Helen Freedhoff facts for kids
Quick facts for kids
Helen Freedhoff
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Helen Freedhoff, 1961
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| Born |
Helen Sarah Goodman
January 9, 1940 |
| Died | June 10, 2017 (aged 77) Muskoka, Ontario
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| Education | Harbord Collegiate Institute |
| Alma mater | University of Toronto |
| Known for |
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| Spouse(s) | Stephen Freedhoff |
| Children |
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| Scientific career | |
| Fields | Theoretical physics |
| Institutions | |
| Thesis | Theory of dipole-dipole interaction in coherent radiation processes (1965) |
| Notable students | Terry Rudolph (PBR theorem) |
Helen Sarah Freedhoff (born January 9, 1940 – died June 10, 2017) was a Canadian theoretical physicist. She studied how light and tiny particles called atoms interact.
She earned her highest degree, a doctorate, from the University of Toronto in 1965. After that, she did more advanced research at Imperial College in London. Helen Freedhoff made history as the first woman to become a physics professor at York University in Toronto. At the time, she was likely the only woman professor of theoretical physics in all of Canada.
Becoming a Scientist
Helen Freedhoff was born Helen Sarah Goodman in Toronto on January 9, 1940. Her parents were Ethel and Sholom Goodman. She also had two brothers, David and Irving. Her family often called her "Henchy."
In 1957, she finished high school at Harbord Collegiate Institute. This school was known for its many successful former students. These included Charles Best, who helped discover insulin, and famous architect Frank Gehry.
It was quite unusual for women in North America to pursue a science career in the 1950s. After World War II, many young men entered science. Women were often expected to step aside. But at Harbord, Helen didn't face these challenges. She remembered that her teachers really encouraged her. She felt there was nothing wrong with having a career.
Helen went to the University of Toronto. She chose to study Mathematics, Physics, and Chemistry. She was one of only 10-15 women among 120 first-year students. She first planned to study math but soon found she liked physics more. Helen was the only woman in her year to major in physics. She graduated with the best grades and won a special award called the Governor General's Gold Medal. She didn't feel held back by being the only woman. In fact, she thought it could even be an advantage to stand out.
During her summers, Helen worked in Harold Johns' biophysics lab. Harold Johns was a leader in medical biophysics. He helped create cobalt radiation therapy for cancer in the 1940s. Helen enjoyed her time there. She was also interested in the laser work of Harry Welsh. But she realized that hands-on lab work wasn't her favorite. She was inspired by Jan Van Kranendonk, a theoretical physicist. He encouraged her to continue her studies with him. From then on, she loved "the excitement of scientific research" and teaching. She believed that "basic science" was a high form of culture, like music or literature.
Her Work in Physics
Between 1890 and 1933, almost 20% of physics doctorates at the University of Toronto went to women. However, no other women earned physics PhDs there until 1962. Helen Freedhoff became the second, earning her PhD in 1965. Her research was about how tiny particles interact when light shines on them.
After her PhD, Helen received a special research grant. She worked at Imperial College in London from 1965 to 1967. There, she studied ways to identify parts of atoms trapped in metals using a method called spectroscopy. This work was partly supported by the United States Air Force.
While in London, she looked for job openings back in Toronto. In 1967, she became an assistant professor of physics at York University. She was the first woman physics professor at the university. People believed she was also Canada's only woman professor in theoretical physics at that time.
Helen Freedhoff stayed at York University until she retired in 2005. She took one year off in 1986 to work at Technion, the Israel Institute of Technology in Haifa. During her career, she published over 40 research papers. She also worked with physicists in Australia. This led to Terry Rudolph studying for his doctorate under her guidance in the 1990s. Terry Rudolph is now a physics professor at Imperial College. He is known for helping develop the PBR theorem, an important idea in quantum mechanics. Terry Rudolph, who is the grandson of famous physicist Erwin Schrödinger, spoke at Helen Freedhoff's funeral.
Family Life
Helen married Stephen Freedhoff when she was about 20 years old. Stephen had studied business at the University of Toronto. He became a chartered accountant and consultant. They had a daughter, Michal Ilana Freedhoff, and a son, Yoni Freedhoff. They also had seven grandchildren.
Their daughter, Michal Freedhoff, earned a doctorate in chemistry. She later worked for the US government in environmental protection. In 2021, she was appointed to a high position at the US Environmental Protection Agency (EPA). Their son, Yoni Freedhoff, is a professor at the University of Ottawa. He is also an author.
In her free time, Helen Freedhoff enjoyed reading and playing the piano. She also liked solving KenKen puzzles and practicing yoga.
Helen Freedhoff passed away suddenly on June 10, 2017. She was at her family's cottage in Muskoka, Ontario, a lakeside area near Toronto.
Selected Publications
- W.R. Bruce, M.L. Pearson, Helen S. Freedhoff. The Linear Energy Transfer Distributions Resulting from Primary and Scattered X-Rays and Gamma Rays with Primary HVL's from 1.25 mm Cu to 11 mm Pb. Radiation Research, 19 (4): 606-620.
- Helen Freedhoff, J. Van Kranendonk (1967). Theory of coherent resonant absorption and emission at infrared and optical frequencies. Can. J. Physics, 45(5): 1833-1859.
- Helen S. Freedhoff (1979). Collective atomic effects in resonance fluorescence: Dipole-dipole interaction. Phys. Rev. A 19, 1132.
- Helen S. Freedhoff (1982). Collective atomic effects in resonance fluorescence: The "scaling factor". Phys. Rev. A 26, 684.
- Helen Freedhoff, Zhidang Chen (1990). Resonance fluorescence of a two-level atom in a strong bichromatic field. Phys. Rev. A 41, 6013.
- Tran Quang, Helen Freedhoff (1993). Index of refraction of a system of strongly driven two-level atoms. Phys. Rev. A 48, 3216.
- Helen Freedhoff (2004). Evolution in time of an N-atom system. I. A physical basis set for the projection of the master equation. Physical Review A. 69 (1).
