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Chap.2.4 The electrical currents: what modern physics explains with hands and feet …

Chapter 2.4 The electrical currents: what modern physics explains with  hands and feet …


Many mysteries are hidden in the most common experiences of a school laboratory or a manual of basic electrical engineering, where the phenomena are measured and repeated, but they cannot be explained in any way. Think, for example, the right-hand rule, or  Fleming’s, to determine the direction of the current that is generated in a conductor moving through a magnetic field. Any physical reason is considered as unimportant  to leave the textbooks  perpetuate the conventional false of the direction of electric current from positive pole to negative one, while it is known that the electrons flow in the opposite direction. On the contrary, we need the feet of the ‘”Ampère’s observer” to know the direction of the magnetic lines that surround a wire crossed by the current.

Ask now any  physicist or he demands it himself, if he knows the reason why two parallel currents attract each other, when they have the same direction, and repel each other, if they have the opposite direction. He will answer or respond to himself that, from Newton onwards, modern science does not ask the why of the phenomena, but only the  how and how much.

 But since we premised  that we are not willing to accept without discussion any rules  pre-established by other, even if Newton were (more than three centuries by him passed, moreover), unless you want to fall in the much deprecated ipse dixit, we will give the answer .

In a conductor consisting of a metallic wire,  the flow of electrons travels very slowly from one end to the other, at a speed of half a millimeter per second (WR Fuchs, La fisica moderna illustrata, p.  65-66); naturally the perturbation, that is  the shock, moves at the speed of light. The electrons proceed in  tight helical chains – hence the slowness of the overall transfer – and uniquely polarized, as evidenced by the precise direction  of the magnetic lines surrounding the conductor (counter-clockwise for  the aforementioned “observer of Ampère”; the  lines, apparently circular, are actually very tight helixes too). It follows that, by combining two parallel wires, if the electronic flow goes into them in the same direction, the relative speeds  between the electronic chains of a conductor and the other ones are very low, theoretically down to zero: the electrons of the two conductors   keep going, in an orderly manner. For our physics, this is the basic condition (the other is the reduction of distances) in order to have the  prevalence of the mutual  attraction among  the electrons, which  in fact are strongly attracted each other by dragging the two conductors in the motion of approach.  The phenomenon of attraction concerns directly the electrons, and this is proved by the “pinch effect” in the same electric current, considered as a beam of filiform equiverse currents: for example, in a plasma.

 If the electronic flow in the two conductors is in the opposite direction, the relative velocities among the electrons traveling in one and in the  other conductor are high, because the directions meet, and therefore events to escape to the outside prevail: the two conductors, driven by such events, appear to repel each other.

 

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