My view on SR is of course that it can not be possible. But it does give some interesting and correct answers, now impossible is still impossible, but... If we reduce the magnet in Einstein's example to an electromagnet, or better yet just one straight wire carrying a DC current. (or a macro model of this with a pipe and charged balls) And if the coil with relative motion is reduced to just a straight wire... (or a macro model)
If the relative motion of the electrons caused them to flatten and pancake (length contraction), then the protons (spherical) field would not cancel the electrons field which has been compressed from length contraction, this would make a voltage appear which would be identical to the motional E-field proposed by Hooper. If we now approached this wire with a second parallel wire, we would now see the electrons moving on a different angle, each electrons pancaking field would now look different, what did look like this |||||||||| (electric field squashed perpendicular to wire) now looks like this ////////// electric field squashed on a slant. This would cause a voltage to appear along the parallel wire that is approaching our simplified magnet. The direction of this field would be to repel the electrons in this wire from the direction the electrons are moving in the 'magnet' wire. And this is precisely the induction that we would expect from cutting line of magnetic force, the direction is correct and I presume so is the magnitude. If the pickup wire was moving with the electrons in the magnet wire (not typical, but easy to imagine) then the protons field would be seen to pancake. This would lead to the opposite voltage gradient (which is seldom looked for or detected) from the wire due to pancaking now being protonic, If this moving wire (moving with the electrons in the other wire) now also moves towards the magnet wire with it's apparent protonic current, the pancaking of the protons would now also slant this way \\\\\\\\\\ and since electrons are attracted to protons, the voltage induced would be the same. The field would have the same observed induction if it is from electrons moving to our left or protons moving to our right. But what of the electric field from just electron motion, if that is switching from positive to negative, shouldn't there be effects? If we now construct a coil of one magnet wire and we move in a circle along it, we would have an N-machine, or homopolar motor/generator. The Homopolar generator is essentially experiencing induction from the Hooper motional E-field, or from direct charge pancaking. I am unsure, does anyone know if the faster a homopolar generator turns the higher the voltage? Since motion of a disk in an all electromagnetic n-machine (no ferromagnetic help) would have only the slight difference in speed between the electron drift and the protons. So I wonder if such a generator would reach full voltage as extremely slow rpm? If the voltage does keep growing by the electrons moving slightly faster, then this would imply that a coil that not only approaches a magnet but is given a twist should have a larger voltage induced since the pancaking of the electrons would be greater. John On Fri, Feb 21, 2014 at 7:06 AM, H Veeder <hveeder...@gmail.com> wrote: > As Dave has mentioned, Einstein's reason for postulating the constancy of > c was partly motivated by his examination of the laws of electrodynamics. > > Here is the introduction to his paper ON THE ELECTRODYNAMICS OF MOVING > BODIES. You can see he is bothered by a lack of symmetry in the laws but a > lack symmetry does not mean a lack of integrity. The lack of symmetry is an > aesthetic judgement. Also he claims the electromotive force has no > corresponding energy, but I am not sure why he would say this since it does > have a potential energy. Perhaps he expects it to have kinetic energy, but > this would reflect an implicit philosophical prejudice against > non-mechanical causes. > > Harry > > > ---------------------- > ON THE ELECTRODYNAMICS OF MOVING BODIES > > By A. Einstein > June 30, 1905 > > It is known that Maxwell's electrodynamics--as usually understood at the > present time--when applied to moving bodies, leads to asymmetries which do > not appear to be inherent in the phenomena. Take, for example, the > reciprocal electrodynamic action of a magnet and a conductor. The > observable phenomenon here depends only on the relative motion of the > conductor and the magnet, whereas the customary view draws a sharp > distinction between the two cases in which either the one or the other of > these bodies is in motion. For if the magnet is in motion and the conductor > at rest, there arises in the neighbourhood of the magnet an electric field > with a certain definite energy, producing a current at the places where > parts of the conductor are situated. But if the magnet is stationary and > the conductor in motion, no electric field arises in the neighbourhood of > the magnet. In the conductor, however, we find an electromotive force, to > which in itself there is no corresponding energy, but which gives > rise--assuming equality of relative motion in the two cases discussed--to > electric currents of the same path and intensity as those produced by the > electric forces in the former case. > > Examples of this sort, together with the unsuccessful attempts to discover > any motion of the earth relatively to the "light medium," suggest that the > phenomena of electrodynamics as well as of mechanics possess no properties > corresponding to the idea of absolute rest. They suggest rather that, as > has already been shown to the first order of small quantities, the same > laws of electrodynamics and optics will be valid for all frames of > reference for which the equations of mechanics hold good.1 We will raise > this conjecture (the purport of which will hereafter be called the > "Principle of Relativity") to the status of a postulate, and also introduce > another postulate, which is only apparently irreconcilable with the former, > namely, that light is always propagated in empty space with a definite > velocity c which is independent of the state of motion of the emitting > body. These two postulates suffice for the attainment of a simple and > consistent theory of the electrodynamics of moving bodies based on > Maxwell's theory for stationary bodies. The introduction of a "luminiferous > ether" will prove to be superfluous inasmuch as the view here to be > developed will not require an "absolutely stationary space" provided with > special properties, nor assign a velocity-vector to a point of the empty > space in which electromagnetic processes take place. > > The theory to be developed is based--like all electrodynamics--on the > kinematics of the rigid body, since the assertions of any such theory have > to do with the relationships between rigid bodies (systems of > co-ordinates), clocks, and electromagnetic processes. Insufficient > consideration of this circumstance lies at the root of the difficulties > which the electrodynamics of moving bodies at present encounters. > > The rest of paper is here: > https://www.fourmilab.ch/etexts/einstein/specrel/www/ >
