Adolphe Hirsch | |
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| Born | 21 May 1830  Halberstadt |
| Died | 16 April 1901 (aged 70) |
| Nationality | Swiss |
| Academic career | |
| Institutions | Neuchâtel Observatory Swiss Geodetic Commission International Association of Geodesy International Committee for Weights and Measures |
Adolphe Hirsch (21 May 1830 - 16 April 1901) was a German born, Swiss astronomer and geodesist. [1] [2]
Adolph Hirsch was born in Halberstadt. He studied astronomy at the universities of Heidelberg and Vienna. In the spring of 1848 (March Revolution), Hirsch, as president of the "Democratic Student Association" in Heidelberg, was committed to the radical ideas of introducing a republic in the Grand Duchy of Baden. The association was subsequently banned. Now the entire student body reacted under the chairmanship of Alexander Spengler. As a result of the dispute between the students, the University of Heidelberg and the Grand Ducal Government, two thirds of the Heidelberg students moved to Neustadt under the leadership of Adolph Hirsch (at that time he still went by the name Adolph, later Adolphe). After further disputes between Hirsch and his fellow students and the university, he left Heidelberg in autumn 1848 and continued his studies in Berlin.
He founded and directed the Observatory of Neuchâtel which ensured the precise determination of the time for local clock industry. [3] He was also professor of geophysics and astronomy at the Academy of Neuchâtel and secretary then president of the Swiss Geodetic Commission. [4]
In 1866, the Permanent Commission of the Central European Arc Measurement met in Neuchâtel, and Hirsch was appointed, along with Bruhns, of Leipzig, as secretary of the session. The following year, the General Conference of the Central European Arc Measurement, meeting in Berlin, voted a motion in ten articles laying the foundations of the international organization of the metric system, and thus prepared the work which ended on 20 May 1875 with the signing of the Convention of Metre. Throughout the preparatory period Hirsch showed such great activity, such a clear-sighted mind, and identified himself so well with the common work, that he was, by a unanimous vote, chosen as secretary of the new committee in charge of high management of the International Bureau of Weights and Measures. At the same time, the International Geodetic Association was born of the Commission of the Central European Arc Measurement, and, by an understanding the good effects of which were subsequently recognized, it was believed that the two new organizations, which creation had been almost parallel, would benefit from being run by the same men. General Carlos Ibáñez e Ibañez de Ibero, director of the Geodetic and Statistical Institute of Spain, was made chairman of both Commissions and Hirsch became the sole secretary of the International Geodetic Association. [5] [6]
The work of the two Associations is well known: the International Bureau of Weights and Measures, in its twenty-five first years of activity, has ensured the precise unification of the metric system in all civilized countries; The Geodesic Association caused great works, coordinated scattered measurements, made them stand out from each other, and finally, gave us a more perfect knowledge of the shape and dimensions of our globe, of the distribution of the gravity, seas' and continents' level, at the same time that it provided, to all the staffs, the solid bases on which the charts were built. [5]
The works have grown under a skilful direction. In the year of the centenary of the metric system, the International Bureau was completing its first quarter of a century. Hirsch had the great satisfaction of seeing it in full prosperity; and if, last year before his death, his weakened health made him desire a well-earned rest and urged him to pass the secretariat of the Geodetic Association into younger hands, he found, still taking care of the International Bureau, a kind of paternal joy that made him overcome, by dint of energy, intolerable sufferings. [5]
Friedrich Wilhelm Bessel was a German astronomer, mathematician, physicist, and geodesist. He was the first astronomer who determined reliable values for the distance from the sun to another star by the method of parallax. Certain important mathematical functions were named Bessel functions after Bessel's death, though they had originally been discovered by Daniel Bernoulli before being generalised by Bessel.
The metre is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second, where the second is defined by a hyperfine transition frequency of caesium.
Metrication or metrification is the act or process of converting to the metric system of measurement. All over the world, countries have transitioned from local and traditional units of measurement to the metric system. This process began in France during the 1790s, and has persistently advanced over two centuries, accumulating into 95% of the world officially only using the modern metric system. Nonetheless, this also highlights that certain countries and sectors are either still transitioning or have chosen not to fully adopt the metric system.
