Our behavior toward each other is the strangest, most unpredictable, and most unaccountable of all the phenomena with which we are obliged to live. In all of nature, there is nothing so threatening to humanity as humanity itself.

Science is founded on uncertainty. Each time we learn something new and surprising, the astonishment comes with the realization that we were wrong before.

The literature has become too vast to comprehend...It is...difficult to grasp even for workers in closely neighboring fields. ...There is much more reliance on word of mouth for the transmission of scientific data...gossip.

All of today's DNA, strung through all the cells of the earth, is simply an extension and elaboration of [the] first molecule.

Viewed from the distance of the moon, the astonishing thing about the earth, catching the breath, is that it is alive. The photographs show the dry, pounded surface of the moon in the foreground, dry as an old bone. Aloft, floating free beneath the moist, gleaming, membrane of bright blue sky, is the rising earth, the only exuberant thing in this part of the cosmos.

I do not understand modern physics at all, but my colleagues who know a lot about the physics of very small things, like the particles in atoms, or very large things, like the universe, seem to be running into one queerness after another, from puzzle to puzzle.

If we are to be destroyed we will do it ourselves by warfare with thermonuclear weaponry.