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

[Kepler] preferred the hard truth to his dearest illusions, and that is the heart of science.

My view is that if there is no evidence for it, then forget about it. An agnostic is somebody who doesn’t believe in something until there is evidence for it, so I’m agnostic.

The fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses.

Because men, compared to male chimps, have such relatively small testicles (large testicles indicate a species where many males mate, one after the other, with the same female), we might guess that promiscuous societies were uncommon in the immediate human past.

The universe forces those who live in it to understand it.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience..... To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.