Big Ben: accurate to one second an hour, but today we can build clocks that loose one second in 138 million years. Credit: Taz Wake
There was an interesting TV documentary last night telling the history of the science of measurement.
Throughout our history, developments in our ability to measure the world around us have changed our lives. In the documentary, Prof. Marcus du Sautoy explores how seconds and metres came to be as two of the most fundamental units of measure, how distance and time are linked, and the quest for ever greater precision in science.
Catch it on BBC iplayer:
Further documentaries in the same series will be on in the next couple of weeks: