World Metrology Day
Celebrated on 20 May each year, World Metrology Day helps the public to understand what is meant by the science of measurement and why we are so dependent upon it. This little-known science underpins countless aspects of our daily lives. Every time we buy a kilogram of oranges, use the GPS in our car to navigate, swallow a pill, cross a bridge or enter a building, we should spare a thought for the metrologists who made this possible. Thanks to the metric system, an architect trained in Sudan will be able to design an office building in Mexico, as the standard measurements will be the same in both countries.
A bit of history: the metric system which is now the universal standard for measurements was created over 200 years ago. World Metrology Day commemorates the signing, on 20 May 1875, of the Metre Convention, an international treaty designed to ensure that everyone around the world used the same metric system to measure weight and length, in order to ensure fair trade. Today, over 100 countries and economies participate in the worldwide measurement system. In November 2023, UNESCO’s governing bodies proclaimed that 20 May would henceforth be celebrated as World Metrology Day (). Celebrations of the Day each year are jointly supported by the International Bureau of Weights and Measures and the International Organization of Legal Metrology.
World Metrology Day promotes the benefits of measurement science to a global audience, emphasizing metrology's value for quality of life and environmental preservation - a mission in harmony with UNESCO's goal of building a better world through science and education.
"At UNESCO, the lead United Nations agency for science, metrology underpins all our work. From mapping the ocean floor to assessing the volume of glacier melt in the Andes and Central Asia – two flagship initiatives by UNESCO – we depend on measurements as powerful tools to drive scientific discovery, technological innovation and sustainable development."
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Celebrating World Metrology Day: interview with Anthony Donnellan, Director of OIML
Although often unnoticed, the standardised metric system is essential in our daily lives, ensuring accurate and safe measurements worldwide. Join metrology expert Anthony Donnellan, director of the International Organization of Legal Metrology (OIML), as he shares invaluable insights into the importance of this science in our society. As we mark World Metrology Day, take a moment to reflect on how this system impacts you.
What is metrology?
What can go wrong when the wrong units of measure are used
UNESCO's expertise in Science, Technology, Engineering and Mathematics (STEM)
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