#562 – Electroboom!

[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!"

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.

[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.  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!

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

[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.

[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!"

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.  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!

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

And you neither understand Faradays' Law nor do you understand what a path integral is, and in particular what Faradays' Law says about closed paths:

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

So, the result of the experiment can be exactly predicted by application of Faraday's Law. You just have to understand it first.

[ogden]

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.

[ogden]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

[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.

[ogden]

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.

It is huge surprise to hear from you - that emf is indeed generated in the probe leads. Good. As emf generated in probe lead and wire connecting probing point and resistor on same side as voltmeter, are of same polarity - they cancel out meaning  voltage we see on voltmeter is equal to voltage drop on resistor. Glad you can learn too. Congrats!

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

Maybe you catch him out of context? Anyway I strongly disagree

[thinkfat]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

You said you understood circuit theory. Then you should know how each loop (mesh) in a circuit is to be evaluated separately, to later sum up all contributions. So, in Dr. Lewins circuit there are three loops, only one of which encloses an area with time-varying magnetic flux. Or do you suddenly want to argue that circuit theory cannot be applied any more? But KVL still works?

[ogden]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

You said you understood circuit theory. Then you should know how each loop (mesh) in a circuit is to be evaluated separately, to later sum up all contributions. So, in Dr. Lewins circuit there are three loops, only one of which encloses an area with time-varying magnetic flux. Or do you suddenly want to argue that circuit theory cannot be applied any more? But KVL still works?

Could be good we first clear question I asked you in my previous post because it lets you really question "three loops, only one of which encloses an area with time-varying magnetic flux", but it seems you just take it for a granted as usually true believers do. You are just believer or you can think too? Visualization attached for case 3.

[thinkfat]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

You said you understood circuit theory. Then you should know how each loop (mesh) in a circuit is to be evaluated separately, to later sum up all contributions. So, in Dr. Lewins circuit there are three loops, only one of which encloses an area with time-varying magnetic flux. Or do you suddenly want to argue that circuit theory cannot be applied any more? But KVL still works?

Could be good we first clear question I asked you in my previous post because it lets you really question "three loops, only one of which encloses an area with time-varying magnetic flux", but it seems you just take it for a granted as usually true believers do. You are just believer or you can think too? Visualization attached for case 3.

What's that supposed to change? The loop formed by the voltmeter and R2 still doesn't enclose any time-varying magnetic flux. You'd just have to analyze the circuit a little differently, but the result would stay the same.

PS: I found this video quite enlightening:
https://youtu.be/OmlnGei1xo8

[ogden]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

You said you understood circuit theory. Then you should know how each loop (mesh) in a circuit is to be evaluated separately, to later sum up all contributions. So, in Dr. Lewins circuit there are three loops, only one of which encloses an area with time-varying magnetic flux. Or do you suddenly want to argue that circuit theory cannot be applied any more? But KVL still works?

Could be good we first clear question I asked you in my previous post because it lets you really question "three loops, only one of which encloses an area with time-varying magnetic flux", but it seems you just take it for a granted as usually true believers do. You are just believer or you can think too? Visualization attached for case 3.

What's that supposed to change? The loop formed by the voltmeter and R2 still doesn't enclose any time-varying magnetic flux. You'd just have to analyze the circuit a little differently, but the result would stay the same.

It was supposed to let you actually think. Please be so kind, spread your wisdom. If as you say wires of outer loop having R2 do not receive any EMF, then I am all ears of your little different analysis for case #3. I am sure many others will be interested to hear it as well.

[edit] The best part of that video is at the end

[thinkfat]

There is no EMF induced in the loops formed by the probe wires and the resistors they connect to, because the paths \$C_1, C_2\$ don't enclose the magnetic flux region. This is a claim anyone can easily verify: Just take your oscilloscope probe, connect the ground lead to the tip and move it around the core, see if you can pick up any significant EMF.  Also, it would be quite miraculous how any induced EMF caused by "stray magnetic flux" would exactly make the two voltages reproduce the ratio between the resistors, to conveniently coincide with what is expected through Ohms law.

Here we go again. One of many fallacies of Lewin's cultists. Think about various values of R2, ranging from 900 Ohms till open (no resistor):

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

You said you understood circuit theory. Then you should know how each loop (mesh) in a circuit is to be evaluated separately, to later sum up all contributions. So, in Dr. Lewins circuit there are three loops, only one of which encloses an area with time-varying magnetic flux. Or do you suddenly want to argue that circuit theory cannot be applied any more? But KVL still works?

Could be good we first clear question I asked you in my previous post because it lets you really question "three loops, only one of which encloses an area with time-varying magnetic flux", but it seems you just take it for a granted as usually true believers do. You are just believer or you can think too? Visualization attached for case 3.

What's that supposed to change? The loop formed by the voltmeter and R2 still doesn't enclose any time-varying magnetic flux. You'd just have to analyze the circuit a little differently, but the result would stay the same.

It was supposed to let you actually think. Please be so kind, spread your wisdom. If as you say wires of outer loop having R2 do not receive any EMF, then I am all ears of your little different analysis for case #3. I am sure many others will be interested to hear it as well.

PS: I found this video quite enlightening:
https://youtu.be/OmlnGei1xo8

You can't say that there is no EMF in the wires of outer loop, at the time time agreeing to this video! 

What I say is that \$ \oint E \cdot dl = 0\$ for the measurement loop. Remember that the dispute is about Faradays' Law and whether volt meters conncted to the same nodes can show different values, depending on the path of measurement. Nothing else was claimed by Dr. Lewin.

[Sredni]

I wonder if Ogden is capable of computing and comparing the currents in the loop R1 R2 alone, in the loop R1 voltmeter alone and then in the full circuit with R1 R2 and the voltmeter.

