For many, to live in a universe that may have no purpose, and no creator, is unthinkable.

I hope that every [person] at one point in their life has the opportunity to have something that is at the heart of their being, something so central to their being that if they lose it they won't feel they're human anymore, to be proved wrong because that's the liberation that science provides. The realization that to assume the truth, to assume the answer before you ask the questions leads you nowhere.

For, after all, in science one achieves the greatest impact (and often the greatest headlines) not by going along with the herd, but by bucking against it.

I cannot stress often enough that what science is all about is not proving things to be true but proving them to be false.

If we wish to draw philosophical conclusions about our own existence, our significance, and the significance of the universe itself, our conclusions should be based on empirical knowledge. A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa, whether or not we like the implications.

In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection.

Aside from communications satellites, space is devoid of industry.