Lucy Mensing: Forgotten Pioneer of Quantum Mechanics

In 1925 a young postdoc, Lucy Mensing, came to Göttingen to do research with the new matrix mechanics, which had just been formulated. In the following years she did groundbreaking work. She successfully made the first application of the new theory to diatomic molecules. As a by-product of this work, she was the first who found that, even though in general both integer and half-integer values are allowed for angular momentum, orbital angular momentum always takes on integer values. Impressed by her clear and masterful treatment of the problem, Pauli invited her to work with him on the polarizability of gases. After that, she worked in Tübingen. In this talk I will sketch Mensing's pioneering work and give a brief account of her life. I will also discuss why she gave up her career, which ended in 1930 after she married and started a family.