"Veritasium" (YT) - "The Big Misconception About Electricity" ?

[EEVblog]

Up to you  I think the Falstad demo is really good at showing how a transmission line with lumped elements produces a delay though...
Which other wire? Both the positive and negative side wires will have series inductance elements with a capacitance between the wires in the "correct" model.

The bottom wire which is just shown as one long straight wire with no inductance along it's entire length. Visually I think it's poor.
I don't want to show how the waves travel, I'm just trying to explain how 1m/c answer is derived because of the nearby capacitance between cables.
Just showing the Falstead demo makes it hard to visually relate the Veritasium circuit I show above. It's all about the visuals and trying to match it so people understand.
Which one makes it more obvious what's happening?

[sandalcandal]

Up to you  I think the Falstad demo is really good at showing how a transmission line with lumped elements produces a delay though...
Which other wire? Both the positive and negative side wires will have series inductance elements with a capacitance between the wires in the "correct" model.

The bottom wire which is just shown as one long straight wire with no inductance along it's entire length. Visually I think it's poor.
I don't want to show how the waves travel, I'm just trying to explain how 1m/c answer is derived because of the nearby capacitance between cables.
Just showing the Falstead demo makes it hard to visually relate the Veritasium circuit I show above. It's all about the visuals and trying to match it so people understand.
Which one makes it more obvious what's happening?

I get what you mean but it really does irk me as an "incorrect" model that doesn't actually model the behaviour in question: the delay.

Attached is a lumped element model setup as I think should give delay.

[EEVblog]

Up to you  I think the Falstad demo is really good at showing how a transmission line with lumped elements produces a delay though...
Which other wire? Both the positive and negative side wires will have series inductance elements with a capacitance between the wires in the "correct" model.

The bottom wire which is just shown as one long straight wire with no inductance along it's entire length. Visually I think it's poor.
I don't want to show how the waves travel, I'm just trying to explain how 1m/c answer is derived because of the nearby capacitance between cables.
Just showing the Falstead demo makes it hard to visually relate the Veritasium circuit I show above. It's all about the visuals and trying to match it so people understand.
Which one makes it more obvious what's happening?

I get what you mean but it really does irk me as an "incorrect" model that doesn't actually model the behaviour in question: the delay.

Sorry, but I don't care. That's not what I'm going for.

[eti]

I think “science” YouTubers ought to stick to a field within which they specialise, as a whole. We have some exceptions, such as the savant-esque, polymath that is “Tech Ingredients”, who seems to genuinely possess a VAST amount of deep and wide knowledge across various disciplines of science and engineering, but I don’t see many of his ilk around the net. Portraying yourself as a jack of all trades “scientist” means you better REALLY REALLY REALLY REALLY know what you’re on about, down to the excruciating detail, as there’s always someone with greater knowledge in the specific subject, and they’re very likely to have dedicated most of their life to that one subject or discipline.

Then again, this mass appeal “science” gets hits and makes him money, and so many people can’t see any further than that - whether he’s right or wrong, or a bit of both, he’s still attracted himself a nice income, and it’s sad that this is increasingly seen to be of more value than humility and knowing your actual stuff, regardless of your wealth.

Ps, I don’t give a shit what “respected scientists” nod in agreement with him about - we use wires and solder down here on planet practical, that’s most of what matters - leave the intellectuals to play their thought experiments if they want to.

[sandalcandal]

I get what you mean but it really does irk me as an "incorrect" model that doesn't actually model the behaviour in question: the delay.

Sorry, but I don't care. That's not what I'm going for.

Well, glad you are at least aware and acknowledge it. 

[EEVblog]

I think “science” YouTubers ought to stick to a field within which they specialise, as a whole. We have some exceptions, such as the savant-esque, polymath that is “Tech Ingredients”, who seems to genuinely possess a VAST amount of deep and wide knowledge across various disciplines of science and engineering, but I don’t see many of his ilk around the net. Portraying yourself as a jack of all trades “scientist” means you better REALLY REALLY REALLY REALLY know what you’re on about, down to the excruciating detail, as there’s always someone with greater knowledge in the specific subject, and they’re very likely to have dedicated most of their life to that one subject or discipline.

Then again, this mass appeal “science” gets hits and makes him money, and so many people can’t see any further than that - whether he’s right or wrong, or a bit of both, he’s still attracted himself a nice income, and it’s sad that this is increasingly seen to be of more value than humility and knowing your actual stuff, regardless of your wealth.

