Guide to Theory C Electromagnetics Computer Simulations


Forrest Bishop, May 27, 2006

All images and animations are Copyright © 2006, Forrest Bishop, All Rights Reserved

View roughly in this order:


LEGEND1.jpg  (May 24, 2006)

   The various characters and conventions used in the computer simulations are introduced.


SWITCHCLOSE.avi  (May 24, 2006)

   A switches closes and reopens. The moving blue or purple box represents an idealized energy current (a TEM pulse) that is released from the battery side while the switch is closed. The vectors E and H represent the electric and magnetic fields of the energy current traveling between the wires.


PULSEGEN.avi  (May 21, 2006)

   Same picture as in SWITCH CLOSE.avi with more details. A TEM pulse is generated when two (or one) switches close and reopen. A ‘battery’ (a cell, that is) composed of only two plates is shown for simplicity.


fieldtest.avi and fieldtest3.avi  (May 23, 2006)

   Are more accurate representations of a slab of energy current moving along two wires at the speed of light. The reddish cylinders represent the electric field between the wires; the blueish cylinders around each wire represent the magnetic fields. The purple boxes of energy current in other simulations are a substitute for these complicated fields.


OPENREFLECTIONb.avi (May 21, 2006)

   A TEM pulse is generated when the two switches close and open. The wires are not connected together at the far end. When the pulse moving along the wires reaches this open end, it reflects back toward the battery. The electric field is oriented the same way (no polarity reversal), and the magnetic field is reversed. The two magnetic fields appear to cancel each other fro a time, as the two electric fields appear to add together. The added electric fields appear to form a static, electric field between the two wires.


REFLECT TWICE.avi  (May 22, 2006)

   Similar picture as OPEN REFLECTION.avi . The reflected pulse finds another open end when it returns to where the switches are, and so reflects again, back to the original form and direction.


fieldtest2c.avi  (May 23, 2006)

   Two TEM pulses moving along the two wires pass through each other, going in opposite directions. This is like the reflection process shown with the moving purple boxes in OPEN REFLECTION.avi and the others.



   Same picture as REFLECT TWICE.avi . Can be set to ~seamlessly “Loop” or “Repeat” in a computer movie player.


REFLECT SHORT.avi  (May 23, 2006)

   The two far (right-hand side) ends of the wires are connected together, forming a short-circuit. When the TEM pulse of energy current reaches the short, it reflects with inversion. The polarity of the electric field reverses for the reflected TEM wave. The magnetic fields then appear to add together to from a static magnetic field. The electric fields appear to disappear at one point.


REFLECT TWO SHORTS.avi  (May 24, 2006)

   Similar to REFLECT SHORT.avi except a different kind of switch is used. As the reflected pulse of energy current approaches the battery, the two open switches are moved to a new position which forms a short between the two wires. The pulse then reflects from this end in the same manner as from the other, shorted end. Illustrates how an apparent ‘electric current’ is maintained in a (superconducting) current loop, along with the apparently static magnetic field.