Biography of Walter Wilhelm Bothe (1891-1957)

German physicist, born on 8 January 1891 in Oranienburg, near Berlin Town, and died in Heidelberg on August 2, 1957, which in 1954 was awarded the Nobel Prize in Physics (shared with the British Max Born) for his research on the development of the spectroscopy of coincidence and its application in the study of cosmic rays and other penetrating radiation.

From 1908 until 1912 study physics, mathematics, chemistry and music at the University of Berlin. From 1912 to 1914 he/she made his doctoral thesis on a theoretical model of diffraction and reflection of light by individual atoms under the tutelage of Max Planck, who considered it among his top students and with whom he/she retained the friendship during their lifetime.

In 1913 he/she began working at the Physikalisch-Technische Reichsanstalt in Berlin as an Assistant of Hans Geiger , who had just returned from England and who had a remarkable influence on Bothe. There he/she met Einsteinand Otto Hahn, Lise Meitner, Erwin Schrödinger.

Working with Geiger was abruptly interrupted at the outbreak of the first world war. Designed in the campaigns of the Russian front, he/she was captured and sent to a camp for prisoners in Siberia for five years. To make easier its Siberian isolation Bothe learned Russian, calculated its own table of logarithms and worked on the mathematical development of his doctoral thesis.

In 1920 he/she was released and returned to Germany, married with the Muscovite Barbara Below. He/She joined his work at the Physikalisch-Technische Reichsanstalt, where he/she developed the matching method of analysis of gamma radiation which was published jointly with Geiger in 1924. This method is based on a provision of multiple geiger counters next each other. Any particles of high energy that crosses the whole will leave a trail of pulses at different counters that will coincide in time and which determine the trajectory of the particle or photon. Thanks to the matching method they could analyse and differentiate the multiple products of disintegration of atoms.

From 1923 to 1926 he/she concentrated on the theoretical and experimental study on the particle nature of light. Illuminating with x-ray a Chamber full of hydrogen Wilson observed trajectories of electrons of recoil (recoil) produced by x-ray photons, which would later become known as the Compton effect. Bothe the coincidence method applied was unfortunately not him who interpreted correctly the phenomenon, but Compton a few months later and so was awarded the Nobel Prize.

In collaboration with H. Becker in 1927 he/she began the study of transformations by bombardment of light elements with alpha particles from the polonium. In 1930, when he/she already held the position of Professor of physics and director of the Institute of Physics of the University of Giessen, bombing beryllium with alpha particles obtained a much more penetrating than those known up to then, radiation able to easily cross the lead. Bothe thought that it was a new type of gamma radiation, but not satisfied asked Irene Joliot-Curie. It was not then right with the exact nature of this radiation (neutrons), which Yes was James Chadwick in 1932.

From 1929, and in collaboration with W. Kolhörster and Italian Bernardo Rosi, Bothe began studying the cosmic and ultraviolet radiation using the method of coincidence. This it made measurements in different parts of the world, coming to the conclusion that this radiation came always from the space deep and was not gamma radiation as it was thought previously, but high energy particles that we know today as Mesons.

In 1932 he/she was appointed director of the Institute of Physics of the University of Heidelberg in succession of Philipp Lenard , who had retired. It was short-lived in this position since it does not hit or with classical theories that defended the University nor with the anti-Semitism that existed in the same and that it worsened with the rise of Hitler to power in 1933. For this reason he/she had to resign from that post in 1934 accepting Director of physics which is today called Instituto Max Planck (MPI) for the medical research of the same city.

The laboratory had few resources and materials but in return was free from the political influence of the University and enjoyed absolute freedom of research. There, in 1936, and in collaboration with Wolfgang Gentner, built a generator Van der Graaff (the first in Europe) for experimentation with nuclei of atoms of average weight.

In June 1939, he/she was called to Berlin to participate in the Uranverein (uranium Club), group of scientists created with the purpose of investigating the military applications of atomic fission.

During the period 1939-1945, with great difficulty got the money to build a cyclotron, worked on the diffusion and detection of neutrons, and published his Atlas of images with fog Chamber.

At the end of the second world war, the allies suspended all the research in nuclear physics and the same Bothe was investigated over his possible collaboration with the nazis. While the Americans used all means to deprive Germany of scientists and take America, Bothe persisted in reconstructing the MPI.

At that time, was appointed new director of the Department of Physics of the University of Heidelberg, who combined with his work at the MPI, until his death in that city on August 2, 1957.

He was a member of the academies of Sciences of Heidelberg, Göttingen, and Saxony; He/She was awarded the Max Planck medal and the Grand Cross of the order of federal service; in 1952 he/she was appointed Knight of the order of merit of the sciences and arts; and in 1954, he/she received the Nobel Prize in Physics (shared with Max Born).

He was considered to be a Professor, full, hard and demanding, without any dogmatism and with ability to assess rightly both any new idea and the merits of his collaborators. However in personal treatment was known for its great hospitality, as well as his wife Barbara Below with whom he/she had two children.

The virtues of Bothe were not only applied to physics. He/She had a great capacity for concentration and habit of doing his time the best possible use, which conferred a great capacity and working speed. Always considered a German Patriot and collaborated with the German arms industry with all its excitement, something so it never apologized. However, due to their integrity had frequent problems with the Nazi party and the Gestapo.

He was fond of classical music, and frequently attended concerts of Bach and Beethoven. He/She also played the piano and painting (usually Court Impressionist landscapes) with the same passion and effort which carried out its work in the laboratory.

Links on the Internet

http://sun0.mpimf-heidelberg.mpg.de/History/Bothe1.html; more information about his life and work.

GMM

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