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.

Alltami (n.) The ancient art of being able to balance the hot and cold shower taps.

It takes a long time before we really get to grips with this [Darwin's 'On the Origin of Species'] and begin to understand it, because not only does it seem incredible and thoroughly demeaning to us, but it's yet another shock to our system to discover that not only are we not the centre of the Universe and we're not made by anything, but we started out as some kind of slime and got to where we are via being a monkey. It just doesn't read well.

The impossible often has a kind of integrity to it which the merely improbable lacks. How often have you been presented with an apparently rational explanation of something that works in all respects other than one, which is just that it is hopelessly improbable? Your instinct is to say, 'Yes, but he or she simply wouldn't do that.

and we’ll be saying a big hello to all intelligent life forms everywhere … and to everyone else out there, the secret is to bang the rocks together, guys.

Anyone who is capable of getting themselves made President should on no account be allowed to do the job.

My capacity for happiness," he added, "you could fit into a matchbox without taking out the matches first