Frits Zernike was born on July 16, 1888, in Amsterdam, the son of two mathematicians, Carl Frederick August Zernike and Antje Dieperink Zernike. While still young, Zernike was recognized for his mathematical abilities. He received both his B.S. and his Ph.D. in physics from the University of Amsterdam, and he worked at an astronomical laboratory while pursuing his graduate studies. 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, and he remained at Groningen for the rest of his career.

It was while working in the field of astronomy that Zernike first discovered the advantages of phase-contrast techniques. Irregularities on the surfaces of the curved mirrors of telescopes were a common problem at that time; these mirrors sometimes produced "ghost" images...