Pieter Zeeman

Pieter Zeeman (Template:IPAc-en Template:Respell; ; 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.

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 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, 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 languages, then a requirement for admission to university. He stayed at the home of Dr J. W. Lely, co-principal of the 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.

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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 Kerr effect. In 1893, he submitted his doctoral thesis on the Kerr effect, the reflection of polarized light on a magnetized surface. After receiving his Ph.D., he went for half a year to Friedrich Kohlrausch's institute at the University of Strassburg. In 1895, he returned to Leiden to become a Privatdozent in mathematics and physics.

Zeeman effect

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A photo Zeeman took of the Zeeman effect.

In 1896, shortly before moving from Leiden to Amsterdam, Zeeman measured the splitting of spectral lines 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. 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.

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 structure of the atom.

Career in Amsterdam

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Albert Einstein visiting Pieter Zeeman in Amsterdam, accompanied by Paul Ehrenfest (circa 1920).

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1929 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. 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 effects. 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.

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

Awards and honors

• 1898: elected a Member of the Royal Netherlands Academy of Arts and Sciences
• 1902: Nobel Prize in Physics of the Royal Swedish Academy of Sciences
• 1912: Matteucci Medal of the Italian Society of Sciences
• 1921: elected a Foreign Member of the Royal Society
• 1921: Henry Draper Medal of the National Academy of Sciences
• 1922: Rumford Medal of the Royal Society
• 1925: Franklin Medal of the Franklin Institute

Zeeman crater on the Moon is named in his honor.

See also

• Atom and Atomic Theory
• Bohr–Sommerfeld model
• Fresnel drag coefficient
• Light-dragging effects

External links

• Template:Commons category-inline
• , 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 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.
• Biography at the Nobel e-museum and Nobel Lecture.
• Template:Nobelprize
• P.F.A. Klinkenberg, Zeeman, Pieter (1865-1943), in Biografisch Woordenboek van Nederland.
• Biography of Pieter Zeeman (1865 – 1943) at the National library of the Netherlands.
• Anne J. Kox, Wetenschappelijke feiten en postmoderne fictie in de wetenschapsgeschiedenis, Inaugural lecture (1999).
• Pim de Bie, prof.dr. P. Zeeman Zonnemaire 25 mei 1865 - Amsterdam 9 oktober 1943 Gravesite of Pieter Zeeman
• Pieter Zeeman, Bijzondere collecties Leiden.
• photo & short info