View source for Pieter Zeeman

{{Short description|Dutch experimental physicist (1865–1943)}}
{{Use dmy dates|date=September 2025}}
{{Infobox scientist
| name              = Pieter Zeeman
| image             = Pieter Zeeman.jpg
| caption           = Zeeman, {{Circa|1920}}
| birth_date        = {{Birth date|1865|05|25|df=yes}}
| birth_place       = [[Zonnemaire]], [[Zeeland]], Netherlands
| death_date        = {{Death date and age|1943|10|9|1865|5|25|df=yes}}
| death_place       = [[Amsterdam]], Netherlands
| alma_mater        = [[Leiden University]] ([[PhD]])
| known_for         = [[Zeeman effect]]
| spouse            = {{Marriage|Johanna Lebret|1895}}
| children          = 4
| awards            = {{Indented plainlist|
* [[Nobel Prize in Physics]] (1902)
* [[Matteucci Medal]] (1912)
* [[Henry Draper Medal]] (1921)
* [[Rumford Medal]] (1922)
* [[Franklin Medal]] (1925)}}
| fields            = {{Flat list|
* [[Magnetism]]
* [[optics]]}}
| work_institutions = {{Indented plainlist|
* Leiden University <br/> (1895–1896)
* [[University of Amsterdam]] (1896–1935)}}
| thesis_title      = Metingen over het verschijnsel van Kerr bij polaire terugkaatsing op ijzer, kobalt en nikkel, in ’t bijzonder over Sissingh’s magneto-optisch phaseverschil
| thesis_url        = https://digital-research-books-beta.nypl.org/work/8b6e307f-ec13-4e66-a7e0-aa5be86a4114
| thesis_year       = 1893
| doctoral_advisor  = [[Heike Kamerlingh Onnes]]
| academic_advisors = [[Hendrik Lorentz]]
| doctoral_students = [[Cornelis Bakker]] (1931)<ref>{{Cite web|title=Pieter Zeeman - Physics Tree|url=https://academictree.org/physics/peopleinfo.php?pid=2260|website=academictree.org|access-date=2025-09-01}}</ref>
}}

'''Pieter Zeeman''' ({{IPAc-en|ˈ|z|eɪ|m|ɑː|n}} {{Respell|ZAY|mahn}};<ref>{{Cite dictionary|title=Zeeman|url=https://www.dictionary.com/browse/zeeman|url-status=live|dictionary=[[Dictionary.com]]|archive-url=https://web.archive.org/web/20250525151524/https://www.dictionary.com/browse/zeeman|archive-date=2025-05-25|access-date=2025-05-25}}</ref> {{IPA|nl|ˈzeːmɑn|lang|Nl-zeeman.ogg}}; 25 May 1865 – 9 October 1943) was a Dutch [[experimental physicist]] who shared the 1902 [[Nobel Prize in Physics]] with [[Hendrik Lorentz]] for their discovery and theoretical explanation of the [[Zeeman effect]].<ref>{{Cite journal | last1 = Zeeman | first1 = P. | title = The Effect of Magnetisation on the Nature of Light Emitted by a Substance | doi = 10.1038/055347a0 | journal = Nature | volume = 55 | issue = 1424 | pages = 347 | year = 1897 |bibcode = 1897Natur..55..347Z | doi-access = free }}</ref><ref>{{Cite journal | doi = 10.1098/rspl.1896.0079 | title = The Influence of a Magnetic Field on Radiation Frequency | journal = Proceedings of the Royal Society of London | volume = 60 | pages = 513–514 | year = 1896 | issue = 359–367 | doi-access =  }}</ref><ref>{{Cite journal | doi = 10.1098/rspl.1896.0080 | title = The Influence of a Magnetic Field on Radiation Frequency | journal = Proceedings of the Royal Society of London | volume = 60 | pages = 514–515 | year = 1896 | issue = 359–367 | doi-access =  }}</ref><ref>{{cite journal | last = Zeeman | first = P | year = 1914 | title = Fresnel's coefficient for light of different colours. (First part) | journal = Royal Netherlands Academy of Art and Sciences, Proceedings | volume = 17 | issue = I | pages = 445–451 | bibcode = 1914KNAB...17..445Z | url = http://www.historyofscience.nl/search/detail.cfm?pubid=1708&view=image&startrow=1 | access-date = 2006-10-05 | archive-url = https://web.archive.org/web/20090519003222/http://www.historyofscience.nl/search/detail.cfm?pubid=1708&view=image&startrow=1 | archive-date = 2009-05-19 | url-status = dead }}</ref><ref>{{cite journal | last = Zeeman | first = P | year = 1915 | title = Fresnel's coefficient for light of different colours. (Second part) | journal = Royal Netherlands Academy of Art and Sciences, Proceedings | volume = 18 | issue = I | pages = 398–408 | bibcode = 1915KNAB...18..398Z | url = http://www.historyofscience.nl/search/detail.cfm?pubid=1847&view=image&startrow=1 | access-date = 2006-10-05 | archive-url = https://web.archive.org/web/20090519003227/http://www.historyofscience.nl/search/detail.cfm?pubid=1847&view=image&startrow=1 | archive-date = 2009-05-19 | url-status = dead }}</ref>

