How Electricity Actually Works


In November of last year I posted a Vertasium YT vid titled "The Big Misconception About Electricity".  Well it caused quite a stir and like an arachnid had many legs many of which attempted to draw A'gonrs into the poison fangs!

Well, here is the follow-up to that original vid which caused quite a stir in the "intellectual" community as well.

Vertasium "How Electricity Actually Works".

 

This does have implications for our audio cabling...

Regards,

barts 

128x128barts
deludedaudiophile "I have a PhD (yes really - feel free to test me) in solid-state physics, have worked extensively in semiconductor processing"
This is quite funny and amusing and a frequent, common, and typical response that reflects your youth and inexperience so I will help you. While you were waving your degree that you claim to have you completely, entirely, aand totally failed to see that you’d already flunked the test. The proper aanswer was to show that you can think, reason, and apply logic not touting a a degree.

"I have refrained from stating my full qualifications as for the most part, they are not relevant"

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

@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 , perhaps you know nothing you try to talk about. what you've posted comes from the same basics of prior educational university text books. Ralph Morrison isn't describing such basics. He is describing what can be done and how, but at the end any Electric Current  within an enclosed and loaded electric circuit is nothing else as ordered (or directed as described by Ralph) motion of electrons. Find more basic college textbooks on Electrical Engineering, basics of Charge and Ohm's law.

 

electric signal travels through the conductor approximately 5c i.e. 5 speeds of light

 

I assume you made a typo?

 

Regarding EE texts, you have reviewed all of them?   I have to expect people making these statements are not themselves students of 4+ year engineering disciplines.  I took a quick search for curriculums and noted virtually all have at least one course in electricity and magnetism that covers electrical and magnetic fields, delves into Maxwell's equations, etc.   Some undergrad have antenna theory though this seems to be more Master's level. It would impossible to take such a course and have a purely electrons view of electricity.

 

 

This does have implications for our audio cabling...

I haven't seen anyone explain how...does it have any implication for wireless speakers? 

@rodman99999 
I managed to 
get through the first page of the discussion you referenced and there had already been two pleas to steer it off to a siding. I noted that ‘This discussion is closed’ sign. I don’t believe that discussion had anywhere to go, like you say; I had hopes for this one. 

@czarivey

Current doesn’t carry the signal. The electric charge moves too slow... As slow as cold Maple Syrup. Electrons don’t carry the signal either. They pretty much vibrate in place and hardly move at all. And the signal definitely does not flow back in forth from the source to the load. The signal travels is one direction from the source to the load in the form of an electromagnet wave in the space between the conductors at near the speed of of light in a vacuum.

As for Ralph Morrison you obviously don’t understand what he is saying.

It is also obvious you didn’t read the other link I provided for you to read.

@jea48

 

I skimmed it. What were you questioning?

@deludedaudiophile

I wasn’t questioning anything the educator had to say. I just wanted to see if you agreed....

.

@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.

@jea48 That's more like critique and expressing opinions instead of EE text book.

 

Post removed 

@deludedaudiophile

Thanks for the thoughtful and intelligent response. I still have a problem wrapping my mind around some of it. For one you can create a magnetic field from an electric field. And an electric field can be created from a magnetic field.

I am still a little confused what exactly creates the current in the conductor. I have read the EM wave energy creates it. The bigger the connected loaded to the source the greater the energy from the source is required. More energy the greater the current in the circuit conductor.

My understanding;

Energy is consumed by a load. Current is not. Current leaves the source and returns to the source. The EM wave does not flow in the conductor. Therefore energy does not flow in the conductor. The EM wave energy flows in the space between the conductors in one direction from the source to the load at near the speed of light in vacuum. Current returns to the source. Energy does not.

.

Post removed 
Post removed 
Post removed 

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 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).

Energy does flow in the conductor, if it didn't the wire wouldn't get hot. Current doesn't leave and return, charge flows, current is the measurement (time) of the flow ( Quantity of charge) through a cross section of the conductor. 

It's not the electrons that flow, it's the electro-magnetic field that flows.

 

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.

Electricity travels like Light in a wave and the voltage and current travel out of phase. Watch the video it Cool 😎 as they go where few have to explain. Still there is much we do not know🤷‍♂️

https://www.youtube.com/watch?v=bHIhgxav9LY

 

Post removed 

@barts -

     Inescapable FACT:  No one understands exactly how electricity works.

