According to Rachel Riley on BBC News this morning, it’s National Numeracy Day today. So I thought I’d find an interesting word to do with maths. I failed at this (not to say there aren’t any interesting maths words – just none of them interested me this morning. I have a very short attention span).

Obviously my next port of call for an idea was the box set I’m watching at the moment – a Danish drama on Netflix called ‘The Rain’. That took me to English words we get from Danish. And one of these is femto, a prefix in the metric system from the Danish word for 15, ‘femten’. A femtometre is equal to one quadrillionth of a meter (we got there eventually). Which is really freaking small. To put that into some kind of context, a proton has a diameter of roughly 1.6 femtometers. Like I said, they’re really freaking small.