Joan Feynman grew up in the shadow of her older brother, the brilliant scientist and Nobel laureate Richard Feynman. When she expressed interest in following in his footsteps, her mother crushed the impulse.
“My mother warned me, ‘Women’s brains can’t do science,’” Ms. Feynman recalled in a 2018 speech at the California Institute of Technology.
Despite those discouraging words, Ms. Feynman went on to become a world-famous astrophysicist. She predicted sunspot cycles and figured out how many high-energy particles were likely to hit a spacecraft over its lifetime, allowing the space industry to design satellites and capsules with greater longevity. Her crowning achievement was understanding the origin of auroras, those dazzling, psychedelic displays of colors — known as the aurora borealis in the Northern Hemisphere and the aurora australis in the Southern — that inflame the night skies.
Ms. Feynman was 93 when she died on July 22 at her home in Oxnard, Calif., just northwest of Los Angeles. Her husband, Alexander Ruzmaikin, also an astrophysicist, said the cause was heart failure.
Over a career that spanned more than six decades, Ms. Feynman was a pioneer in solar physics and later delved into the science behind climate change. She conducted research at some of the nation’s top scientific institutions, including NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
But her love of science never would have blossomed if not for her charismatic brother, a renowned theoretical physicist whose high-flying career would include working on the Manhattan Project and investigating the explosion of the space shuttle Challenger.
“Richard was my first teacher,” she recalled in the Caltech speech, delivered at an event celebrating the legacy of her brother, who was nine years older. When he was 14, he built an electronics lab in his bedroom and hired her as his assistant for pennies a week.
Their mother was a sophisticated woman who in her youth had marched for women’s suffrage. She was also fun-loving. But she was far more encouraging of her son than of her daughter, even as Joan was learning at Richard’s side.
“When I learned something, my mother was impressed with his teaching ability, not my learning it,” Ms. Feynman said.
Fortunately for her, Richard kept up his tutelage.
“He would run her hand over the corner of a picture frame, describe a right triangle and make her repeat that the sum of the square of the sides was equal to the square of the hypotenuse,” her son Charles Hirshberg wrote in a 2002 essay about her for Popular Science.
When Joan was 8 and announced that she wanted to be a scientist, her mother’s harsh declaration sent her sobbing into a cushion.
“I know she thought she was telling me the inescapable truth,” Ms. Feynman told her son. “But it was devastating for a little girl to be told that all of her dreams were impossible. And I’ve doubted my abilities ever since.”
A breakthrough came after her 14th birthday, when her brother gave her a college textbook called “Astronomy” that included a chart of scientific data based on research by a female astrophysicist. Ms. Feynman suddenly felt validated. And she realized that to pursue a career in science, “you didn’t have to be Marie Curie,” a woman scientist of such stratospheric accomplishment that she was not a plausible role model.
“It took courage to be a woman scientist, and determination and hard work,” she said. She had found inspiration in Proverbs, in which it is written that a virtuous woman “considereth a field, and buyeth it: with the fruit of her hands she planteth a vineyard.”
Reflecting on that passage in her Caltech speech, she noted that it did not say “she seeth a vineyard and it looks pretty good to her so she goes and asks her husband whether they should think about buying it.”
Joan Feynman was born on March 30, 1927, in Queens. Her father, Melville Arthur Feynman, was a businessman. Her mother, Lucille (Phillips) Feynman, was a homemaker.
At one point her father became ill, but her mother “didn’t know how to make a living,” Ms. Feynman said, so he continued to work. Later, as his daughter headed off to Oberlin College in Ohio, he advised her to learn to make a living “because you never know what life brings.”
“Only men made good livings,” she concluded, “so I figured I should go into a man’s profession.” She chose physics.
She graduated from Oberlin in 1948, the year she married Richard Hirshberg, also a scientist, whom she had met there; they separated in 1974 and later divorced. She married Mr. Ruzmaikin, who was 18 years her junior, in 1992. In addition to him and her son Charles, she is survived by another son, Matthew; a daughter, Susan Hirshberg; and four grandchildren. Her brother died in 1988 at 69.
After Oberlin, Ms. Feynman went to graduate school at Syracuse University, where she found the sexism pervasive. One professor advised her to write her dissertation on cobwebs because that is what she would encounter while cleaning house. Rejecting this advice, she wrote a thesis titled “Absorption of Infrared Radiation in Crystals of Diamond-Type Lattice Structure.” She earned her doctorate in physics from Syracuse in 1958.
When she couldn’t find work, she spent a few years as a homemaker, which her son said left her depressed. She went to a psychiatrist, who urged her to apply to what is now called the Lamont-Doherty Earth Observatory at Columbia University. She was hired, and her career took off.
While there, her pioneering work on Earth’s magnetosphere led to her research into auroras, which her brother had introduced her to when she was a girl. He had woken her up one night and taken her away from the city lights to a golf course to show her the aurora borealis.
“He said, ‘Nobody knows how it happens,’” she recalled. “And I thought that was very, very interesting, so I ended up studying auroras.”
She was so excited by what she was learning at Lamont that her first impulse was to tell Richard about it.
But she worried that if she did, he might make the key discovery about the origin of auroras before she could, according to a chapter about her in a collection of essays called “A Passion for Science: Stories of Discovery and Invention” (2013). So she offered her brother a deal.
“I said, ‘Look, I don’t want us to compete, so let’s divide up physics between us,’” she said. “‘I’ll take auroras and you take the rest of the universe.’ And he said OK!”
In 1963, Ms. Feynman’s husband was offered a job in California, and she joined NASA at the Ames Research Center in Silicon Valley. When its funding was cut in the early 1970s, she was suddenly out of a job.
She bounced around after that, including stints at the High Altitude Observatory in Boulder, Colo., and the Air Force Geophysics Lab near Lexington, Mass., before landing at the Jet Propulsion Lab in 1985. There she was able to demonstrate that auroras occur when solar particles penetrate the magnetosphere and that it is the collision of particles that creates the brilliant colors.
Ms. Feynman was named an elite senior scientist at the lab in 1999. In 2000 she received NASA’s Exceptional Scientific Medal for her “pioneering contribution to the study of solar causes of geomagnetic and climate disturbances.”
She officially retired from the lab in 2004 but continued to publish articles and work at her office until 2017. “How could I retire,” she once said, “when the sun is doing such crazy things?”