How Electricity Actually Works

This does have implications for our audio cabling...

 

What implication would that be?

Would it be possible for the primaries here, in what I find to be a "very interesting" debate! To attempt a simple step or two back to take a breath, reset and recompose??

When half the primaries substitute wishful thinking for reality and make calls to magic based on ignoring 100+ years in the development of our knowledge, then the answer to your question would be no.

Some here need to accept that their knowledge in this area is akin to a car mechanic offering to do heart surgery. Posting links of things you barely grasp does not change that. Don't feel bad, many cable vendors appear to have even less knowledge. The models we have are exceptionally precise to very small scales and very high (and low frequencies). Learning new things does not negate present models no more than relativity negated Newton's laws for the vast majority of the human experience to exceptional precision .

 

 

Fortunately at the frequencies of concern for analog audio and our wire length field, signal propogation is not a concern though audiophiles get themselves worked up easily. For digital cables it is important but something figured out long ago.

 

Most obvious is why the dielectric, insulation, used to cover the bare conductor on ICs and speaker cables can effect the sound. Example Teflon vs cheap PVC. Going even deeper it may also explain why the geometry build of a cable can have an impact on the sound of a cable.

 

Can does not mean does in a fashion that can detected by human hearing. Everything can have an effect. Fortunately all these things are well understood by many, are easily modelled, and can be related directly back to electrical signal levels. That should be sufficient to make an accurate estimate if humans are able to detect the change.

Good reason to use coaxial cable.

@carlsbad ,

BTW, I do know bernoulli’s equation. It is what makes a plane fly, it isn’t a magic equation that causes a sail to push the winds.

No luck needed. I have taught physics. At the university level. Technically I was just the TA, but I essentially taught a few courses.

Perhaps you need to read less and criticize more?

In the faster than wind car (in the direction of wind), the rotating propeller provides the speed differential between the car and the wind hence generating thrust beyond the speed of the wind.

And here, before you teach your next class, the physics of sailing.

https://physicstoday.scitation.org/doi/10.1063/1.2883908

p.s. I will take that apology at any time.

On another controversial claim seen in a YouTube video, the notion that you can make a wind powered car that can go down wind faster than the wind still messes with my head.

My understanding is there are two effective forces, one is the wind pushing, but the other, less obvious, is the wind "pulling"  (though still pushing). Sail boats can also go much faster than the wind.

I didn't spend a lot of time looking at this, but appears to be Bernoulli force, just like an airplane. The wind travels faster over the sail, which causes low pressure, so you have additional force acting on the sail which makes the boat go faster.

In the ground car, the low pressure is created by the propeller. The wind does not spin the propeller, it moves the car whose wheels are connected to the propeller causing it to spin.

 

If we are going to be pedantic. Electrons don’t flow, but they have a net biased movement direction where a current exists. The total kinetic momentum (embodied energy) will be a factor of current. Energy does not flow in the conductor, but there is energy in the conductor in the form of net kinetic momentum.

EM fields don’t flow, they propagate. The energy is transferred in the EM field.

@rodman99999 ,

No, I think you completely missed the point.

Come on guys, I read some of that Crump stuff. The best word I can come up with is lunacy. If you are experiencing:

"Interconnects or speaker wires that have pianos wandering all over the stage normally have their signal and return going in the same direction"

It is time to put down the wacky tobaccy or whatever else you are on, or throw out the record or pick a different recording. This sounds like someone who has convinced themselves of something, and now hears it all the time. I don’t think that is wire direction, I think that is paranoia. If there is any validity to this audiophile tale, I expect it comes down to cleaning contacts and eventually getting it right, but it could have gone either way, literally.

@builder3 I expect most here are from an older generation but who have equally invalid reasons for believing what they think is correct.

Correct "Signal Propagation" with integrity is ALWAYS a concern. "If it is not? You may have chosen the wrong hobby.

I have chosen an advanced degree in solid state physics and a career in semiconductors and batteries. You may want to pick someone else to chant your voodoo perceptions of how electric fields work.

Are you "Really" going to try to argue that there would not be any appreciable change in that systems functionality, if a full accounting and then following that a correction was applied?

 

I most certainly am. We are discussing audio and human beings. Everything you mentioned can be reduced to simple parameters that can be used to evaluate performance at audio frequencies and the distances involved. 

We build nanometer scale semiconductor devices now. Billions of transistors on a chip. We make nanometer scale materials and membranes for batteries that change the chemical and electrical interactions on that same scale. Do you really think we don't understand electricity and materials well enough to understand with sufficient detail wire for analog audio?

 

@carlsbad 

Are you seriously telling scientists who have researched this, modelled it, simulated it, and know all the forces in detail of how this works, that they are wrong?

The "car" they made goes in exactly the same direction as the wind and goes 2.5 times faster than the wind. They are going down-wind at 2.5 times the wind speed.

The bernoulli forces are similar to a plane. Faster moving air is lower pressure. They create a low pressure so that the air on the opposite side pushes towards the low pressure area.

The Vector math explanation YOU gave is wrong. They definitely did not say what you said. The vector has effect, but that is it. It does not define the speed. It is akin to angle of attack. However, the primary force is Bernoulli effect. To that end, the shape of the sail has a large effect as it forms the wing. Trade-off losses versus lift for maximum speed for given hull drag at a given speed. Having a hard time believing you are a physicist since you don’t seem to have understood the article and certainly not to any level of nuance.

Anyone who reads that article, even laypeople, will see that you are wrong.

https://physicstoday.scitation.org/doi/10.1063/1.2883908

 

Moving air has kinetic energy that can, through its interaction with the sails, be used to propel a sailboat. Like airplane wings, sails exploit Bernoulli’s principle. An airplane wing is designed to cause the air moving over its top to move faster than the air moving along its undersurface. That results in lower pressure above the wing than below it. The pressure difference generates the lift provided by the wing.

 

The wind is doing two things,” said Margot Gerritsen, an engineering professor at Stanford. “It’s pushing, but there’s also a part of this wind that is dragging. That dragging is done with this force called lift."

“Lift,” in the case of a sailboat, doesn’t mean “up” although it does in the case of an airplane. In fact, the physics that allow an airplane to fly are the same physics that allow a sailboat to travel faster than the wind. The difference is that airplanes lift up off the ground, and sailboats lift parallel to the ground— as if they’re flying sideways.

 

 

@clearthink ,

I have a PhD (yes really -  feel free to test me) in solid-state physics, have worked extensively in semiconductor processing. I am now a technical director for one of the largest battery companies on the planet.

Feel free to share your qualifications that you feel are so extensive that you believe your insults were warranted.

I have refrained from stating my full qualifications as for the most part, they are not relevant. I also have never felt the need to ask anyone else their qualifications here. I based my opinions on the quality of their posts.

I suggest dialing back the insults and dialing up dealing with what has been posted in the thread. Everyone will benefit.

 

@jea48 

 

I skimmed it. What were you questioning?

There seems to be a misconception on this site that Electrical Engineers are not exposed to this and think electrons do all the work. I think that has been incorrect for a very long time. We had a lot of interaction between the engineering and physics faculties at my university.  I do know that antennas were a standard course. Perhaps that is not universally true. I don't know how you could study antennas and still have a simplistic view of electricity. I would expect the same after learning electromagnetics.  Perhaps like most of us we file it away as fundamental knowledge but not important in day to day work where simpler models are sufficient?

@clearthink 

 

You have stated you’re qualifications here on many, multiple, repeated occasions just as you did here.

It is nice that you have so much interest in me that you have read my posts even if you have misstated what I previously said about myself. Someone so concerned about others post should strive for accuracy. I am disappointed.

 

@jea48 ,

I just skimmed. It all appears to be classical electrodynamics so nothing seemed out of order. I thought the way he approached the argument, i.e. arguing what is wrong with electrons moving was both effective, but at times convoluted due to the wording.

The problem in discussions like this and the audience is misuse and misunderstanding. The moving charges (electrons in this case) are still required for the magnetic field. There is more complexity than most of the energy is outside the wire. But even though most of the energy is outside the wire, does not mean for the use case, audio, specifically analog, that fancy dielectrics, special geometries, and other claimed design features are relevant. To be relevant, they need to be quantified, and then compared to the signal. A critical parameter is wavelength/distance. When this is a very large number, then connection systems can be modelled with simple parameters such as R,L, and C and related to C, dielectric absorption, though in most cases, low source or load impedances would make this irrelevant. Going up in frequency, skin effect is the next likely to be relevant. Shielding is relevant, but there is well understood practices to limit the effects of external fields.

While the conversation, in the link I'm going to post, regards some very high freqs: keep in mind how very harmonically complex the signals carrying our music are and that Poynting Vectors are affected by frequency shifts.

    Just my own opinion, but: seems to me an excellent rationale for the careful selection of cable materials,

 

I won't repeat the joke about opinions. However I will say that fortunately opinions only carry weight in physics and engineering when they come from experienced knowledgeable people. Audio with all it's audible harmonics is all low frequency in a discussion of dielectrics.  When doing our test fixtures and test boards for semis standard PCB material was used up to 100s of MHz. RF substrates were only used for high frequency RF products.

If it not quantified to a number and related back to audio it is just marketing. It's not real.

 

@jea48 I will respond to your question when I am at keyboard

@jea48 ,

I am going to start with a simple explanation. There are probably people much better at me in teaching this topic. However, I think some basics will move you much farther ahead:

- Electrons are charged particles. An electric field will cause the movement of charged particles. Larger the field greater the total movement.

- Moving charged particles are what causes a magnetic field

- If something is preventing the easy movement of those charges, something we lump together and call resistance, then naturally there are less overall charges moving in total in a given direction.

- The Poynting vector which represent power, is the cross product of the electric field and magnetic field. If the electric field changes polarity, the magnetic field does too, but the product always is in the same direction.  As the power is a function of electrical field and magnetic field, the power is directly related to both. No charges moving, no magnetic field, no power.

- It is better to say that power (energy) is transformed by the load, than consumed. Thermodynamics, conservation of energy. From a basic electrodynamic view, for resistance, the electrons "collide" with atoms, and give up their energy, key note, kinetic energy, which results in heat (referred to as Joule heating). However, that energy can be transformed through through the magnetic fields or electrical fields such that those electrons slow, and other accelerate (transformers, motors, energy transfer through a capacitor, etc).

The quantum mechanical view of how the electrons transfer their energy is much more complicated but really also not necessary for the discussion.

A point or two:

- A conductor, having no voltage field differential (effectively), means the electric field within the conductor is 0-small. Hence the transfer of "conduction" of energy from the electric field to the electrons happens on the surface/outside the conductor. This is also why poor conductors have a much deeper skin depth. The electric field extends into the conductor because there is a voltage field differential in the conductor.

- From above, we can ascertain that the energy is predominantly transferred outside the wire, not in the wire.

- There is energy in the moving electrons, kinetic, but the energy is predominantly in the EM field.

 

Clear as mud?

 

I gave an analogy once as electricity, fields, resistance and electrons are like modern banking and finance. Entities with real assets are the fields. The electrons are like a modern bank. They hold no actual money (energy), but they facilitate the transfer of energy (money), and they take their cut (resistance).

Tesla said the following on the theory of relativity in a 1935 New York Times interview: "The theory, wraps all these errors and fallacies and clothes them in magnificent mathematical garb which fascinates, dazzles and makes people blind to the underlying errors.

Someone got the last laugh, and it was not Tesla. Einstein was both confident and humble. Tesla not so much.

The number of Wiki-Scientists on these pages, attempting to win the IG-Nobel Prize in Pseudo-Physics, is always amusing.

I believe the Wiki-Scientist award goes to those who post the most links and use the fewest of their own words.

I will say one thing though. Within a framework of audio, 99.99% if not 100% of this discussion is meaningless since 100+ year old physical models are far more than sufficient to describe anything happening unless you are the guy working on the semiconductor processes and device physics underpinning the chips and discrete semiconductor components no matter what you may read on a forum or in marketing literature which makes all of this an academic discussion in a non-academic forum.

@jea48,

 

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.

 

 

 

 

 

 

 

@jw944ts ,

How does the insulation and multistrand design of most of our cables enter into this discussion? 

