Failed Theories of Superconductivity

The microscopic theory of superconductivity was developed by John Bardeen, Leon N Cooper and J. Robert Schrieffer. It is among the most beautiful and outstanding achievements of modern scientific research. Almost half a century passed between the initial discovery of superconductivity by Kamerlingh Onnes and the theoretical explanation of the phenomenon. During the intervening years the brightest minds in theoretical physics tried and failed to develop a microscopic understanding of the effect. I will discuss some of those unsuccessful attempts to understand superconductivity. This not only demonstrates the extraordinary achievement made by formulating the BCS theory, but also illustrates that mistakes are a natural and healthy part of scientific discourse, and that inapplicable, even incorrect theories can turn out to be interesting and inspiring.