General > General Technical Chat
Veritasium "How Electricity Actually Works"
electrodacus:
--- Quote from: EEVblog on May 12, 2022, 02:30:49 am ---
The other big thread used to be filled with the Maxwell/Poynting Bro's absolutely shooting down anyone who dared even hinted at suggesting anything other than a 100% Poynting explanation, and heaven forbid if you got even even the slightest direction of Poynting vector wrong, it's was flaming pitchforks.
Now all the Poynting bros have vanished and both threads are now completely dominated by the Energy In The Wire (EIT) absolutists.
LOL :-DD :popcorn:
--- End quote ---
:) This is not a political or philosophical discussion (or at least it should not be as it is not for me).
As you showed in your own video the transmission line model where you use finite RLC elements works perfect in predicting what you see in real tests.
Claim Derek made is that energy transfer is done outside the wire. Then the most pertinent question is why you even need the wires? They are quite expensive so it will be great if you could transfer electrical energy efficiency without needing them.
Also how come that from experimental result and transmission line calculations you get the same thing and that is energy output from the source equals energy delivered to lamp/load plus the losses in wires. If wires were not delivering the energy then why will all the losses (except some ultra small leakage) are found as heat in the wires. The lamp or resistor is also a wire with higher resistance.
I'm willing to admit that I'm wrong if a pertinent alternative explanation is available with the correct math to back that up.
The simulation I have done in LTspice perfectly matches the experimental result Derek got in his last video and there you can look at all aspects of the model to see where energy is at any point in time.
To have electrical power (energy is the integral of that over time) you need both a voltage potential and a current flow. Unless voltage is so high that current flows through air the current will follow the path of least resistance and that is the wire.
Derek's only so called evidence is that he sees some energy used by the lamp way before the electron wave had time to travel through wire and that is very simply explained by the two capacitors formed by the transmission line on each side of the lamp and showed to be the case form the spice simulation of a transmission line.
That current is needed to charge the capacitors that are just an energy storage device and current cannot flow through them (ignoring again ultra small leakage) but flows in or out of them.
So everything will reduce to the question of current flows through capacitors or in/out of capacitors.
Charging a capacitor requires adding electrons on one side while removing the same amount from the other side. And the electric field that the extra electron produces to push an electron out of the other side will be there only after you have that electron imbalance. Is not the electric field that magically appears between the plates of a capacitors (they are an electric shield) but the field is the result of electron imbalance.
IanB:
--- Quote from: EEVblog on May 12, 2022, 02:30:49 am ---The other big thread used to be filled with the Maxwell/Poynting Bro's absolutely shooting down anyone who dared even hinted at suggesting anything other than a 100% Poynting explanation, and heaven forbid if you got even even the slightest direction of Poynting vector wrong, it's was flaming pitchforks.
Now all the Poynting bros have vanished and both threads are now completely dominated by the Energy In The Wire (EIT) absolutists.
LOL :-DD :popcorn:
--- End quote ---
It seems that Mr Poynting got around a bit. I am familiar with the name from my field, chemical engineering:
https://en.wikipedia.org/wiki/Poynting_effect
(Nothing whatsoever to do with electricity.)
But it seems this is the same John Henry Poynting who is associated with the Poynting vector:
https://en.wikipedia.org/wiki/Poynting_vector
In the old days, it appears people were much more able to study everything:
https://en.wikipedia.org/wiki/John_Henry_Poynting
electrodacus:
--- Quote from: IanB on May 12, 2022, 03:01:35 am ---It seems that Mr Poynting got around a bit. I am familiar with the name from my field, chemical engineering:
https://en.wikipedia.org/wiki/Poynting_effect
(Nothing whatsoever to do with electricity.)
But it seems this is the same John Henry Poynting who is associated with the Poynting vector:
https://en.wikipedia.org/wiki/Poynting_vector
In the old days, it appears people were much more able to study everything:
https://en.wikipedia.org/wiki/John_Henry_Poynting
--- End quote ---
That guy was dead by the time people found out what atoms are made out of. I sure not heard about him at university (Electrical engineering in some east european country).
TimFox:
Yeah, the guys who figured out how atoms are constructed are now dead, too.
Funny how real progress in science often builds on previous results.
IanB:
--- Quote from: electrodacus on May 12, 2022, 02:59:30 am ---This is not a political or philosophical discussion (or at least it should not be as it is not for me).
--- End quote ---
It seems to be 100% a philosophical discussion for you. You seem to be arguing about nothing.
--- Quote ---As you showed in your own video the transmission line model where you use finite RLC elements works perfect in predicting what you see in real tests.
--- End quote ---
So that's good right? What is there to argue about?
--- Quote ---Claim Derek made is that energy transfer is done outside the wire.
--- End quote ---
The claim Derek made is that enough power would arrive to light a lamp after a certain amount of time. The experiment showed this to be true. The calculations gave the same answer.
--- Quote ---Then the most pertinent question is why you even need the wires? They are quite expensive so it will be great if you could transfer electrical energy efficiency without needing them.
--- End quote ---
Because the wires are part of the experiment. Derek did not suggest the wires are not needed. Quite the contrary, in fact. So why would you suggest the wires are not needed? Nobody even hinted at such a thing.
--- Quote ---Also how come that from experimental result and transmission line calculations you get the same thing and that is energy output from the source equals energy delivered to lamp/load plus the losses in wires.
--- End quote ---
Because this is how things are supposed to work? Why is it strange to you that the calculations and experiment give the same result?
At this point, it is really not clear what you disagree with.
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