Crothers, Stephen J.
Mechanics / Electrodynamics
December 7, 2015
In their article  ‘An apparent paradox: Catt’s anomaly’, the Italian authors Pieraccini and Selleri refer to the Catt Question as “Catt’s Anomaly”. Although until 2001 ‘The Catt
Question’ was called ‘The Catt Anomaly’, it was in fact always a question, to be answered.The Catt Question  pertains to the propagation of a Transverse Electromagnitic (TEM) wave along a transmission line. Upon closure of a switch, the TEM wave (step) travels at the speed of light between the conducting wires of the transmission line, from battery to load, as depicted in figure 1. An electric field E appears between the conductors, directed from the top wire to the bottom wire. This electric field is orthogonal to the two parallel wires and moves towards the load; thus there are positive charges on the top conductor and negative charges on the bottom conductor in the region of the
transverse electric field. The Catt Question is: Where does this new charge come from?