Magnetism known from early times was of practical use in navigation and had consequently been much studied. The attractions to amber (Greek name elektron) that were evident after rubbing it with fur, had, from ancient times, been more of an academic interest. Any connection between the two had been dismissed by Willam Gilbert’s “De Magnete” work of 1600 and that continued to be the situation until Oersted’s work of 1820.
Some 20 years after Volta had constructed a voltaic pile (battery), Oersted, when using a pile that delivered a good charge flow (current) in a wire, observed how a magnetic compass reacted to it. An explosion of interest followed, with many repeats of the experiment, all seeking to explain it and expand on it. Ampere, for example showed that parallel wires passing currents reacted to each other, suggesting that the magnetism involved was the result of circling molecular currents that attracted when circling in the same direction.
Now, a steady electric current produced a steady magnetic field. But, as Faraday came to realise via many experiments, a steady magnetic field did not deliver a steady current. But then in 1831 came success and it wasn’t with a steady magnetic field.
Using apparatus like that shown Faraday saw how in closing or opening the switch in the one circuit, a current flow was momentarily produced in the other circuit. He described the action as being induced and visualised a field of magnetic flux as the link between the two circuits.
Later still Faraday showed how moving a magnet in or out of a coil delivered an electric charge flow. He then went on to create a disk that many regard as the first electric dynamo (electric generator). His observations and that of Oersted now clearly linked magnetism and electricity.
Early 1860’s and a James Clerk Maxwell wrote 4 equations based on the electrical and magnetic works of Gauss, Faraday and Ampère. Faraday had shown how magnetic changes in the presence of charged particles resulted in electric changes. Ampère had shown how a magnetic energy field circled a current carrying wire. Maxwell intuitively added an extra term, he called displacement current, to Ampère’s Law. The magnetic field could be a changing one and he decided that such changes were linked to electric field changes. Out of his equations came the speed of light and our view of light as a self propagating electromagnetic wave.
The mathematics was correct but Faraday’s law requires charge particle presence to work. Similarly, Maxwell’s changing electric field will only result in a changing magnetic field when if charge is present.
So how was it, that by applying conditions to two of his equations, Maxwell got light speed? But also, if electric and magnetic fields don’t generate one another in space, what is the real nature of the energy moving through space?
Light speed of the changing electric field came from Faraday’s law by regarding charge density as zero. The electric field is one of photons; their energy, frequency and speed of delivery into space results from vibrating electron to proton energy interactions, whose charges cancel one another. Light speed of the changing magnetic field came from the time changing part of the Maxwell Ampère law. It ignored the steady state aspect.
Where does the circling magnetic field energy come from? In my blog, living spin I explain in more detail how the magnetic field is not a circling one but one that spirals out from and returns to electron to proton movements and in a direction related to those movements. Living electrons spiral out photon energies that return to satisfy particle energy desires.
Magnetic field energies and changes to them are from moving electrons whose numbers are their response to the electric field energies and their changes as determined by the voltage supply. Rising electron numbers expand the magnetic field. It’s at the expense of and thereby delaying the electric field rise and rise in electron numbers. A reducing electric field results in reduced electron movements and a collapsing magnetic field whose energy flow delays the collapse in the electric field and electron motions. That is the very nature of induction.
Photons are emitted at light speed relative to electron /proton particles whose interacting energy desires and controls involve both linear (electric) and rotational (magnetic) energies, that are rising and falling. Maxwell’s calculations of light speed were at the emitting source. There are no oscillating photon fields in particle free space.
We are better viewing the light speed emitted photons not as having interacting, oscillating electric and magnetic waves but as light speed travelling three dimensional energy pulses, not carrying but delivering electrical and magnetic effects to structures, that red or blue shift them so as to process them a light speed relative to them.
Most of science says that a magnetic field like that around a wire applies between the plates of a charging or discharging capacitor there is no clear proof that that is so and some agree with my view that any such field there is due to electron movements on the plates and within the dielectric material. After all, electron movements on the plates and in the dielectric material are in a direction that would deliver such fields.
This blog has concentrated on what induction is and how it is the result of living particle actions. It reveals how electric and magnetic fields are aspects of the same thing and questions our concept of circling magnetic fields. In another blog on inductance I will deal with some of its considerable applications.
that any fScience has not succeeded in demonstrating that Maxwell’s displacement current delivers a magnetic field in