== Education ==
Pieter Zeeman was born on 25 May 1865 in [[Zonnemaire]], Netherlands, the son of the Reverend Catharinus Forandinus Zeeman, a minister of the [[Dutch Reformed Church]], and Willemina Worst.

Zeeman became interested in physics at an early age. In 1883, the [[Aurora (astronomy)|aurora borealis]] happened to be visible in the Netherlands; Zeeman, then a student at the high school in [[Zierikzee]], made a drawing and description of the phenomenon and submitted it to ''[[Nature (journal)|Nature]]'', where it was published. The editor praised "the careful observations of Professor Zeeman from his observatory in Zonnemaire."

After finishing high school in 1883, Zeeman went to [[Delft]] for supplementary education in [[classical language]]s, then a requirement for admission to university. He stayed at the home of Dr J. W. Lely, co-principal of the [[Gymnasium (school)|gymnasium]] and brother of [[Cornelis Lely]], who was responsible for the concept and realization of the [[Zuiderzee Works]]. While in Delft, he first met [[Heike Kamerlingh Onnes]], who would become his doctoral advisor.

[[Image:Zeeman, Pieter.jpg|thumb|left|Portrait of Pieter Zeeman by [[Jan Veth]], 1925]]

After passing the qualification exams in 1885, Zeeman entered [[Leiden University]] to study physics under Kamerlingh Onnes and [[Hendrik Lorentz]]. In 1890, he became Lorentz's assistant, which allowed him to participate in a research programme on the [[Magneto-optic Kerr effect|Kerr effect]]. In 1893, he submitted his doctoral thesis on the Kerr effect,<ref>{{cite web|author=Pieter Zeeman |url=http://ilorentz.org/history/proefschriften/sources/Zeeman_1893.pdf |title=Metingen over het verschijnsel van Kerr bij polaire terugkaatsing op ijzer, kobalt en nikkel, in 't bijzonder over Sissingh's magneto-optisch phaseverschil  |year=1893}}</ref> the reflection of [[polarized light]] on a magnetized surface. After receiving his [[Ph.D.]], he went for half a year to [[Friedrich Kohlrausch (physicist)|Friedrich Kohlrausch]]'s institute at the [[University of Strassburg]]. In 1895, he returned to Leiden to become a ''[[Privatdozent]]'' in mathematics and physics.<ref>Paul Forman, "[[Alfred Landé]] and the anomalous Zeeman Effect, 1919-1921", Historical Studies in the Physical Sciences, Vol. 2, 1970, 153-261.</ref><ref>{{Cite journal | last1 = Kox | first1 = A. J. | title = The discovery of the electron: II. The Zeeman effect | doi = 10.1088/0143-0807/18/3/003 | journal = European Journal of Physics | volume = 18 | issue = 3 | pages = 139–144 | year = 1997 |bibcode = 1997EJPh...18..139K | s2cid = 250826469 | url = https://pure.uva.nl/ws/files/3655500/2775_26336y.pdf }}</ref><ref>{{Cite journal | last1 = Spencer | first1 = J. B. | doi = 10.1086/350577 | title = On the Varieties of Nineteenth-Century Magneto-Optical Discovery | journal = Isis | volume = 61 | pages = 34–51 | year = 1970 | s2cid = 145139903 }}</ref><ref name=nobelbio>{{cite web|title=Pieter Zeeman – Biographical|url=https://www.nobelprize.org/prizes/physics/1902/zeeman/biographical/|url-status=live|publisher=[[Nobel Foundation]]|archive-url=https://web.archive.org/web/20180719052239/https://www.nobelprize.org/nobel_prizes/physics/laureates/1902/zeeman-bio.html|archive-date=2018-07-19|access-date=2013-11-25}}</ref>