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, Germany, Italy, Peru, Portugal, Russia, Spain, Sweden and Norway, Switzerland, Ottoman Empire, United States of America, and Venezuela.
Jean-Charles, chevalier de Borda was a French mathematician, physicist, and Navy officer.
A Kater's pendulum is a reversible free swinging pendulum invented by British physicist and army captain Henry Kater in 1817, published 29th January 1818 for use as a gravimeter instrument to measure the local acceleration of gravity. Its advantage is that, unlike previous pendulum gravimeters, the pendulum's centre of gravity and center of oscillation do not have to be determined, allowing a greater accuracy. For about a century, until the 1930s, Kater's pendulum and its various refinements remained the standard method for measuring the strength of the Earth's gravity during geodetic surveys. It is now used only for demonstrating pendulum principles.
The history of geodesy (/dʒiːˈɒdɪsi/) began during antiquity and ultimately blossomed during the Age of Enlightenment.
The vertical deflection (VD) or deflection of the vertical (DoV), also known as deflection of the plumb line and astro-geodetic deflection, is a measure of how far the gravity direction at a given point of interest is rotated by local mass anomalies such as nearby mountains. They are widely used in geodesy, for surveying networks and for geophysical purposes.
Arc measurement, sometimes degree measurement, is the astrogeodetic technique of determining the radius of Earth – more specifically, the local Earth radius of curvature of the figure of the Earth – by relating the latitude difference and the geographic distance surveyed between two locations on Earth's surface. The most common variant involves only astronomical latitudes and the meridian arc length and is called meridian arc measurement; other variants may involve only astronomical longitude or both geographic coordinates . Arc measurement campaigns in Europe were the precursors to the International Association of Geodesy (IAG).
The Paris meridian is a meridian line running through the Paris Observatory in Paris, France – now longitude 2°20′14.02500″ East. It was a long-standing rival to the Greenwich meridian as the prime meridian of the world. The "Paris meridian arc" or "French meridian arc" is the name of the meridian arc measured along the Paris meridian.
The Frankfurter Wachensturm on 3 April 1833 was a failed attempt to start a revolution in Germany.
Friedrich Hopfner was an Austrian geodesist, geophysicist and planetary scientist.
Alexander Spengler was a Swiss physician of German origin and the first physician specializing in tuberculosis in Davos.
The Bessel ellipsoid is an important reference ellipsoid of geodesy. It is currently used by several countries for their national geodetic surveys, but will be replaced in the next decades by modern ellipsoids of satellite geodesy.
1556 Wingolfia, provisional designation 1942 AA, is a metallic asteroid from the outer regions of the asteroid belt, approximately 30 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory on 14 January 1942. The asteroid was named after Wingolf, a student fraternity in Heidelberg.
The International Association of Geodesy (IAG) is a constituent association of the International Union of Geodesy and Geophysics.
The history of the metre starts with the Scientific Revolution that is considered to have begun with Nicolaus Copernicus's publication of De revolutionibus orbium coelestium in 1543. Increasingly accurate measurements were required, and scientists looked for measures that were universal and could be based on natural phenomena rather than royal decree or physical prototypes. Rather than the various complex systems of subdivision then in use, they also preferred a decimal system to ease their calculations.
Ismail Mustafa, Ismail Effendi Mustafa,Ismail Bey Mustapha, Ismail Mustafa al-Falaki or Ismail Pasha al-Falaki was an Egyptian astronomer and mathematician. Effendi, Bey and Pasha corresponded to the different ranks he attained along his career; "al-Falaki" was added to his name literally meaning "the astronomer". He was born in Cairo to a family of Turkish origin and was educated in Paris, France.
Carlos Ibáñez e Ibáñez de Ibero, 1st Marquis of Mulhacén, was a Spanish divisional general and geodesist. He represented Spain at the 1875 Conference of the Metre Convention and was the first president of the International Committee for Weights and Measures. As a forerunner geodesist and president of the International Geodetic Association, he played a leading role in the worldwide dissemination of the metric system. His activities resulted in the distribution of a platinum and iridium prototype of the metre to all States parties to the Metre Convention during the first meeting of the General Conference on Weights and Measures in 1889. These prototypes defined the metre right up until 1960.
Immo Appenzeller is a German astronomer.
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