Ps, I don’t give a shit what “respected scientists” nod in agreement with him about - we use wires and solder down here on planet practical, that’s most of what matters - leave the intellectuals to play their thought experiments if they want to.

I'm not sure that's fair. The video does present Poynting vectors and energy in a nice and useful way I think. If it was simply titled "Poynting vectors and energy flow" and left out the "trick" question, then it's a solid video. But as presented, it does kinda tick off engineers.
But that's his shtick, presenting "misconceptions" and then busting them. He did his PhD thesis on this in fact.
If it gets more people to watch science video then I'm fine with that.

[eti]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

[EEVblog]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

[eti]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

The one you’ve linked is not on either of your channels as viewable - only found it here as unlisted mate.

[eti]

Possible: Derek has a secret - he’s an investor in some giant Chinese wireless charging eqt manufacturer. 😜

[EEVblog]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

The one you’ve linked is not on either of your channels as viewable - only found it here as unlisted mate.

I have not released the main channel video yet, will do so at midnight when the eyeballs timing is better.
The other shot one was not meant to be released, it was just a clip for this forum.

[eti]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

The one you’ve linked is not on either of your channels as viewable - only found it here as unlisted mate.

I have not released the main channel video yet, will do so at midnight when the eyeballs timing is better.
The other shot one was not meant to be released, it was just a clip for this forum.

What, this 45 min long clip? You posted it on page 11 mate.

https://www.eevblog.com/forum/chat/veritasium-(yt)-the-big-misconception-about-electricity/msg3833039/#msg3833039

[EEVblog]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

The one you’ve linked is not on either of your channels as viewable - only found it here as unlisted mate.

I have not released the main channel video yet, will do so at midnight when the eyeballs timing is better.
The other shot one was not meant to be released, it was just a clip for this forum.

What, this 45 min long clip? You posted it on page 11 mate.

I meant that it hasn't been released to the public on my channel yet, it's still set as unlisted. This is why it only has 71 views instead of 10's of thousands.

[eti]

Dave I’ve downloaded your unlinked video in case you decide to delete it. I won’t share it but thanks mate 😎

It's all in the main channel video BTW.

The one you’ve linked is not on either of your channels as viewable - only found it here as unlisted mate.

I have not released the main channel video yet, will do so at midnight when the eyeballs timing is better.
The other shot one was not meant to be released, it was just a clip for this forum.

What, this 45 min long clip? You posted it on page 11 mate.

I meant that it hasn't been released to the public on my channel yet, it's still set as unlisted. This is why it only has 71 views instead of 10's of thousands.

Oh, of course.  Oops and duh. Ignore me 😁

[antenna]

Dumb question then...

Wikipedia says that as the resistance near the surface of the wire increases, the poynting vector tilts towards the conductor, and this is said to slow the velocity of propagation.  Does this mean that the velocity factor of a wire/transmission line is not only dependent on the insulation's permeability, but also on the conductor's resistivity/skin effect?  Will a thin wire propagate energy slower than a thick wire (...if that answer reverts to inductance and capacitance, ill be like )?  And now I am really confused, because all that silver nitrate that I electrodeposited allegedly required electrons, something that I now hear doesn't move but at a snail's pace, (some millimeters/second? they must be really tightly packed in there!!!).  So, a relation between all of this theory and Faraday's constant would be wonderful!  Isn't that 6.252 x 10^18 electrons in one second for 1 amp?  That's slow?

[sectokia]

I think “science” YouTubers ought to stick to a field within which they specialise, as a whole. We have some exceptions, such as the savant-esque, polymath that is “Tech Ingredients”, who seems to genuinely possess a VAST amount of deep and wide knowledge across various disciplines of science and engineering, but I don’t see many of his ilk around the net. Portraying yourself as a jack of all trades “scientist” means you better REALLY REALLY REALLY REALLY know what you’re on about, down to the excruciating detail, as there’s always someone with greater knowledge in the specific subject, and they’re very likely to have dedicated most of their life to that one subject or discipline.

Then again, this mass appeal “science” gets hits and makes him money, and so many people can’t see any further than that - whether he’s right or wrong, or a bit of both, he’s still attracted himself a nice income, and it’s sad that this is increasingly seen to be of more value than humility and knowing your actual stuff, regardless of your wealth.

