#562 – Electroboom!

[ogden]

Nice job! Appreciate your work and dedication. Especially nice is 2*10K solution which could spark new controversy - because it is "inner loop"

Meanwhile those who are not yet made their mind, can read detailed article about controversy, Do not miss to watch all the videos linked:
https://www.electronicdesign.com/technologies/analog/article/21808474/when-kirchhoffs-law-doesnt-work

For those who want to repeat experiment - many toroidal inductors out of your scrap box can be ok for the job.

[bsfeechannel]

Look at that: KVL works again!!! 

Yes. KVL holds for meshes I and II,  because they do not encircle a varying magnetic flux anymore, but you created a third mesh and behold there KVL fails. Guess why. Besides, points A and D still exhibit different voltages as clearly shown by your meters, which means that along the closed path of R1 an R2, the  voltages still do not add up to zero and KVL fails again.

Kirchhoff hates you.

[Sredni]

Okay. So, none of you, neither ogden or jesuscf are able to provide an equivalent circuit that reproduces Dr. Lewins experiment, right? And your whole defence to why you cannot do it boils down to "Lewin is an idiot!"

PS: before you go about bringing "stray magnetic flux" into the game again, watch this video maybe:

https://youtu.be/u6ud7JD0fV4

Ring core transformer, magnetic flux well confined inside the core. But the outcome is the same.

You don't understand how Faraday's law work!    If the circuit formed by the probes of your instrument go around the 'confined' varying magnetic core, there is going to be an induced EMF in the probes unless you align the probes carefully.

What you KVLers keep missing is that this emf makes the charge in the probes move and accumulate at the voltmeter's internal resistance and the field that is generated by that charge will cancel the induced field in the probes. Leaving nearly nothing in the probes.

  That is what is happening in the video you posted; there is definitively an induced EMF in the oscilloscope probes.  They are making exactly the same mistake Lewin made!

Sure. The MIT has always been a nest of incompetent physicists and engineers.
They should hire you, instead!

Watch this video from Trevor Kearney and pay attention to everything what he says.  In particular, since you don't seem to understand how is done, look carefully how he derives the equivalent circuit for the RHS of the setup.  That is what Lewin should have done.

https://youtu.be/FR8k12j7_Eo

Did you ask Trevor if he thinks Lewin is in error?
Are you afraid of asking?
Because I am pretty sure you are misunderstanding his point of view.

Why should I ask Trevor Kearney a question he has already answer in his videos?  You should go and watch his videos and try to understand them!  Once you have done that, you'll know for sure who is correct.

Also, do you remember that time you asked me if I had a toroid?  Well, I have one now!  This beauty just arrived:

Good. So now you can tell me what are the voltages in the arcs of the ring. I mean from A to R1, from R1 to D, from D to R2, and from R2 to A.

[thinkfat]

Okay. So, none of you, neither ogden or jesuscf are able to provide an equivalent circuit that reproduces Dr. Lewins experiment, right? And your whole defence to why you cannot do it boils down to "Lewin is an idiot!"

Can you read? https://www.eevblog.com/forum/amphour/562-electroboom!/msg3927647/#msg3927647. Dr.Lewin frustrated himself with overcomplicated experiment, drew wrong conclusions out of measurement results. If you see someone making error - you immediately label him an idiot? Dr.Lewin is brilliant teacher with loads of educating videos, I suggested one for you as well.

I specifically asked jesuscf if he thinks Dr. Lewin is an idiot and he confirmed it.

I don't remember saying that.  Can point me where I said it?

EDIT: I see it.  You can interpret that in many ways, but I didn't say Lewin is an idiot.  I just said 'yes' to your convoluted question.  But anyhow, believe what you want, that doesn't change reality.  Also, just for the record 'fool' != 'idiot'.

Convoluted, huh? The question was really just what you quoted in your response. I think you understood it quite well. What lead to the question was you quite correctly stating that connecting a measurement instrument to a circuit changes the circuit. So I asked if you thought Lewin was such a "massive fool" that he didn't understand this.

You answering "Yes" means you hold Lewin to be "massive fool who doesn't understand his own experiment". Which is of course completely, entirely different from calling him an idiot.

[thinkfat]

...

