Atoms are mainly empty space. Matter is composed chiefly of nothing.

Some racists still reject the plain testimony written in the DNA that all the races are not only human but nearly indistinguishable. . . .

I think the discomfort that some people feel in going to the monkey cages at the zoo is a warning sign.

Our passion for learning ... is our tool for survival.

A book is made from a tree. It is an assemblage of flat, flexible parts (still called "leaves") imprinted with dark pigmented squiggles. One glance at it and you hear the voice of another person, perhaps someone dead for thousands of years. Across the millennia, the author is speaking, clearly and silently, inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people, citizens of distant epochs, who never knew one another. Books break the shackles of time ― proof that humans can work magic.

Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs — in time, in space, and in potential — the tidy anthropocentric proscenium of our ancestors.

The cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature.