Veritasium "How Electricity Actually Works"

[PlainName]

Woah! No-one's talking resistance here (except you, as a diversion). You said "you will see that the conductor heats uniformly on the entire conductor cross section" - that is heat, thermal. I am wondering just how you can measure the internal temperature of a conductor, and you Internet isn't any help there.

So, just how do you see that? If you make a hole and place a probe you're affecting the conductor integrity, and even with a thermal imager you're only going to see the outside.

Or was this just another 'fact' or 'law' you made up on the spot?

I guess you will need to learn about another type of energy storage and that will be thermal storage.
If the electrons travel closer to the outside surface of the wire like in AC then resistive losses will show that so there will be no need to even measure the temperature.

More diversion. You said we would see, as a pillar of your argument. So we want to see it, to recognise what you said was so. Now, when asked how to do that, you say we don't need to, or that it's an obvious effect of something else.

You made it up, didn't you? You can't prove it or show it and all you can do is circular arguments hoping that's not the one you end with when the music stops.

[T3sl4co1l]

For consideration:



That was something like 3kW for a minute, at 10kHz or so, on a very rusty 1/4" thick steel plate.

The heating pattern is indicative of skin effect around the outer edge of the workpiece, though the glowing areas are much wider than the current paths due to the long heating duration.  Nonetheless it's more than adequate to see the superficial current flow path, preference for long sides, and avoidance of corners.

Tim

[SandyCox]

I sure not heard about him at university (Electrical engineering in some east european country).

The fact that you haven't heard about something doesn't mean that is wrong or unimportant. It just means that your education was bad. You also didn't know about preservation of charge which is a fundamental concept. I suggest that you work through a good book on Electromagnetics. You are clearly out of your depth.   

[electrodacus]

Why will I be bothered by that ?

And it doesn't bother you at all that there is no circuit you can put in region A in the diagram below that can extract energy from the wires that surround it? Even a DC/DC convertor? Even if you can connect it to a GND? But extracting energy from regions B or C is a piece of cake?

And I guess that it doesn't bother you if an isolated charge is placed in region A and it stays where it is put, but if the same charge is placed in B or C it will accelerate, acquiring energy ultimately suppled from the battery, without being connected to it?

And it doesn't both you if you charge a capacitor between +110V and +100V is has exactly the same stored energy as one charged between 0V and -10V?  Even though one has been charged at a higher energy? And the other has been charged at a completely different polarity?

And it doesn't bother you that a transformer can get 95%+ transfer of energy from one wire to the other, even though the wires don't touch, and no charges from the input wire get transferred to the output wire?

And it doesn't bother you that for your version of electrostatics  (sum of force between charges), every charge needs to be in consistent communication with every other charge in the universe, to work out how far away they are, and at what direction?

And it doesn't bother you that a transmission line is a series of inductors and capacitors, however on inspection those capacitors and inductors can neither be identified or isolated?

And it doesn't bother you that commercial radio transmitters can get kilowatts of energy to disappear into literally thin air?

You must be a firm believer in the Lumped Element Model. It seems to work, so to you it must reflect the mechanics of reality, rather than an useful abstraction and approximation that allows you to get stuff done.

Not sure where to start from but you have a lot of misconception about how things work.

Yes regions B and C have an electric field but you can still do not extract energy from that. Same with magnetic field that is also constant basically like a permanent magnet. Let me know how you extract energy from a permanent magnet and we can clarify from where you actually extracted the energy because it was sure not from the magnet.

Yes if you place a charged particle in an electric field it will be accelerated but note the action you take to put a charged particle there.

The potential difference for the capacitor is 10V in both cases and as far as energy is concerned it makes absolutely no difference. The zero/ground is something arbitrary that we chose.
If a capacitor is placed on the positive of two power supplies that have common negative tied together and we consider that the zero point then we connect a capacitor with one plate to positive of the 100V supply and the other plate to the positive of the 110V supply you just have a 10V potential and as far as capacitor is concerned that is all he will see thus it will store the exact same amount of energy as the one connected to what you call a 0 to -10V supply that can also be seen as a 0V to +10V supply is all a matter of definition or how it is connected to other things where you may already have defined a "ground"/zero point/reference point.

