Otto Robert Frisch: Difference between revisions

Otto Robert Frisch
OBE FRS
Otto Robert Frisch OBE FRS
	Otto Robert Frisch's wartime Los Alamos ID badge photo
Born	1 October 1904; Vienna, Austria-Hungary
Died	22 September 1979 (aged 74); Cambridge, United Kingdom
Nationality	Austrian
Citizenship	Austria; United Kingdom
Alma mater	University of Vienna
Known for	Atomic bomb
Awards	Fellow of the Royal Society
	Scientific career
Fields	Physics
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Otto Robert Frisch OBE FRS^[1] (1 October 1904 – 22 September 1979) was an Austrian-born British physicist who worked on nuclear physics. With Otto Stern and Immanuel Estermann he first measured the magnetic moment of the proton. With Lise Meitner he advanced the first theoretical explanation of nuclear fission (coining the term) and first experimentally detected the fission by-products. Later, with his collaborator Rudolf Peierls^[1] he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940.^[2]

Early life

Frisch was born in Vienna in 1904 to a Jewish family, the son of Justinian Frisch, a painter, and Auguste Meitner Frisch, a concert pianist.^[3] He himself was talented at both but also shared his aunt Lise Meitner's love of physics and commenced a period of study at the University of Vienna, graduating in 1926 with some work on the effect of the newly discovered electron on salts.

Nuclear physics

After some years working in relatively obscure laboratories in Germany, Frisch obtained a position in Hamburg under the Nobel Prize-winning scientist Otto Stern. Here he produced work on the diffraction of atoms (using crystal surfaces) and also proved that the magnetic moment of the proton was much larger than had been previously supposed.^[4]

The accession of Adolf Hitler to the chancellorship of Germany in 1933 caused Otto Robert Frisch to make the decision to move to London, where he joined the staff at Birkbeck College^[5] and worked with the physicist Patrick Maynard Stuart Blackett on cloud chamber technology and artificial radioactivity. He followed this with a five-year stint in Copenhagen with Niels Bohr where he increasingly specialised in nuclear physics, particularly in neutron physics.

Nuclear fission

During the Christmas holiday in 1938, he visited his aunt Lise Meitner in Kungälv. While there she received the news that Otto Hahn and Fritz Strassmann in Berlin had discovered that the collision of a neutron with a uranium nucleus produced the element barium as one of its byproducts. Hahn, in a letter to Meitner, called this new reaction a "bursting" of the uranium nucleus. Frisch and Meitner hypothesized that the uranium nucleus had split in two, explained the process, and estimated the energy released, and Frisch coined the term fission, adopted from a process in biology, to describe it.^[6]^[7]

Political restraints of the Nazi era forced the teams of Hahn and Strassmann and that of Frisch and Meitner (both of whom were Jewish) to publish separately. Hahn's paper described the experiment and the finding of the barium byproduct.^[8] Meitner's and Frisch's paper explained the physics behind the phenomenon.^[9]

Frisch went back to Copenhagen, where he was quickly able to isolate the pieces produced by fission reactions.^[10] As Frisch himself later recalled, a fundamental idea of the direct experimental proof of the nuclear fission was suggested to him by George Placzek.^[11]^[12] Many feel that Meitner and Frisch deserved Nobel Prize recognition for their contributions to understanding fission.^[13]

In mid-1939 Frisch left Denmark for what he anticipated would be a short trip to Birmingham, but the outbreak of World War II precluded his return. With war on his mind, he and the physicist Rudolf Peierls produced the Frisch–Peierls memorandum at the University of Birmingham, which was the first document to set out a process by which an atomic explosion could be generated. Their process would use separated uranium-235, which would require a fairly small critical mass and could be made to achieve criticality using conventional explosives to create an immensely powerful detonation. The memorandum went on to predict the effects of such an explosion—from the initial blast to the resulting fallout. This memorandum was the basis of British work on building an atomic device (the Tube Alloys project) and also that of the Manhattan Project on which Frisch worked as part of the British delegation. Frisch and Rudolf Peierls worked together in the Physics Department at the University of Birmingham 1939–40.^[14] He went to America in 1943 having been hurriedly made a British citizen.

Manhattan Project

Complex scientific apparatus with metal frame surrounding three sections of a sphere held in the center by a system of rods, and separated vertically from one another so as to form a complete sphere when brought together — The Godiva device at Los Alamos

In 1944 at Los Alamos, one of Frisch's tasks as the leader of the Critical Assemblies group was to accurately determine the exact amount of enriched uranium which would be required to create the critical mass, the mass of uranium which would sustain a nuclear chain reaction.^[15] He did this by stacking several dozen 3 cm bars of enriched uranium hydride at a time and measuring rising neutron activity as the critical mass was approached. The hydrogen in the metal bars increased the time that the reaction required to accelerate. One day Frisch almost caused a runaway reaction by leaning over the stack, which he termed the "Lady Godiva assembly".^[16] His body reflected neutrons back into the stack. Out of the corner of his eye he saw that the red lamps that flickered intermittently when neutrons were being emitted, were 'glowing continuously'.^[16] Realizing what was happening, Frisch quickly scattered the bars with his hand. Later he calculated that the radiation dose was "quite harmless" but that if he "had hesitated for another two seconds before removing the material ... the dose would have been fatal".^[16] "In two seconds he received, by the generous standards of the time, a full day's permissible dose of neutron radiation."^[17] In this way his experiments determined the exact masses of uranium required to fire the Little Boy bomb over Hiroshima.

