Eun Joo Ahn and the History of Physics at Yale University

In my doctoral research on the history of snowflake science, Vincent Schaefer plays an important role for his contributions to the field in the 1940s. His 1941 discovery of a method to preserve snow crystals indefinitely by fossilizing them in plastic garnered much attention both within the scientific community and outside of it. Among his papers in the M.E. Grenander Special Collections and Archives, I was able to browse through dozens of letters from colleagues, educators, and schoolchildren seeking advice on how to create their own snowflake fossils. Six years later, another discovery—that dry ice can be used to induce snowfall in supercooled clouds—would cause the volume of incoming mail to balloon even more dramatically, with correspondents ranging from farmers to government agencies calling on his expertise in weather control. Many of these letters have also made it into his papers, alongside the numerous reports and depositions on the topic of experimental meteorology that he would produce over subsequent decades.

As a postdoc at Yale University, I have been working on documenting the history of physics at the university. The narrative spans over three centuries, starting from the natural philosophy curriculum of a religious college in the early 1700s to the diverse field of teaching, research, and outreach of today. The work aims to tell an inclusive story that is not definitive and final but will serve as a baseline that can be used in the future to highlight specific topics. This inclusivity can highlight the nuanced complexity of racial and gender discrimination. For example, though Edward Alexander Bouchet (1852–1918) was one of the first African American graduates of Yale College and the sixth recipient of a physics PhD at Yale in 1876, he was denied a teaching post at his alma mater due to his race.

The work also includes places that have received less attention in the history of modern physics: in the latter half of the mid-twentieth century, Yale’s Wright Nuclear Structure Laboratory (WNSL) was an active center of experimental nuclear physics and nuclear astrophysics. Yale physicists and external users utilized the MP tandem accelerator and the Extended Stretched TransUranium tandem accelerator housed at WNSL. The university laboratory setting allows a view of the work dynamics different from large national laboratories. I have interviewed Professor Emeritus Peter D. Parker, who has been at Yale since 1966. As well as contributing to nuclear physics and nuclear astrophysics, Parker has been a well-loved teacher and mentor to physics students and an advocate for gender rights during his many years at Yale. The transcript is available on the AIP website.

This report is reprinted from the Fall 2024 History Newsletter.