What do you mean with "debunked the MIT guys"? Apparently you have perfectly recreated their experiment. VR1 and VR2 still show different voltages and they are not going to change when you connect your volt meters directly to A and D instead of to the resistor terminals. So, now you have three voltages for VAD, on three different paths. I'd call that a success.

[Sredni]

Nice job! Appreciate your work and dedication. Especially nice is 2*10K solution which could spark new controversy - because it is "inner loop"

Meanwhile those who are not yet made their mind, can read detailed article about controversy, Do not miss to watch all the videos linked:
https://www.electronicdesign.com/technologies/analog/article/21808474/when-kirchhoffs-law-doesnt-work

For those who want to repeat experiment - many toroidal inductors out of your scrap box can be ok for the job.

I was well aware of this article, and as much as I like Rako's articles on EDN, he is dead wrong in thinking this is a probing issue.
He should know better, because he knows how to compute path integrals - unlike the vast majority of the garage gang.
At the end he quotes one of the comments where someone tries to explains where he is wrong, but he seems not to have anything to say about it. I wonder why.

Also, really bad taste in suggesting that Lewin's personal life could mean anything about the physics he discusses.
The only error Lewin committed in his videos are slips of the tongue regarding terminology. He sometimes said potential difference instead of voltage (he recently changed his boilerplate to fix that, upon suggestions by Mick Vall) and then there's that thing about the emf: in the ring with lumped resistors the induced Eind field gets obliterated in the conductive arc, while the field inside the resistors' adds up to a voltage equivalent to the emf linked by the circular path. That's why Lewin says the emf is at the resistors.

Chances are, Rako gets partial inductance wrong, as well. (And I could make an ever bigger name who does get that wrong, but I'm keeping it to myself)

[HuronKing]

Also, really bad taste in suggesting that Lewin's personal life could mean anything about the physics he discusses.
The only error Lewin committed in his videos are slips of the tongue regarding terminology.

It's really freaking weird too how these types of articles and comments focus so much on Lewin's politeness, tact, 'arrogance,' blah blah blah, or lack thereof, or whatever.

Meanwhile, I've met many of these same kind of engineers who pride themselves on their "blunt tactlessness" and "telling it like it is, man!"

And in the annals of the history of physics and engineering, we have quite a few characters who were pretty famously cantankerous or wryly abrasive but no less absolutely correct  - like Heaviside.

Lastly, it's also really weird how much attention is paid to how funny ElectroBoom is and how not-funny Lewin was... despite Lewin developing a reputation as one of the most entertaining physics educators ever to teach at MIT. Clowning in his lectures and telling jokes is trademark of his style. In fact, NONE of this would've even been controversial if he hadn't uttered the phrase 'Kirchhoff is for the birds and Faraday is not.'

I betcha if he had hidden the truth behind the calculus and jargon no one who doesn't understand path-dependent line integrals and non-conservative fields would've even noticed.

[jesuscf]

Nice job! Appreciate your work and dedication. Especially nice is 2*10K solution which could spark new controversy - because it is "inner loop"

Meanwhile those who are not yet made their mind, can read detailed article about controversy, Do not miss to watch all the videos linked:
https://www.electronicdesign.com/technologies/analog/article/21808474/when-kirchhoffs-law-doesnt-work

For those who want to repeat experiment - many toroidal inductors out of your scrap box can be ok for the job.

I am very thankful for your appreciation.  The reason I bought the toroid was to test the 2*10k circuit idea; it works really well.

Yes, I read the Electronic Design article some time ago.  It is good you posted the link so other people can get the full picture of this controversy.

I looked and looked for a big toroid with circular cross section, but I couldn't find any.  Decide to buy the one with rectangular cross are instead, which worked out OK for the setup.  With smaller toroids it could be difficult to solder the inner connecting wire.

[jesuscf]

Look at that: KVL works again!!! 

Yes. KVL holds for meshes I and II,  because they do not encircle a varying magnetic flux anymore, but you created a third mesh and behold there KVL fails. Guess why. Besides, points A and D still exhibit different voltages as clearly shown by your meters, which means that along the closed path of R1 an R2, the  voltages still do not add up to zero and KVL fails again.

Kirchhoff hates you.

I see you don't know how mesh analysis work either.  Lewin has a video on that, well, actually more like 5 videos on that.  So go watch them then come back to what you said above and see if you can find where you are wrong.

