WOMEN IN MEDICAL PHYSICS
Traditionally, physics has been a male-dominated occupation. However, throughout history there have been exceptional women who have risen above society’s restrictions and contributed greatly to the advancement of physics. Women have played an important role in the creation, advancement and application of medical physics. As a frontier science, medical physics is less likely to be bound by society’s norms and less subject to the inherent glass ceiling limiting female participation. Women such as Marie Curie, Harriet Brooks, and Rosalind Franklin helped break through that ceiling, and their contributions are worth observing.
In the early 1900’s, medical physics was a young and vibrant science. With Roentgen’s discovery of X-rays in 1895, scientists began exploring the exciting field of radiation physics. His work won him the first Noble prize in physics, in an area of physics that would become no stranger to Noble prizes.[1] From the very beginning, a female perspective was left on the science, with Roentgen’s wife’s hand immortalized in an early X-ray picture. In a more important way, female scientists left their mark on the fledging science, and continue to contribute today.
Marie Curie is possibly the most well known female pioneer in this new field of science. Born as Manya Sklodowska in Poland in 1867, she grew up in a poor family in a country under the yoke of Russian oppression. Marie and her older sister Bronia had dreams of making their mark on the world from a young age; Marie as a scientist and Bronia as a doctor. Despites the odds, they would both reach their goals (Rayner-Canham, 1997).
While her elder sister studied in France, Marie worked as a governess for a wealthy Polish family, teaching and training their children in their school studies. Eventually Marie fell in love with Casimir, the eldest son who was attending university. They planned to marry, and Marie would have known a life of relative luxury, but it would have probably been the end of her scientific ambitions (McClafferty 2006).
However, his parents objected to a marriage with a poor woman from a lower class, and Marie was heartbroken. She eventually left Poland and joined her sister in France, studying at the University of Paris, known as the Sarbonne. She would finish master’s degrees in physics and mathematics, and eventually become the first woman to teach there. She would also become the first woman to earn a doctorate degree in France (McClafferty 2006). During her studies she met Pierre Currie, a fellow physicist who had already done some important work in piezoelectricity. Together they would form both a marital and scientific partnership. Pierre was a very supportive spouse, and despite the contemporary social expectations for a married woman, Marie continued her scientific work. When the couple began having children, they hired nurses and had the aid of Pierre’s father in taking care of the children, freeing Marie from the expected housewife role and motherly duties (Rayner-Canham, 1997). As a result, Marie was able to overcome two common hurdles that still exist in a lesser form today, and focus on experimental physics in the laboratory.
Marie worked with uranium and thorium using a piezoelectric quartz electrometer invented by her husband. Together they also worked on a multi-compound ore called pitchblende. They were able to isolate and discover two new elements, polonium, named after Poland, and the element radium. Pierre, Marie, and Becquerel were given the Noble prize in physics for their work in spontaneous radioactivity. [2] Keeping with the norms of the age, the Noble Prize committee had originally planned to give the prize only to the two men. However, Pierre wrote to them when he heard he was being considered and explained and reinforced Marie’s important role in their discoveries (McClafferty 2006).
Marie and Pierre refused to patent their discovery of radium and its extraction process. Instead, they encouraged the free use of radium by the scientific community. Radium treatments were used successfully to treat cancers, especially skin cancers which were easy to expose to radium. There were also some successes in treating internal cancers. However, there were many foolish and unfounded claims for the use of radium. There was also no knowledge of the potential dangers of radium. The Currie’s themselves were unwittingly sick and fatigued from their constant radiation exposure (McClafferty 2006).
Marie continued her scientific work after her husband died in tragic street accident in 1906. There was some doubt regarding the element status of radium by various scientists, including the famous Lord Kelvin. Marie perfected the extraction process of radium, produced its pure metallic form, and was able to finally prove that radium was indeed an element (Rayner-Canham, 1997). For her work on radium and polonium she was awarded the 1911 Noble prize in chemistry, and became the first person to receive two Noble Prizes. [3] While she received the award, Marie was facing scandal in France. The press believed she was having an affair with another physicist, Paul Langevin. Around the same time, Marie’s application to join the French Academy of Sciences was rejected by a single vote, and the academy remained a male only institute (McClafferty 2006).
During World War I, Marie helped create mobile X-ray units that were used to treat soldiers at the trenches. X-rays were ideal for finding bullets in wounded soldiers and the machines were called “little Curies’. Marie continued to contribute to scientific research and education until her death, which was caused by her long term exposure to radiation. She was eventually reburied in the Pantheon, a famous French burial place, and was the first woman to be laid to rest there (McClafferty 2006).
Harriet Brooks was a Canadian physicist who was deemed by Ernest Rutherford to be second only to Marie Curie, as a female scientist in the field of radioactivity (Rayner-Canham, 1997). She was born in Ontario, to a lower class family. She entered McGill University in 1894 with the aid of several scholarships. After graduating in 1898, she became Rutherford’s first graduate student. She completed her master’s degree in electromagnetism in 1901, becoming one of the first women at McGill to receive a master’s degree. At the same time, Brooks worked as a mathematics tutor in the Royal Victoria woman’s college at McGill. She worked for over six years with Rutherford, and she helped discover radon gas and provide support for Rutherford and Soddy’s discovery that elements can decay into other elements.[4] Rutherford would eventually win the Noble Prize for chemistry in 1908.
The contributions made by Brooks while she was a graduate student are often overlooked (Rayner-Canham, 1997). However, Rutherford himself was an excellent mentor and supportive friend for Brooks. He had accepted several female graduate students at McGill, and often praised Brooks’ work. He helped her attain a position working at Cavendish Laboratory in Cambridge. While Brooks took good advantage of this great opportunity, she found it hard to work with her supervisor J.J. Thomson, winner of the 1906 Nobel Prize in physics. While Thompson was not prejudiced against female scientists, she still felt the dual handicap of being a woman and not a well known scientist, so it was difficult for her to present experimental results that might challenge his opinions. Brooks returned to McGill and continued her work at the women’s college and in Rutherford’s group. She “observed that a non-radioactive plate placed inside a radioactive container itself became radioactive” (Rayner-Canham, 1997). Rutherford presented her results, but later disagreed with her correct interpretation. Brooks did not receive credit for the discovery of radioactive recoil, which was given to another group. Rutherford continued to present her continuing work on radioactive decay, making sure to give proper credit (Rayner-Canham, 1997).
Brooks became a teacher at Barnard College, Columbia University’s women’s college. She fell in love with Bergen Davis, a Columbia physics professor. When they became engaged, the college notified her that she should resign from her academic duties once she married, as that was the social norm of the time. Brooks delayed her marriage and appealed the decision with help from influential members of the college. The college responded that they couldn’t “afford to have women on the staff to whom the college work is secondary… [and] the college is not willing to stamp with approval a woman to whom self-elected home duties can be secondary.” Brooks commented, “”I think it is a duty I owe to my profession and to my sex to show that a woman has a right to the practice of her profession and cannot be condemned to abandon it merely because she marries. “ Brooks broke the engagement due to personal reasons, but she resigned from the college because of the embarrassing social situation at work (Rayner-Canham, 1997).
Brooks visited France and worked for a short time with Marie Curie. Curie offered her a position to stay with her, but Brooks declined and applied for the John Harling Fellowship at Manchester. Rutherford was returning to Manchester, and wanted her as part of his research group again. While she was still waiting for the decision, Brooks married Frank Pitcher, and retired from physics research (Rayner-Canham, 1997). There are several reasons why she might have married without a fight to continue her scientific work. She was in her thirties, and facing the contemporary societal pressure to marry and the stigma attached to a single woman that still exists today. The state of radioactivity research at McGill had collapsed after Rutherford’s departure, and starting again in a new position would have been very difficult. There simply weren’t many opportunities for a female physicist at that time. She returned to Montreal, but devoted herself to the life of a housewife. Brooks’ contributions are often overlooked and forgotten, and her premature exit from the scientific arena is a regrettable historical footnote.
The early pioneers in the field of radioactivity also opened up many potential experimental and practical applications. Rosalind Franklin is one of the better known female experimental scientists, as a physical chemist and X-ray crystallography specialist. She was born to a moderately wealthy Jewish family in England in 1920. She entered studies at Newnham women’s college at Cambridge in 1938. Cambridge did not consider women as official members of the university, and would only give them nominal degrees known as “degrees titular.” There was a quota set so that women would not exceed 10% of the undergraduate body. Franklin focused on taking chemistry, physics and mathematics courses. After graduating with a titular degree in 1941, she worked with several British companies that were involved in the World War II effort (Maddox 2002).
She studied coal porosity and structure, and began work on a PHD. She had her father’s support throughout her studies, and she refused to be condemned to the restrictive role of a housewife as she “[couldn’t] see how it can be anything but dull.” She earned her doctorate in 1945 and with the help and contacts of Adrienne Weill, another female physicist, she obtained an opportunity to work in Paris and learn X-ray diffraction techniques (Maddox 2002).
Franklin returned to England, and began work as a research associate at King’s College in London. The director of the biophysics unit, John Randall, was very fair with female scientists, and eight of his thirty one staff members were women. Working with her graduate student Raymond Gosling, they discovered the A (dry) and B (wet) forms of DNA. Franklin had a tumultuous and unstable work relationship with fellow researcher Maurice Wilkins. Randall had to intervene on occasion and set them on independent research paths (Maddox 2002).
Franklin would go on to present some of her findings in November 1951. In the audience was James Watson, who was working with Francis Crick on trying to model DNA structure. The two men proposed a failed model of DNA that year, but continued work on building new models. In 1953, Maurice Wilkins, still on adversarial terms with Franklin, showed Watson one of Franklin’s unpublished X-ray photographs. It was enough, along with some of Franklin’s unpublished data, to help Watson and Crick finalize their DNA model. Watson and Crick offered Wilkins the possibility of joint authorship with them (Sayre 1975).
Wilkins denied the offer, and did not involve Franklin in the decision, despite the fact that they had used her unpublished X-ray image and data. When Watson and Crick published their results, Wilkins agreed to publish an accompanying note, which gave no credit to Franklin (Maddox 2002). Franklin did publish her work as well as a supporting article for the new DNA model, and Watson and Crick mentioned some help that they received from Franklin. However, Franklin’s days at King’s College were over, as she was asked to leave and even recommended to “cease to work on the nucleic acid problem, and take up something else” (Maddox 2002).
Franklin worked at Birkbeck College from 1953 to 1956, focusing her skills on various plant viruses, the most famous being the Tobacco mosaic virus. Franklin enjoying working there, but she still did not receive the full wage a woman was entitled to at the time (Maddox 2002). In 1956 Franklin was diagnosed with cancer, and after a long struggle, died in 1958. The cancer may have been caused by radiation exposure during her work (Sayre 1975). She had published or co-published thirty seven scientific papers and provided a lot of useful information for applied medical physics (Maddox 2002). Her help in discovering the structure of DNA was crucial, and that discovery sparked a revolution in molecular biology that continues to this day.
Bernal, her lab supervisor at Birkbeck wrote positively of her in her obituary, and mentioned that “her photographs are among the most beautiful X-ray photographs of any substance ever taken” (Maddox 2002). Watson, Crick and Wilkins were awarded a Noble Prize in 1962 for their work on discovering DNA’s structure. [5] Franklin could not be considered for the award because she had died in 1958. Watson published The Double Helix, a reflecting book about his experiences in life and science in which he wrote unflatteringly about Franklin’s character (Maddox 2002). Watson later apologized for his writings, but there still remains some stigma and doubt cast about the events at King’s College around the time of Watson and Crick’s discovery of DNA structure.
Marie Curie is one of the most famous female scientists, and her legacy along with her husband’s is honoured today with the curie unit of activity, and the very word radioactivity, which the couple invented during their work. Harriet Brooks is not well documented in the annals of history, but definitely deserves to be recognized for her work. Rosalind Franklin has received acknowledgement for her work in recent years. When looking at the grievous discrimination and challenges they all faced, it is sometimes easy to forget that there were many male scientists and nonscientists that supported their right to pursue a scientific career. Pierre Curie was a very supportive colleague and husband, and ensured his wife’s rightful receiving of her first Noble prize. Rutherford was ever the staunch supporter of Brooks, and helped her find opportunities throughout her career. While Franklin faced trouble working at King’s College, Randall was relatively fair in his views towards female scientists, and had no qualms about hiring a staff that involved a substantial amount of women for the time. Aaron Klug, a coworker and friend of Franklin from her time at Birkbeck college, mentioned her various research achievements and scientific career when he won a Noble Prize in chemistry in 1982 (Maddox 2002). Klug defended Franklin’s character and also mused that “Rosalind was not a feminist in the ordinary sense…., [but] was determine[d] to be treated equally just like anybody else” (Maddox 2002).
Physics has often lagged behind other fields in terms of female enrollment. This is both embarrassing and harmful, because physics is a science where multiple view points and ways of seeing the world are needed. Indeed, “women represent a largely untapped source of talent and innovation.” [6] To truly explore the mysteries of nature, the participation of both men and women is required. To be fair, conditions for women in physics have improved greatly in recent years. Medical physics, one of the forefronts of current physics research and application, is also on the forefront of increased female enrollment. [7] It is certain that if Curie, Brooks, and Franklin were reborn today, they would have a somewhat easier time in pursuing their scientific research and careers in a modern arena of balanced social support and relative gender equality.
References
Maddox Brenda. Rosalind Franklin; The Dark Lady of DNA. New York, United States: HarperCollins Publishers, 2002.
McClafferty, Carla K. Something Out of Nothing; Marie Curie and Radium. New York, United States: Douglas and McIntyre Ltd, 2006
Rayner-Canham, Marelene. Pioneer Women of Radioactivity. Quebec, Canada: McGill-Queen’s University Press, 1997
Sayre, Anne. Rosalind Franklin and DNA. Toronto, Canada: George J. McLeod Limited, 1975
Endnotes
1 – The Noble Foundation. 2006 link
2-5 – Ibid
6 – Hartline, Beverly K; Li Dongqi. Women In Physics : The IUPAP International Conference on Women in Physics. New York, United States: American Institute of Physics, 2002
7 – Ibid