As many scientists working long hours for limited pay can tell you, passion for science can be a stronger motivating force than the pursuit of wealth. This week’s WiSE Wednesday honoree, Maria Goeppert-Mayer, worked for years in volunteer positions before becoming the second (and most recent) woman to receive the Nobel Prize in Physics (1963). Born in Germany in 1906, she entered the University of Göttingen intending to study mathematics, but a quantum mechanics seminar by Max Born inspired her to switch her focus to physics. After obtaining her PhD, she followed her husband, physical chemist Joseph Mayer to Johns Hopkins University. Nepotism rules served as justification for denying her a job there, so she continued her research without pay. After a similar situation at Columbia, she volunteered as a part-time professor at the University of Chicago in 1946. While there, she obtained a part-time job at the Argonne National Laboratory – the first time she was paid a salary commensurate with her work. While at Chicago and Argonne, she conducted research on the structure of atomic nuclei. Discovering that elements with specific “magic numbers” of protons and neutrons were more stable than other elements, she came up with the nuclear shell model to describe the position of protons and neutrons in atomic nuclei. In this model, protons and neutrons rotate around each other in a series of onion-like layers. German physicist J. Hans D. Jensen, working independently, came up with the same model and, for this work, the two of them shared the Nobel Prize for Physics, along with Eugene Paul Wigner, in 1963. Maria did not obtain a full Professorship position until 1960, when she became a Professor of Physics at UC San Diego. She passed away from heart failure in 1972, but her story of perseverance continues to inspire.