== Zeeman effect ==
{{Main|Zeeman effect}}
[[Image:ZeemanEffect.GIF|thumb|right|A photo Zeeman took of the [[Zeeman effect]].<ref>[http://www.chemteam.info/Chem-History/Zeeman-effect.html "Although not included in the published paper, you may be interested in a picture of Pieter Zeeman, as well as a photo he took of the effect named for him."]</ref>]]

In 1896, shortly before moving from Leiden to Amsterdam,<ref name=DvD>{{cite web|author=Dirk van Delft |url=http://www.dwc.knaw.nl/wp-content/HSSN/2007-10-Van%20Delft-Freezing%20Physics.pdf |title=Freezing physics |year=2007|page=260}}</ref> Zeeman measured the splitting of [[spectral line]]s by a strong [[magnetic field]], a discovery now known as the [[Zeeman effect]]. This research involved an investigation of the effect of magnetic fields on a light source. He discovered that a spectral line is split into several components in the presence of a magnetic field. [[Hendrik Lorentz]] first heard about Zeeman's observations on Saturday 31 October 1896 at the meeting of the [[Royal Netherlands Academy of Arts and Sciences]], where these results were communicated by [[Heike Kamerlingh Onnes]].<ref>See:
* {{cite journal |last1=Zeeman |first1=P. |title=Over de invloed eener magnetisatie op den aard van het door een stof uitgezonden licht |journal=Verslagen van de Gewone Vergaderingen der Wis- en Natuurkundige Afdeeling (Koninklijk Akademie van Wetenschappen te Amsterdam) [Reports of the Ordinary Sessions of the Mathematical and Physical Section (Royal Academy of Sciences in Amsterdam)] |date=1896 |volume=5 |pages=181–184 and 242–248 |bibcode=1896VMKAN...5..181Z |url=https://babel.hathitrust.org/cgi/pt?id=uiug.30112109543402;view=1up;seq=201 |trans-title=On the influence of magnetism on the nature of the light emitted by a substance |language=nl}}
* {{cite journal |last1=Zeeman |first1=P. |title=On the influence of magnetism on the nature of the light emitted by a substance |journal=Philosophical Magazine |date=1897 |volume=43 |pages=226–239 |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015024088695;view=1up;seq=238 |series=5th series}}</ref> The next Monday, Lorentz called Zeeman into his office and presented him with an explanation of his observations, based on Lorentz's theory of [[electromagnetic radiation]]. In 1902, Zeeman and Lorentz were jointly awarded the [[Nobel Prize in Physics]] for their respective experimental and theoretical work on the Zeeman effect.<ref name=Nobel1902>{{Cite web|title=The Nobel Prize in Physics 1902|url=https://www.nobelprize.org/prizes/physics/1902/summary/|url-status=live|publisher=[[Nobel Foundation]]|archive-url=https://web.archive.org/web/20081021034748/http://nobelprize.org/nobel_prizes/physics/laureates/1902/index.html|archive-date=2008-10-21|access-date=2008-10-09}}</ref>

The importance of Zeeman's discovery soon became apparent; it confirmed Lorentz's prediction about the polarization of light emitted in the presence of a magnetic field. Thanks to Zeeman's work, it became clear that the [[oscillating]] particles, according to Lorentz were the source of light emission, were negatively charged, and were a thousandfold lighter than the [[hydrogen atom]]. This conclusion was reached well before [[J. J. Thomson]]'s discovery of the [[electron]]. The Zeeman effect thus became an important tool for elucidating the [[Atom#Structure|structure of the atom]].

== Career in Amsterdam ==
[[Image:EinsteinZeemanEhrenfest.jpg|thumb|280px|[[Albert Einstein]] visiting Pieter Zeeman in Amsterdam, accompanied by [[Paul Ehrenfest]] (circa 1920).]]
[[File:1929 Pieter Zeeman.jpg|thumb|1929 [[Autochrome Lumière|Autochrome]] by Georges Chevalier]]

Shortly after his discovery, Zeeman was offered a position as a lecturer at the [[University of Amsterdam]], where he started to work in the autumn of 1896.<ref name=DvD/> This was followed by his promotion to Professor of Physics in 1900. In 1908, he succeeded [[Johannes van der Waals]] as full professor and Director of the Physics Institute. He retired as a professor in 1935.

In 1918, Zeeman published "Some experiments on gravitation: The ratio of mass to weight for crystals and radioactive substances" in the ''Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen'', experimentally confirming the [[equivalence principle]] with regard to gravitational and inertial mass.