He also designed the "dragon's tail" or "guillotine" experiment in which a uranium slug was dropped through a hole in larger fixed mass of uranium, reaching just above critical mass (0.1%) for a fraction of a second.^[18] At the meeting to approve the experiment, Richard Feynman, commenting on the transient danger involved, said it was "just like tickling the tail of a sleeping dragon." In the period of about 3 milliseconds, the temperature rose at a rate of 2000 °C per sec and over 10¹⁵ excess neutrons were emitted.^[19]

Return to England

In 1946 he returned to England to take up the post of head of the nuclear physics division of the Atomic Energy Research Establishment at Harwell, though he also spent much of the next thirty years teaching at Cambridge where he was Jacksonian Professor of Natural Philosophy^[5] and a fellow of Trinity College.

Before he retired he designed^[20] a device, SWEEPNIK, that used a laser and computer to measure tracks in bubble chambers. Seeing that this had wider applications, he helped found a company, Laser-Scan Limited, now known as Laser-Scan Engineering Ltd., to exploit the idea.

Retirement

He retired from the chair in 1972 as required by University regulations.^[20] He died on 22 September 1979.^[5]^[21]

References

^ ^a ^b ^c Peierls, R. (1981). "Otto Robert Frisch. 1 October 1904 – 22 September 1979". Biographical Memoirs of Fellows of the Royal Society. 27: 283–306. doi:10.1098/rsbm.1981.0012. JSTOR 769874.
^ Bethe, H. A.; Winter, George (January 1980). "Obituary: Otto Robert Frisch". Physics Today. 33 (1): 99–100. Bibcode:1980PhT....33a..99B. doi:10.1063/1.2913924. Archived from the original on 28 September 2013.
^ "Otto Robert Frisch | Biography & Facts". Encyclopedia Brittanica. Retrieved 21 December 2023.
^ Frisch, Otto R.; Stern, Otto (1933). "Über die magnetische Ablenkung von Wasserstoffmolekülen und das magnetische Moment des Protons". Zeitschrift für Physik (in German). 85 (1–2): 4–16. Bibcode:1933ZPhy...85....4F. doi:10.1007/BF01330773. S2CID 120793548.
^ ^a ^b ^c Gribbin, J. (2000). Q is for Quantum: An Encyclopedia of Particle Physics. Simon & Schuster. p. 150. ISBN 978-0-684-86315-3. Retrieved 4 December 2021.
^ Sullivan, Neil J. (2016). The Prometheus Bomb: The Manhattan Project and Government in the Dark. Lincoln: University of Nebraska Press. p. 19. ISBN 978-1-61234-890-2.
^ Rhodes, Richard (1986). The Making of the Atomic Bomb. New York: Simon & Schuster. p. 263. ISBN 978-0-684-81378-3. OCLC 13793436.
^ Hahn, O.; Strassmann, F. (1939). "Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle [On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium without neutrons]". Naturwissenschaften (in German). 27 (1): 11–15. Bibcode:1939NW.....27...11H. doi:10.1007/BF01488241. S2CID 5920336. The authors were identified as being at the Kaiser-Wilhelm-Institut für Chemie, Berlin-Dahlem. Received 22 December 1938.
^ Meitner, Lise; Frisch, O. R. (1939). "Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction". Nature. 143 (3615): 239–240. Bibcode:1939Natur.143..239M. doi:10.1038/143239a0. S2CID 4113262. The paper is dated 16 January 1939. Meitner is identified as being at the Physical Institute, Academy of Sciences, Stockholm. Frisch is identified as being at the Institute of Theoretical Physics, University of Copenhagen.
^ Frisch, O. R. (1939). "Physical Evidence for the Division of Heavy Nuclei under Neutron Bombardment". Nature. 143 (3616): 276. Bibcode:1939Natur.143..276F. doi:10.1038/143276a0. S2CID 4076376. The paper is dated 17 January 1939. [The experiment for this letter to the editor was conducted on 13 January 1939; see Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 263 and 268.
^ Otto R. Frisch, "The Discovery of Fission – How It All Began", Physics Today, V20, N11, pp. 43-48 (1967).
^ J. A. Wheeler, "Mechanism of Fission", Physics Today V20, N11, pp. 49-52 (1967).
^ "Fame without a Nobel Prize". 5 November 2015.
^ "Culture trails – Blue Plaque Guide" (PDF). University of Birmingham. Retrieved 4 December 2021.
^ Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 612–613.
^ ^a ^b ^c Frisch, Otto Robert (1980). What Little I Remember. Cambridge University Press. pp. 161–162. ISBN 0-52-128010-9. We were building an unusual assembly, with no reflecting material around it; just the reacting compound of uranium-235 ... For obvious reasons we called it the Lady Godiva assembly.
^ Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 610–11. ISBN 9780671441333.
^ "Here Be Dragons".
^ r.e. Malenfant (2005). "Experiments with the Dragon Machine". doi:10.2172/876514. OSTI 876514. S2CID 108799363. {{cite journal}}: Cite journal requires |journal= (help)
^ ^a ^b Otto Frisch, "What Little I Remember", Cambridge University Press (1979), ISBN 0-521-40583-1
^ Peierls, Rudolf Ernst (1 November 1981). "Otto Robert Frisch, 1 October 1904 - 22 September 1979". Biographical Memoirs of Fellows of the Royal Society. 27: 283–306. doi:10.1098/rsbm.1981.0012. ISSN 0080-4606. O. R. Frisch brought to physics the approach of a craftsman. He enjoyed, above all, doing experiments with his own hands, preferably on apparatus of his own design, aimed at simple basic questions. This approach required the ability to think about the important problems of physics simply, but deeply, an ability underlying the two contributions for which he was best known: his share in the explanation of the fission process and that in the recognition of the feasibility of an atomic weapon.

Bibliography

Atomic Physics Today (1961)
Working with ATOMS (1965)
What Little I Remember (1979)

External links

Academic offices
Preceded by John Cockcroft	Jacksonian Professor of Natural Philosophy 1947–1972	Succeeded by Alan Cook

[frs-1] Peierls, R. (1981). "Otto Robert Frisch. 1 October 1904 – 22 September 1979". Biographical Memoirs of Fellows of the Royal Society. 27: 283–306. doi:10.1098/rsbm.1981.0012. JSTOR 769874.

