Why can't Pluto be a planet? Some people like Pluto. And if it doesn't exist then they don't have a favorite planet. Right? Please write back but not in cursive because I can't read cursive.

We need more science in the world. Train me.

People think about life from day-to-day rather than thinking about life as something that invents a new kind of tomorrow.

I'm often asked whether I believe in Global Warming. I now just reply with the question: "Do you believe in Gravity?"

I look up at the night sky, and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than both of those facts is that the Universe is in us. When I reflect on that fact, I look up — many people feel small, because they’re small and the Universe is big, but I feel big, because my atoms came from those stars.

Your center of mass is a place you cannot visit but you always carry with you. Like memories, it is part of life's baggage.

We are in the universe and the universe is in us.