Why Meissner Was Wrong (or a Classical Explanation of Flux Expulsion from Superconductors)

Abstract

The discovery by Meissner and Ochsenfeld in 1933 that the magnetic field inside a conductor is expelled when it is cooled down to become superconducting was considered very surprising at the time. Meissner wrote that this has no classical explanation. Since then virtually every textbook stresses that this means that a superconductor is in fact not just a zero resistivity perfect conductor but in addition has the mysterious property that it can expel internal magnetic flux. In this colloquium I will present evidence that this is all a misunderstanding based on insufficient knowledge of what classical physics in fact predicts about the magnetic flux inside perfect conductors.