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

The near side of a galaxy is tens of thousands of light-years closer to us than the far side; thus we see the front as it was tens of thousands of years before the back. But typical events in galactic dynamics occupy tens of millions of years, so the error in thinking of an image of a galaxy as frozen in one moment of time is small.

There is no other species on Earth that does science. It is, so far, entirely a human invention, evolved by natural selection in the cerebral cortex for one simple reason: it works. It is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything.

We on Earth have just awakened to the great oceans of space and time from which we have emerged.

Man is a transitional animal. He is not the climax of creation

Perhaps the depth of love can be calibrated by the number of different selves that are actively involved in a given relationship.

Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves.