Directionality of wire

herman                                                      1,946 posts08-06-2017 12:42pm

about this

The speaker transducer moves forward and backward according to EMF acting on the voice coil - see Faraday’s law and Maxwells equations - so both +ve and -ve current direction along the speaker wire causes transducer movement.

Again, it has nothing to do with we commonly call "current" which most visualize as electrons flowing back and forth. It simply doesn’t work that way. There is an electro-magnetic wave that transfers energy to the coil of the speaker. If applied to a resistor it creates heat. If applied to an inductor (coil) it creates a constantly changing magnetic field which pushes and pulls against a fixed magnet creating motion. Those stuck in a world of flowing electrons are just that, stuck there. Energy flows, electrons do not.

Thanks herman for the explanation.
Jim

geoffkait:
It is illogical to say that "electricity" or current or voltage is an electromagnetic wave ...

>>>>While you may think it's illogical, electrical energy transfer still happens through the electromagnetic field. The paper I referred to earlier shows how this works for DC. The energy flows in the direction of the Poynting vector. For a zero resistance cable, this vector is zero inside the cable (there is no electric field), and it is oriented parallel to cable outside the cable. For a non-ideal cable the Poynting vector has a small component directed  perpendicular to cable, transferring energy into the cable, causing ohmic heating.

geoffkait:
The reason why the audio signal travels at say, 70% the speed of light in a copper conductor is because the audio signal is traveling through copper.

>>>>This is patently untrue. The propagation speed is limited by the dielectric constant of the material surrounding the conductor. Look up, e.g., propagation speeds for coaxial cables.

It is illogical to say that "electricity" or current or voltage is an electromagnetic wave.

This all means the electromagnetic waves must be traveling through the copper, not outside the copper.

First they aren’t and then they are? To deny that audio signals are EM waves is to deny basic physics. I suggest you go take a basic physics class about these topics as your analysis is I’m sorry to say.. fundamentally flawed. Take a look at this chart

https://en.wikipedia.org/wiki/Electromagnetic_spectrum

Using the common ways of describing it in terms of voltage and current always breaks down at some point, like the water through a hose analogy. It’s OK for grade school to start to get a grasp but it oversimplifies in ways that can’t be supported and at some point (we are there) just causes confusion.

Trying  to differentiate some portions of the spectrum by saying  that some are made of photons  is basically incorrect. There are two common ways to analyze light and all other EM waves. Photons, which treats it as particles and the EM wave which of course, treats it like a wave. For some phenomena particles works better, for some waves work better. To try and differentiate between the 2 to explain an ill-conceived position just muddies the waters. Since to get the clearest picture you need to use quantum physics which is clearly beyond the capabilities of most here including me, we simply must trust those physicists who do understand it.. like Einstein.

It is not incorrect to use photons to discuss EM waves at audio frequencies, it just generally serves no useful purpose.

Once again and I will drop it, but to claim that all of the energy is contained inside the wire falls apart with simple experimentation. Electromagnets would not exist, electric motors would not work, and on and on like I pointed out above. To deny this is again denying basic physics. I guess the earth is flat too since you can’t see the curvature from where you are standing?


BTW, you may or may not have noticed that I haven’t posted much for several years and this thread is a perfect example of why. A perfectly logical question is asked (cable direction in case you forgot) and somebody (usually the same guy) jumps in with pseudo-science and voodoo to try to explain a position that is fundamentally flawed and flies in the face of all known physics. Said person will then endlessly defend their defenseless position until we end up where we are today. My apologies to the OP but sometimes you see something that is just so blatantly wrong you have to speak up.

jea48, I confess all those quotes you posted from Ralph Morrison do not actually prove anything. Saying that Maxwell’s equations prove he’s (Ralph) right is nothing more than a cheap Appeal to Authority. Many folks use that logical fallacy, e.g., "the answer is in Maxwell’s equations." Those paragraphs you cited are statements but not evidence or proof of anything. They sound OK, though. Wouldn't it be nice if there was an electronics textbook or a technical paper in some scientific journal that came right out and demonstrated how wire can or cannot be directional? But then all this discourse would stop. Nobody wants that, do they? 😀

Herman stated recently regarding wire directionality, "if you can hear it it’s real." I hate to be the one to point this out but that’s unfortunately not really the right answer, at for the purposes of this thread, since the naysayers or skeptics whatever never try listening for directionality - or if they do they can’t hear it. So they say. That why they’ve taken the tack of using mathematical and physics explanations to debunk the whole idea. In fact these attempts to debunk wire directionality are very reminiscent of theological arguments. Even of medieval witch hunts or whatever. Not that I’m trying to bring up theological arguments here or any such thing. But it is curious that these things are very difficult to prove or even to provide evidence other than personal testimony. Which I actually find rather convincing given the sheer number of such reports. It’s like UFO sightings, report and videos; eventually you start to say, gee, maybe there’s something to that. Regardless of the fact that US Air Force Operation Blue Book, which was right down the street from my first job in a pink building with no windows at Wright Patterson AFB, closed its doors in 1968 or thereabouts due to lack of evidence and or lack of funds. So they said.