If NASA were advancing a space frontier there would be challenges you've never seen before. You have to be creative and you have to patent some new idea. You get to Mars...well, how do we get the water from the soil? I gotta invent a new device that will do that. And the carbon dioxide in the atmosphere, how can we use that? Can we breathe the oxygen from the carbon dioxide?

When scientifically investigating the natural world, the only thing worse than a blind believer is a seeing denier.

I am not the most annoying person to bring to a movie 'cause I basically hold it in and write about it later or tweet about it. The most annoying people to bring to movies, I think we all agree, are those who read the book first.

Science reveals that all life on Earth is one.

Long ago Mars was an oasis of running water.Today the Martiansurfaceis a sterile,barren desert. Here on Earth, who knows what climactic knobs we unwittingly turn,which might one day render Earth as dry and lifeless as Mars. (From the cover of Old Poison by Joan Francis)

You can make a stack high enough to reach the moon and back, and only then will you have used your 100 billion hamburgers. This is terrifying news to cows.

The universe for me was other planets and other star systems and other galaxies. I enjoyed tracking it, but it had no specific influence on my ambitions for that reason. It wasn't really far enough away from Earth to matter to me.