A new laboratory built in Amsterdam in 1923 was renamed the Zeeman Laboratory in 1940. This new facility allowed Zeeman to pursue a refined investigation of the [[Zeeman effect]]. For the remainder of his career he remained interested in research in [[magneto-optic effect]]s. He also investigated the propagation of light in moving media. This subject became the focus of a renewed interest because of [[special relativity]], and enjoyed a keen interest from Lorentz and [[Albert Einstein]]. Later in his career, he became interested in [[mass spectrometry]].

== Personal life and death ==
In 1895, Zeeman married Johanna Elisabeth Lebret (1873–1962), with whom he had three daughters and one son.<ref name=nobelbio/>

Zeeman died on 9 October 1943 in [[Amsterdam]] at the age of 78, and was buried in [[Haarlem]].

== Recognition ==
=== Memberships ===
{| class="wikitable"
! Country
! Year
! Institute
! Type
! {{Reference column heading}}
|-
| {{Flag|Netherlands}}
| 1898
| [[Royal Netherlands Academy of Arts and Sciences]]
| Member
| <ref>{{Cite web|title=Pieter Zeeman|url=http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00004018|url-status=live|publisher=[[Royal Netherlands Academy of Arts and Sciences]]|archive-url=https://web.archive.org/web/20250213024726/https://dwc.knaw.nl/biografie/biografisch-apparaat/pmknaw/?pagetype=authorDetail&aId=PE00004018|archive-date=2025-02-13|access-date=2015-07-17}}</ref>
|-
| {{Flagdeco|United Kingdom}} [[United Kingdom of Great Britain and Ireland|United Kingdom]]
| 1921
| [[Royal Society]]
| Foreign Member
| <ref>{{Cite web|title=Search past Fellows|url=https://catalogues.royalsociety.org/CalmView/Record.aspx?src=CalmView.Persons&id=NA5889&pos=2|publisher=[[Royal Society]]|access-date=2025-11-23}}</ref>
|-
| {{Flag|Vatican City}}
| 1936
| [[Pontifical Academy of Sciences]]
| Academician
| <ref>{{Cite web|title=Pieter Zeeman|url=https://www.pas.va/en/academicians/deceased/zeeman.html|url-status=live|publisher=[[Pontifical Academy of Sciences]]|archive-url=https://web.archive.org/web/20250718141540/https://www.pas.va/en/academicians/deceased/zeeman.html|archive-date=2025-07-18|access-date=2025-12-02}}</ref>
|}

=== Awards ===
{| class="wikitable"
! Country
! Year
! Institute
! Award
! Citation
! {{Reference column heading}}
|-
| {{Flag|Sweden|1844}}
| 1902
| [[Royal Swedish Academy of Sciences]]
| [[Nobel Prize in Physics]]
| "In recognition of the extraordinary service they rendered by their researches into the influence of magnetism upon radiation phenomena" (with [[Hendrik Lorentz]])
| <ref name=Nobel1902/>
|-
| {{Flagdeco|Kingdom of Italy}} [[Kingdom of Italy|Italy]]
| 1912
| [[Accademia dei XL]]
| [[Matteucci Medal]]
|
| <ref>{{Cite web|title=Medals|url=https://www.accademiaxl.it/en/activities/medals/|publisher=[[Accademia dei XL]]|access-date=2025-11-04}}</ref>
|-
| {{Flag|United States|1912}}
| 1921
| [[National Academy of Sciences]]
| [[Henry Draper Medal]]
| "For his discovery of the so-called Zeeman effect and for its application on magneto-optics"
| <ref>{{Cite web|title=Henry Draper Medal |url=http://www.nasonline.org/about-nas/awards/henry-draper-medal.html|url-status=dead|publisher=[[National Academy of Sciences]]|archive-url=https://web.archive.org/web/20130126003930/http://www.nasonline.org/about-nas/awards/henry-draper-medal.html|archive-date=2013-01-26|access-date=2011-02-19}}</ref>
|-
| {{Flag|United Kingdom}}
| 1922
| [[Royal Society]]
| [[Rumford Medal]]
| "For his researches in optics"
| <ref>{{Cite web|title=Rumford Medal|url=https://royalsociety.org/medals-and-prizes/rumford-medal/|publisher=[[Royal Society]]|access-date=2024-06-19}}</ref>
|-
| {{Flag|United States|1912}}
| 1925
| [[Franklin Institute]]
| [[Franklin Medal]]
| "Discovery of the effect of a magnetic field upon the frequencies of the light from a radiating source"
| <ref>{{Cite web|title=Pieter Zeeman|url=https://fi.edu/en/awards/laureates/pieter-zeeman|publisher=[[Franklin Institute]]|access-date=2025-11-23 }}</ref>
|}

