Science is a collaborative enterprise, spanning the generations. When it permits us to see the far side of some new horizon, we remember those who prepared the way - seeing for them also.

We live in a vast and awesome universe in which, daily, suns are made and worlds destroyed, where humanity clings to an obscure clod of rock.

For years I've been stressing with regard to UFOs that extraordinary claims require extraordinary evidence.

The surface of the Earth is the shore of the cosmic ocean.

Scientists make mistakes. Accordingly, it is the job of the scientist to recognize our weakness, to examine the widest range of opinions, to be ruthlessly self-critical. Science is a collective enterprise with the error-correction machinery often running smoothly.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.

Valid criticism does you a favor.