     That’s why there’s so much Electrical THEORY.

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

     Whenever some highly educated person actually does discover exactly how electricity functions, they’ll be lauded by the scientific community, will have solved some of the disparities between Relativity and Quantum Mechanics, receive a Nobel and we’ll hear about it.

     Newton’s THEORIES were largely superseded by Einstein and Bohr's.   Then came Feynman’s.

     For now; none of you can absolutely prove your statements (theories), regarding electricity, fuses, wires, or anything else, as regards our systems.

     The following articles illustrate my point:

    https://www.thegreatcoursesdaily.com/how-einstein-challenged-newtonian-physics/     

    then: http://hyperphysics.phy-astr.gsu.edu/hbase/Forces/qed.html#:~:text=Quantum%20electrodynamics%2C%20co...

    and: https://bigthink.com/philip-perry/an-updated-feynman-experiment-could-heal-the-rift-between-quantum-...                          

     Feynman was and will remain, my favorite lecturer (yeah: I'm that old).

     He mentioned often (and: I took to heart) his favorite Rule of Life: "Never stop learning!"

     For all his genius, he never grew overly confident in his beliefs.    The perfect obverse to the Dunning-Kruger sufferer.

     ie:  “I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong.”

     and: “I have approximate answers, and possible beliefs, and different degrees of certainty about different things, but I’m not absolutely sure of anything.”

     Tesla is probably my favorite innovator, who (despite the incessant, projectile vomit, from his day's naysayers), took the World, kicking and screaming, into the 20th century, with his inventions.

                                                  His thoughts: 

     “Anti-social behavior is a trait of intelligence in a world full of conformists.”

     “All that was great in the past was ridiculed, condemned, combatted, suppressed, only to emerge all the more powerfully, all the more triumphantly from the struggle.”

@the likes of czarivey, djones51, etal-

                                             Electrons flow?

     Try a little update there, at least to the last (20th) Century’s theories, Sparky!

https://www.quora.com/Are-photons-emitted-inside-a-wire-when-a-current-is-run-through-it

and:

https://van.physics.illinois.edu/qa/listing.php?id=2348

     For those interested in expanding their understanding: be certain to click on the MORE tabs, when applicable, to get the rest of the story.

                                         AGAIN: THEORIES!

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.

the likes of czarivey, djones51, etal-

Electrons flow?

I never said electrons flow, though they do drift. This thread is a discussion about the weirdness or non intuitivness of electricity not the audibility of fuses and wires in sound systems. You like Feynman, here you go.

https://www.feynmanlectures.caltech.edu/II_27.html

 

While you're at it you might want to brush up on what a scientific Theory is, it's not Billy Bob Bodine guessing why beer has bubbles.

@deludedaudiophile

Thanks for the response.

Your comments are on par with things I have read since 2010 on the subject matter.

I read nothing in your post that differed from what the Late Ralph Morrison, Herman (agon member), the Late almarg (agon member), William J Beaty ( Misconceptions Spread By K-6 Textbooks: "Electricity"), Ian M. Sefton (School of Physics, The University of Sydney, Australia), and countless others I consider authorities on the subject matter.

 

I knew better when I said the load consumes energy. It really doesn’t. Energy is not consumed... I like your term the energy is transferred.

 

Question:

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.

His words:

Storing or moving energy.

There is a common misconception that signals are carried in conductors. Somehow this association crosses over to the idea that conductors carry both signals and energy. A few simple calculations can show that this is a false idea. Consider a 50-ohm transmission line carrying a 5-volt logic signal. The initial current at switch closure is 500 mA. A typical trace is a a gram-mole of copper that has 6 x 1023 copper atoms (Avogadro’s number). Each atom can contribute one electron to current flow. Knowing the charge on an electron makes it easy to show that the average electron velocity for 500 mA is a few centimeters per second. What is even more interesting is that only a trillion electrons are involved in this current flow. This means that only one electron in a trillion carries the current. This also says that the magnetic field that moves energy is not located in the conductors. The only explanation that makes sense is that energy in the magnetic field must be located in the space between two conductors.Conductors end up directing energy flow - not carrying the energy.

