Wilhelm Lenz
Encyclopedia
Wilhelm Lenz was a German physicist
, most notable for his invention of the Ising model
and for his application of the Laplace–Runge–Lenz vector to the (old) quantum mechanical
treatment of hydrogen-like atom
s.
In 1906, Lenz graduated from the Klinger-Oberralschule, a non-classical secondary school in Frankfurt-am-Main, and went to study mathematics and physics at the University of Göttingen. From 1908 to 1911, Lenz studied under Arnold Sommerfeld
, at the University of Munich, and he was granted his doctorate
on March 2, 1911. Upon graduation, he stayed on at the University, became Sommerfeld’s assistant on April 1, 1911, and he completed his Habilitation
on February 20, 1914, becoming a Privatdozent
on April 4, 1914. During World War I
, he served as a radio operator in France
and was awarded the Iron Cross
Second Class in 1916. From September 30, 1920, he was again an assistant to Sommerfeld at the University of Munich’s Institute of Theoretical Physics, and he was appointed to the title and rank of extraordinarius professor at the University, on November 11, 1920. On December 1, 1920 he became an extraordinarius professor at the University of Rostock
. From 1921, until his retirement in 1956, he was at the University of Hamburg
, as Ordinarius Professor of Theoretical Physics and Director of the Institute of Theoretical Physics.
The formation of the new chair and institute for theoretical physics at Hamburg was a result of advances being made in Germany on atomic physics
and quantum mechanics
and the personal intervention of Sommerfeld, who helped many of his students get such professorships.
At Hamburg, Lenz trained Ernst Ising
and J. Hans D. Jensen
; his assistants there included Wolfgang Pauli
Pascual Jordan
, and Albrecht Unsöld
. Together with Pauli and Otto Stern
, Lenz built up the Institute into an international center for nuclear physics. They maintained close scientific and personal exchanges with the institutes for theoretical physics at the Universities in Munich (Sommerfeld), Göttingen (Max Born
), and Copenhagen
(Niels Bohr
).
When Lenz retired in 1956 he was succeeded by Harry Lehmann
.
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, most notable for his invention of the Ising model
Ising model
The Ising model is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables called spins that can be in one of two states . The spins are arranged in a graph , and each spin interacts with its nearest neighbors...
and for his application of the Laplace–Runge–Lenz vector to the (old) quantum mechanical
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
treatment of hydrogen-like atom
Hydrogen-like atom
A hydrogen-like ion is any atomic nucleus with one electron and thus is isoelectronic with hydrogen. Except for the hydrogen atom itself , these ions carry the positive charge e, where Z is the atomic number of the atom. Examples of hydrogen-like ions are He+, Li2+, Be3+ and B4+...
s.
In 1906, Lenz graduated from the Klinger-Oberralschule, a non-classical secondary school in Frankfurt-am-Main, and went to study mathematics and physics at the University of Göttingen. From 1908 to 1911, Lenz studied under Arnold Sommerfeld
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and groomed a large number of students for the new era of theoretical physics...
, at the University of Munich, and he was granted his doctorate
on March 2, 1911. Upon graduation, he stayed on at the University, became Sommerfeld’s assistant on April 1, 1911, and he completed his Habilitation
Habilitation
Habilitation is the highest academic qualification a scholar can achieve by his or her own pursuit in several European and Asian countries. Earned after obtaining a research doctorate, such as a PhD, habilitation requires the candidate to write a professorial thesis based on independent...
on February 20, 1914, becoming a Privatdozent
Privatdozent
Privatdozent or Private lecturer is a title conferred in some European university systems, especially in German-speaking countries, for someone who pursues an academic career and holds all formal qualifications to become a tenured university professor...
on April 4, 1914. 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 served as a radio operator in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and was awarded the Iron Cross
Iron Cross
The Iron Cross is a cross symbol typically in black with a white or silver outline that originated after 1219 when the Kingdom of Jerusalem granted the Teutonic Order the right to combine the Teutonic Black Cross placed above a silver Cross of Jerusalem....
Second Class in 1916. From September 30, 1920, he was again an assistant to Sommerfeld at the University of Munich’s Institute of Theoretical Physics, and he was appointed to the title and rank of extraordinarius professor at the University, on November 11, 1920. On December 1, 1920 he became an extraordinarius professor at the University of Rostock
University of Rostock
The University of Rostock is the university of the city Rostock, in the German state of Mecklenburg-Vorpommern.Founded in 1419, it is the oldest and largest university in continental northern Europe and the Baltic Sea area...
. From 1921, until his retirement in 1956, he was at the University of Hamburg
University of Hamburg
The University of Hamburg is a university in Hamburg, Germany. It was founded on 28 March 1919 by Wilhelm Stern and others. It grew out of the previous Allgemeines Vorlesungswesen and the Kolonialinstitut as well as the Akademisches Gymnasium. There are around 38,000 students as of the start of...
, as Ordinarius Professor of Theoretical Physics and Director of the Institute of Theoretical Physics.
The formation of the new chair and institute for theoretical physics at Hamburg was a result of advances being made in Germany on atomic physics
Atomic physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and...
and quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
and the personal intervention of Sommerfeld, who helped many of his students get such professorships.
At Hamburg, Lenz trained Ernst Ising
Ernst Ising
Ernst Ising was a German physicist, who is best remembered for the development of the Ising model. He was a professor of physics at Bradley University until his retirement in 1976.-Life:Ernst Ising was born in Cologne in 1900...
and J. Hans D. Jensen
J. Hans D. Jensen
Johannes Hans Daniel Jensen was a German nuclear physicist. During World War II, he worked on the German nuclear energy project, known as the Uranium Club, in which he made contributions to the separation of uranium isotopes. After the war Jensen was a professor at the University of Heidelberg...
; his assistants there included Wolfgang Pauli
Wolfgang Pauli
Wolfgang Ernst Pauli was an Austrian theoretical physicist and one of the pioneers of quantum physics. In 1945, after being nominated by Albert Einstein, he received the Nobel Prize in Physics for his "decisive contribution through his discovery of a new law of Nature, the exclusion principle or...
Pascual Jordan
Pascual Jordan
-Further reading:...
, and Albrecht Unsöld
Albrecht Unsöld
Albrecht Otto Johannes Unsöld was a German astrophysicist known for his contributions to spectroscopic analysis of stellar atmospheres.-Career:...
. Together with Pauli and Otto Stern
Otto Stern
Otto Stern was a German physicist and Nobel laureate in physics.-Biography:Stern was born in Sohrau, now Żory in the German Empire's Kingdom of Prussia and studied at Breslau, now Wrocław in Lower Silesia....
, Lenz built up the Institute into an international center for nuclear physics. They maintained close scientific and personal exchanges with the institutes for theoretical physics at the Universities in Munich (Sommerfeld), Göttingen (Max Born
Max Born
Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...
), and Copenhagen
University of Copenhagen
The University of Copenhagen is the oldest and largest university and research institution in Denmark. Founded in 1479, it has more than 37,000 students, the majority of whom are female , and more than 7,000 employees. The university has several campuses located in and around Copenhagen, with the...
(Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...
).
When Lenz retired in 1956 he was succeeded by Harry Lehmann
Harry Lehmann
Harry Lehmann was a German physicist.Lehmann studied physics at Rostock and the Humboldt-Universität zu Berlin....
.