Friedrich Hopfner
Encyclopedia
Friedrich Hopfner was an Austrian geodesist, geophysicist and planetary scientist.

As an officer of the Austro-Hungarian Empire he began his scientific work at the Bureau of Meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

. In 1921 he became Chief Astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 at the new Geodetic Survey of Austria (Federal Office of Metrology and Survey or Bundesamt für Eich- und Vermessungswesen). From 1936 to 1942 and from 1945 to 1949 he was a Professor at the Vienna University of Technology
Vienna University of Technology
Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" , it currently has about 26,200 students , 8 faculties and about 4,000 staff members...

 (TU Wien) and over the 1948-9 term he was the university's rector
Rector
The word rector has a number of different meanings; it is widely used to refer to an academic, religious or political administrator...

.

Life

He was born on 28 October 1881 in Trautenau, northern Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...

 (now Trutnov
Trutnov
Trutnov is a city in the Hradec Králové Region of the Czech Republic. It has a population of 31,239 and lies in the Krkonoše in the valley of the Úpa River....

, Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

). He studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

, geophysics
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...

 and astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 at the University of Prague
Charles University in Prague
Charles University in Prague is the oldest and largest university in the Czech Republic. Founded in 1348, it was the first university in Central Europe and is also considered the earliest German university...

 and the University of Munich between 1899 and 1904. In 1905 at the Charles University in Prague
Charles University in Prague
Charles University in Prague is the oldest and largest university in the Czech Republic. Founded in 1348, it was the first university in Central Europe and is also considered the earliest German university...

 he delivered his dissertation on "The average and relative distribution of temperature on the Earth's surface."

His first job was as an assistant at the Prague Observatory, and then at the Bureaux of Meteorology in Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, Innsbruck
Innsbruck
- Main sights :- Buildings :*Golden Roof*Kaiserliche Hofburg *Hofkirche with the cenotaph of Maximilian I, Holy Roman Emperor*Altes Landhaus...

 and Vienna
Vienna
Vienna is the capital and largest city of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million , and is by far the largest city in Austria, as well as its cultural, economic, and political centre...

. In 1908 he transferred to the Maritime Observatory in Trieste
Trieste
Trieste is a city and seaport in northeastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south and east of the city...

 (now the Istituto Talassografico di Trieste or ITT), then in 1912 to the Bureau of Geodesy (Gradmessungsbüro) in Vienna.

During World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 he was head of the meteorological service for the Isonzo army of Austria-Hungary
Austria-Hungary
Austria-Hungary , more formally known as the Kingdoms and Lands Represented in the Imperial Council and the Lands of the Holy Hungarian Crown of Saint Stephen, was a constitutional monarchic union between the crowns of the Austrian Empire and the Kingdom of Hungary in...

. In 1921 he became Chief Astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 at the new Geodetic Survey of Austria ("Bureau of Weights, Measures and Surveying" or Bundesamt für Eich- und Vermessungswesen).

In 1936 he was appointed Professor of Theoretical Geodesy
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...

 and Spherical astronomy
Spherical astronomy
Spherical astronomy or positional astronomy is the branch of astronomy that is used to determine the location of objects on the celestial sphere, as seen at a particular date, time, and location on the Earth. It relies on the mathematical methods of spherical geometry and the measurements of...

 at the Vienna University of Technology
Vienna University of Technology
Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" , it currently has about 26,200 students , 8 faculties and about 4,000 staff members...

, as successor to Richard Schumann. In autumn 1942 he declined Hitler's invitation into his newly-created Academy of Sciences (Akademie der Wissenschaften) in Prague, and was forced into retirement, moving with his family to Schönbühel on the Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

, where he devoted himself exclusively to research. After the war he was restored to his position in Vienna, and was later elected Dean of the Faculty of Applied Maths and Physics.

His pleasant friendliness made him popular with colleagues and students, and in the 1948-9 term he was voted Rector magnificus at the Technical High School of Vienna. In the last month of his incumbency, he drowned in a boating accident on the Hintersteiner See
Hintersteiner See
Hintersteiner See is a lake of Tyrol, Austria....

, near Kufstein
Kufstein
Kufstein is a city in Tyrol, Austria, located along the river Inn, in the lower Inn valley, near the border with Bavaria, Germany, and is the site of a post World War II French sector United Nations Relief and Rehabilitation Administration Displaced Persons camp.Kufstein is the second largest city...

.

Work

From the very beginning of his career he made valuable contributions to astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

, geodesy
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...

, geophysics
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...

 and meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

, in the applied fields as well as the theoretical, and published a great deal on all four subjects. He wrote three well-known textbooks.

