Where were you on World Metrology Day?
I was in Paris, attending a meeting at the International Bureau of Weights and Measures (BIPM).
The Bureau is reached by turning off the busy main street through Sevres, and turning up a narrow cobbled path to the historic Pavillon de Breteuil
As I entered the splendid gardens of the Pavilion on this bright Tuesday morning, I found myself taking coffee with the creme-de-la-creme of world experts in every aspect of temperature measurement.
They were gathered for the 27th meeting of the Consultative Committee on Thermometry (CCT), and I was there to update my colleagues in Working Group 4 of the CCT on the progress of my research.
Personally, I find the formality of these meetings a little intimidating, and I guess everybody else does too. But it is hard to imagine that things would be very different in any organisation with the stated aims of BIPM
…to ensure world-wide uniformity of measurements and their traceability to the International System of Units (SI).
And what gives BIPM the right to do this? The Convention of the Metre, a diplomatic treaty between fifty-six nations. It is the first signing of this treaty in 1875 which is commemorated each year on 20th May.
Despite it’s name, the convention applies does not just apply to measurements of length.
So when a thermometer in Japan agrees with one in Australia, this has not happened by coincidence. It is has happened because of ongoing active collaborations mediated formally and informally via the BIPM.
This coherence of measurement brings benefits to everyone at very little cost or inconvenience. However because BIPM’s goal of world-wide uniformity of measurements has been substantially achieved – people just don’t notice that this coherence is a positive achievement, and that it needs active ongoing attention for it to be maintained.
As I whisper to myself during the long hours of our meetings, “We worry about the millikelvins so that you don’t have to”
By the way, I feel obliged to mention that my wife, Stephanie Bell, sits on the CCT itself and is thus metrologically more important than me: I only sit on a Working Group.
But because of our shared involvement in CCT, these triennial committee meetings represent a significant childcare problem for us – a problem which is probably unique in the history of the CCT.
So this week Stephanie travelled to CCT on Sunday, returning to the UK on Monday to make sure the children were up for their exams on Tuesday morning. She then returned to Paris on Tuesday afternoon for more meetings – and I hope she will be back home on Friday
My own travel arrangements were relatively straightforward. I left the UK on Monday for a Tuesday morning meeting and then returned immediately afterwards.
But by good chance, our paths crossed late on Monday afternoon at the Gare du Nord as I travelled to BIPM and she travelled home.
So for 10 precious minutes we stood still amongst the hurly burly of the moving world, and shared a beer. And then we went on our respective ways. Santé