A single inductor is an energy storage device same as the capacitor is an energy storage device and so with transformer you can store energy by creating a magnetic field while supplying the primary and then retrieve that stored energy with the secondary or the other way around or with the same.
So by running a current through any of the two coils you are creating a magnetic field that remains there as long as there is no change in current flow.
If you suddenly stop the current flow by disconnecting the source voltage on the both coils (primary and secondary) will increase and so you can take that stored energy out through any of them.
But if you run a DC current through primary then you can not take energy out from secondary. You still have a strong magnetic field but it is constant so energy storage is maintained full.

Of course a transmission line is a series of inductors, capacitors and resistors and of course you can see them if you can see the wires of the transmission line and understand what a capacitor, inductor and resistor are.

The energy of a radio transmitter will not disappear. As a simplification is a capacitor with one plate as the transmitter the ground as one of the conductors and the other plate is the receiver again with ground as the common conductor.
The capacitor is charged and discharged multiple times per second depending on radio frequency and of course there will e a lot of power loss due to resistance in this circuit.

The lumped model works because it is a representation of reality. And yes it will be an approximation as in simulation you may use just like me hundreds of this groups for a 20m transmission line to keep the calculations manageable and the results more than close enough for what we need them.
If you think you have a better model that allows to make accurate predictions about what happens on a transmission line then please share as I will be curious to hear.  I will like to see the equations not just some story.

[electrodacus]

More diversion. You said we would see, as a pillar of your argument. So we want to see it, to recognise what you said was so. Now, when asked how to do that, you say we don't need to, or that it's an obvious effect of something else.

You made it up, didn't you? You can't prove it or show it and all you can do is circular arguments hoping that's not the one you end with when the music stops.

I already did but you may have missed that post or it went over your head.
Take a multimeter set it on resistance and measure the resistance of a copper pipe and then of a copper bar.  Let me know if you will measure the same resistance.
If you measure a lower resistance for the copper bar and it just happens to be proportional with the sectional area of the copper that means electrons are free to travel through the entire section of the wire not just the outside portion for a DC current.
 

[electrodacus]

For consideration:


That was something like 3kW for a minute, at 10kHz or so, on a very rusty 1/4" thick steel plate.

The heating pattern is indicative of skin effect around the outer edge of the workpiece, though the glowing areas are much wider than the current paths due to the long heating duration.  Nonetheless it's more than adequate to see the superficial current flow path, preference for long sides, and avoidance of corners.

Tim

You do not understand what happens there and how an induction heater works. Also the skin effect has nothing to do with Derek's DC experiment nor it has anything to do with energy traveling through or outside the wire question.
The steel piece that you are heating is magnetic and those losses are due to resistance to magnetic field not electric current.
Nobody denies the skin effect exist for AC and at high frequency is very significant it just has nothing to do with the discussion about electrical energy flowing through wires or not.

[PlainName]

More diversion. You said we would see, as a pillar of your argument. So we want to see it, to recognise what you said was so. Now, when asked how to do that, you say we don't need to, or that it's an obvious effect of something else.

You made it up, didn't you? You can't prove it or show it and all you can do is circular arguments hoping that's not the one you end with when the music stops.

I already did

No, you did not.

but you may have missed that post

I thought perhaps I had, but apparently I saw what you think passes for it.

or it went over your head.

Ha ha! Just solve everything with the ad homs, eh.

Take a multimeter set it on resistance and measure the resistance of a copper pipe and then of a copper bar.  Let me know if you will measure the same resistance.
If you measure a lower resistance for the copper bar and it just happens to be proportional with the sectional area of the copper that means electrons are free to travel through the entire section of the wire not just the outside portion for a DC current.

Do you normally have problems comprehending a simple question? (Answer: yes, this web forum is full of examples)

Resistance has got nothing whatever to do with this. Once again, you said "you will see that the conductor heats uniformly on the entire conductor cross section" (my emphasis because you apparently can't recognise your own words).

So once again, how does one "see that the conductor heats uniformly on the entire conductor cross section"? We don't want it implied by measuring resistance, we want to be able to see it, as you told us we could and would.

[electrodacus]

I sure not heard about him at university (Electrical engineering in some east european country).

The fact that you haven't heard about something doesn't mean that is wrong or unimportant. It just means that your education was bad. You also didn't know about preservation of charge which is a fundamental concept. I suggest that you work through a good book on Electromagnetics. You are clearly out of your depth.

