Life existed on Earth for nearly four billion years before anything remotely resembling a human being showed up. And even then, when we started to branch off from other apes about 10,000,000 years ago, our ancestors looked pretty different.

Gamma rays are the sort of radiation you should avoid. Want proof? Just remember how the comic strip character "The Hulk" became big, green, and ugly.

Grab something off the shelf that's on the spaceship-an ashtray, it doesn't matter what. Because I can tell you, if they flew here from another galaxy, no matter what you've pulled off the shelf, it'll be unlike anything we have on Earth.

Scientists are human. We have our blind spots and prejudices. Science is a mechanism designed to ferret them out. Problem is we aren't always faithful to the core values of science.

I would teach how science works as much as I would teach what science knows. I would assert (given that essentially, everyone will learn to read) that science literacy is the most important kind of literacy they can take into the 21st century. I would undervalue grades based on knowing things and find ways to reward curiosity. In the end, it's the people who are curious who change the world.

There are books on my shelf that I'm not into. They are things I don't know anything about yet. It's going to lead me off into a new place. The books don't represent an interest; they represent a source of my ignorance.

We are all connected; To each other, biologically. To the earth, chemically. To the rest of the universe atomically.