Letter to officials

 

 

 

..

Commentary on electromagnetic theory

Ivor Catt 28 March 2006

Some further comment on electromagnetism by me is called for. It is about the nature of the TEM Wave. I have now realised that worldwide there exists minimal grasp of the TEM wave by today's professors and text book writers.

I used to look back on the allegedly halcyon days of the past when text books made a real effort to address such fundamentals as Displacement Current and the TEM Wave. However, recent revisiting of old books has shown me that the halcyon past was not very halcyon, although better than those of today's abysmal text books. Very little attention was paid to these fundamentals at any time. I garnered just enough from a number of books, such as Schelkunoff, Carter, Kip, to put together what I needed to successfully interconnect high speed ( 1 nsec ) logic gates. Few people would have been so motivated at that time. I had to get it right, or leave Motorola and leave town. With wife and children, this would have been expensive.

In 1964, a combination of text books and the best equipment [Tektronix 661 sampling oscilloscope with 4S1 (350psec) and 4S2 (100psec) plug-ins; E-H 125 (10v, 150psec) pulse generator] gave me what I needed to grasp the whole picture. Very few or even no other people had the equipment and motivation.

The primary building block in electromagnetic theory is the TEM Wave. This travels at the fixed speed of light, 300,000, and has two lateral dimensions, E and H. The ratio of E to H is fixed.at 377. These assertions are fact, since they are directly measured.

This paragraph is more speculative, and is not mandatory. The speed of a TEM Wave appears to drop to a new fixed value if it travels through another medium. However, my theoretical position is that this is an illusion, and the only change in another medium than vacuum is that a TEM Waves follows an eccentric path instead of the straight path is pursues in vacuo. Its speed remains 300,000.

Now we turn to the capacitor made of two concentric conducting spheres . Such a charged capacitor exists, and will follow the style of the Contrapuntal, or Catt, model for a charged capacitor, described in "The Pulse" . If this model is correct, then the spherical capacitor has to follow from the same model.

Now we increase the radius of the outer sphere to infinity. The capacitance does not decrease to zero, but reaches a finite final value. Thus, if we accept the Catt model for a charged capacitor, we have to accept the capacitor made up of a single conductor. This approaches the idea of a particle, but there are difficulties.

 

Forrest on Displacement Current

Addendum to Forrest;.

Partial reflection in a transmission line

Under this title, there is the statement; "Consideration of conservation of energy and also that the voltage across the discontinuity must be continuous lead us to the same formula for the reflection coefficient." Given the abysmal lack of knowledge and grasp of the transmission line and the TEM Wave, worse than I thought in 1995 when I published this statement, I should have also said; "Consideration of continuity of electric current ...."

That is, the "Reflection Coefficient" used by electrical engineers to deal with a change in the characteristic impedance of a trnasmission line is designed to ensure that the current continuing forward east of the discontinuity is equal to the incident current from the west. The very formula assumes that the dD/dt across the wave front has nothing to do with the need to observe Kirchhoff's First Law in continuity of (real) electric current.

This is why it is necessary for nobody to notice that a capacitor is a transmission line, and it will be impossible to publish or teach this fact. When a transmission line feeds into a capacitor, it is merely entering a further stretch of transmission line with different (very low) characteristic impedance. What does "Displacement Current" do for us? It gets us to think we "obey" Kirchhoff's First Law when we have not noticed the electric current exiting from the critical point of entry into the capacitor plate; the current which then travels very slowly along the face of the capacitor plate.

Note that I told May Chaio of "Nature Physics" that if she published an article which pointed out that a capacitor was a transmission line, her career as a journal editor would end; certainly if the article also mentioned "Displacement Current". See "The Diagonal"

Ivor Catt 22 April 2006.

Also Forrest

 

.

.

Homepage | Electromagnetism1 | Old Website