6 June

Darkness and light. Geometry. The Romans and Egyptians entombed things, some of their greatest legacies are their tombs. But it's not just about death, to entomb is to make implicit, rather than explicit. Knowledge can be explicit or implicit. Then along came the Greeks and Jerusalem, civilisations of light. Thales the Greek at the pyramids, measuring the shadows to create geometry. Look at what the Greeks did to solids - completely empty spaces, filled with light. This is still our civilisation today, we still live in the light, forgetting the dark or implicit. Our main infrastructure is communications, pure light, weighing less than the tiniest grain of sand. And the implied of settled habitual institutions has been smashed to make everything explicit in the full glare of light.