Ps, I don’t give a shit what “respected scientists” nod in agreement with him about - we use wires and solder down here on planet practical, that’s most of what matters - leave the intellectuals to play their thought experiments if they want to.

I can't believe there is a 45 minute video for this... to me this just highlights how poorly everyone understand this.

I think this whole thing is way way easier to explain using elementary particles.

1- When the switch is flipped an electron will accelerate (the first one at the switch itself). This causes a changing magnetic field. This field is mediated by a gauged boson - which for electromagnetism is the photon. So it 'travels' at the speed of light. The changing magnetic field will induce a movement of charge at the light bulb after 1m/c seconds. Veritasium defined his light bulb as lighting from *any* amount of current. So the induced current, no matter how small, turns on his light globe 'wirelessly'.

2- So why don't we wirelessly light light bulbs? Because the force is extremely weak. Electrons in copper wire are on the order of 1 angstrom apart (thats 1e-10m). Magnetic force drops off as per inverse square law. So the force on the electon at the bulb will be 1e20 times weaker than the force from one electron to the next one in the wire. Obviously not enough to light a real world light bulb.

3-Why we use wires: When one electron 'pushes' on the next, the next electron is a charge itself, so the field strength 'resets' at each electron instead of deteriorating with distance. This push on each electrons is though an exchange of virtual photos, traveling at speed of light (in zero resistance wire). So it reaches the light bulb after 1 second. Only its field strength will be on the order of 1e20 times stronger than the 'wireless' one above. This is the force that for example, lights a real world light bulb, or is the 'wave' in time domain reflectometry.

4-You can see the above clearly in the professors answer. The professor basically says there is induction after 1m/c seconds, and then a step up in after 1 second. The situation is more complicated because every electron moving causes a 'wireless' wave. Then you also have the wave reflections before reaching steady state.

5- Veritasium has been mislead because he did not understand the implication of saying his magic bulb lights *at any current*. This enables it to light wirelessly from any changing magnetic field anywhere in the universe - the change just has to propagate at light speed though space.

6-As to energy going through space instead of the 'wire' - this is something also answered by quantum mechanics. An electron is a point particle. It has no dimensions in 3D space. So the field is entirely outside the electron. In a wire you have a whole bunch of electrons with overlapping fields. Thus some of the net field is within the wire and some is outside the wire, but all of it is through space.

[EEVblog]

1- When the switch is flipped an electron will accelerate (the first one at the switch itself). This causes a changing magnetic field. This field is mediated by a gauged boson - which for electromagnetism is the photon. So it 'travels' at the speed of light. The changing magnetic field will induce a movement of charge at the light bulb after 1m/c seconds. Veritasium defined his light bulb as lighting from *any* amount of current. So the induced current, no matter how small, turns on his light globe 'wirelessly'.

So does the capacitance between the wires.
Everyone with even fairly basic knowledge of electronics can understand the capacitor model. No guaged bosons or magnetic field knowledge required.
But hey, that's not the cool physics explanation, engineers are boring 

[sectokia]

1- When the switch is flipped an electron will accelerate (the first one at the switch itself). This causes a changing magnetic field. This field is mediated by a gauged boson - which for electromagnetism is the photon. So it 'travels' at the speed of light. The changing magnetic field will induce a movement of charge at the light bulb after 1m/c seconds. Veritasium defined his light bulb as lighting from *any* amount of current. So the induced current, no matter how small, turns on his light globe 'wirelessly'.

So does the capacitance between the wires.
Everyone with even fairly basic knowledge of electronics can understand the capacitor model. No guaged bosons or magnetic field knowledge required.
But hey, that's not the cool physics explanation, engineers are boring 

I guess my point is... all you need for this experiment is: electron, photon, and the electromagnetic field. You don't need capacitors, or transmission lines, and its a round about way to arrive at the same conclusion. Why not break it down the most elementary minimum of components? His bulb lights lights on any current. Therefore it can be 1 electron. Another electron 1 meter away accelerating will light the light bulb after 1m/c seconds due to electromagnetism. There is really nothing more that needs explaining.

[EEVblog]

1- When the switch is flipped an electron will accelerate (the first one at the switch itself). This causes a changing magnetic field. This field is mediated by a gauged boson - which for electromagnetism is the photon. So it 'travels' at the speed of light. The changing magnetic field will induce a movement of charge at the light bulb after 1m/c seconds. Veritasium defined his light bulb as lighting from *any* amount of current. So the induced current, no matter how small, turns on his light globe 'wirelessly'.

