Is there a "magnetic" field?
No, it is fiction, gauss said "imagine" there is nothing there!
Electromagnetism theory reached its pinnacle in the nineteenth century with
Maxwell's famous equations.
Let us take two examples.
The case of two parallel conductors carrying current.
1. Currents parallel.
The current is a slow movement of electrons with fixed positive charges.
The electrons are moving parallel in the two wires so are stationary
relative to each other. The positive charges are seen as moving. According
to Einstein's theory of relativity the length of the positive charge is
contracted as seen by the electrons and so the electrons see an increased
charge density over the charge density of the electrons. This makes the
force of attraction between unlike charges slightly greater than the force
of repulsion between unlike charges. This means that there is a net force of
2. Currents anti-parallel.
The electrons are now moving antiparallel and so they see a length
contraction of the other electron charge. The positive charges are also
seen contracted but not as much. So the electrons are seen as having a
greater charge density than the fixed positive charges. Thus the force of
repulsion of like charges is greater than the force of attraction of unlike
charges. This means there is a net force of repulsion. Induction. Consider
two conducting wires parallel. One conductor has an alternating current
flowing in it. This means that the electrons are accelerating and thus
their electric field lines have a kink in them so there is a transverse
component this field moves the electrons in the other wire. Thus producing
an induced potential. The magnitude of the induced potential would be
proportional to the rate of change of the current in the first conductor.
In all these cases no magnetic field was required to account for the
phenomena involved. So invoking Occums razor, the magnetic field in not
required and so does not exist.
Consider two long straight copper conductors each carrying the same current
in the same direction. The electrons move together at the same velocity in
each cable. They repel one another. The fixed positive charges repel each
other. However the electrons wire A attract the fixed charges in wire B but
because the electrons are moving relative to the fixed charges they will see
a higher charge density than the charge density due to the electrons in B so
the attraction of electrons to fixed positive charges is higher than the
repulsion between the same number of electrons in B. Similarly for electrons
in wire B and the fixed positive charges in wire A.
n=number of atoms per meter e=electronic charge d=separation l=length
v=drift velocity of electrons c=velocity of light
The force of repulsion is P*2*((e*n)^2)*l /d (= F)
And the force of attraction is P*(2*((e*n)^2)*l/d)/sqr(1-(v/c)^2)
So the resultant force is F-F/sqr(1-(v/c)^2)=F(1-1/sqr(1-(v/c)^2))
So P/c is the "permeability" and the force is proportional to the current
squared and the length but inversely proportional to the separation.
There is no need for the idea of the magnetic field. There is no magnetic
Karl Popper has explained the scientific method. Use the predictions of the
theory and test experimentally when judging a philosophical idea.
Science in only science if you carry out experiments to test the theories of
yourself or another. To play philosophical games with words and equations
is no science.
Go get a bit of wire make a straight part 40 cm long and connect it to a
constant current source of say 1 amp.
Get the old electrostatic kit out of the 18th century box and using a glass
rod wiped with silk make a pith ball coated with gold leaf charged by
bringing the glass rod close to the ball and touch the ball briefly with a
finger. The ball will be repelled by the glass rod.
Put the pith ball (suspended by a silk thread from a curved glass stand)
near the wire and note the deflection from the vertical when the current is
I predict it will be repelled if negatively charged and attracted if
A bar magnet is in fact a group of spinning electrons which are coupled by
spin-spin interactions (Quantum mechanics) that are mediated by virtual
photons again a force that is electronic and connected to the Lorenz
contraction.. The force on another bar magnet is actually due to spin-spin
interactions (Quantum mechanics) which is electronic and related to the
A loop of wire carrying a current is again interacting with another current
carrying conductor by the electrostatic force (mediated by virtual photons)
and is again a result of the Lorenz contraction.
The calculation to use is the biot-savart hypothesis integrated.
In view of this new insight we should re-name magnetism as the "Lorenz
force". It also means that many of our reasoning based on observations made
300 years ago before Einstein developed his special theory of relativity are
misconceived as they are based on the wrong model.
The Gaussian construction of magnetic shells does not come into it there is
no magnetic flux or lines of force.
As a disclaimer I will point out that I am not the first or only person to
point this out.
- posted 15 years ago