Gustav Ludwig Hertz

German physicist (1887–1975)

A nephew of the distinguished physicist Heinrich Hertz, Gustav Hertz was born in Hamburg and educated at the universities of Munich and Berlin. He taught in Berlin and Halle before his appointment in 1928 to the professorship of experimental physics at the Technical University, Berlin. Hertz, as a Jew, was dismissed from his post in 1935. He worked for the Siemens company from 1935 until 1945, somehow managing to survive World War II, when he was captured by the Russians. He reemerged in 1955 to become director of the Physics Institute in Leipzig, then in East Germany.

In 1925 Hertz was awarded the Nobel Prize for physics for his work with James Franck on the quantized nature of energy transfer.

Known for his collaborations with fellow colleague James Franck at the University of Berlin, German scientist Gustav Hertz (1887-1975) achieved fame and success early in life when he and Franck documented the changes in energy that occur when an electron strikes an atom. The information the two men discovered confirmed the quantum theory put forth by physicist Neils Bohr regarding the amount of energy that can be absorbed by an atom. For their work Hertz and Franck received the Nobel Prize in Physics in 1925. Hertz was also involved in some of the Soviet Union's early research into atomic energy.

Hertz was born on July 27, 1887, in Hamburg, Germany to Auguste Arning and Gustav Hertz, an attorney. His uncle, Heinrich Rudolf Hertz, had studied electromagnetic waves in the 1880s and he is the man for whom the unit of frequency is now named. Hertz first attended the Johanneum Realgymnasium in Hamburg, and after graduating in 1906 he began his college education at the University of Göttingen, majoring in mathematics and physics. He later transferred to the University of Münich and eventually ended up at the University of Berlin where he completed his education. During his studies Hertz developed an interest in the field of experimental physics and ultimately finished his studies in this field. In 1911, he graduated from the University of Berlin with a Ph.D., his doctorate studies focusing on the infrared absorption spectrum of carbon dioxide with relation to pressure and partial pressure.

Bombarded Metal with Electrons

In 1913 Hertz was offered the position of research assistant at the University of Berlin's Physical Institute. It was at this post that he first met Franck. Interested in the same questions of experimental physics, the two men decided to pursue their research collaboratively. The first assignment they resolved to concentrate on involved bombarding a metal surface with a stream of electrons and then studying the emission of electrons from the metal, thereby determining the effect the impact of electrons had on atoms. They were especially interested in the changes this bombardment would have on the atomic energy level. This kind of research was similar to past studies of the photoelectric effect, which occurs when a metal surface is exposed to light energy and is measured through the emission of electrons from the metal surface. A study of the photoelectric effect was undertaken in 1902 by German physicist Philipp E. A. von Lenard, and a short time later Albert Einstein figured out a theory to explain von Lenard's data and the photoelectric effect in general. Taking this kind of experiment one step further, Hertz and Franck attempted to glean the make-up of electrons given off by a metal surface when it was bombarded by electrons instead of light.

Hertz and Franck sped up electrons by heating up a wire by means of a positively charged metal gauze placed a short distance from the wire. They forced the electrons to pass through a vapor of mercury and then placed a second wire gauze to catch the electrons that had not bumped into the mercury atoms and had therefore not lost their energy; the electrons that had lost their energy would not hit the second gauze, but would be motionless. They discovered that the loss of energy was negligible at the temperature they started from and so they increased the charge on the metal gauze and continued to track the loss of energy for electrons reaching the screen. They still measured little loss of energy as they slowly increased the voltage. The measurements remained relatively constant until they reached 4.9 volts. At that point, the electron current reaching the detector plunged almost to zero.

