Hendrika Johanna van Leeuwen
|Hendrika Johanna van Leeuwen|
July 3, 1887|
|Died||February 26, 1974
|Institutions||Delft University of Technology|
|Alma mater||Leiden University|
|Thesis||Vraagstukken uit de electronentheorie van het magnetisme (1919)|
|Doctoral advisor||Hendrik Antoon Lorentz|
|Known for||Bohr-van Leeuwen theorem|
Hendrika Johanna van Leeuwen (1887–1974) was a Dutch physicist, known for her early contributions to the theory of magnetism. She studied at Leiden University under the guidance of Hendrik Antoon Lorentz, obtaining her doctorate in 1919. Her thesis  explained why magnetism is an essentially quantum mechanical effect, a result now referred to as the Bohr–van Leeuwen theorem. (Niels Bohr had arrived at the same conclusion a few years earlier.) She continued to investigate magnetic materials at the "Technische Hogeschool Delft" (now called the Delft University of Technology), first as "assistant" until 1947, when she was promoted to "lector in de theoretische en toegepaste natuurkunde" (reader in theoretical and applied physics).
Hendrika van Leeuwen was the sister-in-law of Gunnar Nordstrom, known as the "Einstein of Finland", who studied in Leiden with Paul Ehrenfest, the successor of Lorentz. She was present at the celebration of the golden anniversary of the doctorate of Lorentz, on 11 December 1925, and on that occasion reported on the role of Lorentz as scientist and teacher.
- van Leeuwen, Hendrika Johanna (1921). "Problèmes de la théorie électronique du magnétisme". Journal de Physique et le Radium 2 (12): 361–377.
- de Jong, Frida (1997). "Standhouden in Delft". Gewina 20 (4): 227–242.
- In the photograph of the dinner guests H.J. van Leeuwen is standing to the left of Albert Einstein, below Niels Bohr. The photograph is reproduced on the last page of this newsletter: http://www.noord-hollandsarchief.nl/content/downloads/files/s.pdf
- van Leeuwen, H.J. (11 December 1925). "Professor dr. H.A. Lorentz bij zijn gouden doctoraat". Nieuwe Rotterdamsche Courant. p. 9. The English translation of the Dutch text reads: For us, his pupils, Lorentz was not only the great scientist, but also an example to follow as a friendly, upbeat person with a great sense of duty, admirable simplicity and warm interest for all around him. Many a great physicist enjoyed being one of Lorentz's students for a shorter or longer period of time. There is no better way to honor our great teacher, than to attempt to continue our own work with all our strengths, enthusiasm and care.