[jesuscf]

Okay. So, none of you, neither ogden or jesuscf are able to provide an equivalent circuit that reproduces Dr. Lewins experiment, right? And your whole defence to why you cannot do it boils down to "Lewin is an idiot!"

PS: before you go about bringing "stray magnetic flux" into the game again, watch this video maybe:

https://youtu.be/u6ud7JD0fV4

Ring core transformer, magnetic flux well confined inside the core. But the outcome is the same.

You don't understand how Faraday's law work!    If the circuit formed by the probes of your instrument go around the 'confined' varying magnetic core, there is going to be an induced EMF in the probes unless you align the probes carefully.

What you KVLers keep missing is that this emf makes the charge in the probes move and accumulate at the voltmeter's internal resistance and the field that is generated by that charge will cancel the induced field in the probes. Leaving nearly nothing in the probes.

  That is what is happening in the video you posted; there is definitively an induced EMF in the oscilloscope probes.  They are making exactly the same mistake Lewin made!

Sure. The MIT has always been a nest of incompetent physicists and engineers.
They should hire you, instead!

Watch this video from Trevor Kearney and pay attention to everything what he says.  In particular, since you don't seem to understand how is done, look carefully how he derives the equivalent circuit for the RHS of the setup.  That is what Lewin should have done.

https://youtu.be/FR8k12j7_Eo

Did you ask Trevor if he thinks Lewin is in error?
Are you afraid of asking?
Because I am pretty sure you are misunderstanding his point of view.

Why should I ask Trevor Kearney a question he has already answer in his videos?  You should go and watch his videos and try to understand them!  Once you have done that, you'll know for sure who is correct.

Also, do you remember that time you asked me if I had a toroid?  Well, I have one now!  This beauty just arrived:

Good. So now you can tell me what are the voltages in the arcs of the ring. I mean from A to R1, from R1 to D, from D to R2, and from R2 to A.

V_{A_to_R1}=16.9mV
V_{R1_to_D}=16.9mV
V_{D_to_R2}=16.9mV
V_{R2_to_A}=16.9mV

[jesuscf]

Okay. So, none of you, neither ogden or jesuscf are able to provide an equivalent circuit that reproduces Dr. Lewins experiment, right? And your whole defence to why you cannot do it boils down to "Lewin is an idiot!"

Can you read? https://www.eevblog.com/forum/amphour/562-electroboom!/msg3927647/#msg3927647. Dr.Lewin frustrated himself with overcomplicated experiment, drew wrong conclusions out of measurement results. If you see someone making error - you immediately label him an idiot? Dr.Lewin is brilliant teacher with loads of educating videos, I suggested one for you as well.

I specifically asked jesuscf if he thinks Dr. Lewin is an idiot and he confirmed it.

I don't remember saying that.  Can point me where I said it?

EDIT: I see it.  You can interpret that in many ways, but I didn't say Lewin is an idiot.  I just said 'yes' to your convoluted question.  But anyhow, believe what you want, that doesn't change reality.  Also, just for the record 'fool' != 'idiot'.

Convoluted, huh? The question was really just what you quoted in your response. I think you understood it quite well. What lead to the question was you quite correctly stating that connecting a measurement instrument to a circuit changes the circuit. So I asked if you thought Lewin was such a "massive fool" that he didn't understand this.

You answering "Yes" means you hold Lewin to be "massive fool who doesn't understand his own experiment". Which is of course completely, entirely different from calling him an idiot.

I see you are using the "look a squirrel!" fallacy.  (Sorry, I forgot the formal name of the fallacy)

[jesuscf]

...

What do you mean with "debunked the MIT guys"? Apparently you have perfectly recreated their experiment. VR1 and VR2 still show different voltages and they are not going to change when you connect your volt meters directly to A and D instead of to the resistor terminals. So, now you have three voltages for VAD, on three different paths. I'd call that a success.

There is only one correctly measured V_AD, which matches the KVL computation.  The other two measurements are not for V_AD;  one is for V_R1 and the other is for V_R2.   Saying otherwise is incorrect.

V_AD!=V_R1
V_AD!=V_R2

[Sredni]

Good. So now you can tell me what are the voltages in the arcs of the ring. I mean from A to R1, from R1 to D, from D to R2, and from R2 to A.

