That's one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.

Science fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.

When all else failed, you had to rely on eyeball intrumentation.

If man survives for as long as the least successful of the dinosaurs-those creatures whom we often deride as nature's failures-then we may be certain of this: for all but a vanishingly brief instant near the dawn of history, the word 'ship' will mean- 'spaceship.'

It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars.

The only way to define your limits is by going beyond them.

Once you can reproduce a phenomenon, you are well on the way to understanding it.