Time, we know, is relative. You can travel light years through the stars and back, and if you do it at the speed of light then, when you return, you may have aged mere seconds while your twin brother or sister will have aged twenty, thirty, forty or however many years it is, depending on how far you traveled. This will come to you as a profound shock, particularly if you didn't know you had a twin brother or sister.

He felt a spasm of excitement because he knew instinctively who it was, or at least knew who it was he wanted it to be, and once you know what it is you want to be true, instinct is a very useful device for enabling you to know that it is.

It is most gratifying," it said, "that your enthusiasm for our planet continues unabated, and so we would like to assure you that the guided missiles currently converging with your ship are part of a special service we extend to all of our most enthusiastic clients, and the fully armed nuclear warheads are of course merely a courtesy detail. We look forward to your custom in future lives ... thank you.

That was it. That was really it. She knew that she had told herself that that was it only seconds earlier, but this was now the final real ulimate it.

The simple truth is that interstellar distances will not fit into the human imagination.

Fiordland, a vast tract of mountainous terrain that occupies the south-west corner of South Island, New Zealand, is one of the most astounding pieces of land anywhere on God's earth, and one's first impulse, standing on a cliff top surveying it all, is simply to burst into spontaneous applause.

The storm had now definitely abated, and what thunder there was now grumbled over more distant hills, like a man saying 'And another thing...' twenty minutes after admitting he'd lost the argument.