For years, I’ve been using this silly play on words to introduce some of the interesting structures that can hide within a perfectly innocent looking set of error bars. An error bar is a way of indicating graphically the uncertainty on a quantity, but it also has deliciously evocative connotations. Errors and bars seem to go together. The former can lead to the latter and vice versa.
Last year, I was invited to talk about uncertainty in long-term climate data sets at a meeting which was being held at NPL. I was immensely excited by this and it seemed like the perfect opportunity to turn the play on words into something more visual. I had hoped to find a real “error bar”, but alas, I could not. I still believe that somewhere out there in the wild is the genuine article, the real deal.