"Jim Kelley" bravely wrote to "All" (29 Nov 05 14:46:41)
--- on the heady topic of " Antenna reception theory"

JK From: Jim Kelley
JK Xref: core-easynews rec.radio.amateur.antenna:220573

JK "Asimov" wrote:

A static E field can exist alone but to detect it requires something
like a field-mill

JK It's similar in some ways to a method for detecting magnetic fields
JK used prior to the advent of Hall effect devices. Not sure how it
JK relates to relativity.

I think a saturable core can be used to measure a static magnetic
field. Early computer magnetic core memories worked like this.

Relativity transforms static fields into dynamic fields by adding a
velocity component to the measurement.


JK Perhaps it's true that an electric field is simpler create than to
JK detect by direct means. But it isn't really any more difficult than,
JK for example, measuring power by direct means. I think Ben Franklin
JK measured the E field in a Leyden Jar by calibrating the leaf
JK displacement caused by the Coulomb force resulting from the electric
JK field between the two similarly charged surfaces.

That Leyden Jar experiment was measuring charges not the E field
itself. An E field doesn't require the exchange of charges.
I wonder if it is possible to directly measure an E field by the
effect of the virtual quanta in its close vicinity?

A*s*i*m*o*v

.... Quoting one is plagiarism. Quoting many is research.