----- Original Message -----

From: Ivor Catt

To: Darren ; info@educause.edu

Sent: Friday, March 19, 2010 6:36 PM

Subject: Paper by J. Edwards


To Peter Edwards,


Perhaps I should explain why Peter Edwards' ""Capacitors can be considered to be transverse electromagnetic (TEM) transmission lines .... " is radically different from a statement "Capacitors are transverse electromagnetic (TEM) transmission lines". Publishing the second statement, which Edwards would be unable to publish because of 100% rejection by journal referees, would lead to excommunication. This is because the way classical electromagnetic theory treats a transmission line contradicts the way classical theory treats the capacitor. If energy enters a capacitor sideways, there would be no need for Maxwell's "Leap of Genius" in proposing Displacement Current. In fact, since under classical theory electric current flows along the conductor(s), extra electric current represented by Displacement Current would contradict Kirchhoff's First Law, about continuity of electric current.



"At Trinity High Table a year or two ago, I told May Chiao, deputy editor of "Nature Physics", that if she published an article which contained the information; "A capacitor is a transmission line," that would be the end of her editorial career - certainly if the article also mentioned Displacement Current. I told her she could hosever publish "A transmission line is a capacitor." Five minutes later she said; "But a transmission line is a capacitor!"

The May Chiao experience has to be considered alongside the statement by Nobel Prizewinner Josephson, above; " .... it is unfortunate if a paper pointing this out was not accepted for
publication anywhere other than Wireless World" - Brian Josephson, 28sept08..


Peter Edwards confuses the matter by talking a great deal about Displacement Current, and he talks of its presence in a transmission line. What I said above involves not taking note of the approach in the Peter Edwards paper http://www.itee.uq.edu.au/~aupec/aupec04/papers/PaperID84.pdf . My framework is the assumptuion that Maxwell had the leap of genius when he proposed Displacement Current to deal with an anomaly at the capacitor for Ampere's Rule http://en.wikipedia.org/wiki/Amp%C3%A8re's_circuital_law . Heaviside thought this was why Maxwell invented Displacement Current. Maxwell and Faraday did not notice that a capacitor is a transmission line, so they could not see the problem of the contradiction between their treatment of the two. I pointed it out in 1978, but I have been ignored. http://www.ivorcatt.co.uk/x0357.htm .



See http://www.itee.uq.edu.au/~aupec/aupec04/papers/PaperID84.pdf by Peter Edwards;

"The E field is across the plates and enters the

system at the terminal end of the capacitor plates. Any

change (DE) in the electric field E produces a

displacement current (ID = DE/Zo), where Zo is the

characteristic impedance (also known as the field

impedance, Zf) of the space between the plates [2].

{What about the magnetic field in the forward direction caused by the displacement current? This of course undermines the idea of a TEM Wave, where all electric and magnetic field is sideways to the direction of propagation. " .... capacitor current produces .... ", see below, refers to the electric current in the capacitor plates. That produces a sideways magnetic field, so the idea of TEM is not undermined. Not so with the vertical Displacement Current, which produces a forward magnetic field, contradicting the TEM idea. This Displacement Current must produce magnetic field, because Maxwell invented it in order to produce magnetic field - but in a capacitor, not a transmission line. The only purpose for Displacement Current is to produce magnetic field. Ivor Catt 19th March 2010.]

Any capacitor current produces a magnetic field H that

exists mainly in the space between the plates, and is

parallel to them as indicated in Fig 1(b). Thus E and H

fields direct power into the space between the

capacitor plates via the Poynting vector P=EH as .... "

indicated in Fig 1(a).

[Also http://www.itee.uq.edu.au/~aupec/aupec04/papers/PaperID85.pdf ]


Another suggestion that a capacitor could be regarded as a transmission line. http://www.electromagnetism.demon.co.uk/ub07mgib.htm