I did not studied history of electricity but applied electrical engineering based on latest understanding of the subject.
You do not understand what conservation of charge means and how it applies to an isolated system.
What you care about in the two or three parallel capacitor problem is conservation of energy.
You are unable to make predictions about a system because you do not understand how to apply the known equations.
That is why people do not think paralleling two ideal and identical capacitors (no resistance in circuit) 3V for charged one will result in 2.121V
And you can get very close to that also by using a DC-DC converter to transfer energy from one capacitor to the other.   

[hamster_nz]

Yes if you place a charged particle in an electric field it will be accelerated but note the action you take to put a charged particle there.

And placing the charge in the central region takes more 'action', and it stubbornly refuses to accelerate. It just sits there.

The potential difference for the capacitor is 10V in both cases and as far as energy is concerned it makes absolutely no difference. The zero/ground is something arbitrary that we chose.

And yet you say that an charge that you say a charge in a wire is carrying high potential energy is somehow 'different' to one that has zero potential energy? You talk of "high energy electrons" moving slowly in the wires.

A single inductor is an energy storage device same as the capacitor is an energy storage device and so with transformer you can store energy by creating a magnetic field while supplying the primary and then retrieve that stored energy with the secondary or the other way around or with the same.

I can't resolve your statements with that all the energy is in the wires, when now you are talking about storing it (and even transferring it) in a magnetic field

Of course a transmission line is a series of inductors, capacitors and resistors and of course you can see them if you can see the wires of the transmission line and understand what a capacitor, inductor and resistor are.

Show me a picture of an inductor in Derick's video, or even just a capacitor

The energy of a radio transmitter will not disappear. As a simplification is a capacitor with one plate as the transmitter the ground as one of the conductors and the other plate is the receiver again with ground as the common conductor.

A capacitor with the physical dimensions of "two thin wires separated by kilometers" is so close to zero that no meaningful power transfer can occur. Strange how my phone's radio still work in my pocket, and radios even in space where there is no common ground...

If you think you have a better model that allows to make accurate predictions about what happens on a transmission line then please share as I will be curious to hear.  I will like to see the equations not just some story.

Sure. Wikipedia does a better job of documenting them than I ever could.

Gauss's law - https://en.wikipedia.org/wiki/Gauss%27s_law
Gauss's law for magnetism - https://en.wikipedia.org/wiki/Gauss%27s_law_for_magnetism
Faraday's law of induction - https://en.wikipedia.org/wiki/Faraday%27s_law_of_induction
The Ampère–Maxwell equation - https://en.wikipedia.org/wiki/Amp%C3%A8re%27s_circuital_law#Extending_the_original_law:_the_Amp%C3%A8re%E2%80%93Maxwell_equation

Between them this system of equations can explain all the little wrinkles that you are unable to.

[IanB]

If you think you have a better model that allows to make accurate predictions about what happens on a transmission line then please share as I will be curious to hear.  I will like to see the equations not just some story.

Sure. Wikipedia does a better job of documenting them than I ever could.

But you really shouldn't try. Electrodacus has a habit of saying things that are clearly wrong, muddled or confusing, and then inviting people to argue about them. It's no surprise that threads like this one tend to go on and one without end. That's the goal, to play people like a fiddle and goad them in to making more and more responses. The best solution is to simply ignore the posts and decline to respond. Electrodacus will eventually get bored and go away.

"Don't feed the trolls"

[hamster_nz]

And you can get very close to that also by using a DC-DC converter to transfer energy from one capacitor to the other.   

You keep saying this, and demanding "proof" from others, but you have yet to demonstrate this, even though you assert it over and over. Please demonstrate that this is at all possible.

I think you will find that because the capacitor is a low impedance load (it will store all the energy you can give it) the transfer from the DC-DC convertor will be limited by the convertor's input and output impedance. When the voltages in the capacitors are equal you will end up with less than 0.5 V_initial in both.

[PlainName]

That's the goal, to play people like a fiddle and goad them in to making more and more responses.

I think he genuinely believes what he says (that he is correct and everyone else "doesn't understand properly"). And much of the arguments are merely ways to not have to accept that he is wrong.

The best solution is to simply ignore the posts and decline to respond. Electrodacus will eventually get bored and go away.

If other topics are any guide, that would only be temporary until he starts up a new thread to demonstrate that, actually, he was right all along. Looks like a troll but I am not convinced.

What did turn off the lights on the faster than the wind thing was making him see he hadn't got a leg to stand on. That shut him up about it, until now (when it is far enough back that he can pretend he missed the end and insist energy storage is the answer to everything, as any fule would kno).