[2] Bethe, H. A.; Winter, George (January 1980). "Obituary: Otto Robert Frisch". Physics Today. 33 (1): 99–100. Bibcode:1980PhT....33a..99B. doi:10.1063/1.2913924. Archived from the original on 28 September 2013.

[3] "Otto Robert Frisch | Biography & Facts". Encyclopedia Brittanica. Retrieved 21 December 2023.

[4] Frisch, Otto R.; Stern, Otto (1933). "Über die magnetische Ablenkung von Wasserstoffmolekülen und das magnetische Moment des Protons". Zeitschrift für Physik (in German). 85 (1–2): 4–16. Bibcode:1933ZPhy...85....4F. doi:10.1007/BF01330773. S2CID 120793548.

[Gribbin_2000_p._150-5] Gribbin, J. (2000). Q is for Quantum: An Encyclopedia of Particle Physics. Simon & Schuster. p. 150. ISBN 978-0-684-86315-3. Retrieved 4 December 2021.

[Sullivan_2016_p.19-6] Sullivan, Neil J. (2016). The Prometheus Bomb: The Manhattan Project and Government in the Dark. Lincoln: University of Nebraska Press. p. 19. ISBN 978-1-61234-890-2.

[Rhodes_1986_p.263-7] Rhodes, Richard (1986). The Making of the Atomic Bomb. New York: Simon & Schuster. p. 263. ISBN 978-0-684-81378-3. OCLC 13793436.

[8] Hahn, O.; Strassmann, F. (1939). "Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle [On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium without neutrons]". Naturwissenschaften (in German). 27 (1): 11–15. Bibcode:1939NW.....27...11H. doi:10.1007/BF01488241. S2CID 5920336. The authors were identified as being at the Kaiser-Wilhelm-Institut für Chemie, Berlin-Dahlem. Received 22 December 1938.

[9] Meitner, Lise; Frisch, O. R. (1939). "Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction". Nature. 143 (3615): 239–240. Bibcode:1939Natur.143..239M. doi:10.1038/143239a0. S2CID 4113262. The paper is dated 16 January 1939. Meitner is identified as being at the Physical Institute, Academy of Sciences, Stockholm. Frisch is identified as being at the Institute of Theoretical Physics, University of Copenhagen.

[10] Frisch, O. R. (1939). "Physical Evidence for the Division of Heavy Nuclei under Neutron Bombardment". Nature. 143 (3616): 276. Bibcode:1939Natur.143..276F. doi:10.1038/143276a0. S2CID 4076376. The paper is dated 17 January 1939. [The experiment for this letter to the editor was conducted on 13 January 1939; see Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 263 and 268.

[11] Otto R. Frisch, "The Discovery of Fission – How It All Began", Physics Today, V20, N11, pp. 43-48 (1967).

[12] J. A. Wheeler, "Mechanism of Fission", Physics Today V20, N11, pp. 49-52 (1967).

[13] "Fame without a Nobel Prize". 5 November 2015.

[University_of_Birmingham-14] "Culture trails – Blue Plaque Guide" (PDF). University of Birmingham. Retrieved 4 December 2021.

[15] Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 612–613.

[Frisch-16] Frisch, Otto Robert (1980). What Little I Remember. Cambridge University Press. pp. 161–162. ISBN 0-52-128010-9. We were building an unusual assembly, with no reflecting material around it; just the reacting compound of uranium-235 ... For obvious reasons we called it the Lady Godiva assembly.

[17] Rhodes, Richard (1986). The Making of the Atomic Bomb. Simon and Schuster. pp. 610–11. ISBN 9780671441333.

[18] "Here Be Dragons".

[19] r.e. Malenfant (2005). "Experiments with the Dragon Machine". doi:10.2172/876514. OSTI 876514. S2CID 108799363. {{cite journal}}: Cite journal requires |journal= (help)

[WhatLittle-20] Otto Frisch, "What Little I Remember", Cambridge University Press (1979), ISBN 0-521-40583-1

[21] Peierls, Rudolf Ernst (1 November 1981). "Otto Robert Frisch, 1 October 1904 - 22 September 1979". Biographical Memoirs of Fellows of the Royal Society. 27: 283–306. doi:10.1098/rsbm.1981.0012. ISSN 0080-4606. O. R. Frisch brought to physics the approach of a craftsman. He enjoyed, above all, doing experiments with his own hands, preferably on apparatus of his own design, aimed at simple basic questions. This approach required the ability to think about the important problems of physics simply, but deeply, an ability underlying the two contributions for which he was best known: his share in the explanation of the fission process and that in the recognition of the feasibility of an atomic weapon.