So does the capacitance between the wires.
Everyone with even fairly basic knowledge of electronics can understand the capacitor model. No guaged bosons or magnetic field knowledge required.
But hey, that's not the cool physics explanation, engineers are boring 

I guess my point is... all you need for this experiment is: electron, photon, and the electromagnetic field. You don't need capacitors, or transmission lines, and its a round about way to arrive at the same conclusion. Why not break it down the most elementary minimum of components? His bulb lights lights on any current. Therefore it can be 1 electron. Another electron 1 meter away accelerating will light the light bulb after 1m/c seconds due to electromagnetism. There is really nothing more that needs explaining.

Sure, multiple ways to explain it. Some people know more about or are more familiar with capacitors than photons and electromagnetic fields and virce-versa. The best explanation is the one that works for the individual.

[EEVblog]

I can't believe there is a 45 minute video for this... to me this just highlights how poorly everyone understand this.

It doesn't take me 45min to explain it. It really only takes a few minutes if you skip to the simulation part.
People wanted me to analyse the video, so I did a 20min odd reaction to various points. There are many timestamps in the video of the veriosu things talked about you can jump to.

[snarkysparky]

If the energy transfer is due to the fields outside the wire what happens when you make a tiny cut in the wire midway to the load.

I bet the light goes out.   Or does it?

[bsfeechannel]

A note on KVL with respect to Maxwell. Many seem to believe that KVL is is derived from Farady's Law (in the correct modern form formulated by Maxwell) as ∮ E • dL=0 and ∑ Vn=0 is a consequence when in reality it is historically the other way around! Kirchoff developed and published his laws of closed loop circuits independently in 1845 *16 years* before Maxwell publish his work on electromagnetics in 1861. You can see the original publication yourself in german here: https://gallica.bnf.fr/ark:/12148/bpt6k151490/f509 The typical introduction to KVL as a derivation of Faraday's law in typical physics pedagogy (and in physics textbooks) is a result of the tendency to introduce the less abstract Faraday's law first. Engineering education often simply states the law as is was originally defined since Faraday's law is often not introduced early in the engineering pedagogy.

[KVL is not a special case of Faraday’s law, it was derived first and exists by itself as a consequence of conservation of energy.]

Some more notes on history here: https://en.wikipedia.org/wiki/Maxwell%27s_equations#Historical_publications

Derived doesn't mean that one discovery led to another. Derived means that Faraday's law INCLUDES KVL. You can deduce KVL from Faraday's. Faraday's law, therefore, is a more complete, precise and accurate description of the circuital phenomenon than KVL.

For the record, Faraday discovered the phenomenon of magnetic induction BEFORE KVL. Maxwell just gave a math description to it.

[sandalcandal]

A note on KVL with respect to Maxwell. Many seem to believe that KVL is is derived from Farady's Law (in the correct modern form formulated by Maxwell) as ∮ E • dL=0 and ∑ Vn=0 is a consequence when in reality it is historically the other way around! Kirchoff developed and published his laws of closed loop circuits independently in 1845 *16 years* before Maxwell publish his work on electromagnetics in 1861. You can see the original publication yourself in german here: https://gallica.bnf.fr/ark:/12148/bpt6k151490/f509 The typical introduction to KVL as a derivation of Faraday's law in typical physics pedagogy (and in physics textbooks) is a result of the tendency to introduce the less abstract Faraday's law first. Engineering education often simply states the law as is was originally defined since Faraday's law is often not introduced early in the engineering pedagogy.

[KVL is not a special case of Faraday’s law, it was derived first and exists by itself as a consequence of conservation of energy.]

Some more notes on history here: https://en.wikipedia.org/wiki/Maxwell%27s_equations#Historical_publications

Derived doesn't mean that one discovery led to another. Derived means that Faraday's law INCLUDES KVL. You can deduce KVL from Faraday's. Faraday's law, therefore, is a more complete, precise and accurate description of the circuital phenomenon than KVL.

Not entirely sure you're agree or disagreeing. This a response to the comment made in the video that KVL came about as a construct after the formulation of Maxwell's equations and also the general misconception that KVL historically arose as a simplification of Faraday's law which is not the case since KVL was formulated (aka derived, aka written down and publish) before Faraday's Law was.

