James Weatherall (University of California, Irvine)
I will connect recent discussions of the (in)equivalence of different formulations of electromagnetism in philosophy of science with the large literature in physics on "electromagnetic duality", a special case of "S duality". I will argue that the electromagnetic duality indicates a sense in which the mathematical formalism of electromagnetism may be understood to be (non-trivially) equivalent to itself, by the lights of the criteria philosophers have introduced. But I will also argue that this simple example shows that a condition philosophers of science have taken to be necessary for theoretical equivalence is not realized by (all) dualities in physics.