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@@ Line 1: / Line 1: @@
+{{Short description|Austrian-born British nuclear physicist}}
-{{Use dmy dates|date=August 2016}}
+{{Use dmy dates|date=June 2021}}
 {{Use British English|date=August 2016}}
 {{Infobox scientist
-|name = Otto Robert Frisch
+| name              = Otto Robert Frisch
-|image =Otto Frisch ID badge.png
+| image             = Otto Frisch Los Alamos ID badge photo.jpg
+| caption           = Otto Robert Frisch's wartime [[Los Alamos National Laboratory|Los Alamos]] ID badge photo
-|image_size = 150px
+| birth_date        = {{birth date|1904|10|01|df=y}}
-|caption = Otto Robert Frisch's wartime [[Los Alamos National Laboratory|Los Alamos]] ID badge photo.
+| birth_place       = [[Vienna]], [[Austria-Hungary]]
-|birth_date = {{birth date|1904|10|01|df=y}}
+| death_date        = {{death date and age|1979|09|22|1904|10|01|df=y}}
-|birth_place = [[Vienna]], [[Austria-Hungary]]
+| death_place       = [[Cambridge]], United Kingdom
-|death_date = {{death date and age|1979|09|22|1904|10|01|df=y}}
+| residence         =
-|death_place = [[Cambridge]], United Kingdom
+| nationality       = [[Austrians|Austrian]]
-|residence =
+| citizenship       = Austria<br>United Kingdom
-|nationality = [[Austrians|Austrian]]
+| ethnicity         =
-|citizenship = Austria<br>United Kingdom
+| field             = [[Physics]]
-|ethnicity =
+| work_institutions =
-|field = [[Physics]]
+| alma_mater        = [[University of Vienna]]
-|work_institutions =
+| doctoral_advisor  =
-|alma_mater =
+| doctoral_students =
-|doctoral_advisor =
+| known_for         = [[Atomic bomb]]
-|doctoral_students =
+| prizes            = [[Fellow of the Royal Society]]<ref name="frs">{{Cite journal | last1 = Peierls | first1 = R. | author-link = Rudolf Peierls| doi = 10.1098/rsbm.1981.0012 | title = Otto Robert Frisch. 1 October 1904 – 22 September 1979 | journal = [[Biographical Memoirs of Fellows of the Royal Society]] | volume = 27 | pages = 283–306 | year = 1981 | jstor = 769874| doi-access = free }}</ref>
-|known_for = [[Atomic bomb]]
+| religion          =
-|influences = [[Rudolf Peierls]]
+| footnotes         =
-|influenced =
+| signature         = Otto Robert Frisch signature.svg
-|prizes = [[Fellow of the Royal Society]]<ref name="frs">{{Cite journal | last1 = Peierls | first1 = R. | author-link = Rudolf Peierls| doi = 10.1098/rsbm.1981.0012 | title = Otto Robert Frisch. 1 October 1904 – 22 September 1979 | journal = [[Biographical Memoirs of Fellows of the Royal Society]] | volume = 27 | pages = 283–306 | year = 1981 | jstor = 769874| doi-access = free }}</ref>
+| post-nominals     = {{Post-nominals|country=GBR|OBE|FRS|size=100%}}
-|religion =
-|footnotes =
-|signature = Otto Robert Frisch signature.svg
 }}
-'''Otto Robert Frisch''' [[Fellow of the Royal Society|FRS]]<ref name="frs"/> (1 October 1904 – 22 September 1979) was an Austrian-born British [[physicist]] who worked on [[nuclear physics]]. With [[Lise Meitner]] he advanced the first theoretical explanation of [[nuclear fission]] (coining the term) and first experimentally detected the fission by-products. Later, with his collaborator [[Rudolf Peierls]]<ref name="frs"/> he designed the first theoretical mechanism for the detonation of an [[atomic bomb]] in 1940.<ref>{{cite journal|author=Bethe, H. A.|author-link=Hans Bethe|author2=Winter, George|title=Obituary: Otto Robert Frisch|journal=Physics Today|date=January 1980|volume=33|issue=1|pages=99–100|url=http://www.physicstoday.org/resource/1/phtoad/v33/i1/p99_s1?bypassSSO=1|archive-url=https://archive.is/20130928152655/http://www.physicstoday.org/resource/1/phtoad/v33/i1/p99_s1?bypassSSO=1|url-status=dead|archive-date=2013-09-28|doi=10.1063/1.2913924|bibcode=1980PhT....33a..99B}}</ref>
+'''Otto Robert Frisch''' {{Post-nominals|country=GBR|OBE|FRS}}<ref name="frs"/> (1 October 1904 – 22 September 1979) was an Austrian-born British [[physicist]] who worked on [[nuclear physics]]. With [[Otto Stern]] and [[Immanuel Estermann]] he first measured the [[magnetic moment]] of the [[proton]]. With [[Lise Meitner]] he advanced the first theoretical explanation of [[nuclear fission]] (coining the term) and first experimentally detected the fission by-products. Later, with his collaborator [[Rudolf Peierls]]<ref name="frs"/> he designed the first theoretical mechanism for the detonation of an [[atomic bomb]] in 1940.<ref>{{cite journal|author=Bethe, H. A.|author-link=Hans Bethe|author2=Winter, George|title=Obituary: Otto Robert Frisch|journal=Physics Today|date=January 1980|volume=33|issue=1|pages=99–100|url=http://www.physicstoday.org/resource/1/phtoad/v33/i1/p99_s1?bypassSSO=1|archive-url=https://archive.today/20130928152655/http://www.physicstoday.org/resource/1/phtoad/v33/i1/p99_s1?bypassSSO=1|url-status=dead|archive-date=28 September 2013|doi=10.1063/1.2913924|bibcode=1980PhT....33a..99B}}</ref>
 == Early life ==
+{{unreferenced section|date=October 2022}}
-Frisch was born in [[Vienna]] in 1904 to a [[Jewish]] family, the son of Justinian Frisch, a painter, and Auguste Meitner Frisch, a concert pianist. He himself was talented at both but also shared his aunt [[Lise Meitner]]'s love of physics and commenced a period of study at the University of Vienna, graduating in 1926 with some work on the effect of the newly discovered [[electron]] on salts.
+Frisch was born in [[Vienna]] in 1904 to a [[Jewish]] family, the son of Justinian Frisch, a painter, and Auguste Meitner Frisch, a concert pianist.<ref>{{Cite web |title=Otto Robert Frisch {{!}} Biography & Facts |url=https://www.britannica.com/biography/Otto-Robert-Frisch |access-date=December 21, 2023 |website=Encyclopedia Brittanica}}</ref> He himself was talented at both but also shared his aunt [[Lise Meitner]]'s love of physics and commenced a period of study at the [[University of Vienna]], graduating in 1926 with some work on the effect of the newly discovered [[electron]] on salts.