== See also ==
* [[Atom and Atomic Theory]]
* [[Bohr–Sommerfeld model]]
* [[Fresnel drag coefficient]]
* [[Light-dragging effects]]

== References ==
{{reflist|35em}}

== External links ==
*{{commons category-inline|Pieter Zeeman}}
* {{Citation
| last = Bertrand
| first = Gabriel
| author-link = Gabriel Bertrand
| title = Allocution
| journal = [[Comptes rendus de l'Académie des sciences|Comptes rendus hebdomadaires des séances de l'Académie des sciences]]
| place = Paris
| volume = 217
| pages =625–640
| date = 20 December 1943b
| language = fr
| url =http://gallica.bnf.fr/ark:/12148/bpt6k31698/f629.image
}}, available at [[Gallica]]. The "Address" of Gabriel Bertrand of December 20, 1943 at the French Academy: he gives biographical sketches of the lives of recently deceased members, including Pieter Zeeman, [[David Hilbert]] and [[Georges Giraud]].
* Albert van Helden [http://www.historyofscience.nl/author.cfm?RecordId=39 ''Pieter Zeeman 1865 – 1943''] In: K. van Berkel, A. van Helden and L. Palm ed., A History of Science in The Netherlands. Survey, Themes and Reference (Leiden: Brill, 1999) 606 - 608.
* [https://www.nobelprize.org/prizes/physics/1902/zeeman/biographical/ Biography] at the Nobel e-museum and [https://www.nobelprize.org/prizes/physics/1902/zeeman/lecture/ Nobel Lecture].
* {{Nobelprize}}
* P.F.A. Klinkenberg, [http://www.inghist.nl/Onderzoek/Projecten/BWN/lemmata/bwn1/zeeman ''Zeeman, Pieter (1865-1943)''], in Biografisch Woordenboek van Nederland.
* Biography of [https://web.archive.org/web/20120205024954/http://www.kb.nl/hkc/nobel/zeeman/zeeman.html ''Pieter Zeeman (1865 – 1943)''] at the National library of the Netherlands.
*  Anne J. Kox, [https://web.archive.org/web/20070522125032/http://staff.science.uva.nl/~kox/oratie.html ''Wetenschappelijke feiten en postmoderne fictie in de wetenschapsgeschiedenis''], Inaugural lecture (1999).
* Pim de Bie, [https://web.archive.org/web/20100505024427/http://www.dodenakkers.nl/beroemd/wetenschap/158-zeeman.html ''prof.dr. P. Zeeman Zonnemaire 25 mei 1865 - Amsterdam 9 oktober 1943''] Gravesite of Pieter Zeeman
* [https://web.archive.org/web/20110719044852/http://bc.ub.leidenuniv.nl/bc/tentoonstelling/lorentz_zeeman/object3.htm#P ''Pieter Zeeman''], Bijzondere collecties Leiden.
* [https://web.archive.org/web/20060316093221/http://physics.nobel.brainparad.com/pieter_zeeman.html photo & short info]

{{Nobel Prize in Physics Laureates 1901-1925}}
{{1902 Nobel Prize winners}}
{{Nobel Prize laureates from The Netherlands|state=collapsed}}
{{FRS 1921}}
{{Authority control}}

{{DEFAULTSORT:Zeeman, Pieter}}
[[Category:1865 births]]
[[Category:1943 deaths]]
[[Category:20th-century Dutch physicists]]
[[Category:19th-century Dutch physicists]]
[[Category:Nobel laureates in Physics]]
[[Category:Dutch Nobel laureates]]
[[Category:Leiden University alumni]]
[[Category:Academic staff of Leiden University]]
[[Category:Academic staff of the University of Amsterdam]]
[[Category:People from Zonnemaire]]
[[Category:Quantum physicists]]
[[Category:Foreign members of the Royal Society]]
[[Category:Members of the Royal Netherlands Academy of Arts and Sciences]]
[[Category:Members of the Royal Academy of Belgium]]
[[Category:Experimental physicists]]
[[Category:Spectroscopists]]
[[Category:Recipients of the Matteucci Medal]]
[[Category:Recipients of Franklin Medal]]