Assume 10 meg for the voltmeter internal resistance.

[ogden]

What I say is that \$ \oint E \cdot dl = 0\$ for the measurement loop.

Typical tactics of Lewin's team - distraction and/or goalpost shifting.

I wonder if Ogden is capable of computing and comparing the currents in the loop R1 R2 alone, in the loop R1 voltmeter alone and then in the full circuit with R1 R2 and the voltmeter.

Sure. It's because I state that there is no outer loop which miraculously avoids EM induction so it does not matter - you put voltmeter or resistor on outside loop. I am sure you agree because recently stated that EMF is induced in outer wires as well.

[Sredni]

Then please by all means
Compute them and compare the three cases

[ogden]

Then please by all means
Compute them and compare the three cases

Be my guest.
Questions:

1. R1 = 100 Ohms and R2 = open circuit. Do you agree that EMF is induced in voltmeter leads? You shall. Because essentially there is no R2.
2. R1 = 100 Ohms and R2 = 900 Ohms. Now voltmeter leads miraculously do not get any EMF - as soon as you put resistor of *any* resistance closer to solenoid than Voltmeter?
3. What if you exchange R2 = 900 Ohms and voltmeter?  Then what?

Answers:
1. Voltmeter will indicate value close to EMF, ~1V. I say "close" because R1=100 Ohms way smaller than typical 10 Megs of voltmeters, but still not zero.
2. Essentially Lewin's circuit. Yes indeed EMF is generated induced in all wires & leads.
3. It does not matter where you put R2 - on inside or outside loop. EM induction do not miraculously pick inner loop, it acts on all wires unless they are magnetically shielded from time-varying magnetic field. So Lewin's circuit again.

[thinkfat]

What I say is that \$ \oint E \cdot dl = 0\$ for the measurement loop.

Typical tactics of Lewin's team - distraction and/or goalpost shifting.

Huh? I've never claimed anything but what is obvious from the Faraday-Maxwell equation (\$\oint E \cdot dl = -\frac{dB}{dt}\$) and this one only ever makes statements about closed paths. It was jesuscf who started the whole mess with scalar PD and voltages that are supposedly unique, but only until you measure them, when they suddenly become path dependent again.

[Sredni]

@ogden

So you are not able to compute the current in those three simple circuits?

And no, emf is not 'generated in wires'. The induced electric field is in all space, but when you put a good conductor in that space, the free charge inside will start to move, and things change.

Do you think charge will cease to generate an electric field when you move it?

[ogden]

So you are not able to compute the current in those three simple circuits?

I can try, but what's the point. Really. Explain please your aim. What will do calculation of current running through 10 MOhm voltmeters measuring 1mA-capable circuit other than pissing me off? Whatever. You can claim your victory. I wont waste time for stupid requests anyway. Take care.

[thinkfat]

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

Maybe you catch him out of context? Anyway I strongly disagree

Hm.

My question would be: do you really believe that Dr. Lewin is such a massive fool that he didn't understand that the volt meters (or oscilloscopes) he used and the paths they were connected through were part of the circuit?

Yes.

[ogden]

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

Maybe you catch him out of context? Anyway I strongly disagree

Hm.

I strongly disagree with jesuscf in this regard. Hopefully now this is clear and you can stop to bring this up. Better watch some Dr.Lewin's video. [edit] Wait.. I already stated that Dr.Lewin is brilliant teacher yet you are trying to prove something 

[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'.

[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:

[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.

Here, allow me to debunk the MIT guys from the video link you posted above.

With the toroid core I just received, I prepared a setup similar to the one in the video.  Here is a sketch of the circuit:



Instead of making a hole through the toroid to pass a wire to measure the voltage from node A to D without an induced EMF in the voltmeter probes, I used the balanced circuit composed by the two 10kOhm resistors.  Whatever voltage is induced in the left 10kOhm resistor is canceled by the voltage induced in the right 10kOhm resistor and the net EMF induced in the red probe wire is zero.  The total measured EMF is 67.6mV (RMS).  The equivalent circuit we need to solve is (sorry, the polarity of the sources is swapped in the circuit diagram, so fix the polarity before getting the equations):



As usual, calculate the current first:

\$
\begin{array}{l}
 EMF = 67.6mV \\
 I = \frac{{67.6mV}}{{100\Omega  + 910\Omega }} = 66.93\mu A \\
 \end{array}
\$

With the current we can calculate the voltage drop in the resistors:

\$
\begin{array}{l}
 V_{R1}  = 66.93\mu A \times 100\Omega  = 6.693mV \\
 V_{R2}  = 66.93\mu A \times 910\Omega  = 60.91mV \\
 \end{array}
\$

Using the left half or the right half of the circuit we can calculate the voltage V_AD (there is an error in the circuit diagram, the polarity of the sources is the other way around):

\$
\begin{array}{l}
 V_{AD}  = 33.8mV - 66.93\mu A \times 100\Omega  = 27.11mV \\
 V_{AD}  = 66.93\mu A \times 910\Omega  - 33.8mV = 27.11mV \\
 \end{array}
\$

These are the voltages I measured:

\$
\begin{array}{l}
 V_{R1}  = 6.44mV \\
 V_{R2}  = 61.15mV \\
 V_{AD}  = 27.16mV \\
 \end{array}
\$

Look at that: KVL works again!!! 

Here is a picture of the measured V_R1 and V_R2 voltages:



Here is a picture of the measured V_AD voltage:



Here is a view of the setup from the left (yes, those are chopsticks):



Here is a view of the setup from the right:



Hey team Lewin, show us your experiments please!  We are waiting!