 ==Nuclear physics==
 After some years working in relatively obscure laboratories in Germany, Frisch obtained a position in [[Hamburg]] under the [[Nobel Prize]]-winning scientist [[Otto Stern]]. Here he produced work on the diffraction of atoms (using crystal surfaces) and also proved that the [[magnetic moment]] of the [[proton]] was much larger than had been previously supposed.<ref>{{cite journal |first1=Otto R. |last1=Frisch |first2=Otto |last2=Stern |title=Über die magnetische Ablenkung von Wasserstoffmolekülen und das magnetische Moment des Protons  |language=de|journal=[[Zeitschrift für Physik]] |volume=85 |issue=1–2 |pages=4–16 |year=1933 |doi=10.1007/BF01330773 |bibcode = 1933ZPhy...85....4F |s2cid=120793548 }}</ref>
-The accession of [[Adolf Hitler]] to the chancellorship of Germany in 1933 caused Otto Robert Frisch to make the decision to move to [[London, England|London]], where he joined the staff at [[Birkbeck, University of London|Birkbeck College]] and worked with the physicist [[Patrick Maynard Stuart Blackett]] on [[cloud chamber]] technology and artificial [[radioactivity]]. He followed this with a five-year stint in [[Copenhagen]] with [[Niels Bohr]] where he increasingly specialised in [[nuclear physics]], particularly in neutron physics.
+The accession of [[Adolf Hitler]] to the chancellorship of Germany in 1933 caused Otto Robert Frisch to make the decision to move to [[London, England|London]], where he joined the staff at [[Birkbeck, University of London|Birkbeck College]]<ref name="Gribbin 2000 p. 150">{{cite book | last=Gribbin | first=J. | title=Q is for Quantum: An Encyclopedia of Particle Physics | publisher=Simon & Schuster | year=2000 | isbn=978-0-684-86315-3 | url=https://books.google.com/books?id=zBsDkgI1uQsC&pg=PA150 | access-date=2021-12-04 | page=150}}</ref> and worked with the physicist [[Patrick Maynard Stuart Blackett]] on [[cloud chamber]] technology and artificial [[radioactivity]]. He followed this with a five-year stint in [[Copenhagen]] with [[Niels Bohr]] where he increasingly specialised in [[nuclear physics]], particularly in neutron physics.
 ==Nuclear fission==
 {{main|Discovery of nuclear fission}}
 [[File:Lise Meitner.jpg|thumb|Otto Frisch, Lise Meitner, and [[Glenn Seaborg]]]]
-During the Christmas holiday in 1938, he visited his aunt [[Lise Meitner]] in [[Kungälv]]. While there she received the news that [[Otto Hahn]] and [[Fritz Strassmann]] in [[Berlin]] had discovered that the collision of a [[neutron]] with a [[uranium]] nucleus produced the element [[barium]] as one of its byproducts. Hahn, in a letter to Meitner, called this new reaction a "bursting" of the uranium nucleus. Frisch and Meitner hypothesized that the uranium nucleus had split in two, explained the process, and estimated the energy released, and Frisch coined the term [[Nuclear fission|fission]] to describe it.
+During the Christmas holiday in 1938, he visited his aunt [[Lise Meitner]] in [[Kungälv]]. While there she received the news that [[Otto Hahn]] and [[Fritz Strassmann]] in [[Berlin]] had discovered that the collision of a [[neutron]] with a [[uranium]] nucleus produced the element [[barium]] as one of its byproducts. Hahn, in a letter to Meitner, called this new reaction a "bursting" of the uranium nucleus. Frisch and Meitner hypothesized that the uranium nucleus had split in two, explained the process, and estimated the energy released, and Frisch coined the term [[Nuclear fission|fission]], adopted from a [[Fission (biology)|process]] in biology, to describe it.<ref name="Sullivan 2016 p.19">{{cite book | last=Sullivan | first=Neil J. | title=The Prometheus Bomb: The Manhattan Project and Government in the Dark |location=Lincoln | publisher=[[University of Nebraska Press]] | year=2016 | isbn=978-1-61234-890-2 | url=https://books.google.com/books?id=Md4nDwAAQBAJ | page=19}}</ref><ref name="Rhodes 1986 p.263">{{cite book  |last=Rhodes |first=Richard |author-link = Richard Rhodes |year=1986 |title=The Making of the Atomic Bomb |url=https://archive.org/details/makingofatomicbo00rhod |url-access=registration |location=New York |publisher=Simon & Schuster |isbn=978-0-684-81378-3 |oclc=13793436 |page=263}}</ref>
-Political restraints of the Nazi era forced the team of Hahn and that of Frisch and Meitner (both of whom were Jewish) to publish separately.  Hahn's paper described the experiment and the finding of the barium byproduct.<ref>{{cite journal |first1=O. |last1=Hahn |first2=F. |last2=Strassmann |title=Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle [On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium without neutrons]  |language=de|journal=Naturwissenschaften |volume=27 |issue=1 |pages=11–15 |year=1939 |bibcode = 1939NW.....27...11H |doi = 10.1007/BF01488241 |s2cid=5920336 }} The authors were identified as being at the Kaiser-Wilhelm-Institut für Chemie, Berlin-Dahlem. Received 22 December 1938.</ref> Meitner's and Frisch's paper explained the physics behind the phenomenon.<ref>{{cite journal |first1=Lise |last1=Meitner |first2=O. R. |last2=Frisch |title=Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction |journal=[[Nature (journal)|Nature]] |volume=143 |issue=3615 |pages=239–240 |url=http://www.nature.com/physics/looking-back/meitner/index.html |year=1939 |bibcode = 1939Natur.143..239M |doi = 10.1038/143239a0 |s2cid=4113262 }} The paper is dated 16 January 1939. Meitner is identified as being at the Physical Institute, Academy of Sciences, Stockholm. Frisch is identified as being at the Institute of Theoretical Physics, University of Copenhagen.</ref>
