These are the two fundamental truths that transcend culture, they transcend politics, they transcend economic cycles.

Recognize that the very molecules that make up your body...are traceable to the crucibles that were once the centers of high mass stars that exploded their chemically rich guts into the galaxy, enriching pristine gas clouds with the chemistry of life. So that we are all connected to each other biologically, to the earth chemically and to the rest of the universe atomically.

Lots of people think, well, we're humans; we're the most intelligent and accomplished species; we're in charge. Bacteria may have a different outlook: more bacteria live and work in one linear centimeter of your lower colon than all the humans who have ever lived. That's what's going on in your digestive tract right now. Are we in charge, or are we simply hosts for bacteria? It all depends on your outlook.

Some molecules - ammonia, carbon dioxide, water - show up everywhere in the universe, whether life is present or not. But others pop up especially in the presence of life itself. Among the biomarkers in Earth's atmosphere are ozone-destroying chlorofluorocarbons from aerosol sprays, vapor from mineral solvents, escaped coolants from refrigerators and air conditioners, and smog from the burning of fossil fuels. No other way to read that list: sure signs of the absence of intelligence.

The most successful scientists in the history of the world are those who posed the right questions