 

How? Well if I am trying to sell cables that realistically don't sound any different from anyone else, but I want to make it seem like maybe, perhaps it does, then I will bring up insulation, and all kinds of other things that technically have a measurable impact on the wires, but for the purposes of analog audio are completely meaningless so that I can appear differentiated.

 

multistrand design

Flexibility and does improve skin effect but I expect skin effect is not an issue unless you are running a single solid core 18awg, which I don't think anyone is are they?  That was a quick back of envelope estimate for where it may be an issue.

 

Secondly, in light of the role of the fields around the wires, does the separation of the two wires ultimately have an effect?

 

Yes it increases inductance. In any normal construction this is likely to have no audible impact. A poor cable and electrostatic speakers from my limited research may have an issue. I did a quick review of a bunch of speakers impedance plots after my discovery about the high Fidelium resistance.

 

I will raise the issue that for all the marketing claims of cables, the only specifications I could find where inductance, resistance and capacitance. One or two alluded to skin effect, but nothing concrete. No other parameters were provided.

 

 

    You mentioned not knowing a tenth of a percent.

     The percentage of what we know about our universe, is recognized by Scientists/Physicists as 4-5%.

In order to put a percentage on what we don't know, you would have to know accurately what there is to know which is impossible if you only know 1/10% of 4-5%.  I am always amazed by just how much we collectively do know.

@jimrobie however, a DC distribution system would be quite complicated and would replace very simple devices (transformers) with very complicated devices for transforming DC voltages. DC arcing is must nastier than AC too. Even getting a high voltage DC shock is more dangerous. In our audio equipment, we would still need to convert from a high voltage to a low voltage. There is potential for power savings of course.

local 3 Phase DC

That would be AC at that point. You need changing fields to make the motor work. You could remove the AC to DC part, but would still need the DC to AC part.

 

 

There are some interesting and amusing arguments regarding E and B fields and their uses in this thread. Some of what I read here makes me seriously wonder about our education system.

 

That is a bit of a drive-by @audio-union. Can you comment on what specific items are at issue and if they have been suitably addressed?

It’s those studies, and the truths/measurements gleaned, on which I base my opinions/hypotheses, far as the differences many of us hear in our systems, when making various changes/upgrades/tweaks.

Any measurements or truths would clearly indicate that your opinions and hypothesis have no foundational basis and are just that, opinions and hypothesis with no theoretical or experimental validity. It is laudable that you are reading material and seeking out information that perhaps is outside the comfort zone of previous experience, however, from my view, you are not doing this to gain overall knowledge, but in the hopes of finding tidbits that support your preconceived ideas as opposed to understanding the totality of what you are reading and then seeking out further knowledge that will help you understand better what you are reading.

 

Einstein, like all big brains was confident perhaps to the point of arrogance (at times). However, he was also humble enough to admit he was wrong and did that when he was proven wrong.

When Einstein submitted a paper arguing that gravitational waves don't exist to Physical Review, the journal’s editor sent it back to for revisions. Outraged, Einstein withdrew it. By the time he submitted it to another journal, he had corrected his mistake. The revised paper argued that gravitational waves do, in fact, exist.

Almost every "great" physicist and engineer I have worked with will argue to the death that they are right. When you are in their field, they are not humble. However, what separates them from the not great ones is while they are arguing to the death, there is a little voice in their head going "maybe I am wrong". Arguing to the death is part of their process, even if unconsciously, for testing and refining their ideas. The not great ones don't have that voice. Their arguments become emotional, perhaps personal, and they won't go back and look for errors and test their hypothesis, but will look for reasons they are right. Even when it becomes obvious, even to them, that they are wrong, they look for ways to make it seem like something extraneous was responsible for their failing.

It is impossible for those stunk in the belief that an audio signal flows back and forth in a conductor from a source to an amplifier or to a speaker to understand how an interconnect or speaker cable could possibly sound different from one another. But yet for many of us they do...

 

My knowledge is well beyond this, but that still leaves absolutely nothing put forth by cable vendors or any here, beyond the most basic of parameters, that there is any mechanism that is relevant.