For a while, Hertz and Franck were at a loss as to how to interpret their results. They soon found, however, that Bohr's recently announced theory on the quantum model of the atom fit their research perfectly. Hertz and Franck came to the realization that the 4.9 volt result they observed matched up with the change between the first two electron energy levels in the mercury atom. In fact, the number 4.9 matched exactly the energy difference Bohr had predicted in his theory. The results of Hertz and Franck's experiments offered up one of the first pieces of experimental confirmation for Bohr's revolutionary new theory. This research "demonstrated the quantitative relations between the series of spectra lines and the energy losses of electrons in collision with atoms corresponding to the stationary energy states of the atoms," according to Hertz's biography posted on the Nobel Prize Website. Bohr's theory, for which the physicist had won the Nobel Prize in 1922, was an early model of the structure of the atom that has since become common knowledge. In this model the electrons traveled around a nucleus in numerous orbits which could be determined by the theory of quantum conditions. A quantum is the smallest amount by which certain physical quantities can change, especially concerned with electromagnetic radiation. It is the way in which scientists can examine and understand movement at the atomic level.

Awarded the Nobel Prize for Physics

Shortly after his groundbreaking experiment was completed, Hertz was drafted into the German army; the year was now 1914 and World War I had begun. He was gravely wounded in battle in 1915, and his wound was so severe that his recuperation took over a year. At the end of World War I Hertz moved back to Berlin where, in 1917, he was offered a position as a lecturer, or privatdozent. While this proved a good position from which to gain experience, the position was, unfortunately, unpaid.

In 1919 Hertz married Ellen Dihlmann. The couple eventually had two sons, Hellmuth and Johannes, and both boys eventually became involved in physics. Hellmuth Hertz became a professor at the Technical College in Lund, and Johannes Hertz went on to work at the Institute for Optics and Spectroscopy at the German Academy of Sciences in Berlin. Fortunately for Hertz and his growing family, in 1920 he was offered a position at the Philips Incandescent Lamp Works in Eindhoven, Netherlands, and he and his family moved to the Netherlands where they stayed for five years. The Philips Incandescent Lamp Works was one of the first major corporations to establish and run a full-time research laboratory. His new employment allowed Hertz freedom to continue with his research work.

In 1925 Hertz and his family again returned to Germany, where Hertz had been offered the position of professor of physics at the University of Hale. He also took over as the director of the Physical Institute at that university. In that same year, in recognition of his earlier work with Franck, the two men were jointly awarded the 1925 Nobel Prize for Physics for their work with atomic energy.

Hertz stayed at the University of Hale for three years before he once again moved back to Berlin. In 1928 he became a professor of physics at the Charlottenburg Technical University. He was also entrusted with the task of rebuilding the school's Physics Institute, a job that required much of his time. Still, Hertz also continued his work in physics, and discovered a method of separating neon isotopes using a diffusion cascade.

Moved to Soviet Union

In the 1930s National Socialism gained strength in Germany through the growth of the Nazi Party. Hertz did not approve of the fascism that was the backbone of the Nazi party and he was unwilling to pledge his allegiance to this new government. Because of this, Nazi officials forced him to resign from his position at the Charlottenburg Technical University. Despite his refusal to back the Nazi party, however, and much to his surprise, Hertz was offered a position at the Siemens and Halske Company in Berlin in 1935. He remained at that position, continuing his research, throughout World War II. Tragically, his wife Ellen died in 1941, and two years later he remarried, to Charlotte Jollasse. At the close of World War II, with the German economy now in ruins, things became increasingly turbulent in Germany, and in 1945 Hertz and his family moved to the Soviet Union.

Although Hertz had hoped to contribute to Soviet physics, he and other German colleagues who had fled Germany with him were not allowed to participate to any great extent in government-sponsored science programs. Swept up in the fervor of communism, the Soviets moved these German scientists to a remote area in Sukhumi near the Black Sea that was separated from the rest of the country. More significantly, for Hertz, was the fact that Sukhumi was far removed from the Soviet scientists he had hoped to work with. However, because he had made a commitment to work in the Soviet Union for ten years, he stayed in the Soviet Union, working on supersonics, radar, and continuing his research into atomic energy. Although he was seemingly hidden away, Hertz's work did not go unnoticed. In 1951 he won the Stalin Prize for his work on atomic energy. Hertz stayed in the Soviet Union until he finished his term of employment in 1954. After living briefly in East Germany, he was offered and accepted the position of director at the Karl Marx University's Physics Institute, located in Leipzig, Germany.