+Political restraints of the Nazi era forced the teams of Hahn and Strassmann and that of Frisch and Meitner (both of whom were Jewish) to publish separately. Hahn's paper described the experiment and the finding of the barium byproduct.<ref>{{cite journal |first1=O. |last1=Hahn |first2=F. |last2=Strassmann |title=Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle [On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium without neutrons]  |language=de|journal=Naturwissenschaften |volume=27 |issue=1 |pages=11–15 |year=1939 |bibcode = 1939NW.....27...11H |doi = 10.1007/BF01488241 |s2cid=5920336 }} The authors were identified as being at the Kaiser-Wilhelm-Institut für Chemie, Berlin-Dahlem. Received 22 December 1938.</ref> Meitner's and Frisch's paper explained the physics behind the phenomenon.<ref>{{cite journal |first1=Lise |last1=Meitner |first2=O. R. |last2=Frisch |title=Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction |journal=[[Nature (journal)|Nature]] |volume=143 |issue=3615 |pages=239–240 |url=https://www.atomicarchive.com/resources/documents/beginnings/nature_meitner.html |year=1939 |bibcode = 1939Natur.143..239M |doi = 10.1038/143239a0 |s2cid=4113262 }} The paper is dated 16 January 1939. Meitner is identified as being at the Physical Institute, Academy of Sciences, Stockholm. Frisch is identified as being at the Institute of Theoretical Physics, University of Copenhagen.</ref>
-Frisch went back to Copenhagen, where he was quickly able to isolate the pieces produced by fission reactions.<ref>{{cite journal |first=O. R. |last=Frisch |title=Physical Evidence for the Division of Heavy Nuclei under Neutron Bombardment |journal=Nature |volume=143 |issue=3616 |pages=276 |url=http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Frisch-Fission-1939.html |year=1939 |bibcode=1939Natur.143..276F |doi=10.1038/143276a0 |s2cid=4076376 |url-status=dead |archive-url=https://web.archive.org/web/20040803185959/http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Frisch-Fission-1939.html |archive-date=3 August 2004 |df=dmy-all }} The paper is dated 17 January 1939. [The experiment for this letter to the editor was conducted on 13 January 1939; see {{cite book |first=Richard |last=Rhodes |title=The Making of the Atomic Bomb |url=https://archive.org/details/makingofatomicbo00rhod |url-access=registration |pages=[https://archive.org/details/makingofatomicbo00rhod/page/263 263] and 268 |publisher=Simon and Schuster |year=1986 }}</ref> As Frisch himself later recalled, a fundamental idea of the direct experimental proof of the nuclear fission was suggested to him by [[George Placzek]].<ref>Otto R. Frisch, "The Discovery of Fission – How It All Began", ''Physics Today'', V20, N11, pp. 43-48 (1967).</ref><ref>J. A. Wheeler, "Mechanism of Fission", ''Physics Today'' V20, N11, pp. 49-52 (1967).</ref> Many feel that Meitner and Frisch deserved Nobel Prize recognition for their contributions to understanding fission.<ref>{{cite web|url=http://www.lindau-nobel.org/lise-meitner-fame-without-a-nobel-prize/|title=Fame without a Nobel Prize}}</ref>
+Frisch went back to Copenhagen, where he was quickly able to isolate the pieces produced by fission reactions.<ref>{{cite journal |first=O. R. |last=Frisch |title=Physical Evidence for the Division of Heavy Nuclei under Neutron Bombardment |journal=Nature |volume=143 |issue=3616 |pages=276 |year=1939 |bibcode=1939Natur.143..276F |doi=10.1038/143276a0 |s2cid=4076376 |doi-access=free }} The paper is dated 17 January 1939. [The experiment for this letter to the editor was conducted on 13 January 1939; see {{cite book |first=Richard |last=Rhodes |title=The Making of the Atomic Bomb |url=https://archive.org/details/makingofatomicbo00rhod |url-access=registration |pages=[https://archive.org/details/makingofatomicbo00rhod/page/263 263] and 268 |publisher=Simon and Schuster |year=1986 }}</ref> As Frisch himself later recalled, a fundamental idea of the direct experimental proof of the nuclear fission was suggested to him by [[George Placzek]].<ref>Otto R. Frisch, "The Discovery of Fission – How It All Began", ''Physics Today'', V20, N11, pp. 43-48 (1967).</ref><ref>J. A. Wheeler, "Mechanism of Fission", ''Physics Today'' V20, N11, pp. 49-52 (1967).</ref> Many feel that Meitner and Frisch deserved Nobel Prize recognition for their contributions to understanding fission.<ref>{{cite web|url=http://www.lindau-nobel.org/lise-meitner-fame-without-a-nobel-prize/|title=Fame without a Nobel Prize|date=5 November 2015}}</ref>
-In mid-1939 Frisch left Denmark for what he anticipated would be a short trip to [[Birmingham]], but the outbreak of [[World War II]] precluded his return. With war on his mind, he and the physicist [[Rudolf Peierls]] produced the [[Frisch–Peierls memorandum]] at the [[University of Birmingham]], which was the first document to set out a process by which an atomic explosion could be generated. Their process would use separated uranium-235, which would require a fairly small [[Critical mass (nuclear)|critical mass]] and could be made to achieve criticality using conventional explosives to create an immensely powerful detonation. The memorandum went on to predict the effects of such an explosion—from the initial blast to the resulting [[Nuclear fallout|fallout]]. This memorandum was the basis of British work on building an atomic device (the [[Tube Alloys]] project) and also that of the [[Manhattan Project]] on which Frisch worked as [[British contribution to the Manhattan Project|part of the British delegation]]. Frisch and [[Rudolf Peierls]] worked together in the Physics Department at the [[University of Birmingham]] 1939–40.<ref>http://www.birmingham.ac.uk/documents/culture/bookletfinalpdf.pdf</ref> He went to America in 1943 having been hurriedly made a [[British subject|British citizen]].
