Long have we read about the prejudices against women in the STEM fields. Most scientists and engineers are men. While women are better represented in the biological sciences, according to the National Girls Collaborative Project, less then 20% of undergraduate degrees in computer science, engineering, and physics go to women.
Women have been a part of scientific inquiry and made significant findings, but they often go unrecognized. Cecilia Payne discovered the composition of stars, though credit was given to her male colleague Henry Norris Russell. Chien Shiung Wu’s experiments disproving the Principle of Conservation of Parity went unrecorded by her male colleagues Chen Ning Yang and Tsung Dao Lee, who later won the Nobel Prize for Wu’s discovery.
Closer to home, Henrietta Swan Leavitt, born in Lancaster, MA, in 1868, made powerhouse contributions to the field of astronomy, but her working conditions and recognition were fitting to her gender. Leavitt began working at the Harvard College Observatory in 1892 for 30 cents an hour with a number of other women under astronomer Edward Pickering. This feminine workforce was casually called “Pickering’s Harem.”
Leavitt worked on surveying and measuring Cepheid variable stars in the Magellanic Cloud. Such stars pulsate and so appear brighter or dimmer according to a cycle of luminance. By 1912, after collecting images of these pulsating stars from observatories around the world, Leavitt proposed that the brightness of these stars related to the time between blinks, or their periodicity. Further, she determined that knowing the distance between earth and the Cepheid variable stars in the Magellanic Cloud would provide a yardstick to measure distances to other stars.
Unfortunately, Leavitt was not in the position to launch such research, but her work and methods became the starting point of Ejnar Hertzsprung’s 1913 study on measuring distances to Cepheid variable stars. Leavitt’s measuring stick showed stargazers that each star was actually the mark of another galaxy. Discoveries based on Leavitt’s luminosityperiod relationship helped other astronomers like Harlow Shapley and Edwin Hubble more accurately measure the limits of our galaxy and eventually establish the galaxy as a structural unit of the universe.
Staring at space brought Leavitt to not only open up a more precise way to measure distance in deep space, she discovered over 2,400 stars in the process. Celebrating the shining achievements, discoveries and innovations of women in the sciences should not be the exception anymore.