[electrodacus]

And you can get very close to that also by using a DC-DC converter to transfer energy from one capacitor to the other.   

You keep saying this, and demanding "proof" from others, but you have yet to demonstrate this, even though you assert it over and over. Please demonstrate that this is at all possible.

I think you will find that because the capacitor is a low impedance load (it will store all the energy you can give it) the transfer from the DC-DC convertor will be limited by the convertor's input and output impedance. When the voltages in the capacitors are equal you will end up with less than 0.5 V_initial in both.

I will not even bother to answer your comments as it will be a never ending story. You clearly lack basic understanding.

What is your prediction if you are using say a 80% efficient DC-DC converter with constant current limiting with current limited so that wires and capacitor internal resistance is basically insignificant in therms of extra losses or say the 80% efficiency includes those losses to make the calculation simpler.
What will be the end voltage if you transfer from a charge 1F capacitor 3V to a identical 1F capacitor that is fully discharged so 0V

Unless you can offer a prediction you can not claim you understand how any of this works.  And feel free to use any tool you want to come up with the answer.
Also when I mentioned that end voltage will be higher than 1.5V some of you (not sure if you included) had concerned about the fact that a DC-DC converter uses active components. This will again be a lack of understanding if you or the ones that made this comment think extra energy will somehow magically appear in this isolated circuit because of the use of a DC-DC converter that is only powered by the charged capacitor.

[electrodacus]

But you really shouldn't try. Electrodacus has a habit of saying things that are clearly wrong, muddled or confusing, and then inviting people to argue about them. It's no surprise that threads like this one tend to go on and one without end. That's the goal, to play people like a fiddle and goad them in to making more and more responses. The best solution is to simply ignore the posts and decline to respond. Electrodacus will eventually get bored and go away.

"Don't feed the trolls"

You are welcome in providing the answer to the question I posted to hamster_nz. In fact anyone is welcome.

[hamster_nz]

And you can get very close to that also by using a DC-DC converter to transfer energy from one capacitor to the other.   

You keep saying this, and demanding "proof" from others, but you have yet to demonstrate this, even though you assert it over and over. Please demonstrate that this is at all possible.

I think you will find that because the capacitor is a low impedance load (it will store all the energy you can give it) the transfer from the DC-DC convertor will be limited by the convertor's input and output impedance. When the voltages in the capacitors are equal you will end up with less than 0.5 V_initial in both.

I will not even bother to answer your comments as it will be a never ending story. You clearly lack basic understanding.

What is your prediction if you are using say a 80% efficient DC-DC converter with constant current limiting with current limited so that wires and capacitor internal resistance is basically insignificant in therms of extra losses or say the 80% efficiency includes those losses to make the calculation simpler.
What will be the end voltage if you transfer from a charge 1F capacitor 3V to a identical 1F capacitor that is fully discharged so 0V

Unless you can offer a prediction you can not claim you understand how any of this works.

What part of "When the voltages in the capacitors are equal you will end up with less than 0.5 V_initial in both." is not "offering a prediction"?

[electrodacus]

What part of "When the voltages in the capacitors are equal you will end up with less than 0.5 V_initial in both." is not "offering a prediction"?

Show me the math you use to get to that conclusion.
The question I asked involves a DC-DC converter with constant current control between the two capacitors and total efficiency of 80%.
Say you start at 3V for the charged capacitor and you stop the discharge when the charged capacitor voltage drops to 2.121V so half the initial energy.
What will be the voltage on the other capacitor the one that started empty at 0V.

[hamster_nz]

The question I asked involves a DC-DC converter with constant current control between the two capacitors and total efficiency of 80%.
Say you start at 3V for the charged capacitor and you stop the discharge when the charged capacitor voltage drops to 2.121V so half the initial energy.
What will be the voltage on the other capacitor the one that started empty at 0V.

What you are saying is "If I had a Unicorn, then I could open a Unicorn Zoo - prove me wrong!".

No, you prove me wrong. Show me your unicorn!

[Naej]

I must have missed it. Please explain what experiment was done,

Very funny. The only thing I did in this thread was to indicate all the experimental data that support the energy flowing in space.

Really, where then?
Please explain what experiment was done, what S=JV predicted, what Poynting predicted and what was found.
There's none.

what was predicted by the S=JV folks, and what was found. (And why Poynting-Heaviside-etc. do not talk about it.)

