Before another century is done it will be hard for people to imagine a time when humanity was confined to one world, and it will seem to them incredible that there was ever anybody who doubted the value of space and wanted to turn his or her back on the Universe.

What lasts in the reader's mind is not the phrase but the effect the phrase created: laughter, tears, pain, joy. If the phrase is not affecting the reader, what's it doing there? Make it do its job or cut it without mercy or remorse.

You must keep sending work out; you must never let a manuscript do nothing but eat its head off in a drawer. You send that work out again and again, while you're working on another one. If you have talent, you will receive some measure of success - but only if you persist.

Maybe happiness is this: not feeling like you should be elsewhere, doing something else, being someone else.

This idea [standardized time zones] was first advanced and fought for by Sandford Fleming of Canada and Charles F. Dowd of the United States. I mention them chiefly because like so many benefactors of mankind they have been rewarded by total obscurity.

People are entirely too disbelieving of coincidence. They are far too ready to dismiss it and to build arcane structures of extremely rickety substance in order to avoid it. I, on the other hand, see coincidence everywhere as an inevitable consequence of the laws of probability, according to which having no unusual coincidence is far more unusual than any coincidence could possibly be.

Of course there are worlds. Millions of them! Every star you see has worlds, and most of those you don't see.