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Created page with "'''Felix Bloch''' (23 October 1905 – 10 September 1983) was a Swiss-American theoretical physicist<ref>{{cite journal|author=Hofstadter, Robert|author-link=Robert Hofstadter|title=Obituary: Felix Bloch|journal=Physics Today|date=March 1984|volume=37|issue=3|pages=115–116|url=http://www.physicstoday.org/resource/1/phtoad/v37/i3/p115_s1?bypassSSO=1|archive-url=https://archive.today/20130930140642/http://www.physicstoday.org/resource/1/phtoad/v37/i3/p115_s1?bypassSSO=1|..."

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'''Felix Bloch''' (23 October 1905 – 10 September 1983) was a Swiss-American theoretical physicist<ref>{{cite journal|author=Hofstadter, Robert|author-link=Robert Hofstadter|title=Obituary: Felix Bloch|journal=Physics Today|date=March 1984|volume=37|issue=3|pages=115–116|url=http://www.physicstoday.org/resource/1/phtoad/v37/i3/p115_s1?bypassSSO=1|archive-url=https://archive.today/20130930140642/http://www.physicstoday.org/resource/1/phtoad/v37/i3/p115_s1?bypassSSO=1|url-status=dead|archive-date=2013-09-30|doi=10.1063/1.2916128|bibcode=1984PhT....37c.115H|url-access=subscription}}</ref> who shared the 1952 Nobel Prize in Physics with [[wikipedia:Edward Mills Purcell|Edward Mills Purcell]] "for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith".<ref name="fn_1">Sohlman, M (Ed.) ''Nobel Foundation directory 2003.'' Vastervik, Sweden: AB CO Ekblad; 2003.</ref>

He was the first Stanford University Nobel laureate.

Bloch made fundamental theoretical contributions to the understanding of ferromagnetism and electron behavior in crystal lattices. He is also considered one of the developers of nuclear magnetic resonance.

==Education==
Bloch entered public elementary school at the age of six and is said to have been teased, in part because he "spoke Swiss German with a somewhat different accent than most members of the class".<ref name="HofstadterBioMemoir">{{Cite book |last=Hofstadter |first=Richard |author-link=Richard Hofstadter |url=https://www.nap.edu/read/4547/chapter/3 |title=Read "Biographical Memoirs: V.64" at NAP.edu |year=1994 |isbn=978-0-309-04978-8 |language=en |chapter=3 |doi=10.17226/4547}}</ref> He received support from his older sister during much of this time, but she died at the age of 12, devastating Felix, who is said to have lived a "depressed and isolated life" in the following years.<ref name="HofstadterBioMemoir" /> Bloch learned to play the piano by the age of 8 and was drawn to arithmetic for its "clarity and beauty".<ref name="HofstadterBioMemoir" /> Bloch graduated from elementary school at twelve and enrolled in the Cantonal Gymnasium in Zurich for secondary school in 1918. He was placed on a six-year curriculum here to prepare him for university. He continued his curriculum through 1924, even through his study of engineering and physics in other schools, though it was limited to mathematics and languages after the first three years.

After these first three years at the Gymnasium, at the age of 15, Bloch began to study at the ETH Zurich. Although he initially studied engineering, he soon changed to physics. During this time, he attended lectures and seminars given by Peter Debye and Hermann Weyl at the ETH Zurich and Erwin Schrödinger at the neighboring University of Zurich. A fellow student in these seminars was John von Neumann.

Bloch graduated in 1927, and was encouraged by Debye to go to the University of Leipzig to study under [[Werner Heisenberg]].<ref name="Stanford-physics-memorial">{{cite web |title=Memorial Resolution: Felix Bloch (1905 - 1983) |last1=Hofstadter |first1=Robert |last2=Chodorow |first2=Marvin |last3=Schawlow |first3=Arthur |last4=Walecka |first4=Dirk |url=https://physics.stanford.edu/sites/default/files/BlochF.pdf |archive-url=https://wayback.archive-it.org/all/20170311100004/https://physics.stanford.edu/sites/default/files/BlochF.pdf |url-status=dead |archive-date=11 March 2017 |access-date=11 November 2017 |df=dmy-all }}</ref> Bloch became Heisenberg's first graduate student, and gained his doctorate in 1928.<ref name="Stanford-physics-memorial" /> His doctoral thesis established the quantum theory of solids, using waves to describe electrons in periodic lattices.

==Career and research==
Bloch remained in European academia, working on superconductivity with [[Wolfgang Pauli]] in Zurich; with Hans Kramers and Adriaan Fokker in the Netherlands; with Heisenberg on ferromagnetism, where he developed a description of boundaries between magnetic domains, now known as [[wikipedia:Domain wall (magnetism)#Bloch wall|Bloch walls]], and theoretically proposed a concept of spin waves, excitations of magnetic structure; with [[Niels Bohr]] in Copenhagen, where he worked on a theoretical description of the stopping of charged particles traveling through matter; and with [[Enrico Fermi]] in Rome.<ref name="Stanford-physics-memorial"/>

In 1932, Bloch returned to Leipzig to assume a position as ''Privatdozent'' (lecturer).<ref name="Stanford-physics-memorial"/> In 1933, immediately after Adolf Hitler came to power, Bloch left Germany out of fear of anti-Jewish persecution, returning to Zurich before traveling to Paris to lecture at the Institut Henri Poincaré.<ref>[https://books.google.com/books?id=PQgaAAAAYAAJ&q=%22Because+of+his+Jewish+faith%22 "Bloch, Felix"], ''[[Current Biography]]'', [[H. W. Wilson Company]], 1954. Accessed 24 February 2013. "Because of his Jewish faith, his position soon became uncomfortable and he went to Paris, where he lectured at the Institut Henri Poincaré."</ref>

In 1934, the chairman of Stanford Physics invited Bloch to join the faculty.<ref name="Stanford-physics-memorial"/> Bloch accepted the offer and emigrated to the United States. In the fall of 1938, Bloch began working with the 37 inch cyclotron at the University of California, Berkeley, to determine the magnetic moment of the neutron. Bloch went on to become the first professor of theoretical physics at Stanford. In 1939, he became a naturalized citizen of the United States.

