In the early to mid 1900's there was a noticeable increase in the number of individuals enthralled in the world of science. Many of these individuals became famous for their work, others did not. The lives of most of these famous scientists are well know, such as Ernest Rutherford, Albert Einstein, Alfred Nobel, as well as many others. The mere mention of their names bring up images of accomplishments and long lasting achievements. One such name is Geiger, upon hearing this most minds immediately leap to the Geiger counter. Besides this, hardly any other aspects of his life and other works are know. Johannes (Hans) Wilhelm Geiger is known mainly for his radiation counter, the other information of his life and accomplishments have fallen through the cracks of history.
Hans Geiger had a very simple, yet impressive, beginning. Born on Sept. 30, 1882 in Neustadt-an-der-Haardt in the heart of Rheinland-Pfaltz in Germany. Unlike some other important physicists, such as Einstein, he attended grade school and high school with little difficulty. After the standard schooling Geiger enrolled into the University in Munich. At the university his work in physics was outstanding, he continued on to do his doctoral thesis at Friedrich-Alexanders University at Erlangen in 1906. The work that he did was based on studies by A. Wehnelt of the Physics Institute. The experiments for his thesis required accurate measurements of electrical discharges in a vacuum-tube cathode of Wehnelt's design. Accurate measurements of this sort would be the basis of most of Geiger's work throughout his career. For his extensive collegiate work he was awarded the John Harlis Fellowship which led him to Manchester. Now at this University, Geiger began working under professor Ernest Rutherford. By working with Rutherford and his experiments in atomic physics, Geiger found ways to measure atomic events. Here is where Geiger's life long atomic physics career began.
At Manchester, Rutherford was experimenting with radioactivity. For these experiments Geiger had to accurately measure the emanations from radium. Thus in 1908 Geiger created the first Geiger counter; which consisted of a glass tube which contained a wire with an electric current. This tube is filled with a combination of an inert gas, such as argon, and another gas, most commonly methane which resets the counter after each detection. Within the tube, the wire is then charged almost to the point of electrical discharge. This allows the counting of various particles in that when the particle travels through the tube it collides with the gas producing ions which collect and produce a spark. This each spark signifies a particle, whereby the total particle emission is determined from the number of discharges. This counter, like the tedious scintillation counting method, gave an accurate count of the number of particles but with more relative ease. Paired with a string electrometer, the individual charge of each particle could be determined. As it is not greatly know, throughout the years the Geiger counter went through many improvements but not while at Manchester. While still working under Rutherford, Geiger persuaded him to allow Ernest Marsden to investigate wide-angle alpha particle scattering. This experiment led these three to discover the existence of the atomic nucleus.
After the ground breaking discovery of the nucleus, Geiger went on to work on the "Geiger formula" which determined the velocities of particles in 1910. Later in 1911 with the contributions of J. M. Nuttall, the "Geiger-Nuttall" rule was developed which related the lifetime of an element to the distance between its particles. In 1912 due to the fame acquired at Manchester, Germany asked if he wanted to return to head the new radioactivity lab in Berlin (Physikalisch-Technische Reichsanstalt). After his acceptance and arrival, Geiger and co-worker W. Bothe worked productively on the topic of radiation. During these years of work came the first upgrade for the Geiger counter. It was remade to be able to detect beta and gamma particles besides the alpha which it could originally detect. A short time after work had begun in Berlin, World War I interrupted the experiments. During the war Geiger was conscripted for military service, he detested being involved. After the war the research resumed and in 1925 Geiger confirmed the existence of the Compton effect. This effect was the increase in wavelength of X rays scattered by the electrons of lighter atoms. This was postulated in 1923 but was only able to be proven with the use of two Geiger counters. The counter was able to prove the Compton effect because it could detect electrons, radiation quanta, and neutrons as well as gamma radiation.
As well as proving the Compton effect, in 1925 Geiger left Berlin and went to the university of Kiel to take the chair for physics. In 1928 further improvements were made to the Geiger counter with the assistance of Mueller. The Geiger-Mueller counter used a photon tube as a detector for the first automatic scintillation counter. This new counter was a highly accurate tool for nuclear scientists which accelerated subatomic studies. After a relatively short stay at Kiel, in 1929 Geiger took a position at the University of Tubingen. During his stay here he made his first observation of a cosmic-ray shower. Later in 1936 he transferred once again, this time Geiger went to Berlin-Charlottenburg to be the chief of the physics department at the Technische Hochschule. With the added work of administration he still continued work on cosmic radiation, artificial radioactivity, and uranium fission. His work in the latter topic led to his involvement in the German atom bomb project, along with eight other scientist, in 1939. Geiger supported the research into the likelihood of an atomic bomb; however, it is known that Geiger disliked the military and no source could be found to determine if he personally agreed or disagreed with Nazi ideals. Luckily the combination of Hitler's lack of vision, unwillingness of the scientists to give this power to an insane dictator, and lack of uranium available for bomb research led to Germany not developing an atomic bomb. By 1940 rheumatism began to take its toll on Geiger but he still continued work as editor of Zeitschrift fur Physik and Handbuch der Physik. After the Reich had been defeated Geiger's health improved in 1945, but did not last for long. In June of 1945 his home near Babelsburg was occupied and Geiger was kicked out without any possessions. He was able to make it to Postdam, it was here that he learned of the atomic bomb that was dropped on Japan. Broken and in ill health due to poor food and difficult living conditions, at age the age of sixty-two just six days before his birthday, Hans Geiger died.
Throughout his life, Geiger made long lasting contributions to the fields of atomic and nuclear research. Like most other scientists of this age, Geiger's research led to other discoveries by others. Without Geiger's work on particle detection, the Joliot-Curies might not have been able to find their Nobel Prize winning process for creating artificial radioactivity. Along those same lines Walther Bothe could not have detected artificial nuclear gamma radiation in beryllium, for which he too received the Prize. Without the Geiger counter most nuclear or atomic physics would have been hindered in some way. Even the early studies of Rutherford's on the alpha, beta, and gamma particles as well as his realization of the nucleus, would have been much more involved and difficult without the easy that even the early Geiger counter provided. Besides the Geiger counter, without Hans Geiger who knows when the Compton effect would have been proven. In this situation it was both the counter and the man that led to the final proof. The advances that Hans Geiger brought to the scientific community were priceless.
Even though Geiger is most widely know for his counter, there is so much more to his career. The Geiger counter was the result of many years of work and revisions. Hans Geiger also contributed to the discovery of the nucleus and the study of sub-atomic particles. There is more behind the name of Geiger than just a mere particle counter, but that is all that has remained in the public eye after so many years. Other scientists tend to be glamorized for there work, but in many cases without the work of individuals like Geiger, their work would have been delayed or never done at all. There is little written about Geiger's personal life, most of the information available is about his scientific contributions and schooling. There may be information about Geiger's family life and political views, but for the most part texts on Geiger are written in German and only brief biographies in English are readily available. The only available evidence of a family life was a poor picture of a gravestone in which the names Hans and Isabeth, presumably his wife, were barely legible. There is also some information about his father Wilhelm Geiger, who studied remote and eastern cultures and languages, along which there was a mention of his brother Rudolf who studied meteorology and climatology. Besides these smatterings of disconnected information, what is available in English paints a picture of a brilliant scientist who offered many contributions. These contributions of Hans Geiger had long reaching and lasting effects in science, which even aided to the position of science today.