At 6:48 PM 5/10/97, Robert Stirniman wrote:
Horace Heffner wrote:
Sorry, you can't do that without a monopole handy. The sum of
flux out of
any closed surface is exactly equal to the sum of of the flux
into that
closed surface, the net flux is zero. Another way to say this is
B dot dS
= 0. This is equivalent in all respects to saying that each line of
magnetic flux is a closed loop at all times.
Horace. You've seen an article about the recent experiments
by Mikhailov, repeating the experiments of Ehrenhaft.
Magnetic charge is no a fantasy.
Unfortunately, neither are the Maxwellian thought police.
A weber a coulomb. What else do we need?
Regards,
Robert Stirniman
Maybe we need an ehrenhaft? Uh oh! I better hide. I thought the
Maxwellian
Thought Police were imaginary!
I think B dot dS = 0 is totally equivalent to the statement there
is no
monopole. Ignoring the question of whether this Maxwell's equation is
indeed a law -- if it is a law, it is equivalent to the statement that
there are no free monopoles.
All this is a consequence of the postulates (assumptions) of Maxwell's
laws, which of course would need to be revised in the face of the
discovery
of a monopole. The existence or not of such a particle is a fact of
nature
while the rest are assumptions.
It is interresting that monompoles could only exist in pairs and be
consistent with B dot dS = 0 if they at all times occupied exacly
the *same
point* in space. Otherwise, you could always have a way to place the
envelope S around one and exclude the other. However, this being
the case
that they are always co-centered, they would therefore then always
represent a scalar field, unless acted upon by a charged particle
or EM
field in the viciniy.
In regard to the above issues, Robert Stirniman brought to my
attention
some time ago "Advanced Electromagnetism Foundations, Theories and
Applications", edited by Terrence W. Barrett and Dale M. Grimes, World
Scientific Publishing, 1995. Of particular interest is the article
"Six
experiments with Magnetic Charge", V.F. Mikhailov, p. 593 ff., which
discusses a modern look at the work of Felix Eherenhaft (1879-1952).
Eherenhaft performed the magnetic equivalence of a Millikan's oil drop
experiment in the hopes of isolating magnetic monopoles and measuring
magnetic charge. Surprisingly, Eherenhaft had positive results,
obtaining
a value for magnetic charge in the range of 10^-9 to 10^-14
Gauss*cm^2.
Because this did not agree with Dirac's theorized value of 3.29x10^-8
gauss*cm^2, interest waned in Ehrenhafts work.
Mikhailov created 10^-5 to 10^-6 cm dia. ferromagnetic aerosols by
electrospark sputtering. This was accomplished by use of current
interrupter iron contacts in argon at one atmosphere. Helmholtz coils
provided a uniform magnetic field. The falling aerosol was placed
in an
intense light beam and viewed with a microscope. The initial
experiment
showed a roughly equal number of both N and S monopoles. Switching
the
field of the Helmholz coils reversed the lateral motion of the
magnetically
charged particles. It was noted that increasing *either* magnetic
field
intensity or light intensity increased the lateral rate of travel.
Many of the particles were electrically and magnetically charged,
permiting
a comparison of the electrostatic quantum to the magnetic quantum of
charge. Mikhailov found agreement with Eherenhaft that the quantum of
magnetic charge is g = (a)(e)/6 = (1/3)(a^2)(gD) = 5.84x10^-13
gauss*cm^2,
where Gd is the charge of Dirac's theoretical monopole, a is the fine
structure constant a = (1/137).
The monopoles of Eherenhaft and Mikhailov are not monopole
particles in the
conventional sense, however. Mikhailov states: "Magnetic charges
(monopoles) are experimentally observed only in the presence of two
components: light and ferromagnetic particles. It seems therefore,
that
magnetic charges are created a a consequence of of an interaction
between
photons ans ferromagnetic particles, and moreover, such charges
cannnot
exists without these physical conditions: without light a particle
loses
magnetic charge almost instantaneously."
Some observations and experiment suggestions in regard to Mikhailov's
experiments:
1. Lateral motion observed in a uniform magnetic field, regadless
of light
direction, appears to be a clear violation of Maxwell's laws,
regardless of
other conclusions drawn by Mikhailov. The existence of a monopole of
course also denies the law being the orginal subject, namely B dot
dS = 0.
2. The magnetic charge, though apparently produced in pairs, is not
conservative in that the dual requirements for existence imply you can
separate the N and S particles, turn off the light which sustains,
say, the
S particles, leaving only the N particles. (Save a sufficient
number and
you can lift off the North magnetic pole! 8^)
3. There might just possibly be a convenient way for amateurs to
experiment
with this. There now exist ferrofluids which could be used in
Millikan
style experiments. Since sputtering would not be involved, it might be
necessary to artificially charge the drops when atomizing the
ferrofluid.
Bill Beaty posted 9/23/96 that ferrofluid might be available from
Ferrofluidics Inc. I checked and found <http://www.fero.com>, email:
<[email protected]>, phone 603-883-9800. They sell 30 ml kits for
prototyping
loudspeakers.
