How long is a piece of string?

You'd think it was a straightforward enough question, but as Alan Davies discovers in tonight's Horizon (BBC 2, 9pm), things are never that straightforward. The programme is full of the sort of fascinating facts we love here at Match Wits.


For example, did you know that if all the space around the molecules in the human body was removed the whole human population on Earth would be reduced to the size of a sugar cube? Also, if you hit a sugar cube in a cupboard (or anywhere dark) you can sometimes see little blue sparks.