In recognition of Women's month (and thank you Professor Richardson for your wonderful piece on RBG [1]) I thought it would be appropriate to depart from my usual topics and write about a selection of women who in my view were unfairly denied the recognition they deserved, primarily based on their gender.
It may be arbitrary to have favorites, but I have one, and her name was Emmy Noether. Unless you happen to be a physicist, her name is probably unknown to you, and it may be even if you are. Here's how bad it is. When I made my first foray into graduate school, in the mid '60s, her famous theorem was not even mentioned in the almost standard graduate level textbook on classical mechanics, by Herbert Goldstein, published in 1950. [2] Fortunately for me, in my second attempt in grad school, in the '70s, we used the classical mechanics text of Saletan and Cromer [3], which treats Noether's theorem in chapter 3 (of 9). Eternal gratitude to you, Dr. Zuchelli!
So what is Noether's Theorem, anyway, and why is it so important? Emmy Noether was able to prove that there exists a connection between symmetry and conserved quantities. Most of us are surely aware that the universe looks the same no matter where we are located; that's Einstein's principle of equivalence. But that principle implies, via Noether's theorem, that there is a physical quantity (in this case, linear momentum) that does not change under a linear spatial displacement The theorem, in other words, tells us that we can use symmetry principles to discover conserved quantities, and vice versa. So, for example, conservation of angular momentum leads to invariance under rotation. A powerful tool in theoretical physics, leading to deep insights!
Perhaps the most widely known omission of a woman in a physics Nobel prize award was that of Lise Meitner, who along with Otto Hahn predicted the phenomenon of nuclear fission. Hahn received the chemistry award, strangely enough, in 1944. That Meitner never received a Nobel prize was certainly not due to lack of effort by the community: She was nominated 49 times [4]. It is obviously unnecessary to explain the importance of her work.
Jocelyn Bell was a graduate student who worked under the tutelage of Antony Hewish in the field of radio astronomy. She was involved in the process of (literally) building the radio telescope which she and her advisor constructed for the purpose of studying quasars, and it was she who discovered the first two pulsars, a previously unknown and unpredicted entity. She worked alongside Hewish, dissuaded him of the notions that the signals were man-made or due to communications between extraterrestrials, and was co-author of the papers they published. Yet it was Hewish alone who received the Nobel prize for physics in 1974. [5]
Vera Rubin and Henrietta Swan Leavitt are a little different than the foregoing three women, in that nobody won a Nobel prize in their place. I think, however that it is more an indication of bias on the part of the Nobel committee against astrophysics as well as against women, than for the lack of importance of the work they did. Allow me to make my case.
As late as the 1920s, it was thought that our own galaxy, the Milky Way, was the whole universe. The reason for that parochial view had to do with more than anthropocentrism: there were no earth-based methods available to reliably measure distances of more than about 100 light years. Working for Edwin Hubble, Henrietta Swan Leavitt changed all that, enabling the cosmic distance scale to be expanded by a factor of 100,000, and completely demolishing the notion of our centrality in the universe. She did it by discovering that there is a relationship between the luminosity (brightness) and period of luminosity fluctuation in a class of variable stars called Cepheids, and by discovering and measuring the periods and luminosities of such stars in the so-called Andromeda Nebula, (M31 in the Messier catalog, and now recognized as a galaxy, like the Milky Way.) Hubble took the credit for her work, and is recognized even today as a founder of extragalactic astronomy. He tied Leavitt's discovery that M31 lies outside our galaxy to Vesto Slipher's earlier discovery of red shifts in the spectra of like objects and thereby first elucidated empirical evidence supporting the concept of an expanding universe.
Evidence for one of the most important mysteries in all of physics and astronomy was discovered by Vera Rubin: that of Dark Matter, a term that refers to the material that must be present to explain, for example, the rotational profiles of galaxies, but which does not interact with ordinary matter except gravitationally, to the best of our current knowledge. This is not a minor effect, but rather the dominant term in the mass balance of matter in the universe, accounting for around 85% of the total. Rubin and her co-worker Kent Ford made spectroscopic measurements of the velocities of stars in the spiral arms of galaxies. [6] If the galactic mass was concentrated mostly in the bright central bulge of the galaxy, the rotational velocities of the stars should decrease with increasing distance to the galactic center, in a manner similar to those of planets in the solar system. But the measurements did not yield the expected distance-velocity relationship, and can only be explained by a much larger, less centralized mass distribution. That this is not a purely local phenomenon, explainable perhaps by an extended galactic halo of neutral gas, is supported by the necessity for, and evidence of, dark matter at cosmological scales. [7]
I am quite sure that were I to research the topic of unrecognized women scientists more extensively the meager list presented here would grow considerably. It is gratifying to see that the American Physical Society, of which I am a member, has taken a proactive stance in recognizing the role of women in physics, and is making efforts to expand our community to include more females and people of color. By recognizing those whose contributions have been denigrated or ignored, we provide examples and role models for future generations.
PS: Why hasn't Greta Thunberg been given the Nobel Peace Prize? Same reason, I suspect: Misogyny lives on.
Notes
[1]
[2] When Goldstein got around to a second edition, in 1980, he had apparently learned that a connection exists between classical- and quantum mechanics, so he and his co-author tacked on a brief section on Noether's Theorem in the 12th and final chapter of his book. In the third edition, it is literally the final topic in the book, at the end of the 13th chapter. You know as well as I that nobody ever covers an entire 650+ page physics text in a one semester course. Goldstein certainly was not alone. There is no mention of Noether's theorem in the Landau & Lifshitz book, Mechanics, either.
[3] Saletan, E.J. and A. H. Cromer, Theoretical Mechanics. Wiley, 1971. ISBN 0-471-74986-9, pp. 83-86
[4] https://en.wikipedia.org/wiki/Lise_Meitner
[5] https://www.aps.org/publications/apsnews/200602/history.cfm Later she received a special Breakthrough Prize: https://www.npr.org/2018/09/06/645257118/in-1974-they-gave-the-nobel-to-her-supervisor-now-shes-won-a-3-million-prize
[6] https://pubs.aip.org/physicstoday/Online/4557/Vera-Rubin
[7] I am trying to stay nontechnical to the maximum possible degree so I will just say that in cosmology there is a very important parameter called Ω, the energy density of the universe, that comes from the Friedmann equation, and that very much effort is being expended determining both its value and the values of its components. As of the moment, its value is thought to be very close to or equal to unity. Of its components, the matter density in the present epoch is about 0.31 and of that the baryon density, that is, the density of ordinary matter, is around 0.045. The remainder, 0.31 - 0.045 = 0.265, is dark matter. By the way, what about the other 0.69? It's called dark energy. Let's not get into that! If you are interested in exploring this further, Dr. George Djorgovski's Caltech course on the evolving universe can be found here: https://www.coursera.org/learn/evolvinguniverse