Hertz retired from Karl Marx University in 1961, at which time he was made professor emeritus. He returned for the last time to his former home in what still then East Berlin, and died there on October 30, 1975.

Throughout his life Hertz published papers detailing the research he had done, and his work furthered the work of others in the study of atomic energy. He also published frequently with other scientists, including Franck and other colleagues he worked with along the way. His papers run the gamut from the quantitative exchange of energy between electrons and atoms to the measurement of ionization potentials. He also authored some papers concerning the separation of isotopes. Hertz was a member of several prestigious scientific organizations, including the German Academy of Sciences in Berlin, and the Göttingen Academy of Sciences. In addition to receiving the Max Planck Medal from the German Physical Society, he was also named an honorary member of the Hungarian Academy of Sciences, a member of the Czechoslovakian Academy of Sciences, and was a foreign member of the Academy of Sciences of the USSR.

Books

Nobel Lectures, Physics 1922-1941, Elsevier Publishing, 1965.

Notable Scientists: From 1900 to the Present, Gale Group, 2001.

Weber, Robert L., Pioneers of Science: Nobel Prize Winners in Physics, American Institute of Physics, 1980.

World of Scientific Discovery, 2nd edition, Gale Group, 1999.

Periodicals

Poptronics, October, 2001.

Online

Gustav Hertz - Biography, Nobel Prize Website,http://nobelprize.org/physics/laureates/1925/hertz-bio.html (April 5, 2005).

The noun has one meaning:

Meaning #1: German physicist who with James Franck proved the existence of the stationary energy states postulated by Bohr (1887-1975)
  Synonyms: Hertz, Gustav Ludwig Hertz

Gustav Ludwig Hertz
Born	22 July 1887(1887-07-22) Hamburg, Germany
Died	30 October 1975 (aged 88) Berlin, Germany
Nationality	Germany
Fields	Physics
Institutions	Halle University
Alma mater	Humboldt University of Berlin
Doctoral advisor	Heinrich Rubens Max Planck
Known for	Franck-Hertz experiment
Notable awards	Nobel Prize in Physics (1925)
Notes Father of Carl Hellmuth Hertz

Gustav Ludwig Hertz (22 July 1887 – 30 October 1975) was a German experimental physicist and Nobel Prize winner, and a nephew of Heinrich Rudolf Hertz.

Contents 1 Biography 1.1 Career 1.2 The Soviet Union 1.3 Personal life 2 Scientific memberships 3 Publications 4 See also 5 Notes 6 References 7 External links

Biography

Hertz was born in Hamburg and studied at the Georg-August University of Göttingen (1906-1907), the Ludwig Maximilians University of Munich (1907-1908), and the Humboldt University of Berlin (1908-1911). He received his doctorate in 1911 under Heinrich Leopold Rubens.^[1][2]

From 1911 to 1914, Hertz was an assistant to Rubens at the University of Berlin. It was during this time that Hertz and James Franck performed experiments on inelastic electron collisions in gases,^[3] known as the Franck–Hertz experiments, and for which they received the Nobel Prize in Physics in 1925.^[4]

During World War I, Hertz served in the military from 1914. He was seriously wounded in 1915. In 1917, he returned to the University of Berlin as a Privatdozent. In 1920, he took a job as a research physicist at the Philips Incandescent Lamp Factory in Eindhoven, which he held until 1925.^[5]