The electric field in the conductor that causes current flow presents a similar picture. For a transmission line trace 5 mils above a ground plane, the electric field strength in the space under the trace is about 49,000 V/m. The electric field inside the conductor might be 0.1 V per meter. Energy in an electric field is proportional to field strength squared. The ratio of the square of field strengths in and near a conductor is about 2.4 x 1011. It is safe to say that there is very little electric or magnetic field energy in a trace or conducting plane. 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. The path should also control the characteristic impedance so there are controlled reflections. What we really need to do is supply a smooth path for logic energy flow.

The math part is over my head... Do you disagree with what Morrison said? Where would you differ?

 

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?

Would you agree the signal voltage creates the EM wave? If not how would define, explain, it.

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?

Best regards,

Jim

@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.

 

 

 

 

 

 

 

after following this academic debate, and how/if it matters for audio signal transmission, I am left with some questions.  How does the insulation and multistrand design of most of our cables enter into this discussion?  Secondly, in light of the role of the fields around the wires, does the separation of the two wires ultimately have an effect?  AND FINALLY, though this all may matter for those that design  cables, to the end user, isnt the sound all that matters?

@rodman99999 

Thank you for posting the links.  

I have only one theory and that is:  As a species we simply don't know a tenth of a percent about anything.

We may know what works and what doesn't but that's about where it ends.  I'm not attempting to be cute or controversial...call it a belief system if you like.

I'm happy that this posting didn't go off the rails like the last one and enjoy reading this thread.

Regards,

barts  

@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.

 

 

We as a species don't know a tenth of a percent about anything? Pretty pessimistic view of Homosapiens.

I am just an engineer. I worked chemical, electrical, and mechanical engineering. Part of my career I designed Mobile Electric Power equipment, I designed generators. Not just any generator, but one that was hard to detect. The technology is referred to as Low Observable. 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.

@barts -

                          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%.

     Multiple Billions have been/are being spent, in an effort to find out what exactly comprises the other 96%, of the matter and energy, Physicists know surrounds us.

     Einstein recognized there was a whole lot of stuff missing, when he came up with his Math on gravity and considered it his greatest blunder (having to add Lambda/the Cosmological Constant) 

                          Too bad he didn't live to see that proven!

        There are some interesting theories, as to what's going on around us:

 https://science.time.com/2013/02/20/telescope-to-hunt-for-missing-96-of-the-universe/

 

https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

 

https://www.livescience.com/multiverse

 

https://www.vox.com/2015/6/29/8847863/holographic-principle-universe-theory-physics

 

http://httpblogsscientificamericancomdegrees-of-freedom20110725what-do-you-mean-the-universe-is-flat-part-i/#

 

https://www.livescience.com/strange-theories-about-the-universe.html

@djones51 -

     According to you: "This thread is a discussion about the weirdness or non intuitivness of electricity not the audibility of fuses and wires in sound systems."

                                  According to the OP's initial post:

This does have implications for our audio cabling...

Regards,

barts

 

djones51

We as a species don’t know a tenth of a percent about anything? Pretty pessimistic view of Homosapiens.

That depends on how you look at it.

"We still do not know one thousandth of one percent of what nature has revealed to us." (Albert Einstein)

"We don’t know a millionth of one percent about anything." (Thomas Edison)

Lucky for those in this hobby we've managed to blindly stumble upon enough to record and reproduce that recording to an amazing accuracy. Good thing it didn't require us to dissect the Universe. 

Post removed 
Post removed 

I think and i guess i hope that we are heading back to DC current.  Solar panels and Wind Power generate DC, Batteries store in DC, LED run on DC, really efficient motors use inverters to produce clean 3 phase A/C, but could skip the loss of the inverter and run on local 3 Phase DC.  There are limitations and problems and maybe safety concerns.  It would add huge efficiency if we could skip all the inverters, skip the inefficient grid and power plant.  some day.   

@deludedaudiophile

 

The wind does not spin the propeller, it moves the car whose wheels are connected to the propeller causing it to spin.

I think that’s the key concept that allows the effect to happen. It still remains difficult for me to fully visualize. It's like a very good magic trick. It won’t work if you aren’t connected to the ground. Too bad, because then airplanes with no power plant could just magically make headway into the wind!

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?

    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.