The Glass Universe: Another barrier for women to shatter

Screen Shot 2018-06-05 at 11.06.34 PMI love the double meaning hiding in the title of this book.  One hundred years ago, before CCD photography, many astronomers collected light on glass photographic plates, some as large as 17 inches by 14 inches.  On those plates the computers at Harvard Observatory captured images of the universe.

At the same time, women were still discriminated against in the sciences.  Some observatories would not allow women guests.   It was in the 1970’s the phrase “the glass ceiling” was first used to describe the sometimes invisible limits placed on women by society.

The subtitle is “How the Ladies of the Harvard Observatory Took the Measure of the Stars.” and Dana Sobel gives us a gentle peek into their work, into their universe.

What did I learn reading The Glass Universe?

In my Astronomy classes, I‘ve emphasized the groundbreaking work by women astronomers. Certainly America was a” Man’s World” one hundred years ago. Even so, both Edward Pickering, the Director of Harvard Observatory  (1877-1919) and the good people he worked with did wonderful groundbreaking and foundation setting astronomy.

Sobel begins at the beginning, recognizing the importance of Alma Palmer Draper and Catherine Wolfe Bruce whose financial support  made many future astronomical insights possible. Let’s remember to celebrate our patrons today. Those generous angels are the ones who share our vision and have the resources to allow us to search the  heavens for the big questions.

The hint of tension over pay inequality is in this book. We can also read about the slowness of Harvard to recognize the great women who worked at the Observatory.

Cecelia Payne was awarded full professorship in 1956, the first woman so recognized at Harvard.


On March 1, 1900, Annie Jump Canon wanted to move Type O stars to the beginning of the list because of the newly discovered helium lines over the hydrogen. She also thought (mistakenly) that the Types may represent the stages of stellar development; that over the life of a star it would change from a Type O to a Type M.

Around 1903 Pickering and Antonia Maury used the spectra of stars to disclose the speed of stars toward or away fro us.

By 1908 Henrietta Leavitt tabulated the periods of thousands of variable stars right along side their magnitudes and the period-luminosity law emerged,

Neither Pickering nor Williamina Fleming meant for the alphabet letters to be permanent as the names of the types of stars.

In 1913 Annie Jump Cannon reinstated Williamina Fleming’s Types R and N stars cooler than M. “Oh, Be A Fine Girl, Kiss Me Right Now!”

When Cecilia Payne, worried about handling the large photographic glass plates asked what she should do if she broke one, Pickering replied that she could keep the pieces.

I warmly remember the 1999 Astronomy Conference in Toronto. It was there I saw in person (though from a distance) Ellen Dorrit Hoffleit (p. 255).

Here are some other, seemingly random thoughts from Sobel’s book:

  • Repeating a procedure a number of times often improves the accuracy of the measurement. Four times seemed to be the number the Director of Harvard Observatory, Edward Pickering, favored.

  • Sir Isaac Newton coined the word “spectrum” in 1666.

  • In 1888 Simon Newcomb the director of the U.S. Nautical Almanac Office wrote: “We are probably nearing the limit of all we can know about astronomy.”

  • Harvard Observatory astronomers dealt with light pollution in 1890’s Cambridge, Massachusetts.

  • Harlow Shapley thought of humans as being incidental, even “peripheral” to the grander cosmic picture.

  • In 1924 Edwin Hubble wrote Shapley about his use of variable stars he found in the Andromeda Nebula.

  • Hubble wore jodhpurs and a cape!


“The hotter the star, the more readily the electrons around its atoms leapt to higher orbits. With enough heat, the outermost electrons broke free, leaving behind positively charged ions with altered spectral signatures.” p. 206

  • Interstellar extinction was once a very controversial topic.

  • In 1929 Henry Norris Russell finally admitted that Cecelia Payne was correct back in 1924: There is a lot of hydrogen and helium in the stars!

  • Pickering was such a gentleman. His strongest oath was “Oh, Polaris!”

  • Reading about the 1932 eclipse was fun, especially after ours last August.

  • Has there ever been a recovery effort for the sunken Robin Goodfellow? It was torpedoed in the South Atlantic with 1,500 photographs from the Southern Hemisphere. Could they have survived?

If you are interested in the history of astronomy, I think this book is for you. If you want a deeper understanding of the relationships at Harvard, this book is for you. If you are interested in stars, this book is for you.

I am a little disappointed at the abrupt end of the story, the collaboration between the Harvard Observatory and the Smithsonian Center for Astrophysics.  There seemed to be something missing, something unsaid.  But if you are interested in astronomy, this book is for you.



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