It could be that these other civilizations, if they are far more advanced intellectually than we are, would not even measure our existence as a blip on the intelligence radar. They could be so advanced that we are to them what worms are to us.

I've said multiple times that the world's first trillionaire is going to be the person who exploits the resources of asteroids, the natural resources that are rare on earth and common on selected asteroids. So there are many different reasons you might want to go into space. You might want to spend your honeymoon on the far side of the moon.

With ticket prices, do you ask yourself, why I'm paying $70 to see the arts? You say, "No, that's what the symphony is costing me."

There are no wild, seedless watermelons. There's no wild cows... You list all the fruit, and all the vegetables, and ask yourself, is there a wild counterpart to this? If there is, it's not as large, it's not as sweet, it's not as juicy, and it has way more seeds in it. We have systematically genetically modified all the foods, the vegetables and animals that we have eaten ever since we cultivated them. It's called artificial selection.

If humans one day become extinct from a catastrophic collision, there would be no greater tragedy in the history of life in the universe. Not because we lacked the brain power to protect ourselves but because we lacked the foresight. The dominant species that replaces us in post-apocalyptic Earth just might wonder, as they gaze upon our mounted skeletons in their natural history museums, why large headed Homo sapiens fared no better than the proverbially peabrained dinosaurs.

When students cheat on exams, it's because our school system values grades more than students value learning.

Kids should be allowed to break stuff more often. That's a consequence of exploration. Exploration is what you do when you don't know what you're doing.