sci.physics.electromag

On 21 mar, 14:49, "Szczepan Bialek" wrote:
>
>
>
>
> > > Electrons must be. Hydraulic analogy is useless (except teaching).
> > > S*
>
> > In context, it is not useless, but in this model, it is a reflexion
> > of physical reality as far as the substance that "energy" is made
> > of, whatever it may be.
>
> Physical reality in the wire is grad of the electron density (if current
> flow).

True. Physical reality also is the elementary particles that make
up each atom in the wire. It is that level that I am observing.

> By the way. I do not know if the electron beam in a vacum tube create a
> magnetic field

Absolutely. A magnetic field whose density depends on the electrons
velocity and on the number of electrons involved.

> and if such vacum has resistance. I try to find but without
> succes.
> S*

There is a defined value, that has however never been
measured.

Look for impedence of vacuum.

Rated at 376.7303137 Ohms

obtainable from sqrt(mu0/eps0)
or from

(2 alpha h)/e^2

alpha is fine structure constant
h is Planck's constant
e is unit charge

I personally think that vacuum offers no
resistance to the passage of electrons nor
of any other particles.

Andr=E9 Michaud