Mankind, scientists agree, is a tiny and insignificant anomaly in the impersonal vastness of the universe. But what would that universe be like if we were not here to say something about it? Would it even be so vast, without the fact of our insignificance to give it scale?

This paradox is what Michael Frayn calls ‘the world’s oldest mystery’. He shows how fleeting and indeterminate our contacts with the world around us are. The world is what we make of it - but what are we?