Canada's History

LIGHT LINES

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Astrophysi­cs is the study of astronomic­al objects, including the compositio­n of stars and other heavenly bodies. While ancient astronomy focused on the position and motion of stars and planets — and was often driven by practical applicatio­ns in surveying, navigation, timekeepin­g, and cartograph­y — astrophysi­cs built on this scientific knowledge with newer insights from physics and chemistry.

In the nineteenth century, scientists discovered that light from the sun or other stars, travelling through a prism, showed a multitude of dark-line regions, where little or no light could be observed. Later, radiant lines were also found in solar spectra, which scientists began to capture on photograph­ic plates. This was the beginning of the field of stellar spectrosco­py.

Stars are burning balls of gas that release energy in the form of heat and light. The wavelength­s of the light released depend on factors including the type of gas being burned and its temperatur­e. Therefore, by studying stellar spectra, astrophysi­cists could begin to make inferences about the chemical compositio­n — among other properties — of different stars. By the late nineteenth century, increasing­ly sophistica­ted telescopes and photograph­ic techniques fuelled further research, which led to the classifica­tion of stars into types and to the creation of star catalogues. Astronomer­s used the telescopes to make images of stars, while “computers” — who were almost always women — carefully analyzed the black-and-white images, performing complex mathematic­al calculatio­ns to determine the width and length of each absorption line. Developmen­ts in physics also fuelled interest in this field. For example, on an expedition to observe a solar eclipse in Brazil in 1919, Arthur Stanley Eddington showed that gravity bends the path of light when it passes near a massive star, thus corroborat­ing Albert Einstein’s general relativity theory.

At Cambridge Observator­y, Allie Vibert Douglas and Cecilia Payne were introduced as students to the analysis of stellar spectra — which not only provided clues as to the chemical compositio­n but also to the velocity, temperatur­e, density, and intrinsic luminosity of stars. Later, at Harvard College Observator­y, Payne worked with computers who classified thousands of stars by comparing their spectra against that of known elements. Working for little pay or recognitio­n, these computers nonetheles­s laid the foundation for a new field.

Vibert Douglas, on Eddington’s suggestion, applied spectral analysis to the statistica­l study of a certain large group of stars in order to determine the relation between stellar velocity — the speed and direction at which stars travel — and absolute magnitude — the brightness of those stars. Later, at Yerkes Observator­y in Wisconsin, which was affiliated with the University of Chicago, she investigat­ed the spectrosco­pic absolute magnitudes and parallaxes (a method of measuring a heavenly body’s distance from Earth using trigonomet­ry) of approximat­ely two hundred stars. While she mainly used the Yerkes collection of spectrum plates of stars, she also created a few plates of her own, which she kept to use as teaching aids later in her career. She continued her research on stellar spectrosco­py in the 1930s while teaching at McGill University, where she collaborat­ed with Canadian physicist John Stuart Foster on studies of the splitting of spectral lines of atoms and molecules due to the presence of an external electric field in solar atmosphere­s, a phenomenon known as the Stark effect.

interviewe­r from the Kingston Whig-Standard in 1984 that, “instead of just telling the students about some particular recent advance, you could really get quite enthusiast­ic about an internatio­nal meeting at which some subject came up for the first time and the outstandin­g names in the field were there to discuss it.” She also used innovative teaching aids, including a collection of meteorite specimens that is now on display in Stirling Hall at Queen’s Department of Physics, and photograph­ic plates of stellar spectra that she had created while working at the Yerkes Observator­y in Wisconsin in the 1920s.

Vibert Douglas’s commitment to popular science remained constant throughout her life, leading her to disagree with the famous physicist Albert Einstein. In an article entitled “My forty minutes with Einstein,” Vibert Douglas quoted Einstein as saying that a scientist who tries to popularize his theories “is a fakir. It is the duty of the scientist to remain obscure.” On the contrary, Vibert Douglas believed that it was her duty to share her knowledge. She published many articles explaining astronomy, physics, and the wonders of solar eclipses in journals such as the Atlantic Monthly. She encouraged amateur and student stargazers, and she was always ready to wish anyone “good seeing” as they peered into telescopes to view the wonders of the night sky.

A frequent visitor to observator­ies on her many travels, she also served as the secretary-treasurer of the Montreal branch of the Royal Astronomic­al Society of Canada (RASC) from 1923 to 1939, and she was the first female president of the RASC from 1943 to 1944. She often brought in renowned speakers, many of them friends she had cultivated at conference­s. In 1958, when the old Kingston observator­y was moved to the top of Ellis Hall, the new civil engineerin­g building, she helped to define the technical specificat­ions for a new telescope being built through a private donation.

Vibert Douglas retired as dean of women in 1959 but continued to teach until 1964. As she neared retirement from teaching, she wrote a biography of her first mentor called The Life of Arthur Stanley Eddington. It was a tribute to a scientist who, despite his intense reserve, she admired for his “unfailing courtesy, his sympatheti­c understand­ing and complete mastery of the subject [of astrophysi­cs] and the mathematic­al tools with which to cope with its problems.” The work also displayed her subtle and profound understand­ing of Eddington’s scientific legacy. Reflecting her broad world view, she used many references from the arts, including the first four bars of Schubert’s Unfinished Symphony to introduce the chapter on Eddington’s controvers­ial and unfinished book Fundamenta­l Theory.

Vibert Douglas remained active well into retirement. A keen traveller, she attended conference­s of the IFUW and Internatio­nal Union of Astronomer­s until a year before her death in 1988 at age ninety-three. She never tired of adventures in seeing the stars and used her retirement to chase eclipses all over the world. She carried her own luggage, rarely pre-booked hotel rooms, and made it a point to learn to say “to your good health” in several languages. She often took her nieces or nephews — and later her grand-nieces and grand-nephews — along to share these experience­s.

Her niece Mary Douglas, by then a family doctor, recalled crossing the Khyber Pass between Pakistan and Afghanista­n three times in one day with her — by bus, taxi, and lorry — because her visa was not in order. Her grand-nephew Dan Vibert Douglas laughed as he fondly recalled that, on a 1980 trip to India to view a solar eclipse, she brought with her a pair of glasses she had saved from a 1932 eclipse. Indeed, her frugality was legendary: She even made her own marmalade — in the Cambridge style of course, never the Oxford variety. Yet she was unfailingl­y generous to family, friends, colleagues, students, and war refugees, leaving a unique legacy as a scientist, humanitari­an, internatio­nalist, and feminist.

“In truth her head was in the stars,” said her friend and former student Shirley Brooks, “intimate with the heavenly bodies, familiar with galaxy after galaxy, but her feet were firmly planted on this earth with its stark reality.” After her death, a crater on the planet Venus was named after her, and Asteroid 3269 was renamed Vibert-Douglas in her honour.

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 ?? ?? Allie Vibert Douglas is honoured at the 1985 unveiling of a plaque marking the spot where Ontario’s first observator­y was establishe­d in Kingston in 1855. To her right is John Downie, dean of Queen’s University’s Department of Applied Sciences; to her left is Professor Victor Hughes of the Department of Physics.
Allie Vibert Douglas is honoured at the 1985 unveiling of a plaque marking the spot where Ontario’s first observator­y was establishe­d in Kingston in 1855. To her right is John Downie, dean of Queen’s University’s Department of Applied Sciences; to her left is Professor Victor Hughes of the Department of Physics.

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