V_{A_to_R1}=16.9mV
V_{R1_to_D}=16.9mV
V_{D_to_R2}=16.9mV
V_{R2_to_A}=16.9mV

That's funny. You seem to think that the induced electric field is rotationally symmetric around the square section center and perfectly centered with your supposedly perfectly circular ring.

That's also expected.

And it's wrong.

Did you not pay attention to Trevor Kearney's video?

EDIT: in case you are wondering about why distinguish between potential difference and voltage, maybe you can open Hayt, and see if the seventh edition has at the beginning of chapter 9 the following sentence

The departure from static results is clearly shown by (3), for an electric field intensity resulting from a static charge distribution must lead to zero potential difference about a closed path. In electrostatics, the line integral leads to a potential difference; with time-varying fields, the result is an emf or a voltage.

and try to understand why they make this distinction.

[bsfeechannel]

Meanwhile those who are not yet made their mind, can read detailed article about controversy, Do not miss to watch all the videos linked:
https://www.electronicdesign.com/technologies/analog/article/21808474/when-kirchhoffs-law-doesnt-work

This is old news. We've already debunked Mehdi, Mabilde and a string of people who fall for the stupid claims perpetrated by the sick minds of KVLiars.

[thinkfat]

I see you are using the "look a squirrel!" fallacy.  (Sorry, I forgot the formal name of the fallacy)

Here:
https://en.wikipedia.org/wiki/List_of_fallacies

I'm sure you can pull something out of your nose.

[jesuscf]

I see you are using the "look a squirrel!" fallacy.  (Sorry, I forgot the formal name of the fallacy)

Here:
https://en.wikipedia.org/wiki/List_of_fallacies

I'm sure you can pull something out of your nose.

Sure I did:

"Fallacy of quoting out of context (contextotomy, contextomy; quotation mining) – selective excerpting of words from their original context to distort the intended meaning."

Thanks.

[bsfeechannel]

Also, really bad taste in suggesting that Lewin's personal life could mean anything about the physics he discusses.
The only error Lewin committed in his videos are slips of the tongue regarding terminology.

It's really freaking weird too how these types of articles and comments focus so much on Lewin's politeness, tact, 'arrogance,' blah blah blah, or lack thereof, or whatever.

Meanwhile, I've met many of these same kind of engineers who pride themselves on their "blunt tactlessness" and "telling it like it is, man!"

And in the annals of the history of physics and engineering, we have quite a few characters who were pretty famously cantankerous or wryly abrasive but no less absolutely correct  - like Heaviside.

Lastly, it's also really weird how much attention is paid to how funny ElectroBoom is and how not-funny Lewin was... despite Lewin developing a reputation as one of the most entertaining physics educators ever to teach at MIT. Clowning in his lectures and telling jokes is trademark of his style. In fact, NONE of this would've even been controversial if he hadn't uttered the phrase 'Kirchhoff is for the birds and Faraday is not.'

I betcha if he had hidden the truth behind the calculus and jargon no one who doesn't understand path-dependent line integrals and non-conservative fields would've even noticed.

The article also gives too much importance to popularity, which is not a very good parameter to ascertain the techical credibility of an engineer or a scientist.



As for politeness, I like one quote from Linus Torvalds who once suggested that stupid people should be "retroactively aborted" as they wouldn't be likely able to survive babyhood due to their inability "to find a tit to suck on".

He justified his behavior by saying that he saw political correctness destroy multiple projects out there and he didn't want that for Linux kernel.

I've been in the industry long enough to understand what he's talking about.

But since KVLiars love stupidity, and they fail every time, like KVL in a circuit under a varying magnetic field, I tend to belive that they are also incapable of satisfying even their most basic instincts.

Perhaps one redeeming point of the article is that the author admits in the end that KL fail sometimes, contradicting Mehdi, who stupidly asserts that "Kirchhoff always holds".

[thinkfat]

I see you are using the "look a squirrel!" fallacy.  (Sorry, I forgot the formal name of the fallacy)

Here:
https://en.wikipedia.org/wiki/List_of_fallacies

I'm sure you can pull something out of your nose.

