An Asymmetry in the Maxwell Equations
  A term in the Maxwell-Ampere law describes a linear displacement current that is symmetrically enclosed by the curl of a magnetic field. In this context symmetry calls for a term in the Faraday-Lenz law, which in the absence of a conducting coil would describe a loop of displacement current about a linear increment of magnetic flux. This term, introduced to satisfy symmetry, predicts a physical phenomenon that has recently been observed. 
Joseph Towe