Walther Müller (6 September 1905, in

Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...

– 4 December 1979, in

Walnut Creek, California Walnut Creek is a city in Contra Costa County, California, United States, located in the East Bay region of the San Francisco Bay Area, about east of the city of Oakland, California, Oakland. Walnut Creek has a total population of 70,127 per t ...

) was a German

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

, most well known for his improvement of

Hans Geiger Johannes Wilhelm Geiger ( , ; ; 30 September 1882 – 24 September 1945) was a German nuclear physicist. He is known as the inventor of the Geiger counter, a device used to detect ionizing radiation, and for carrying out the Rutherford scatt ...

's counter for

ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...

, now known as the Geiger-Müller tube. Walther Müller studied

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

and

philosophy Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...

at the

University of Kiel Kiel University, officially the Christian Albrecht University of Kiel, (, abbreviated CAU, known informally as Christiana Albertina) is a public research university in the city of Kiel, Germany. It was founded in 1665 as the ''Academia Holsator ...

. In 1925 he became the first PhD student of Hans Geiger, who had just got a professorship in Kiel. Their work on

ionization Ionization or ionisation is the process by which an atom or a molecule acquires a negative or positive Electric charge, charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged at ...

of gases by

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great for ...

lead to the invention of the

Geiger-Müller counter A Geiger counter (, ; also known as a Geiger–Müller counter or G-M counter) is an electronic instrument for detecting and measuring ionizing radiation with the use of a Geiger–Müller tube. It is widely used in applications such as radiat ...

, a now indispensable tool for measuring

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

. After some time as professor at the

University of Tübingen The University of Tübingen, officially the Eberhard Karl University of Tübingen (; ), is a public research university located in the city of Tübingen, Baden-Württemberg, Germany. The University of Tübingen is one of eleven German Excellenc ...

he worked for the rest of his professional life as industrial physicist (i. e. a physicist working in industrial R&D) in

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, then as an advisor for the

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Postmaster-General's Department The Postmaster-General's Department (PMG) was a department of the Australian federal government, established at Federation in 1901, whose responsibilities included the provision of postal and telegraphic services throughout Australia. It was ...

Research Laboratories in

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

,Gerard Ryle, Gary Hughes, "Rocket science", ''Sydney Morning Herald'', 21 August 1999, News Review, p. 40 and then as an industrial physicist in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, where he also founded a company to manufacture

Geiger–Müller tube The Geiger–Müller tube or G–M tube is the sensing element of the Geiger counter instrument used for the detection of ionizing radiation. It is named after Hans Geiger, who invented the principle in 1908, and Walther Müller, who collaborate ...

s. He died in 1979 in California

References

* {{DEFAULTSORT:Muller, Walther 1905 births 1979 deaths Scientists from Hanover 20th-century German physicists Immigrants to Australia Immigrants to the United States