There's a short piece by me here on systems of measurement - for the philosophers among you. It's on something I call the smedlium case : Imagine a world quite similar to our own that contains large quantities of a metal-like material – let's call it smedlium – which gradually and unpredictably alters in size. All smedlium objects expand and contract in unison. At one o'clock on one particular day all the smedlium objects are 5% larger than they were at mid-day; at two o'clock they are all 10% smaller, and so on. Despite this peculiarity, smedlium remains a useful material. In fact, it is the strongest and most durable material available. One of the inhabitants of this world builds machinery made wholly out of smedlium. The machines are used in situations where their size relative to non-smedlium objects doesn't matter. The smedlium engineer constructs and calibrates a measuring rule made out of smedlium to use when manufacturing such machines. She measures dim
Stephen Law is a philosopher and author. Currently Director of Philosophy and Cert HE at Oxford University Department of Continuing Education. Stephen has also published many popular books including The Philosophy Gym, The Complete Philosophy Files, and Believing Bullshit. For school talks/ media: stephenlaw4schools.blogspot.co.uk Email: think-AT-royalinstitutephilosophy.org