An observer studying the Solar system dispassionately, and finding himself capable of bringing the four giant planets to his notice, could reasonably say that the Solar system consisted of one star, four planets, and some traces of debris.

Outside intelligences, exploring the Solar System with true impartiality, would be quite likely to enter the Sun in their records thus: Star X, spectral class G0, 4 planets plus debris.

Predicting the future is a hopeless, thankless task, with ridicule to begin with and, all too often, scorn to end with.

Ten years on the moon could tell us more about the universe than a thousand years on the earth might be able to.

The fact that the general incidence of leukemia has doubled in the last two decades may be due, partly, to the increasing use of x-rays for numerous purposes. The incidence of leukemia in doctors, who are likely to be so exposed, is twice that of the general public. In radiologists the incidence is ten times greater.

By 1204, the only place where the entire body of Greek learning existed, still intact, was Constantinople. As a result of the crusaders' conquest, however, Constantinople was ruthlessly pillaged and destroyed and almost all the great treasures of ancient Greek learning were lost forever. It is because of that sack, for instance, that we have only seven plays left out of the better than one hundred written by Sophocles. The tragedy of 1204 can never be undone and for all of time, only bits and pieces of the marvelous Greek world can be known to us.

History is a story without an end.

Private profit is often hidden under a careful coating of great patriotism.

I don't believe in flying saucers... The energy requirements of interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades.

Start with a planet like the earth, with a complement of simple compounds bound to exist upon it, add the energy of a nearby sun, and you are bound to end with nucleic acids. You can't avoid it.