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There at the Creation

By CHM Editorial | April 19, 2022

Klara Dán von Neumann and the Birth of Computer Programming

She was not just Steve Jobs in a dress.

— Thomas Haigh

For every Marie Curie and Rosalind Franklin, there are likely hundreds of remarkable women in science whose stories have never been told. That’s the premise of the Lost Women of Science Initiative, according to podcast host and journalist Katie Hafner. On April 5, Hafner joined computer historian Thomas Haigh in a CHM Live discussion moderated by computer scientist and Harvey Mudd President Maria Klawe. Their subject was a lost woman of computing science, Hungarian-born Klara—known as Klári—Dán von Neumann, a computer programming pioneer who worked on the Monte Carlo simulations of atomic and thermonuclear explosions immediately after World War II. Made possible by the generous support of the Kapor Center, the event was developed in partnership with the Lost Women of Science Initiative.

Klári was a kind of “super-programmer,” says Thomas Haigh, creating the first modern computer code ever executed. She was there at the very start of the discipline of computer programming, but her role in computing history was hidden.

Finding Klári

Klári was married to brilliant mathematician and physicist John von Neumann, who was one of the first professors at Princeton’s renowned Institute for Advanced Study and played a key role in the Manhattan Project to develop the atomic bomb during World War II. Klári’s papers were buried within the 55 boxes of John’s papers housed at the Library of Congress—and they were all in Hungarian. Finding a translator who could also decipher her difficult handwriting was a challenge. But Katie Hafner says it was well worth it.

Katie Hafner relates Klári’s early history.

Modern Coding

Klári learned to operate the ENIAC, the first programmable electronic computer. Designed to calculate ballistic trajectories, it was a huge machine that had to be reconfigured by wiring electrical circuits with a plugboard and switches by hand. It was clunky and labor-intensive. John von Neumann began to map out the architecture of a successor, and he realized they could emulate it on the ENIAC.

Translating the flow diagram of John’s mathematical treatment to code was a complex job. But Klári did it, and in 1948, she worked with Nick Metropolis from Los Alamos to reconfigure ENIAC to run the code, debug it, and set up test simulations. Thomas Haigh uncovered Klári’s outsize role by deciphering mysterious papers covered with numbers in the archives with the help of a translator, handwriting expert, and technical colleague.

Possibilities and Probabilities

Haigh explains that after the war, there was a push to develop more efficient atomic weapons. However, actually testing these weapons would waste uranium, which is difficult to get, so scientists at Los Alamos needed mathematical simulations instead.

John von Neumann developed the Monte Carlo simulations after talking with colleague Stanislaw Ulam. Today, they are used to predict the outcomes of elections or what might happen next with the pandemic. At Los Alamos, Monte Carlo simulated the second-to-second probabilities of what might be happening to a neutron inside a nuclear weapon. The first time these were provided by a computer it was done by Klári. And she didn’t stop there.

Thomas Haigh explains how spouses contributed at Los Alamos.

Unfinished History

Among the von Neumann papers is Klári’s unfinished memoir titled “A Grasshopper in Very Tall Grass." The title reflects deep insecurities that are also evident in Klári’s correspondence despite her obvious intelligence and talent. How many other women like her remain unknown to us? And, why is it important to tell their stories? Maria Klawe uses the example of computer science to explain.

Maria Klawe describes women’s roles in early computing.

While Katie Hafner argues that computing became regendered even before computer games in the home made it a “boy thing,” as Klawe believes, all the panelists agreed that there is value in searching out stories like Klári’s to combat the “great man” theory of history.

Great inventions and discoveries are not just the work of individual men, but also women and teams. These stories fill out the historical record with portraits of real, complex individuals who can be role models that all kinds of people can relate to.

Klári von Neumann was not just “Steve Jobs in a dress.”

Watch the Full Conversation

Revealing Lost Woman of Science Klári Dán von Neumann | CHM Live, April 5, 2022

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About The Author

CHM Editorial consists of editors, curators, writers, educators, archivists, media producers, researchers, and web designers, looking to bring CHM audiences the best in technology and Museum news.

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