From artefacts to atoms : the BIPM and the search for ultimate measurement standards

The International Bureau of Weights and Measures (BIPM) is currently implementing the greatest change ever in the world's system of weights and measures — it is redefining the kilogram, the final artefact standard, and reorganizing the system of international units. This book tells the inside story of what led to these changes, from the events surrounding the founding of the BIPM in 1875 — a landmark in the history of international cooperation — to the present. It traces not only the evolution of the science, but also the story of the key individuals and events. The BIPM was the first international scientific laboratory. Founded in 1875 by the Metre Convention, its original tasks were to conserve the new international standards of the metre and the kilogram, to carry out calibrations for Member States and undertake research to advance measurement science. The book is based on the substantial archive of the BIPM which, from the very beginning, recounts the many discussions and arguments first as to whether and how such an institute should be created and in due course, how over the next one hundred and thirty years it should develop. Despite many national and personal rivalries, the institute actually created was admirably suited to its declared tasks. In the years and decades that followed, the scientific work of the small group of men who made up its first staff was of a very high order. One of the early Directors received the Nobel Prize for physics in 1920 for his discovery of invar. The international governing Board of the institute, the International Committee of Weights and Measures, has guided the institute from one charged with the conservation of the prototype artefacts to one now at the centre of world metrology and preparing for the redefinition of the last remaining artifact, the kilogram, in terms of a fixed value for one of the fundamental constants of physics, the Planck constant Content: Chapter 1: The origins of the Metre Convention 1851 to 1869 -- Chapter 2: The creation of the International Metre Commission 1869 -- Chapter 3: The International Metre Commission, meetings of 1872/73 -- Chapter 4: The casting of 1874 and the first steps in the fabrication of the new metric standards -- Chapter 5: The Diplomatic Conference of the Metre 1875 -- Chapter 6: The creation of the BIPM and the beginning of the construction of the new metric prototypes problems with the French Section -- Chapter 7: 1879 to 1889, the first decade of scientific work at the International Bureau Progress with metres and instruments -- Chapter 8: New Member States and the first General Conference on Weights and Measures, 1889 -- Chapter 9: The development of the scientific work at the BIPM, the General Conferences of 1895 and 1901 -- Chapter 10: The creation of the Grands Laboratoires Physikalisch-Technische Reichsanstalt (PTR) National Physical Laboratory (NPL) -- Chapter 11: The story of invar and the extension of the role of the International Bureau at the 6th General Conference 1921 -- Chapter 12: The 7th and 8th General Conferences 1927 and 1933, practical metrology and the Bureau during the Second World War -- Chapter 13: The SI, absolute electrical units, the International Committee and the creation of the ionizing radiation section -- Chapter 14: The adoption of the SI, revising the Metre Convention, new definitions of the metre and second at the 11th General Conference 1960 -- Chapter 15: The mole, the speed of light and more about the Metre Convention -- Chapter 16: New science at the BIPM and the Recognition of National measurement Standards -- Chapter 17: The redefinition of the kilogram and the move towards the New SI -- Epilogue: The new SI and the future role of the BIPM -- Appendix English text of the Metre Convention. This is the story of the International Bureau of Weights and Measures-from its origins in the 1860s until today. It highlightes the role of key individuals in the development of the institution and the path from artifact standards of the metre and the kilogram to units based on the fundamental constants of physics.