Posts Tagged ‘BIPM’

Where were you on World Metrology Day?

May 21, 2014
On World Metrology Day 2014 I was attending a meeting of working group 4 of the Consultative Committee on Thermometry at the BIPM in Paris

On World Metrology Day 2014 I was attending a meeting of Working Group 4 of the Consultative Committee on Thermometry at the BIPM in Paris

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 achievedpeople 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

Me and Steph at the Gare du Nord

Stephanie and I cross paths at the Gare du Nord.


A Universal Language: the triumph of the SI

October 17, 2011
The World Standards Day Poster.

The World Standards Day Poster.

A Universal Language – a language that would allow genuine communication among all of humanity – has been a dream for as long as languages have existed. For spoken language, I suspect that this will remain a dream, and indeed the diversity of language is probably a cause for celebration. Scientifically, English is undoubtedly the current lingua franca, but scientists in many countries publish their findings in other languages, notably Russian, Chinese, French and German. However, when it comes to scientific measurement, there is an amazing and near universal agreement: the International System of Units – the SI – is the agreed system of measurement units amongst almost all the scientists in almost every country on Earth.

Just like a spoken language, the shared use of the language of measurement enables communication and indicates the existence of shared culture. I am writing this because this is a truly remarkable achievement which is largely uncommented upon. Despite the astonishing diversity of languages and cultures, there is almost universal use of the SI system of units when scientists communicate their results.

To be sure, there are still exceptions. Many subgroups of scientists value their own group culture above the ability to communicate universally. Typically they say they find their familiar units ‘more convenient’ or ‘more natural’. But time is not on their side . Whereas we are all losers when a spoken language is lost, we are all winners when people abandoned the use of angstroms and chose to use nanometres instead.

The SI system may appear to be essentially unchanging, but like all ‘languages’ it evolves with the culture it supports. I once spoke with Richard Davis, at that time the Executive Secretary of CCT, about the difference between the SI and the previous systems of units – the CGS system (centimetre – gram – second) and the MKS system (metre-kilogram-second). ‘Basically‘ he said, ‘the SI is the MKS system, but it has people who care about it‘.

Measurement may be defined as ‘quantitative comparison of an unknown quantity with a standard quantity’, and practically this requires people to agree about the standard quantities and exactly how they are realised – something which changes with time and technology – and how the comparisons are made. So there is an extensive system of committees which discuss points of  detail which affect the minutiae of the measurement system. But the existence of these committees keeps the system of units ‘alive’.

Whereas ‘globalisation’ is a contentious issue when it comes to manufacturing and industry, when considering the language of science, there is no doubt in my mind that it is an unequivocally positive process. And I think it is worth pausing, perhaps just for a moment, to reflect that occasionally people can cooperate in a global scale and achieve great things.

Pause… … …

Bring on Global Warming!

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