Since the energy is present and it is not in the conductors it must be in the space between the conductors. This is true for sine waves or square waves at all frequencies including dc. This one idea is not often discussed in circuit theory. This one idea solves most interference problems. This one idea is at the heart of a good circuit board layout. If the energy that represents information is carried in spaces it makes sense that we must keep these spaces free from interfering fields.
I don’t really like this statement for a few reasons:
- The electrical field is predominantly between the two conductors. Not exclusively but predominantly,
- While true at DC, this creates a false impression of what will/is happening. If you have two stationary potentials, you can have an e-field, but there is no induced current and hence no magnetic field and hence no Poynting vector, no energy transfer. At least one of those wires must varying in potential which will cause a varying electrical field which will cause the electrons in the other wire to move, inducing a magnetic field, hence energy transfer. You may recognize this by a different name. Capacitor! Hence why in the real world, when people are working on PCBs, they use parasitics extraction software to model the unintentional capacitors and inductors. That is done at the chip level too.
- Just keeping the "spaces" between two conductors involved in the transfer of a signal, where most of the field is, "clear" of fields is only 1/2 the problem. The issue is other non-static fields between either wire and other things. There is both the issue of electrical fields and magnetic fields for interference of course and I don’t think this description does a good job of magnetic interference.
Can we say as a matter of fact the signal does not travel in the conductor but rather outside the conductor in the space between the conductors?
We can say that energy is transferred in the space outside the conductor predominantly. I personally don’t like to use the word signal, as the "signal" at least in an analog form is impacted by the nature of the conductor and if the conductor alters the signal, then you cannot negate that it is involved in information transfer, even if they energy is outside the conductor. I say that as a personal viewpoint. Others may take a less nuanced or alternate view.
Would you agree the signal voltage creates the EM wave? If not how would define, explain, it.
The signal voltage moves the electrons which creates the magnetic field which together are an EM field. However, a magnetic field can move electrons and moving electrons (charges) in a magnetic field induces an electrical field so ... chicken and egg.
Is the Law of Physics considered theory? If yes then why not Ohms Law considered theory? I don’t think the Late Ralph Morrison considered it theory.
Ohm’s law is neither a law nor theory in the traditional sense. It is a best an empirical law, and at worse an inaccurate definition, the original definition being that other conditions keep constant, the current in a conductor will be proportional to the applied voltage. Somewhere along the line it became I = V/R, which with a theoretical perfect R is true, but this is really a definition, not a law. This is much different from say laws of thermodynamics which are universal in their application and appear inviolable, but even that is up for debate.
Also am I wrong in saying there are multitudes of varying signal EM waves in a typical analog recording? Vocal(s), musical instruments.. I would say it is quite complex to say the least. Am I wrong?
I almost don’t want to answer this. Conceptually this is different from say photons (light) singular with specific wavelengths and energy potential. If you look at the electrical field, technically every single pair of excess charges creates a field, so there is not a multitude, there is a near infinite number, and every accelerating electron also has associated a magnetic field that other electrons interact with as well. So there is at once a near infinite number of fields, and one overall field.
You will note I said fields, and not waves? That was intentional. Electromagnetic waves are self propagating electric and magnetic fields travelling in free space. That is not what we are dealing with. We are dealing with propagating and varying electromagnetic fields. --- Anything beyond this gets too complicated and we get into propagating and non propagating solutions to Maxwell’s equations, wave functions, etc. By generally accepted definitions, what occurs in conductors is not EM waves, but propagating time variant EM fields. A key differentiation is EM waves are self oscillating, but the fields in our circuits are not.