Sure I did:

"Fallacy of quoting out of context (contextotomy, contextomy; quotation mining) – selective excerpting of words from their original context to distort the intended meaning."

Thanks.

Given that I explicitly provided the context of the quote to be fully transparent - yep, that is indeed from your nose.

Also, arguing that "massive fool != idiot" -> Logic chopping.

[jesuscf]

Also, really bad taste in suggesting that Lewin's personal life could mean anything about the physics he discusses.
The only error Lewin committed in his videos are slips of the tongue regarding terminology.

It's really freaking weird too how these types of articles and comments focus so much on Lewin's politeness, tact, 'arrogance,' blah blah blah, or lack thereof, or whatever.

Meanwhile, I've met many of these same kind of engineers who pride themselves on their "blunt tactlessness" and "telling it like it is, man!"

And in the annals of the history of physics and engineering, we have quite a few characters who were pretty famously cantankerous or wryly abrasive but no less absolutely correct  - like Heaviside.

Lastly, it's also really weird how much attention is paid to how funny ElectroBoom is and how not-funny Lewin was... despite Lewin developing a reputation as one of the most entertaining physics educators ever to teach at MIT. Clowning in his lectures and telling jokes is trademark of his style. In fact, NONE of this would've even been controversial if he hadn't uttered the phrase 'Kirchhoff is for the birds and Faraday is not.'

I betcha if he had hidden the truth behind the calculus and jargon no one who doesn't understand path-dependent line integrals and non-conservative fields would've even noticed.

The article also gives too much importance to popularity, which is not a very good parameter to ascertain the techical credibility of an engineer or a scientist.



As for politeness, I like one quote from Linus Torvalds who once suggested that stupid people should be "retroactively aborted" as they wouldn't be likely able to survive babyhood due to their inability "to find a tit to suck on".

He justified his behavior by saying that he saw political correctness destroy multiple projects out there and he didn't want that for Linux kernel.

I've been in the industry long enough to understand what he's talking about.

But since KVLiars love stupidity, and they fail every time, like KVL in a circuit under a varying magnetic field, I tend to belive that they are also incapable of satisfying even their most basic instincts.

Perhaps one redeeming point of the article is that the author admits in the end that KL fail sometimes, contradicting Mehdi, who stupidly asserts that "Kirchhoff always holds".

Reading bsfeechannel reminds me of Nathan Thompson.

Reading Sredni reminds me of Nathan Oakley.

[Sredni]

Reading books is what you should do, instead..
Start from Hayt, chapter 9 and try to understand why the author's differentiate between potential difference and voltage.

The books in your picture look alarmingly unread.

[ogden]

Engineer: "That model does not look right"
Scientist: "Eureka!"

When engineer say "you have to place wire here to get voltage X but have to place wire there to get voltage Y"- he gets fired.
When scientist say exactly same words - he gets worshipped.
Go figure.

[bsfeechannel]

I see you don't know how mesh analysis work either.

Translation: you got me again, damn it!

[jesuscf]

Reading books is what you should do, instead..
Start from Hayt, chapter 9 and try to understand why the author's differentiate between potential difference and voltage.

Got it:  Magnetic potential difference units are amperes.  Electric potential difference units are volts.

The books in your picture look alarmingly unread.

Maxwell's book is new.  As for Hayt's book:

[bsfeechannel]

Reading books is what you should do, instead..
Start from Hayt, chapter 9 and try to understand why the author's differentiate between potential difference and voltage.

The books in your picture look alarmingly unread.

Do you expect them to read books and on top of that understand what they read? You're asking too much. KVLism is based on ignorance. The more you're ignorant, the better. Because then they can claim with even more propriety that they have "debunked" some reputable scientist, engineer or scholar.

When they resort to books, it is only to select the passages that, out of context, appear to support their false claims, and rig their experiments until they get the results they think will prove them "right".

The books they show are only to impress the casual reader of the thread, or to serve as an amulet to ward off the evil people that show their favorite ignorant blogger is fundamentally wrong.

[jesuscf]

Engineer: "That model does not look right"
Scientist: "Eureka!"

When engineer say "you have to place wire here to get voltage X but have to place wire there to get voltage Y"- he gets fired.
When scientist say exactly same words - he gets worshipped.
Go figure.

That is so true!