Carl Theodor Albrecht

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Carl Theodor Albrecht

Carl Theodor Albrecht (* thirtieth August 1843 in Dresden , † 31 August 1915 in Potsdam ) was a German surveyor , astronomer and long-time head of the Prussian Geodesy . As such, it marked the beginning of international cooperation of Geodesy and was co-founder of the international width service , which is now under the name International Earth Rotation and Reference Systems Service (IERS; English: International Earth Rotation and Reference Systems Service ) a worldwide service of the International Union of Geodesy and Geophysics (IUGG) is.

Life

Albrecht attended the Kreuzschule in Dresden. As a 17-year-old, he began studying mathematics and natural sciences in the teachers' department at what was then the Polytechnic School in Dresden from 1860 . Here in 1861, together with Baron Carl von Wagner, he founded the Association for the Maintenance of Free Speech Polyhymnia , from which the Freischlagende connection Polyhymnia and then today's Corps Altsachsen emerged . After successfully completing his studies in Dresden, he continued to study physics and astronomy at the University of Berlin in 1865 . His interest in both technical and celestial studies - at that time, astronomy was mainly astrometry , astrophysics was just emerging - led Albrecht to geodesy , where he became the most important German "astrogeodesist" of the turn of the century thanks to his organizational talent and determination. During his studies he became an assistant in the central office of the Central European Degree Measurement on May 1, 1866 . In 1867 Albrecht took part in a telegraphic length determination. It was here that he encountered the field of work that, according to his own admission, most interested him.

The Royal Prussian Geodetic Institute was founded in Potsdam in 1869 and took over the work of the central office. So Albrecht switched to the institute. At first he worked as an employee in various astronomical-geodetic work and measurements of gravity. After the resignation of the head of the astronomical section of the institute in 1873, Albrecht was commissioned by Johann Jacob Baeyer , the director of the institute, to lead the astronomical work. As section head of the institute, he made this central office the world center of geodesy for a few decades. It later developed into the Central Institute for Earth Physics (ZIPE) and today houses the GeoForschungsZentrum Potsdam (GFZ), which is responsible for all of Germany's earth science . In 1895 the General Conference of International Geometric Surveying decided to introduce an international broad service, which Albrecht founded in 1899 together with his colleagues Wilhelm Foerster and Friedrich Robert Helmert . This later became the International Polar Motion Service (IPMS) and is now the International Earth Rotation Service .

This was followed by his initiative to set up a worldwide network of measuring stations for this monitoring of the earth's rotation and also for geophysical research . For Germany, this task is still performed today by the GFZ at Potsdamer Telegrafenberg and the satellite station Wettzell .

In addition to these tasks, Albrecht was also active in astrometric practice: in the course of his life he determined the precise star locations of 39 circumpolar stars , as well as the astronomical plumb line (commonly known as " location ") of around 50 cities, including Paris , Warsaw, Greenwich and New York . He cooperated with other centers of geography and celestial science. Albrecht always tried to improve the methods of observation and to achieve an increase in accuracy. After the emergence of wireless telegraphy in 1904, Albrecht immediately made attempts to use it to determine length. Wireless telegraphy was used as early as 1906 to determine the difference in length between Brocken and Potsdam. In preparation for the broad service, Albrecht made a selection of the observation stations and developed an observation program. The use of standardized methods and instruments made it possible to achieve a high level of accuracy in the measurements.

Albrecht's grave in Berlin

One of his publications, written in 1876 and 1883, became a standard work that is still in use today: the formulas and auxiliary tables for geographic location that he compiled and compiled . It was not until 1980 that its formulas and series developments were finally replaced by IT and new processes, but the tables are still useful for many purposes today.

At the age of 71, he personally measured the difference in length between Borkum and New York at the intermediate station Horta in the Azores. With the outbreak of the First World War , the work had to be interrupted and Albrecht was only able to return with difficulty, where he died shortly afterwards of a stomach ailment.

Albrecht took part in conferences of the international earth survey and submitted 20 reports. He is considered one of the most renowned German earth survey astronomers of the beginning of the 20th century. In 1882 he was elected a member of the Leopoldina Academic Academy .

His grave is in the Protestant Old St. Matthew Cemetery in Berlin-Schöneberg , it was an honorary grave of the city of Berlin until 2009 .

Honors

Albrecht received numerous honors: he was a corresponding or external member of several academies and learned societies. In 1882 he became a member of the Leopoldina and in 1910 a corresponding member of the Académie des Sciences in Paris. The Technical University of Stuttgart awarded him an honorary doctorate . The International Astronomical Union named an asteroid after him in his honor in Paris in 2002 , which Albrecht discovered in 1971 (10656) .

“Albrecht's length compensation” also had a lasting effect throughout Europe (around 1890). Among other things, the international conversion used today, Ferro - Greenwich with 17 ° 40 ′ 00.00 ″ is derived from it (see also Hermannskogel and Rauenberg ). Albrecht himself had determined the value 17 ° 39 ′ 46.02 ″ , which, however , was set to the round value mentioned above because of the absolute deviation from the perpendicular , which happens to be 13-14 ″ in both Vienna and Berlin . The underlying calculations and analyzes go back to Karl Ledersteger (TH Wien), who in the 1940s subjected Albrecht's files for Central Europe to a thorough investigation.

Works

  • Formulas and auxiliary tables for geographic location determinations , 1873
  • Report on the state of research into width variation in December 1897 , Berlin, Reimer, 1898
  • Report on the status of research into width variation in December 1898 , Berlin, Reimer, 1899
  • Report on the state of research into width variation in December 1899 , Berlin, Reimer, 1900
  • Instructions for using the Zenittelcope at the international latitude stations , Berlin, Reimer, 1902
  • Results of the international broad service, Vol. 1 , Berlin, Reimer, 1903
  • Results of the international broad service, Vol. 2 , Berlin, Reimer, 1906
  • Results of the international broad service, Vol. 3 , Berlin, Reimer, 1909
  • Results of the international broad service, Vol. 4 , Berlin, Reimer, 1911
  • Physico-chemical tables (co-author), Berlin, Springer, 1912
  • Results of the broad observations at the observatory in Johannesburg from March 1910 to March 1913 , Berlin, Reimer, 1915
  • The results of his measurements have been published in 20 volumes of the Astronomical Society

literature

Web links

Commons : Carl Theodor Albrecht  - Collection of images, videos and audio files

Individual evidence

  1. ^ List of members since 1666: Letter A. Académie des sciences, accessed on October 1, 2019 (French).
personal data
SURNAME Albrecht, Carl Theodor
ALTERNATIVE NAMES Albrecht, Theodor
BRIEF DESCRIPTION Astronomer and geodesist
DATE OF BIRTH August 30, 1843
PLACE OF BIRTH Dresden
DATE OF DEATH August 31, 1915
Place of death Potsdam