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Christian Bordé
Christian Bordé (15 March 1943 - 30 August 2023) was a French physicist. He has been a member of the French Academy of Sciences since December 2008. Biography Emeritus research director at the CNRS, he is known for his work in the field of ultra-high resolution laser spectroscopy. He invented and developed saturation spectroscopy, which he used to study many new and fundamental effects in molecular physics. His name is attached to the design of a whole class of atomic interferometers based on the recoil effect, which make it possible to produce optical clocks, measure atomic masses and probe the properties of space-time. In particular, he demonstrated that these interferometers allowed very accurate measurement of the fields of inertia. The proximity of his work to the field of metrology has led it to preside on several occasions, on behalf of the French Academy of Sciences, over the meetings of the General Conference on Weights and Measures, the executive organ of the Metre Con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:Category:French Physicists
European physicists Physicists A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ... Physicists by nationality {{CatAutoTOC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Academy Of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefront of scientific developments in Europe in the 17th and 18th centuries, and is one of the earliest Academy of Sciences, Academies of Sciences. Currently headed by Patrick Flandrin (President of the academy), it is one of the five Academies of the . __TOC__ History The Academy of Sciences traces its origin to Colbert's plan to create a general academy. He chose a small group of scholars who met on 22 December 1666 in the King's library, near the present-day Bibliothèque nationale de France, Bibliothèque Nationale, and thereafter held twice-weekly working meetings there in the two rooms assigned to the group. The first 30 years of the academy's existence were relatively informal, since no statutes had as yet been laid down for the ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centre National De La Recherche Scientifique
The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 engineers and technical staff, and 7,085 contractual workers. It is headquartered in Paris and has administrative offices in Brussels, Beijing, Tokyo, Singapore, Washington, D.C., Bonn, Moscow, Tunis, Johannesburg, Santiago de Chile, Israel, and New Delhi. Organization The CNRS operates on the basis of research units, which are of two kinds: "proper units" (UPRs) are operated solely by the CNRS, and Joint Research Units (UMRs – ) are run in association with other institutions, such as universities or INSERM. Members of Joint Research Units may be either CNRS researchers or university employees ( ''maîtres de conférences'' or ''professeurs''). Each research unit has a numeric code attached and is typically headed by a university profe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic, molecular and macro scale, and over astronomical distances. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Current applications of spectroscopy include biomedical spectroscopy in the areas of tissue analysis and medical imaging. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Clock
Optical clocks are the most precise instruments ever developed. The precision of a clock is the smallest unit of time it can measure. Optical clocks reach record-breaking precision by counting oscillations of visible light, which oscillates up to 750 quadrillion times a second. By counting these oscillations, one can divide a second into 750 quadrillion pieces. Each of these pieces is roughly one femtosecond. This means that by counting oscillations of light, one can be certain of the time to within one femtosecond. Oscillations of light are counted using a frequency comb, and stabilized using atoms. Optical clocks are a subset of atomic clocks, which typically measure microwaves. However, microwaves oscillate around 100,000 times slower than visible light. For this reason, optical clocks are expected to replace microwave caesium clocks as the Caesium standard, definition of the second. Several elements have been used in optical clocks, including magnesium, Aluminium, aluminum, pot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of Unit of measurement, units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the ''International Bureau of Weights and Measures, Bureau International des Poids et Mesures'' (BIPM) was established by the Metre Convention. This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960. Metrology is divided into three basic overlapping activities: * The definition of units of measurement * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Conference On Weights And Measures
The General Conference on Weights and Measures (abbreviated CGPM from the ) is the supreme authority of the International Bureau of Weights and Measures (BIPM), the intergovernmental organization established in 1875 under the terms of the Metre Convention through which member states act together on matters related to measurement science and measurement standards. The CGPM is made up of delegates of the governments of the member states and observers from the Associates of the CGPM. It elects the International Committee for Weights and Measures (abbreviated CIPM from the ) as the supervisory board of the BIPM to direct and supervise it. Initially the work of the BIPM concerned the kilogram and the metre, but in 1921 the scope of the Metre Convention was extended to accommodate all Physical quantity, physical measurements and hence all aspects of the metric system. In 1960 the 11th CGPM approved the title International System of Units, usually known as "SI". The General Conferenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metre Convention