Again "derived" here meaning conceived/formulated (then written down and shared with the world). Not saying you can't mathematically derive KVL from Faraday's law, you definitely can. The misconception is that Faraday's law was "derived"/formulated first then KVL came about as a simplification/derivation from Faraday's law.

For the record, Faraday discovered the phenomenon of magnetic induction BEFORE KVL. Maxwell just gave a math description to it.

But point is the description of KVL doesn't come from doing maths on Faraday's law as described mathematically by Maxwell's work. The fact Faraday did his electromagnetic induction experiments before-hand is irrelevant.

[Also, seems my account is shadow banned in the YouTube comments? I guess Dave might have banned me there?  ]

[T3sl4co1l]

Dumb question then...

Wikipedia says that as the resistance near the surface of the wire increases, the poynting vector tilts towards the conductor, and this is said to slow the velocity of propagation.  Does this mean that the velocity factor of a wire/transmission line is not only dependent on the insulation's permeability, but also on the conductor's resistivity/skin effect?  Will a thin wire propagate energy slower than a thick wire (...if that answer reverts to inductance and capacitance, ill be like )?  And now I am really confused, because all that silver nitrate that I electrodeposited allegedly required electrons, something that I now hear doesn't move but at a snail's pace, (some millimeters/second? they must be really tightly packed in there!!!).  So, a relation between all of this theory and Faraday's constant would be wonderful!  Isn't that 6.252 x 10^18 electrons in one second for 1 amp?  That's slow?

Yes!

Mind, the component that "tilts inward", is also absorbed.  So, while it's slowed, it's not slowed externally.

There is still a small amount of the propagating wave that gets dragged by the line; this is improved with a little dielectric, making a Goubau line:
https://en.wikipedia.org/wiki/Goubau_line

If you accept that resistivity, permeability and permittivity all act to increase the index of refraction, then it's easily seen that this is a case of simple refraction.  Waves perfectly parallel to the surface shouldn't penetrate it, but they will in part due to evanescent waves (to use quantum terminology, the waves tunnel through the barrier as they spread out and diffract around it), and due to the dragging effect of loss (as seen in the Poynting vector, giving some radial direction).  The component that dips into the surface, is refracted relative to the angle of the surface and the index of refraction; the trapped wave turns sharply inward (relatively speaking).  Meanwhile, the high loss factor means attenuation is very rapid (within a wavelength or two, say), so whatever turns inward, quickly disappears as heat.

You can actually observe nulls or phase reversals inside wires or sheets (or whatever sorts of small objects), when the thickness is comparable to the skin depth; this may be due in part to phase shift, or to cancellation of the waves from both sides.  (Which is why cylindrical wires for example have a skin effect distribution given by a Bessel function, whereas for the infinite half-plane, the decay is a simple exponential.  Bessel functions are smooth and oscillatory; like sine, but with irregular zeroes.  They aren't particularly friendly to work with (being one of those lesser used, mysterious "special functions"), but frequently show up in problems with repeated cylindrical symmetry: here, the fields AND the wire.)


As for the silver and its electrons, yes indeed!  It's quite dense with electrons, and atoms are very small; this is why it takes so many coulombs of charge to deposit a sizable (some grams) amount of the stuff.  Electrochemistry is rather boring, taking the pace of seconds at best, and often hours or days for typical reactions (like charging batteries, or refining metals).

To be exact, Faraday's constant is a mole of electrons, expressed in units of charge: N_A / n_e.  Which comes out to 26.801 Ah/mol, so a car battery for example does about twice that, or two moles of lead, or at 208 g/mol, around a pound of lead changing oxidation state (between PbO2 / PbSO4 / Pb)!  Per cell, that is.  (So, about six pounds for the whole (12V) battery.  The remaining 20 or so pounds being inactive -- backing, supports, interconnects.)

Tim

[bsfeechannel]

Derived doesn't mean that one discovery led to another. Derived means that Faraday's law INCLUDES KVL. You can deduce KVL from Faraday's. Faraday's law, therefore, is a more complete, precise and accurate description of the circuital phenomenon than KVL.

Not entirely sure you're agree or disagreeing.

I’m just trying to clarify the term “derived”. Albeit KVL was historically formulated first, it can be derived from the later Faraday’s law. And it has to be, since Maxwell’s equations are the theory of everything of classical electromagnetism. So you are right, KVL is not a posterior simplification of Faraday’s law.