Three and a half million years ago our ancestors - yours and mine - left these traces [indicates footprints]. We stood up and parted ways from them. Once we were standing on two feet, our eyes were no longer fixated on the ground. Now, we were free to look up and wonder.

The history of exploration across nations and across time is not one where nations said, 'Let's explore because it's fun.' It was, 'Let's explore so that we can claim lands for our country, so that we can open up new trade routes; let's explore so we can become more powerful.'

WhenIWasYourAge: People were never "living with their disease." We cured them. Or they died from it.

Kids are born curious about the world. What adults primarily do in the presence of kids is unwittingly thwart the curiosity of children.

Some claim evolution is just a theory. As if it were merely an opinion. The theory of evolution, like the theory of gravity, is a scientific fact. Evolution really happened. Accepting our kinship with all life on Earth is not only solid science. In my view, it’s also a soaring spiritual experience.

When you are a hammer, all of your problems will look like nails to you.

Rational thoughts never drive people's creativity the way emotions do.