Frits Zernike. Author Nobel foundation. Wikimedia Commons

Top 10 Intriguing Facts about Frits Zernike


 

Frits Zernike was a Dutch physicist and winner of the Nobel Prize for Physics in 1953 for his invention of the phase-contrast microscope. This is an instrument that permits the study of internal cell structure without the need to stain and thus kill the cells.

He was born on 16 July 1888 in Amsterdam, Netherlands to Carl Friedrich August Zernike and Antje Dieperink. Both parents were teachers of mathematics, and he especially shared his father’s passion for physics. He studied chemistry (his major), mathematics and physics at the University of Amsterdam.

Zernike obtained a doctorate from the University of Amsterdam in 1915. He became an assistant at the State University of Groningen in 1913 and served as a full professor there from 1920 to 1958. His earliest work in optics was concerned with astronomical telescopes.

1. He Discovered The Phase Contrast Principle

While studying the flaws that occur in some diffraction gratings because of the imperfect spacing of engraved lines, he discovered the phase-contrast principle. He noted that he could distinguish the light rays that passed through different transparent materials. He built a microscope using that principle in 1938. In 1952 Zernike was awarded the Rumford Medal of the Royal Society of London.    

2. He Was Rewarded For His Works

In 1912, he was awarded a prize for his work on opalescence in gases. In 1913, he became assistant to Jacobus Kapteyn at the astronomical laboratory of Groningen University. In 1914, Zernike and Leonard Ornstein were jointly responsible for the derivation of the Ornstein–Zernike equation in critical-point theory. In 1915, he became lector in theoretical mechanics and mathematical physics at the same university and in 1920 he was promoted to professor of mathematical physics.

3. Zernike Conducted Research Into Spectral Lines

In 1930, Zernike was conducting research into spectral lines when he discovered that the so-called ghost lines that occur to the left and right of each primary line in spectra created by means of a diffraction grating, have their phase shifted from that of the primary line by 90 degrees.

It was at a Physical and Medical Congress in Wageningen in 1933, that Zernike first described his phase contrast technique in microscopy. He extended his method to test the figure of concave mirrors. His discovery lay at the base of the first phase contrast microscope.

4. He Contributed To The Theory Of Optical Imaging System

He also made another contribution in the field of optics, relating to the efficient description of the imaging defects or aberrations of optical imaging systems like microscopes and telescopes. The representation of aberrations was originally based on the theory developed by Ludwig Seidel in the middle of the nineteenth century.

Seidel’s representation was based on power series expansions and did not allow a clear separation between various types and orders of aberrations. Zernike’s orthogonal circle polynomials provided a solution to the long-standing problem of the optimum ‘balancing’ of the various aberrations of an optical instrument. Since the 1960s, Zernike’s circle polynomials are widely used in optical design, optical metrology, and image analysis.

His work helped awaken interest in coherence theory, the study of partially coherent light sources. In 1938 he published a simpler derivation of Van Cittert’s 1934 theorem on the coherence of radiation from distant sources, now known as the Van Cittert–Zernike theorem..

5. He Developed A Galvanometer

His papers on statistics include a paper with J.A. Prins, introducing the g-function for the correlation of the position of two molecules in a liquid, an extensive article in the Geiger and Scheel handbook, and an approximation method in the order-disorder problem.

He developed a sensitive galvanometer and beginning in 1930 focused on optics, developing phase contrast, and writing about imaging errors of the concave grating and on partial coherence. With the collaboration of his students he solved the problem of the influence of lens aberrations on the diffraction pattern at a focus.

6. His Works Were Recognized By The Royal Microscopical Society

Zernike’s great discovery of the phase-contrast phenomenon, which he discovered one evening in 1930 in his totally black painted optical laboratory, did not immediately receive the attention. The Zeiss factories at Jena completely underestimated the value of his phase-contrast microscope. However, when the German defense forces took stock of all inventions which might serve in the war in 1941 the phase-contrast microscope was at the top of the list. After the war, other firms also took up the production of many thousands of phase-contrast microscopes.

7. Zernike Was A Recipient Of The Nobel Prize

For his phase-contrast research Zernike received the Nobel Prize in 1953. His achievements were also recognized by the Royal Microscopical Society, and the Royal Society (London). He was awarded an honorary doctorate in Medicine from the University of Amsterdam.

8. His Background In Statistical Mathematics And Thermodynamics Influenced His Discoveries

Zernike’s background in statistical mathematics and thermodynamics was responsible for his groundbreaking discovery. A conventional microscope utilizes ordinary light, and under these instruments living tissues, particularly transparent ones, are not visible unless stained. Yet staining usually kills the specimen or produces artifacts that are impossible to differentiate from the specimen. The phase-contrast technique can reveal variations in opacity as well as variations in the thickness of transparent objects.

9. His Doctoral Thesis Propelled Him To Become A Leader In The Field

 His doctoral thesis, “Critical Opalescence, Theoretical and Experimental,” quickly established him as a leader in his field. In 1915 he was appointed lecturer in theoretical physics at the University of Groningen. In 1920, he was promoted to professor, where he remained for the rest of his career.

10. He Had To Wait Longer Before His Discoveries Were Recognized

 He developed a glass plate with tiny grooves etched in it to be placed in the focal plane of the telescope; he called this a phase plate. His experiment worked: when looking through the phase plate, the out-of-phase areas became clearly visible. Zernike published these findings in 1934, and by 1935 he was applying these same principles to microscopes, which he knew had optical problems that were like telescopes.

 Although the practical applications of Zernike’s findings seem obvious now, it was some years before he could find a manufacturer for a phase-contrast microscope. He first approached the German company, Carl Zeiss, in 1932. Finally, in 1941, Carl Zeiss agreed to produce the instrument.

But it was not until American troops arrived in Germany in 1945 and discovered photomicrographs taken by a phase-contrast microscope that Zernike’s instrument received worldwide attention. When he won the Nobel Prize in 1953, the phase-contrast microscope was cited as being a key to insights into cancer research.