Lili Bleeker

Lili Bleeker was born on the 17th of January 1897 as the youngest of 5 children to John Lambert Bleeker, a Lutheran preacher in that city, and Martha Gerhardina Döhne, a housewife.[5] She grew up in Middelburg and showed great brilliance as a young child, so much so that she could skip her first primary school class. Bleeker attended Lange Sint high school in Pietersstraat, Middelburg, the Netherlands and although she was a top student, she was discouraged by her mother from furthering her studies.[6] However, Bleeker refused because she had her sights set on her education even though girls at that time where destined to perform just domestic roles.

In 1916, she enrolled at the University of Utrecht, a large research institution located in Utrecht, Netherlands to study physics and astronomy.[7] Bleeker became a teacher at a secondary school for girls so that she could earn money to pay for her studies, but she herself regarded that job as unsuccessful because she felt that she was too young. So, as a result, she became a private tutor.[5] In 1919, she became a laboratory assistant to various professors at the Utrecht Observatory Sonnenborgh and on January 1, 1926 was named as sole head assistant[1][6] On November 5, 1928, she earned her PhD in physics cum laude from Utrecht University with the reputable Professor Leonard Ornstein, who was impressed by her work under his supervision that he wrote recommendation letters describing her as 'very intelligent and well educated, both theoretically and experimentally.' Bleeker's Ph.D. thesis was on measurements of emission and dispersion in the series spectra of alkali metals, and the printing office responsible for printing her thesis was owned by the father of her fellow student and life partner, Gerard Willemse.[5]

On June 5, 1930, eighteen months after receiving her degree, Bleeker started a successful physical consultancy which advised companies and industries on scientific instruments.[1] Her consultancy firm served as a model for the foundation of TNO in 1932. Later on, Bleeker opened a factory for the construction of scientific and optical equipment. Until 1936, the company's focus was on manufacturing hardware for the laboratory and precision electric measuring instruments. However, in 1936, Bleeker decided to start an optical workshop, and in 1937 started production on optical instruments. Her production spearheaded the optical industry in the Netherlands, which was previously nonexistent. In 1938, Bleeker entered negotiations with the Dutch military to develop binoculars for them. In 1940, The Netherlands entered World War II. Bleeker stopped production of binoculars in her factory because she did not want to produce any products for the German army. She did not stop production entirely in her factory, however. Bleeker developed microscopes for Dutch universities and their students. Bleeker also hid Jewish citizens in her factory, and eventually in 1944, someone told the German authorities about her doing so. She was able to successfully mislead the German authorities and successfully let the Jewish people in hiding escape, but Bleeker and her husband had to go into hiding.[8] Her factory was closed down during that time. After the war, she opened a new factory, which was the first in the world to make the phase-contrast microscope invented by Frits Zernike.[9][8]

• There is a building at Utrecht University named after Bleeker.[8]