What they accomplished no one knows. What they didn't, we know. They didn't manage to come up with an alternative that doesn't break causality, locality, gauge invariance or a combination of these.

That's why, despite objections regarding its counterintuitive nature, Poynting is the most probable explanation for the flow of energy.

You gave no example of an alternative breaking any of this . Coincidence?

I also wonder how exactly all physicists proposing alternatives to the Poynting theorem never saw Derek's antennae coming in the whole 20th century. They must feel very silly now (no).

They didn't. But their peers did and criticized their proposals. That's why Poynting still stands.

Sure so in the 20th century and 21st physicists never heard of antennae. 

[electrodacus]

What you are saying is "If I had a Unicorn, then I could open a Unicorn Zoo - prove me wrong!".

No, you prove me wrong. Show me your unicorn!

You will think that it is a unicorn because you do not understand the subject. It is in fact just a simple horse

But here is the proof

[Naej]

Why will I be bothered by that ?

And it doesn't bother you at all that there is no circuit you can put in region A in the diagram below that can extract energy from the wires that surround it? Even a DC/DC convertor? Even if you can connect it to a GND? But extracting energy from regions B or C is a piece of cake?

And it doesn't bother you at all that energy is supposedly flowing through the region A yet there is no circuit you can put in region A in the diagram that can extract energy from it?
(Hopefully the answer is no)

And it doesn't bother you that for your version of electrostatics  (sum of force between charges), every charge needs to be in consistent communication with every other charge in the universe, to work out how far away they are, and at what direction?

Are you bothered???
Do you think that if every electron could communicate with far away electrons, humans could make machines hacking this property to communicate messages?

And it doesn't bother you that a transmission line is a series of inductors and capacitors, however on inspection those capacitors and inductors can neither be identified or isolated?

A wire is an inductor. With 2 you have an inductor and half a capacitor. And it works even for infinitesimal wires. 

[SiliconWizard]

Yes. A piece of wire has inductance. And conductive hollow cylinders (tubes) are in fact legit transmission lines. AFAIK.

[hamster_nz]

Why will I be bothered by that ?

And it doesn't bother you at all that there is no circuit you can put in region A in the diagram below that can extract energy from the wires that surround it? Even a DC/DC convertor? Even if you can connect it to a GND? But extracting energy from regions B or C is a piece of cake?

And it doesn't bother you at all that energy is supposedly flowing through the region A yet there is no circuit you can put in region A in the diagram that can extract energy from it?
(Hopefully the answer is no)

No, with no voltage potential over region A, there is no way you can extract energy from the field in just that region.

And it doesn't bother you that for your version of electrostatics  (sum of force between charges), every charge needs to be in consistent communication with every other charge in the universe, to work out how far away they are, and at what direction?

Are you bothered???
Do you think that if every electron could communicate with far away electrons, humans could make machines hacking this property to communicate messages?

It did bother me just a little - Every charge being constantly aware of every other charge in the universe does not have the feel of being fundamental to the universe.

An electric field can still be used to communicate messages. "Ripples in the fields" is preferable to "very small pushes and shoves over great distances".

And it doesn't bother you that a transmission line is a series of inductors and capacitors, however on inspection those capacitors and inductors can neither be identified or isolated?

A wire is an inductor. With 2 you have an inductor and half a capacitor. And it works even for infinitesimal wires. 

Fair call. But I still feel that a lumped model of a continuous thing is (very useful) approximation.

[hamster_nz]

What you are saying is "If I had a Unicorn, then I could open a Unicorn Zoo - prove me wrong!".

No, you prove me wrong. Show me your unicorn!

You will think that it is a unicorn because you do not understand the subject. It is in fact just a simple horse

But here is the proof
(Attachment Link)

You are a hard person to goad something out of, but eventually it works.

[electrodacus]

You are a hard person to goad something out of, but eventually it works.

Is that your replay ? How about you understand now that if you transfer energy more efficiently from one capacitor to the other that is identical you get close to 0.707 the voltage of the charged capacitor in both.
It should not be me that is doing the work.

[bsfeechannel]

Really, where then?

Now you're trolling.

You gave no example of an alternative breaking any of this . Coincidence?

If you couldn't recognize it, this means you didn't go very far in your understanding of the problem.

Sure so in the 20th century and 21st physicists never heard of antennae. 

Who knows? What is important to understand is that the alternatives never prospered.