+In mid-1939 Frisch left Denmark for what he anticipated would be a short trip to [[Birmingham]], but the outbreak of [[World War II]] precluded his return. With war on his mind, he and the physicist [[Rudolf Peierls]] produced the [[Frisch–Peierls memorandum]] at the [[University of Birmingham]], which was the first document to set out a process by which an atomic explosion could be generated. Their process would use separated uranium-235, which would require a fairly small [[Critical mass (nuclear)|critical mass]] and could be made to achieve criticality using conventional explosives to create an immensely powerful detonation. The memorandum went on to predict the effects of such an explosion—from the initial blast to the resulting [[Nuclear fallout|fallout]]. This memorandum was the basis of British work on building an atomic device (the [[Tube Alloys]] project) and also that of the [[Manhattan Project]] on which Frisch worked as [[British contribution to the Manhattan Project|part of the British delegation]]. Frisch and [[Rudolf Peierls]] worked together in the Physics Department at the [[University of Birmingham]] 1939–40.<ref name="University of Birmingham">{{cite web | title=Culture trails &ndash; Blue Plaque Guide | website=University of Birmingham | url=https://www.birmingham.ac.uk/Documents/culture/BookletfinalPDF.pdf | access-date=2021-12-04}}</ref> He went to America in 1943 having been hurriedly made a [[British subject|British citizen]].
 ==Manhattan Project==
@@ Line 54: / Line 54: @@
 In 1944 at [[Los Alamos National Laboratory|Los Alamos]], one of Frisch's tasks as the leader of the Critical Assemblies group was to accurately determine the exact amount of [[enriched uranium]] which would be required to create the critical mass, the mass of uranium which would sustain a nuclear chain reaction.<ref>{{cite book |last=Rhodes |first=Richard |title=The Making of the Atomic Bomb |url=https://archive.org/details/makingofatomicbo00rhod |url-access=registration |pages=[https://archive.org/details/makingofatomicbo00rhod/page/612 612–613] |publisher=Simon and Schuster |year=1986 }}</ref> He did this by stacking several dozen 3&nbsp;cm bars of enriched uranium hydride at a time and measuring rising neutron activity as the critical mass was approached. The [[hydrogen]] in the metal bars increased the time that the reaction required to accelerate. One day Frisch almost caused a runaway reaction by leaning over the stack, which he termed the "[[Lady Godiva assembly]]".<ref name="Frisch">{{cite book |last=Frisch |first=Otto Robert |title=What Little I Remember |year=1980 |publisher=Cambridge University Press |isbn=0-52-128010-9 |pages=161–162 |url=https://books.google.com/books?id=WNXQ0EXYyIMC&q=%22lady+godiva%22 |quote=We were building an unusual assembly, with no reflecting material around it; just the reacting compound of uranium-235 ... For obvious reasons we called it the Lady Godiva assembly.}}</ref> His body reflected neutrons back into the stack. Out of the corner of his eye he saw that the red lamps that flickered intermittently when neutrons were being emitted, were 'glowing continuously'.<ref name="Frisch"/> Realizing what was happening, Frisch quickly scattered the bars with his hand. Later he calculated that the radiation dose was "quite harmless" but that if he "had hesitated for another two seconds before removing the material ... the dose would have been fatal".<ref name="Frisch"/> "In two seconds he received, by the generous standards of the time, a full day's permissible dose of neutron radiation."<ref>{{cite book |last=Rhodes |first=Richard |title=The Making of the Atomic Bomb |year=1986 |publisher=Simon and Schuster |isbn= 9780671441333|pages=[https://archive.org/details/makingofatomicbo00rhod/page/610 610]–11 |url=https://archive.org/details/makingofatomicbo00rhod |url-access=registration }}</ref> In this way his experiments determined the exact masses of uranium required to fire the [[Little Boy]] bomb over [[Hiroshima]].
-He also designed the "dragon's tail" or "guillotine" experiment in which a uranium slug was dropped through a hole in larger fixed mass of uranium, reaching just above critical mass (0.1%) for a fraction of a second.<ref>{{cite web|url=http://blog.nuclearsecrecy.com/2015/11/20/here-be-dragons/|title=Here Be Dragons}}</ref> At the meeting to approve the experiment, [[Richard Feynman]], commenting on the transient danger involved, said it was "just like tickling the tail of a sleeping dragon." In the period of about 3 milliseconds, the temperature rose at a rate of 2000&nbsp;°C per sec and over 10<sup>15</sup> excess neutrons were emitted.<ref>{{cite journal|url=https://www.osti.gov/scitech/servlets/purl/876514|title=Experiments with the Dragon Machine|doi=10.2172/876514|year=2005|last1=r.e. Malenfant}}</ref>
+He also designed the "dragon's tail" or "guillotine" experiment in which a uranium slug was dropped through a hole in larger fixed mass of uranium, reaching just above critical mass (0.1%) for a fraction of a second.<ref>{{cite web|url=http://blog.nuclearsecrecy.com/2015/11/20/here-be-dragons/|title=Here Be Dragons}}</ref> At the meeting to approve the experiment, [[Richard Feynman]], commenting on the transient danger involved, said it was "just like tickling the tail of a sleeping dragon." In the period of about 3 milliseconds, the temperature rose at a rate of 2000&nbsp;°C per sec and over 10<sup>15</sup> excess neutrons were emitted.<ref>{{cite journal|url=https://www.osti.gov/scitech/servlets/purl/876514|title=Experiments with the Dragon Machine|doi=10.2172/876514|year=2005|last1=r.e. Malenfant|osti=876514 |s2cid=108799363 }}</ref>
 ==Return to England==