Career

In 1925, Hertz became ordinarius professor and director of the Physics Institute of the Martin Luther University of Halle-Wittenberg. In 1928 he became ordinarius professor of experimental physics and director of the Physics Institute of the Berlin Technische Hochschule (BTH) in Berlin-Charlottenburg. While there, he developed an isotope separation technique via gaseous diffusion. Since Hertz was an officer during WW I, he was temporarily protected from National Socialist policies and the Law for the Restoration of the Professional Civil Service, but eventually the policies and laws became more stringent, and at the end of 1934, he was forced to resign his position at BTH, as he was classified as a “second degree part-Jew”. He then took a position at Siemens, as director of Research Laboratory II. While there, he continued his work on atomic physics and ultrasound, but he eventually discontinued his work on isotope separation. He held this position until he departed for the Soviet Union in 1945.^[2][5][6]

The Soviet Union

Hertz, Manfred von Ardenne, director of his private laboratory Forschungslaboratorium für Elektronenphysik,Peter Adolf Thiessen, ordinarius professor at the Humboldt University of Berlin and director of the Kaiser-Wilhelm Institut für physikalische Chemi und Elektrochemie (KWIPC) in Berlin-Dahlem, and Max Volmer, ordinarius professor and director of the Physical Chemistry Institute at the Berlin Technische Hochschule, had made a pact.^[7] The pact was a pledge that whoever first made contact with the Russians would speak for the rest. The objectives of their pact were threefold: (1) Prevent plunder of their institutes, (2) Continue their work with minimal interruption, and (3) Protect themselves from prosecution for any political acts of the past.^[8] Before the end of World War II, Thiessen, a member of the Nationalsozialistische Deutsche Arbeiterpartei, had Communist contacts.^[9] On 27 April 1945, Thiessen arrived at von Ardenne’s institute in an armored vehicle with a major of the Soviet Army, who was also a leading Soviet chemist.^[10] All four of the pact members were taken to the Soviet Union. Hertz was made head of Institute G, in Agudseri (Agudzery),about 10 km southeast of Sukhumi and a suburb of Gul’rips (Gulrip’shi).^[10][11] Topics assigned to Gustav Hertz’s Institute G included: (1) Separation of isotopes by diffusion in a flow of inert gases, for which Gustav Hertz was the leader, (2) Development of a condensation pump, for which Justus Mühlenpfordt was the leader, (3) Design and build a mass spectrometer for determining the isotopic composition of uranium, for which Werner Schütze was the leader, (4) Development of frameless (ceramic) diffusion partitions for filters, for which Reinhold Reichmann was the leader, and (5) Development of a theory of stability and control of a diffusion cascade, for which Heinz Barwich was the leader;^[10][12] Barwich had been deputy to Hertz at Siemens.^[13] Other members of Institute G were Werner Hartmann and Karl-Franz Zühlke.^[14] Von Ardenne was made head of Institute A, Goals of Manfred von Ardenne’s Institute A included: (1) Electromagnetic separation of isotopes, for which von Ardenne was the leader, (2) Techniques for manufacturing porous barriers for isotope separation, for which Peter Adolf Thiessen was the leader, and (3) Molecular techniques for separation of uranium isotopes, for which Max Steenbeck was the leader. In his first meeting with Lavrentij Beria, von Ardenne was asked to participate in building the bomb, but von Ardenne quickly realized that participation would prohibit his repatriation to Germany, so he suggested isotope enrichment as an objective, which was agreed to. By the end of the 1940s, nearly 300 Germans were working at the institute, and they were not the total work force. Institute A was used as the basis for the Sukhumi Physical-Technical Institute in Sinop, a suburb of Sukhumi.^[10][15] Volmer went to the Nauchno-Issledovatel’skij Institut-9 (NII-9, Scientific Research Institute No. 9),^[16] in Moscow; he was given a design bureau to work on the production of heavy water. In Institute A, Thiessen became leader for developing techniques for manufacturing porous barriers for isotope separation.^[10]