During World War II, Bloch briefly worked on the atomic bomb project at Los Alamos. Disliking the military atmosphere of the laboratory and uninterested in the theoretical work there, Bloch left to join the radar project at Harvard University.<ref name="AIP-oral-history">{{cite web |title=Oral Histories: Felix Bloch |first=Weiner |last=Charles |publisher=American Institute of Physics |date=15 August 1968 |access-date=11 November 2017 |url=https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4510}}</ref>

After the war, he concentrated on investigations into nuclear induction and nuclear magnetic resonance, which are the underlying principles of MRI.<ref>{{cite journal | last1=Alvarez | first1=Luis W. |author-link=Luis Walter Alvarez| last2=Bloch |first2=F. | year=1940 | title=A Quantitative Determination of the Neutron Moment in Absolute Nuclear Magnetons | journal=[[Physical Review]] | volume=57 | issue=2 | pages=111–122 | bibcode=1940PhRv...57..111A | doi=10.1103/PhysRev.57.111}}</ref><ref>{{cite journal | last1=Bloch |first1=F. |last2=Hansen | first2=W. W. |author-link2=W. W. Hansen|last3=Packard |first3=Martin | date=1946-02-01 | title=Nuclear Induction | journal=[[Physical Review]] | volume=69 | issue= 3–4| pages=127 | bibcode=1946PhRv...69..127B | doi=10.1103/PhysRev.69.127| doi-access=free }}</ref><ref>{{cite journal|last=Shampo|first=M A|author2=Kyle R A|date=September 1995|title=Felix Bloch—developer of magnetic resonance imaging|journal=[[Mayo Clin. Proc.]]|volume=70|issue=9|page=889| pmid = 7643644| doi=10.4065/70.9.889}}</ref> In 1946, he proposed the [[wikipedia:Bloch equations|Bloch equations]], which determine the time evolution of nuclear magnetization. He was elected to the National Academy of Sciences in 1948.<ref>{{Cite web |title=Felix Bloch |url=http://www.nasonline.org/member-directory/deceased-members/57619.html |access-date=2022-10-05 |website=www.nasonline.org}}</ref> Along with [[wikipedia:Edward Mills Purcell|Edward Purcell]], Bloch was awarded the Nobel Prize in Physics in 1952 for his work on nuclear magnetic induction.

When [[CERN]] was being set up in the early 1950s, its founders were searching for someone of stature and international prestige to head the fledgling international laboratory, and in 1954 Professor Bloch became CERN's first director-general,<ref>{{Cite journal|url = https://cds.cern.ch/record/1730968|title = People and things : Felix Bloch |access-date = 1 September 2015|journal = CERN Courier|publisher = CERN|year = 1983 }}</ref> at the time when construction was getting under way on the present Meyrin site and plans for the first machines were being drawn up. After leaving CERN, he returned to [[Stanford University]], where he in 1961 was made Max Stein Professor of Physics.

In 1964, he was elected a foreign member of the Royal Netherlands Academy of Arts and Sciences.<ref>{{cite web|url=http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00002770 |title=F. Bloch (1905 - 1983) |publisher=Royal Netherlands Academy of Arts and Sciences |access-date=22 May 2016}}</ref> He was also a member of the American Academy of Arts and Sciences and the American Philosophical Society.<ref>{{Cite web |title=Felix Bloch |url=https://www.amacad.org/person/felix-bloch |access-date=2022-10-05 |website=American Academy of Arts & Sciences |language=en}}</ref><ref>{{Cite web |title=APS Member History |url=https://search.amphilsoc.org/memhist/search?creator=Felix+Bloch&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |access-date=2022-10-05 |website=search.amphilsoc.org}}</ref>

==Family==
On 14 March 1940, Bloch married Lore Clara Misch (1911–1996), a fellow physicist working on X-ray crystallography, whom he had met at an [[American Physical Society]] meeting.<ref name="royalsoced1">[http://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf Former Fellows of The Royal Society of Edinburgh 1783 – 2002] {{Webarchive|url=https://web.archive.org/web/20150919152306/https://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf |date=19 September 2015 }}. royalsoced.org.uk</ref> They had four children, twins George Jacob Bloch and Daniel Arthur Bloch (born 15 January 1941), son Frank Samuel Bloch (born 16 January 1945), and daughter Ruth Hedy Bloch (born 15 September 1949).<ref name="Stanford-physics-memorial"/><ref>{{Cite web | url=https://oac.cdlib.org/findaid/ark:/13030/kt3580367x/admin/ |title = Guide to the Felix Bloch Papers}}</ref>

Bloch died on 10 September 1983 in Zurich at the age of 77.<ref name="royalsoced1"/>

For more information, see [[wikipedia:Felix Bloch|Wikipedia]].
==References==
{{reflist}}{{DEFAULTSORT:Bloch, Felix}}
[[Category:Theoretical physicists]]
[[Category:Administrators]]
[[Category:Directors general of CERN]]
[[Category:Pages linking to Wikipedia]]

Felix Bloch - Revision history