Tuesday, September 04, 2007

A passion for understanding

In 1934, the noted astronomer Annie Jump Cannon returned to her alma mater, Wellesley College, to speak to her 50th class reunion. She told this story:

"During our senior year, one of the distinguished guests was Matthew Arnold, who gave his lecture on Emerson, characterized as the friend and lover of those who live in the spirit. When Mr. Arnold was being driven up through the College grounds, he exclaimed, 'Extraordinary, extraordinary. All for young ladies.' Then, putting his monocle on for a close survey, he asked, 'But what are their chances?'" His question was particularly applicable to young Wellesley women who wished to pursue careers in science.

Annie Cannon made remarkable contributions to astronomy at a time when women were generally thought incapable of serious scientific work. Her love affair with the stars began with a makeshift observatory in the attic of her family's home in Delaware. After study at Wellesley and Radcliffe, in 1897 she joined the staff of the Harvard College Observatory as a protege of Director Edward Pickering.

But not, of course, as an astronomer with academic rank. Cannon was one of "Pickering's harem," a group of women who received twenty-five to thirty-five cents an hour to analyze and catalogue the voluminous stellar data accumulated by male astronomers at telescopes.

Cannon's immediate predecessor, Antonia Maury, had proven unsatisfactory to Pickering because her "passion for understanding" was thought to impede her efficiency for drudge work. Annie Cannon was less offensive to Pickering, but no less talented. Both women made important contributions to the understanding of stellar spectra (the colors in starlight).

In the early decades of the 20th century, Cannon personally classified the spectra of more than 300,000 stars. Every astronomy student today learns by rote the OBAFGKM classification scheme of stellar spectra that Cannon invented ("Oh, be a fine girl, kiss me," is the mnemonic used by generations of mostly male students to remember the sequence of letters). Her work is a pillar upon which rests our knowledge of stars.

Cannon was made an honorary member of the Royal Astronomical Society in 1914, the first woman admitted to that body, and received honorary degrees from institutions here and abroad. But it was not until 1938, when Annie Cannon was 74, that Harvard University granted her academic status by naming her professor of astronomy.

"But what are their chances?" asked Arnold. Even now, more than a century later, the answer to his question (for aspiring women scientists) has to be "better, much better, but still not equal to a man's."