-[[File:William Penney, Otto Frisch, Rudolf Peierls and John Cockroft.jpg|thumb|Left to right: William Penney, Otto Frisch, Rudolf Peierls and John Cockcroft in 1946]]
+[[File:William Penney, Otto Frisch, Rudolf Peierls and John Cockroft.jpg|thumb|Left to right: William Penney, Otto Frisch, [[Rudolf Peierls]] and John Cockcroft in 1946]]
-In 1946 he returned to England to take up the post of head of the nuclear physics division of the [[Atomic Energy Research Establishment]] at Harwell, though he also spent much of the next thirty years teaching at [[Cambridge]] where he was Jacksonian Professor of Natural Philosophy and a fellow of [[Trinity College, Cambridge|Trinity College]].
+In 1946 he returned to England to take up the post of head of the nuclear physics division of the [[Atomic Energy Research Establishment]] at Harwell, though he also spent much of the next thirty years teaching at [[Cambridge]] where he was Jacksonian Professor of Natural Philosophy<ref name="Gribbin 2000 p. 150"/> and a fellow of [[Trinity College, Cambridge|Trinity College]].
-Before he retired he designed<ref name="WhatLittle"/> a device, [[SWEEPNIK]], that used a laser and computer to measure tracks in [[bubble chamber]]s. Seeing that this had wider applications, he helped found a company, Laser-Scan Limited, now known as 1Spatial, to exploit the idea.
+Before he retired he designed<ref name="WhatLittle"/> a device, [[SWEEPNIK]], that used a laser and computer to measure tracks in [[bubble chamber]]s. Seeing that this had wider applications, he helped found a company, Laser-Scan Limited, now known as Laser-Scan Engineering Ltd., to exploit the idea.
 == Retirement ==
 [[File:University of Birmingham - Poynting Physics Building - blue plaques group - Frisch Peierls.jpg|thumb|University of Birmingham - Poynting Physics Building - blue plaque]]
-He retired from the chair in 1972 as required by University regulations.<ref name="WhatLittle">Otto Frisch, "What Little I Remember", Cambridge University Press (1979), {{ISBN|0-521-40583-1}}</ref> He died on 22 September 1979 and was cremated on 5 October at Cambridge City Crematorium. His son, Tony Frisch, is also a physicist.
+He retired from the chair in 1972 as required by University regulations.<ref name="WhatLittle">Otto Frisch, "What Little I Remember", Cambridge University Press (1979), {{ISBN|0-521-40583-1}}</ref> He died on 22 September 1979.<ref name="Gribbin 2000 p. 150"/><ref>{{Cite journal |last=Peierls |first=Rudolf Ernst |author-link=Rudolf Peierls |date=1 November 1981 |title=Otto Robert Frisch, 1 October 1904 - 22 September 1979 |url=https://royalsocietypublishing.org/doi/10.1098/rsbm.1981.0012 |journal=Biographical Memoirs of Fellows of the Royal Society |language=en |volume=27 |pages=283–306 |doi=10.1098/rsbm.1981.0012 |issn=0080-4606|quote=O. R. Frisch brought to physics the approach of a craftsman. He enjoyed, above all, doing experiments with his own hands, preferably on apparatus of his own design, aimed at simple basic questions. This approach required the ability to think about the important problems of physics simply, but deeply, an ability underlying the two contributions for which he was best known: his share in the explanation of the fission process and that in the recognition of the feasibility of an atomic weapon.}}</ref>
 == References ==
@@ Line 71: / Line 71: @@
 ==Bibliography==
 * ''Atomic Physics Today'' (1961)
+* ''Working with ATOMS'' (1965)
 * ''What Little I Remember'' (1979)
@@ Line 77: / Line 78: @@
 * [https://web.archive.org/web/20060828135613/http://alsos.wlu.edu/qsearch.aspx?browse=people%2FFrisch%2C+Otto Annotated bibliography for Otto Frisch from the Alsos Digital Library for Nuclear Issues]
 * [http://lanl.gov/history/wartime/britishmission.shtml Los Alamos National Laboratory on the British mission ]
-* [http://www.aip.org/history/ohilist/4615.html Oral History interview transcript with Otto Robert Frisch 8 May 1963, American Institute of Physics, Niels Bohr Library and Archives]
+* [https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4615 Oral history interview transcript with Otto Robert Frisch on 8 May 1963, American Institute of Physics, Niels Bohr Library & Archives]
-* [http://www.aip.org/history/ohilist/4616.html Oral History interview transcript with Otto Robert Frisch 3 May 1967, American Institute of Physics, Niels Bohr Library and Archives]
+* [https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4616 Oral history interview transcript with Otto Robert Frisch on 3 May 1967, American Institute of Physics, Niels Bohr Library & Archives]
 * [http://www.mpoweruk.com/coal.htm "On the Feasibility of Coal-Driven Power Stations" (Spoof essay by Frisch written in commemoration of the 70th birthday of Niels Bohr, 7 October 1955)]
 *{{Internet Archive author |sname= Robert Frisch}}
+{{s-start}}
+{{s-aca}}
+{{s-bef |before=[[John Cockcroft]]}}
+{{s-ttl |title=[[Jacksonian Professor of Natural Philosophy]] |years=1947–1972}}
+{{s-aft |after=[[Alan Cook (physicist)|Alan Cook]]}}
+{{s-end}}
 {{Authority control}}
@@ Line 86: / Line 95: @@
 [[Category:1904 births]]
 [[Category:1979 deaths]]
-[[Category:20th-century scientists]]
+[[Category:20th-century Austrian scientists]]
 [[Category:Austrian physicists]]
 [[Category:Jewish physicists]]
@@ Line 99: / Line 108: @@
 [[Category:Fellows of the Royal Society]]
 [[Category:Fellows of Trinity College, Cambridge]]
+[[Category:Jacksonian Professors of Natural Philosophy]]
 [[Category:Austrian refugees]]
 [[Category:Jews who immigrated to the United Kingdom to escape Nazism]]
@@ Line 105: / Line 115: @@
 [[Category:British people of Austrian-Jewish descent]]
 [[Category:Fellows of the American Physical Society]]
+[[Category:20th-century British physicists]]

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