The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home.

The well-meaning contention that all ideas have equal merit seems to me little different from the disastrous contention that no ideas have any merit.

I don't know the answer. Maybe no one knows. Maybe when you grow up, you'll be the first to find out.

Curiosity and the urge to solve problems are the emotional hallmarks of our species.

The lifetime of a human being is measured by decades, the lifetime of the Sun is a hundred million times longer. Compared to a star, we are like mayflies, fleeting ephemeral creatures who live out their lives in the course of a single day.

Books are key to understanding the world and participating in a democratic society.

And you are made of a hundred trillion cells. We are, each of us, a multitude.