In 1949, six German scientists, including Hertz, Thiessen, and Barwich were called in for consultation at Sverdlovsk-44, which was responsible for uranium enrichment. The plant, smaller than the American Oak Ridge gaseous diffusion plant, was getting only a little over half of the expected 90% or higher enrichment.^[17]

After 1950, Hertz moved to Moscow. In 1951, Hertz was awarded a Stalin Prize, second class, with Barwich.^[10] In that year, James Franck and Hertz were jointly awarded the Max Planck Medal by the Deutsche Physikalische Gesellschaft. Hertz remained in the Soviet Union until 1955.^[2]

Upon return from the Soviet Union, Hertz became ordinarius professor at the University of Leipzig. From 1955 to 1967, he was also the chairman of the Physical Society of the Deutsche Demokratische Republik; he was honorary chairman from 1967 to 1975.^[4]

Personal life

In 1919, Hertz married Ellen née Dihlmann, who died in 1941. They had two sons, Carl Hellmuth Hertz and Johannes Hertz, both physicists.^[5]

Scientific memberships

Hertz was a Member of the German Academy of Sciences in Berlin, Corresponding Member of the Göttingen Academy of Sciences, an Honorary Member of the Hungarian Academy of Sciences, a Member of the Czechoslovakian Academy of Sciences, and a Foreign Member of the USSR Academy of Sciences.^[5]

Publications

• J. Franck and G. Hertz Über Zusammenstöße zwischen Elektronen und Molekülen des Quecksilberdampfes und die Ionisierungsspannung desselben, Verh. Dtsch. Phys. Ges. 16 457–467 (1914).
• Gustav Hertz Über das ultrarote Adsorptionsspektrum der Kohlensäure in seiner Abhängigkeit von Druck und Partialdruck. (Dissertation). (Vieweg Braunschweig, 1911)
• Gustav Hertz (editor) Lehrbuch der Kernphysik I-III (Teubner, 1961-1966)
• Gustav Hertz (editor) Grundlagen und Arbeitsmethoden der Kernphysik (Akademie Verlag, 1957)
• Gustav Hertz Gustav Hertz in der Entwicklung der modernen Physik (Akademie Verlag, 1967)

See also

• Electron diffraction
• Electric glow discharge
• Franck-Hertz experiment
• Plasma window
• Vacuum tube
• Scattering
• Russian Alsos

Notes

1. ^ Gustav Hertz Über das ultrarote Adsorptionsspektrum der Kohlensäure in seiner Abhängigkeit von Druck und Partialdruck. (Dissertation). (Vieweg Braunschweig, 1911)
2. ^ ^{a b c} Mehra and Rechenberg, 2001, 197.
3. ^ J. Franck and G. Hertz Über Zusammenstöße zwischen Elektronen und Molekülen des Quecksilberdampfes und die Ionisierungsspannung desselben, Verh. Dtsch. Phys. Ges. 16 457–467 (1914).
4. ^ ^{a b} Hentschel, 1996, Appendix F; see entry for Hertz.
5. ^ ^{a b c d} Hertz – Nobel Biography.
6. ^ Hentschel, 1996, 23 and Appendix F – see entry for Hertz.
7. ^ sachen.de - Zur Ehrung von Manfred von Ardenne.
8. ^ Heinemann-Grüder, 2002, 44.
9. ^ Hentschel, 1996, Appendix F; see the entry for Thiessen.
10. ^ ^{a b c d e f} Oleynikov, 2000, pp 5, 10-13, 18, 21
11. ^ Naimark, 1995, 213.
12. ^ Kruglov, 2002, 131.
13. ^ Naimark, 1995, 209.
14. ^ Maddrell, 2006, 179-180.
15. ^ Naimark, 1995, 213.
16. ^ Today, NII-9 is the Bochvar All-Russian Scientific Research Institute of Inorganic Materials, Bochvar VNIINM. See Oleynikov, 2000, 4.
17. ^ Holloway, 1994, 191-192.

