The Glass Universe – Gripping tale of how the dream of a woman to map the sky came true!

“She had barely heeded the stars before she met Henry, any more than she regarded grains of sand at the shore. He was the one who pointed out their subtle colors and differences in brightness, even as he whispered his dream of abjuring medicine for astronomy.” Anna Palmer Draper (1839-1914) could have easily married someone after her husband Henry Draper’s death at an early age of 45. She had inherited a huge amount of wealth from her father. Henry was a medical doctor and had his own funds. Working together, the couple had set up their private observatory at Hastings-on-Hudson. Most of us would love to have wealth however, very few of us would know what to do with it! Anna Draper had wealth and property in the form of houses from both her parents and husband’s side, laboratories and a full-fledged observatory with photographic equipment. Sadly, she lost her love after 15 years of togetherness. In these years she had learnt to use the equipment in the observatory. However, the dream that Henry and Anna had was big… They wanted to solve the puzzle of the chemical composition of stars. Now that was her dream. How was she going to fulfill it alone? In those days, women just had started going to college and some of them took great interest in Science and Mathematics. A few would go for higher studies. Computers as we know of now were non-existent. There were no electronic calculators. The work of computers and calculators was done by these smart ladies whose position was titled as a "computer". The Glass Universe is a detailed story of the hard work of women "computers" at Harvard College Observatory which houses over 500,000 astronomical plates taken between the mid-1880s and 1989 (with a gap from 1953–68). Eminent Science writer Dava Sobel has written this marvelous book that keeps you engaged through the detailed, long 300 + pages narrative. 

Newton declared in the 17th century that white sun light is made of seven colours. Who knew that a couple centuries later, the same mechanism could be used to study millions of stars? This is exactly what was happening in the 19th century. Kirchoff formulated the laws of spectroscopy in 1850 s and observational astronomy changed completely. High resolution prisms and photographic plates could be used to record spectra of hundreds of stars. The stars were not just tiny dots on the print anymore- the photographic plates were treasures of data which needed trained, devoted pairs of eyes and analytical brains. 

Harvard College Observatory was headed by Edward Charles Pickering from 1877 to 1919. A very long period which included the World War I. The demand for computer positions at Harvard was very high and even the qualified women with college degrees would want to work there for free so that they could improve their resume! Pickering’s computers were fondly referred as “Pickering’s Harem” in those days. Mrs. Williamina Fleming, Antonia Maury, Henrietta Swan Leavitt, Annie Jump Cannon, Cecilia Payne to name a few! Each one of these computers has a long story and one can surely write a separate biography on each one! Of these, Henrietta Leavitt is famous for her calculation on Cepheid variables which proved extremely valuable in estimation of distances to distant galaxies. Apart from her, I would like to mention three particular ladies who touched my soul- Mrs. Williamina Fleming, Annie Jump Cannon and Cecilia Payne. 

Williamina Fleming had no familial or collegiate connection to the observatory. She was hired as a maid by Pickering. Although she had some teaching experience back home in Scotland, in America she was forced to work as a housemaid. After her husband’s disappearance while she was pregnant, Pickering found out that she had good analytical skills. However, she went back to Scotland for delivery and returned after a year. She left her son (named after Edward Charles Pickering!) with her mother and grandmother and came back to work at Harvard. Later on, she was given the title of “Curator of astronomical photographs” on Pickering’s request. It was the first title given to any woman at an educational institute! Mrs. Fleming’s work was very monotonous…rather all of the computers were doing a tedious, monotonous work…they had to look at the glass plates, analyze the spectral lines, annotate the spectra and document them in a log book. They did that entire day and sometimes took some work home too or perhaps returned to work after supper. What is remarkable is that with the meagre earnings, living with a frugal lifestyle Mrs. Fleming managed to send her son to MIT! It must have been expensive even in those days! The book not only tells the story of computers but it portrays 19th century and early 20th century American life in a wonderful way. 

In contrast with Mrs. Fleming, Annie Jump Cannon had studied Physics and Astronomy at Wellesley College. She had lost hearing due to scarlet fever and had very little social life. She never married or had any children. Annie was introduced to stars and constellations by her dear mother. After mother’s death, she immersed herself in work at the observatory. In four decades, she classified around 350,000 stars. Any beginner astronomy student knows about the classification system mnemonic- “Oh Be A Fine Girl Kiss Me Right Now”! However, when you look at the spectra, it is not easy to tell one from the other. Ms. Cannon was the master brain behind the classic classification system of stars. In her own words- “It was as if the distant stars had acquired speech and were able to tell the constitution and physical condition!”

Cecilia Payne – the British- American astronomer who arrived in Cambridge from England in 1923 at a tender age of 23. At the observatory, Annie Jump Cannon and Antonia Maury became “mother hens” to her while her English mother worried about her over-enthusiastic child. Back home, once she had heard Eddington’s talk and she was so impressed by it that she did not sleep for three nights. She was equally impressed by Director Harlow Shapley’s talk about structure of our galaxy. She accurately connected the spectral classes to stellar temperatures by using Meghnad Saha’s theory of stellar atmospheres and was the first person to complete Ph.D. in Astronomy from Radcliffe College. The book narrates the exciting story of her affair with Russian astronomer, Sergei Gaposchkin in 1930s, how she managed to get him to the USA and how they lived happily ever after!

The research would not have gone ahead without Mrs. Draper’s lifelong support. It was her dream to come up with a catalogue of stars and several women computers worked to fulfill it. Did “Pickering’s Harem” live up to her expectations? Although, there are separate biographies of some of the computers and plenty of information about their work on the internet, this is a first thorough book about the complete history of Harvard College Observatory which can be enjoyed by a layman. Dava Sobel has put in a great amount of effort in going through the diaries and documents of several people associated with the observatory. She has a knack of weaving personal matters with scientific details which makes the book very interesting!