Re: Theory acceptance- Displacement current?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>



> A few years ago Terry tried very hard to design a machine to detect and 
> measure "displacement current".  Spent quite some time and band width on 
> it.  But, no success.  Then Paul N whispered in his ear, "It can't be 
> done."  Terry immediately abandoned his project.

Gosh! What do you mean you can't measure displacement current ::) Try 
wrapping a plasma globe in tinfoil, then drawing an arc off it with your 
finger. Then tell me you didn't feel anything!

There was no conductive path for that current to flow through since the tin 
foil was separated from the plasma by a piece of glass. Any current that 
did flow therefore must have been displacement current.

Displacement current is a mathematical fiction, if you like, as much as 
"centrifugal" force is. It is a handy way of accounting for the effect that 
when one charged body moves, every other charged body nearby feels a force. 
When you pile electrons onto one plate of a capacitor, the electrons on the 
other plate get shoved off it by electrostatic repulsion. That stream of 
electrons rushing out the back door, to get away from the ones you crammed 
in the front door, is what we call displacement current.

Asking whether displacement current exists in its own right, in a region of 
space that contains no charged particles, is a bit like asking if that tree 
falling in the forest really did make a noise. The only thing that really 
exists in EM is charged particles and the forces they exert on each other. 
All the rest is just structures that we build in our heads to help us 
visualise the forces.


Steve Conner