Trajectories of planetoids

Hopfner's early work was mostly concerned with astronomy and meteorology. In collaboration with Johann Palisa
Johann Palisa
Johann Palisa was an Austrian astronomer, born in Opava in Austrian Silesia .He was a prolific discoverer of asteroids, discovering 122 in all, from 136 Austria in 1874 to 1073 Gellivara in 1923...

, he determined the trajectories
Trajectory
A trajectory is the path that a moving object follows through space as a function of time. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit—the path of a planet, an asteroid or a comet as it travels around a central mass...

 and ephemerides of a number of planetoids.

Mathematical foundations of a theory of climatology

In 1906 he began researching problems bordering both astronomy and geophysics, starting with the warming of the Earth by the Sun. We owe mainly to Hopfner the sharp distinction he made between the daily and seasonal average irradiation. In 1927 he went into the subject in more detail, laying out his discoveries in his Mathematical Foundations of an Astronomical Theory of Climatic Variation (Mathematische Grundlagen zu einer astronomischen Theorie der Klimaschwankungen), which won him the Seegenpreis.

Research on tides

His work at the Maritime Observatory in Trieste
Trieste
Trieste is a city and seaport in northeastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south and east of the city...

 led him to study oceanographical questions, for example on tides and the determination of water levels in Trieste harbour, both very important practical problems.

Advanced geodesy and geophysics

With his entry to the Gradmessungsbüro in 1921 he turned to geomensuration and geophysics, in particular his work on the meridian arc
Meridian arc
In geodesy, a meridian arc measurement is a highly accurate determination of the distance between two points with the same longitude. Two or more such determinations at different locations then specify the shape of the reference ellipsoid which best approximates the shape of the geoid. This...

 Großenhain
Großenhain
Großenhain is a Große Kreisstadt in the district of Meißen, Saxony, Germany.-History:...

-Kremsmünster
Kremsmünster
Kremsmünster is a town in Kirchdorf an der Krems , in Upper Austria, Austria. Its population is 6,450, as of 2001. Settled in 777, it is home to the Kremsmünster Abbey....

-Pola
Pula
Pula is the largest city in Istria County, Croatia, situated at the southern tip of the Istria peninsula, with a population of 62,080 .Like the rest of the region, it is known for its mild climate, smooth sea, and unspoiled nature. The city has a long tradition of winemaking, fishing,...

, which detailed the use of comparisons of vertical deflection
Vertical deflection
The vertical deflection at a point on the earth is a measure of how far the direction of the local gravity field has been shifted by local anomalies such as nearby mountains....

s. Later he studied the important problem of the geoid
Geoid
The geoid is that equipotential surface which would coincide exactly with the mean ocean surface of the Earth, if the oceans were in equilibrium, at rest , and extended through the continents . According to C.F...

 (the Earth's shape), for example through the reduction of observations of weight and the subject known as isostasy
Isostasy
Isostasy is a term used in geology to refer to the state of gravitational equilibrium between the earth's lithosphere and asthenosphere such that the tectonic plates "float" at an elevation which depends on their thickness and density. This concept is invoked to explain how different topographic...

 (the study of gravitational equilibrium within the Earth). From the 1930s he concentrated on the study of the reference ellipsoid
Reference ellipsoid
In geodesy, a reference ellipsoid is a mathematically-defined surface that approximates the geoid, the truer figure of the Earth, or other planetary body....

 and phase diagram
Phase diagram
A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases can occur at equilibrium...

s, as well as the elliptical shape of the Equator, the level spheroid, and the triaxial Jacobi ellipsoid.

Contributions to Austrian science

Hopfner did pioneering work on the determination of geographical distances without the use
of wires (the first employment of time-signals), as well as on gravimetry
Gravimetry
Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of gravitational field or the properties of matter responsible for its creation are of interest...

. His study of the Earth's magnetic field helped make a name for the ZAMG, or Central Institute for Meteorology and Geodynamics (Zentralanstalt für Meteorologie und Geodynamik) in Vienna.

Memberships and responsibilities

  • Member of the Austrian Academy of Sciences
  • President of the Austrian Geodetic Commission (ÖKIE, now ÖGK)
  • Correspondent to the Central Institute for Meteorology and Geodynamics (ZMG)
  • Corresponding member of the German Society for Science and the Arts in the Republic of Czechoslovakia
  • Member of the Mathematical Society of Vienna


Awards

  • 1912 Oskar Freiherr von Rothschild-Preis for astronomy, from the Vienna Academy of Sciences
  • 1923 Seegenpreis from the Society for the Promotion of German Science, Art and Literature in Bohemia
  • 1931 Given the title Hofrat (Counsellor)
  • 1977 The Austrian Geodetic Commission begins awarding the Friedrich Hopfner-Medaille in his honour; it is given every four years for outstanding work in the field of geodesy

External links (German)

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK