Women in Physics – Part 1

Name a famous scientist. Who was the first person that came into your head? Steven Hawking, Albert Einstein or Isaac Newton? Maybe for those of you out there that watch The Big Bang Theory you might be familiar with some of the more obscure people and said Erwin Schrodinger, Galileo Galilei or Robert Oppenheimer. What do all of these people have in common? They’re all men.

In today’s world, the field of science is still dominated by the male of our species however I would like to take a moment to highlight some of the fantastic female minds that have graced the science domain, and in particular, the field of physics.

 

Annie Russell Maunder

Annie Russell Maunder is a home grown girl. She was born Annie Scott Dill Russell in Strabane, Co. Tyrone in 1868. Her father was a Presbyterian minister and she was educated at the Ladies’ Collegiate School in Belfast, which later became Victoria College. She then gained a scholarship to Girton College in Cambridge, and graduated with honours in the mathematical tripos in 1889. At this time however she was not awarded with a degree as women were denied degrees until 1948. Annie spent a year teaching mathematics before she joined the staff of the Royal Greenwich Observatory in London as a “lady computer,” or “supernumerary computers,” in 1891. People in these positions were hired on a short term basis rather than being granted permanent employment. She was assigned to the Solar department and was given a salary of £4 per month (which works out at roughly £240 per month in today’s currency). Annie assisted Walter Maunder, the head of the department, in taking daily photographs of the Sun.

Annie resigned her post in 1895 in preparation for marriage to Walter Maunder. During that time period there was a ban on married women in the public service, which is why she had to resign her position. She was 27 when she married and her new husband was 45 and already had 5 children from a previous marriage in which his wife passed away. Annie edited the journal of the British Astronomical Association and assisted her husband on a voluntary basis once they were married. During the First World War she also returned to formal duties at Greenwich as a volunteer.

Annie continued to pursue her interests in practical astronomy, and she even received a small grant from the Girton College to undertake a photographic study of the Milky Way. She accompanied her husband on several eclipse expeditions and worked with him on the periodicity of sunspot activity. In 1898 the Maunders went on a solar eclipse expedition to India. This is where Annie photographed the solar corona with a camera of her own design. She was also able to photograph a particularly long streamer. Over the expeditions, Annie became regarded as an expert on eclipse photography.

In 1922 Annie Maunder charted the latitude drift of spots during each solar cycle. The chart that she created is sometimes referred to as the butterfly diagram due to the wing like shapes seen on the graph. Annie and her husband were also interested in a period of 70 years from 1645 to 1715 in the middle of the “Little Ice Age” when the Sun was almost devoid of sunspots. The Maunder Minimum, is the name used for the period starting at about 1645 and continuing to about 1715 when sunspots became exceedingly rare. This term was introduced after John A. Eddy published a landmark 1976 paper in Science. Astronomers before Eddy had also named the period after Annie and Walter, as they had studied how sunspot latitudes changed with time.

 

This graph depicts the activity of the Sun during the period of The Maunder Minimum.

 

When Walter passed away in in 1928, Annie continued on in her work and continued on as the editor of The British Astronomical Association journal. She wrote the Association’s history for their 50th Anniversary celebrations. She truly was an inspiration woman, and a credit to the people of Northern Ireland. Both she and her husband have a crater named after them on the moon in commemoration of the ground breaking couple. This crater is known as the Maunder (Lunar Crater), which is not to be confused with the Maunder (Martian Crater) which is named after Walter and is found on Mars.

 

 

Henrietta Swan Leavitt

Henrietta Swan Leavitt

Henrietta Swan Leavitt was born on 4th July 1868, in Cambridge, Massachusetts in the United States of America. She was the daughter of Congressional Church Minister George Roswell Leavitt and his wife Henrietta Swan. She attended Oberlin College, and graduated from Radcliffe College in 1892, which was then called the Society for the Collegiate Instruction for Women. She was an intelligent woman, and was interested in many subjects and studied a broad spectrum including Greek, Fine Art, philosophy, analytic geometry and calculus. It wasn’t until her fourth year of college however that she took her first course in astronomy. After she graduated she took another course in astronomy and she then spent some years at home where she suffered from a serious illness and was left severely deaf.

In 1893, Leavitt began working at the Harvard College Observatory as one of the women human “computers,” hired by Edward Charles Pickering. Pickering recruited over 80 women to work for him, and they were also known as “Pickering’s Harem,” at the time. It was her job to measure and catalogue the brightness of stars as they appeared in the Observatory’s photographic plate collection. At a later date she was made a permanent member of staff and received just $0.30 an hour, which would roughly work out as $8.62 an hour today.

 

Large Magellanic Cloud – Image credit: NASA

 

Leavitt was given the task, by Pickering, of recording and studying variable stars whose luminosity varies over time. Leavitt noted thousands of variable stars in the images of the Magellanic Clouds. There are two Magellanic Clouds, and they are a duo of irregular dwarf galaxies visible from the southern hemisphere, which are members of the Local Group and are orbiting the Milky Way galaxy. Because they both show signs of a bar structure, they are often reclassified as Magellanic spiral galaxies. The two galaxies are: the Large Magellanic Cloud (LMC), and it is about 160,000 light-years away, and the Small Magellanic Cloud (SMC), which is about 200,000 light years away. In 1908 she published her results in the Annals of the Astronomical Observatory of Harvard College, noting that a few of the variables showed a pattern: brighter ones appeared to have longer periods. After further study on this matter, in 1912, Leavitt confirmed that the Cephid variables with greater intrinsic luminosity did have longer periods and that the relationship was quite close and predictable. If a star’s intrinsic brightness could be estimated from its pulsation rate then we could determine how distant any of these Cepheid variable stars were from Earth. This therefore meant that there was now a method to determine the distances of stars from the Earth, which in turn lead to many other discoveries. Rather brilliant for a women stuck in a hugely male dominated scientific practice in the 1900s.

 

Astronomical Observatory of Harvard College 1899

 

After this Leavitt worked sporadically at Harvard, however was plagued with health issues and family obligations. There was no doubt though that she was a women who was passionate and dedicated to her field. In 1921, when Harlow Shapley took over as director of the observatory, Leavitt was made head of stellar photometry. Unfortunately by the end of that year she had succumbed to cancer, and was buried in the Leavitt family plot. Swedish mathematician, Gösta Mittag-Leffler, tried to nominate Leavitt for a Nobel Prize, unfortunately this was after her death, and Nobel Prizes are not awarded posthumously. There is no doubt that she would have been a well deserving winner of the Nobel Prize as her work played a huge role in further discovery about the Universe we live in.

 

 

Vera Rubin

Vera Rubin (2009)

 

Vera Rubin was born 23rd July 1928, in Philadelphia in Pennsylvania, USA. She lived in Washington D.C. until she was ten years old and it was at this age that she started to develop a growing interest in astronomy. She earned her degree in Astronomy at Vassar College and then attempted to enrol at Princeton. She never received their graduate programme as women were not allowed in the graduate programme in Princeton until 1975.

Not put off by this set back, Vera enrolled for her Master’s degree in Science at Cornell University where she studied physics, quantum physics and quantum mechanics. You have to admit, that is seriously impressive. She completed her study in 1951, during which she made her first observations of the deviations from the Hubble Flow in the motions of galaxies. The ‘Hubble flow’ describes the motion of galaxies due solely to the expansion of the Universe. The idea of the expanding Universe was first put forward by Edwin Hubble in 1929, after observing a correlation between the redshifts of galaxies and their distances measured using the period-luminosity relationship for Cepheid variable stars. Hubble found that all galaxies were moving away from us, and that the velocity of their recession was proportional to their distance from us. Vera tried to argue that galaxies might be rotating around an unknown centre, rather than simply moving outwards. She conducted her PhD at Georgetown University and upon her graduation in 1954, her PhD thesis concluded that galaxies clumped together, rather than being randomly distributed through the Universe. The idea of clusters of galaxies existed, but was not pursued seriously by others until two decades after Rubin’s thesis was produced in 1954.

 

After graduating, Vera taught at Montgomery County Junior College, and she also worked at Georgetown University as a research assistant. In 1962, she became an assistant professor at the University. In 1965, she did something that no woman in Physics had ever done before. She became the first woman allowed to use the instruments at the Palomar Observatory. Prior to this, no woman had ever been authorised to access this facility. In the same year she successfully secured a position at the Department of Terrestrial Magnetism at the Carnegie Institution of Washington, where she began work on galaxy clusters. When Rubin observed her galaxies, she found that their rotation curves didn’t match up to theory. Little did she know, she had found the first indicator for dark matter, an elusive material believed to make up around 25% of the missing mass of the universe.

Rubin knew that her findings would be criticised, and in a bid to avoid this, she slanted her research more towards the study of rotation curves of singular galaxies, rather than the widely debated galaxy clusters. She also began research on the Andromeda galaxy. Throughout her career Vera Rubin examined more than 200 galaxies.

During her career Rubin battled with her male counterparts to gain her own credibility, and so she dedicated herself to encouraging young girls and women to pursue their dreams of investigating the universe. It wasn’t just the field of astronomy that she took a stand in, she also was a strong advocate for women in the general field of science. She won a number of awards and as well as becoming the second female astronomer to be elected to the National Academy of Sciences, she also received the National Medal of Science from President Bill Clinton in 1993 for her pioneering research programs in observational cosmology.

 

These are only three of the plethora of women in the physics field, and you can admit that they have done some incredible things. Check in with us again to read part 2 of our look at the incredible women who have changed and are changing the world of science.

 

 

Article written by Heather Taylor, Education Support Officer

Heather Taylor, Education Support Officer