We want to build colonies on the Moon, Mars, the Moons of other planets, and even nearby asteroids. We want to make space tourism and commerce routine.

You must also realize that the stuff of excellence-truth, real scientific truth-can be elusive... It is too often covered by the heavy fog of fear and hidden by the darkness of your detractors.

There are no practical alternatives to air transportation.

When you know you can do something, and you feel good about yourself, you do not have to devalue others.

Changing your mind can move you into another dimension. Passages materialize exposing a hidden world that was there all along.

Creative people are often found either disagreeable or intimidating by mediocrities.

If you're talking to a child, you're going, 'This is the wonder of science and here's why I'm so fascinated by it.'

Some days are better than others ... It's been a long journey, but we're starting to see the light at the end of the tunnel now.

People take issue with individual aspects of Wikipedia all the time. But it's kind of hard to hate the general idea of a free encyclopedia. It's like hating kittens.

God is not a genie in a bottle, and your wish is not His command. His command better be your wish.

If you do things to the limit, and don’t purposely go over that limit, then I think it’s fine to do whatever you want. So long as you enjoy it. That’s what’s important.

The sea ebbs and flows, but the rock remains unmoved.

Fishing, Danny boy, is purely a state of mind. Some men, when they are fishing, are after fish. Me, I'm after things you could never set a barbed hook in.