Walter Gerlach

Walther Gerlach was born on 1 August 1889 at Biebrich am Rhein, now a municipality in the Western Germany. His father, Valentisn Gerlach, was a doctor. His mother’s name was Marie Niederhaeuser.

In 1908, Gerlach enrolled at the Eberhard Karls University of Tübingen. After graduation, he began his doctoral thesis on measurement of radiation in the same university. The eminent German physicist Louis Karl Heinrich Friedrich Paschen was his doctoral advisor. He received his PhD in 1912.

Gerlach next began working for his Habilitation at the University of Tübingen. He had started working as an assistant to Paschen from 1911. In spite of working for Habilitation, he continued assisting Paschen at the laboratory.

However, all these were interrupted as the World War I broke out and Gerlach was inducted into the German Army. He now was assigned to work on wireless telegraphy under Max Wein, the director of the Institute of Physics at the University of Jena.

Later in 1916, he received his Habilitation and became a Privatdozent at the University of Tübingen and then at the Georg-August University of Göttingen. Sometime during the war he also served in the Artillerie-Prüfungs-Kommission (APK) under Rudolf Ladenburg

Gerlach was decommissioned once the war ended in 1918. In 1919, he joined Farbenfabriken Elberfeld as the head of the physics laboratory and worked in that capacity until 1920.

In 1920, he joined the Johann Wolfgang Goethe University in Frankfurt am Main as a teaching assistant and a lecturer. The next year, he was appointed as the Extraordinarius Professor in the Institute of Experimental Physics in the same university.

Some time now, he met Otto Stern, who at the time was working as an assistant in the University’s Institute of Theoretical Physics. Together the two scientists began working on spin quantization.

The first experiment was conducted in 1921, using an electromagnet that enabled the magnetic field to be turned on slowly from a null value. However, in the same year Stern received his first academic post and shifted to University of Rostock. Gerlach stayed behind to complete the experiment.

in 1925, Gerlach left the University of Frankfurt to join University of Tübingen as an Ordinarius Professor. In this, he succeeded his mentor and doctoral advisor Friedrich Paschen.

Gerlach is best known for the Stern–Gerlach experiment of 1922. The experiment was jointly carried on with Otto Stern. They sent silver atoms through a non-uniform magnetic field. The deflected atoms hit a glass plate and split into two beams. The result of this experiment was published in ‘Zeitschrift für Physik’, German scientific journal.

In addition, Gerlach had also made significant contributions in the fields of radiation, spectroscopy and quantum theory.