References

• Albrecht, Ulrich, Andreas Heinemann-Grüder, and Arend Wellmann Die Spezialisten: Deutsche Naturwissenschaftler und Techniker in der Sowjetunion nach 1945 (Dietz, 1992, 2001) ISBN 3320017888
• Barwich, Heinz and Elfi Barwich Das rote Atom (Fischer-TB.-Vlg., 1984)
• Beneke, Klaus Die Kolloidwissenschaftler Peter Adolf Thiessen, Gerhart Jander, Robert Havemann, Hans Witzmann und ihre Zeit (Knof, 2000)
• Heinemann-Grüder, Andreas Die sowjetische Atombombe (Westfaelisches Dampfboot, 1992)
• Heinemann-Grüder, Andreas Keinerlei Untergang: German Armaments Engineers during the Second World War and in the Service of the Victorious Powers in Monika Renneberg and Mark Walker (editors) Science, Technology and National Socialism 30-50 (Cambridge, 2002 paperback edition) ISBN 0-521-528607
• Hentschel, Klaus (editor) and Ann M. Hentschel (editorial assistant and translator) Physics and National Socialism: An Anthology of Primary Sources (Birkhäuser, 1996) ISBN 0-8176-5312-0
• Holloway, David Stalin and the Bomb: The Soviet Union and Atomic Energy 1939–1956 (Yale, 1994) ISBN 0-300-06056-4
• Kruglov, Arkadii The History of the Soviet Atomic Industry (Taylor and Francis, 2002)
• Maddrell, Paul "Spying on Science: Western Intelligence in Divided Germany 1945–1961" (Oxford, 2006) ISBN 0-19-926750-2
• Mehra, Jagdish, and Helmut Rechenberg The Historical Development of Quantum Theory. Volume 1 Part 1 The Quantum Theory of Planck, Einstein, Bohr and Sommerfeld 1900 – 1925: Its Foundation and the Rise of Its Difficulties. (Springer, 2001) ISBN 0-387-95174-1
• Naimark, Norman M. The Russians in Germany: A History of the Soviet Zone of Occupation, 1945-1949 (Belknap, 1995)
• Oleynikov, Pavel V. 2000. German Scientists in the Soviet Atomic Project. The Nonproliferation Review Volume 7, Number 2, 1 – 30 The author has been a group leader at the Institute of Technical Physics of the Russian Federal Nuclear Center in Snezhinsk (Chelyabinsk-70).

External links

• Hertz – Nobel Biography.

v • d • e Nobel Laureates in Physics Wilhelm Röntgen (1901) · Hendrik Lorentz / Pieter Zeeman (1902) · Henri Becquerel / Pierre Curie / Marie Curie (1903) · Lord Rayleigh (1904) · Philipp Lenard (1905) · J. J. Thomson (1906) · Albert Michelson (1907) · Gabriel Lippmann (1908) · Guglielmo Marconi / Ferdinand Braun (1909) · Johannes van der Waals (1910) · Wilhelm Wien (1911) · Gustaf Dalén (1912) · Kamerlingh Onnes (1913) · Max von Laue (1914) · W. L. Bragg / W. H. Bragg (1915) · Charles Barkla (1917) · Max Planck (1918) · Johannes Stark (1919) · Charles Guillaume (1920) · Albert Einstein (1921) · Niels Bohr (1922) · Robert Millikan (1923) · Manne Siegbahn (1924) · James Franck / Gustav Hertz (1925) Complete roster | (1901–1925) | (1926–1950) | (1951–1975) | (1976–2000) | (2001–present)

Persondata
NAME	Hertz, Gustav Ludwig
ALTERNATIVE NAMES
SHORT DESCRIPTION	German Physicist
DATE OF BIRTH	July 22, 1887
PLACE OF BIRTH	Hamburg, Germany
DATE OF DEATH	October 30, 1975
PLACE OF DEATH	Berlin, Germany

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