May 20th is World Metrology Day, marking the anniversary of the signing the Metre Convention in 1875; something that set the way ahead for worldwide standardised measurements. (nothing to do with weather at all!).

To coincide with this year being the International Year of Light , the theme of this year’s World Metrology Day is Measurement and Light. Celebrating this fact, a number of the world’s primary measurement standards laboratories are holding special events. It’s not often that these institutes, which include NPL, (UK) and NIST, (US) open their doors to the public, so the events being held today and over the coming days are a great chance to see some of the exciting projects around the world that use light and measurement, which means that there are likely to be a few exotic lasers on show!