The Metre Convention (), also known as the Treaty of the Metre, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations: Argentina, Austria-Hungary, Belgium, Brazil, Denmark, France, German Empire, Germany, Kingdom of Italy, Italy, Peru, Portugal, Russian Empire, Russia, Kingdom of Spain (1810-1873), Spain, Union between Sweden and Norway, Sweden and Norway, Switzerland, Ottoman Empire, United States, United States of America, and Venezuela. The treaty created the International Bureau of Weights and Measures (BIPM), an intergovernmental organization, under the authority of the General Conference on Weights and Measures (CGPM) and the supervision of the International Committee for Weights and Measures (CIPM). These organizations coordinate international metrology and the development of internationally recognized System of measurement, systems of measurement. The Metre Convention established a permanent organizational structure for memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Academy Of Technologies
The National Academy of Technologies of France (''Académie des technologies'') is a learned society, founded in 2000, with an emphasis on technology, and the newest of French academies. In 2007 it acquired the status of ''établissement public'', which enforces its public role. Its stated missions are as follows: * Help to better exploit technologies in service of mankind * Provide clarity on emerging technologies * Contribute to public discussion of the risks and benefits of technologies * Contribute to professional and technological education * Interest the young and their parents in technologies and new careers * Raise public interest and comprehension in technologies In 2021 the academy had approximately 350 active members, including emeritus and foreign members. It is organized into a number of commissions, committees, and work groups on subjects including information technology, ethics, energy and the environment, transport, simulation, defense, etc. See also * French Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Légion D’Honneur
The National Order of the Legion of Honour ( ), formerly the Imperial Order of the Legion of Honour (), is the highest and most prestigious French national order of merit, both military and Civil society, civil. Currently consisting of five classes, it was originally established in 1802 by Napoleon, Napoleon Bonaparte, and it has been retained (with occasional slight alterations) by all later French governments and regimes. The order's motto is ' ("Honour and Fatherland"); its Seat (legal entity), seat is the Palais de la Légion d'Honneur next to the Musée d'Orsay, on the left bank of the Seine in Paris. Since 1 February 2023, the Order's grand chancellor has been retired General François Lecointre, who succeeded fellow retired General Benoît Puga in office. The order is divided into five degrees of increasing distinction: ' (Knight), ' (Officer), ' (Commander (order), Commander), ' (Grand Officer) and ' (Grand Cross). History Consulate During the French Revolution, all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsey Interferometry
Ramsey interferometry, also known as the separated oscillating fields method, is a form of particle interferometry that uses the phenomenon of magnetic resonance to measure transition frequencies of particles. It was developed in 1949 by Norman Ramsey, who built upon the ideas of his mentor, Isidor Isaac Rabi, who initially developed a technique for measuring particle transition frequencies. Ramsey's method is used today in atomic clocks and in the SI definition of the second. Most precision atomic measurements, such as modern atom interferometers and quantum logic gates, have a Ramsey-type configuration.Deutsch, Ivan. ''Quantum Optics I, PHYS 566, at the University of New Mexico''. Problem Set 3 and Solutions. Fall 2013. A more modern method, known as Ramsey–Bordé interferometry uses a Ramsey configuration and was developed by French physicist Christian Bordé and is known as the Ramsey–Bordé interferometer. Bordé's main idea was to use atomic recoil to create a beam sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Members Of The French Academy Of Sciences
Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science) In data hierarchy, a field (data field) is a Variable (computer science), variable in a record (computer science), record. A record, also known as a data structure, allows logically related data to be identified by a single name. Identifying relate ..., entries in a database ** Member variable, a variable that is associated with a specific object * Limb (anatomy), an appendage of the human or animal body ** Euphemism for penis * Structural component of a truss, connected by nodes * User (computing), a person making use of a computing service, especially on the Internet * Member (geology), a component of a geological formation * Member of parliament * The Members, a British punk rock band * Meronymy, a semantic relationship in linguistics * C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
