• Who the f*** was Zernike?

    Our greatest scientist

    The Zernikeborg, the Zernikeplein, the Zernikelaan: at the Zernike complex in the north of the city, the name Zernike is everywhere you look. But who was Zernike? ‘A scientist or something?’
    By Renée Moezelaar / Video by Beppie van der Sluis / Translation by Mina Solanki
    in short

    Every student in Groningen is familiar with the Zernike complex. But who is the man it was named after? Hardly anyone knows.

    Frederik Zernike (Frits for short) was the only Nobel Prize winner from the RUG. He received the award in 1953 for inventing the phase contrast microscope, which enabled researchers to study living cells for the first time. The 10th of March is the 50th anniversary of his death.

    The famed astronomer Jacobus Kapetyn brought Zernike to Groningen in 1913. The physicist was a loner who liked to assemble instruments.

    This lead to him inventing the phase contrast microscope in 1930: Zernike demonstrated how light, which is passed through thousands of tiny holes, falls on a panel and is then reflected displays a wave difference; that is phase contrast.

    Zernike put the dormant physics department at the RUG back on the map. The RUG is still benefiting from his reputation in the international rankings.

    Even so, little is known about him. An archive is missing, and since Zernike’s Nobel medal went missing during an exhibition about the famous scientist, the relationship between the RUG and his family has been strained.

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    Every student in Groningen is familiar with the Zernike complex. But who is the man it was named after? Not one student can tell you.

    Despite this, Frederik Zernike (Frits for short) is the greatest pride of the RUG. A brilliant physicist, the man who made it possible to study cells and – not unimportant – the only Nobel Prize winner the University of Groningen has ever produced. Exactly 50 years ago, on the 10th of March 1966, he died.

    Singled out

    It was the astronomer Kapteyn – the same one after which the Kapteynborg and the Kapteynlaan are named, and also a leading RUG academic from long ago – who brought the young Zernike to Groningen in 1913. The astronomer needed a physicist who could perform measurements of scattered lights for his model of the Milky Way. He saw something in Zernike. It is actually kind of strange, says science historian Klaas van Berkel. ‘Kapteyn had a good eye for talent. But why he singled Zernike out is unclear, as he had little experience in that field.’

    It proved to be a brilliant move: after two years as Kapteyn’s assistant, Zernike progressed to the position of lecturer of mathematical physics.


    In 1920, Zernike became a professor of theoretical physics and could choose his own path. ‘Zernike was a theoretical physicist, but he was also a real inventor’, says Jan Waling Huisman, administrator of the natural sciences collection in the university museum. Zernike often built his own prototypes. As a result of all his tinkering, there came a point that he was no longer allowed into the lab in the evening. ‘In the evenings, he sifted through all of the desks and drawers in search of things which he could use in his inventions. His colleagues did not exactly appreciate that.’

    Van Berkel says that is a familiar depiction: ‘Zernike preferred to sit and tinker in his own little space.’ This made him a loner who was reluctant to draw attention to himself. Shortly before the war, he was also Rector Magnificus for a year; however, this was more of an obligation than a privilege for him. ‘He was not a leader, he was purely a researcher’, says Van Berkel. ‘He did research in many subjects, even in philosophy, and he did it well.’

    Phase contrast microscope

    The phase contrast microscope isn’t the only thing Zernike invented in his career. Together with Leonard Ornstein, he derived the Ornstein-Zernike comparison. With this formula, you can make extremely precise photographic masks. Chip manufacturer ASML is still using this formula to make their chips today.

    Zernike also put together a new kind of galvanometer. With this instrument, you could measure time in a magnetic field, but it was not precise enough. With his own homemade copper wire and many calculations, Zernike improved the instrument.

    All of this work paid off in 1930. Zernike was studying the refraction of light when something remarkable struck him. He let the light fall onto a so-called grid: a metal plate with thousands of holes which are close together and reflect the light.

    The discovery

    Zernike saw that two beams of light which had been reflected had a different phase – the waves were not the same. He understood that this principle had enormous possibilities. You could make transparent cells visible under a microscope: the phase contrast microscope was born. The difference in phase ensures that the contrast between the cell and its surroundings are made larger, through which the details can be seen more easily.

    This discovery triggered a revolution in the world of biology. ‘Up until that point, you could only see cells under a microscope if you had added a dye to them’, explains Huisman. ‘However, that killed the cells. Living cells had thus not yet been seen.’

    It was a useful principle, but not everyone saw the importance of it straight away. When Zernike presented his idea to the Zeiss factory in Germany, he was told that if it was important, the company would have invented it a long time ago. During the war, the technique turned out to be useful, and Zeiss made off with the patent. Huisman: ‘Luckily, all the patents that the Germans received during the war were annulled, and Zernike got his patent back.’

    Out of place

    It was more than 20 years before Zernike received his Nobel Prize. In 1953, he travelled to Sweden to collect it. In those days, it was not uncommon for researchers to have to wait a long before they received a prize for their work; however, it was still very unexpected for Zernike. ‘At that time, the Nobel Prize was often given to more theoretical subjects, so that made it slightly unusual’, says Van Berkel. ‘But the discovery and the success of the microscope itself presumably triggered it.’


    Winning the Nobel Prize naturally had a huge effect on the physics department of the RUG. Van Berkel: ‘The department was not doing very well at that moment in time, as they did not really have a leader. Zernike, together with his colleague Hendrik Brinkman, brought about change. He lent the department prestige once more and put Groningen on the map.’

    Even today, we still notice the effect he had. Several international ranking lists keep a record of how many Nobel Prizes a university has won. ‘We are now pretty high in the rankings’, says Van Berkel. ‘But who knows where we would be if it hadn’t had been for Zernike’. Huisman shares the view that Zernike put Groningen on the map, but he also makes the observation: ‘It is important for the university, but do you know who won the Nobel Prize for physics last year? In that respect, it is pretty fleeting.’

    Stolen medal

    Zernike most likely meant even more to the university, but unfortunately, relatively little is known about him. ‘We don’t have a dedicated Zernike archive, which makes it difficult to learn things about him’, says Van Berkel. This is also due to the relationship between the university and the family not always being good. The university had borrowed the Nobel Prize medal for an exhibition about Zernike, but the medal disappeared at some point either during or after the exhibition. ‘It was probably stolen’, says Van Berkel. ‘As a result of this, the family was not so keen to share information anymore.’

    According to Van Berkel, we should find out much more about the life of Zernike and share it. ‘We have a debt of honour as a university to know as much as we can about our Nobel Prize winner. We have to take action and introduce Zernike to the public.’