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Author Topic: Professor Walter Lewin's Non-conservative Fields Experiment  (Read 250000 times)

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It's not as complicated as it may seem...
Gibbs,

Here is the idea of my test:

If we all agree that in the inductive loop, induced emf = pd (potential drops), then I propose we measure the pd's, with and without the decoupled measurement leads connected at points D and A.

So we use the in-plane lead orientation to measure the pd across both resistors, once without the decoupled leads connected between points D and A, and once with. We could do this 3 times each to get an average reading for both scenarios.

If the total pd is the same or within a few percent between each scenario, one with the decoupled leads, and one without, then we can say that the decoupled lead measurement DOES NOT have an appreciable effect on the total induced emf. Therefore, the decoupled measurement technique can be approved as a valid method to measure across any two points on the loop.

What do y'all think?

Of course this will only go forward if WW agrees that using the in-plane measurement isn't going to skew or throw off the actual induced emf in the loop.

What do you say WaveWatcher?


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Gibbs,

Here is the idea of my test:

If we all agree that in the inductive loop, induced emf = pd (potential drops), then I propose we measure the pd's, with and without the decoupled measurement leads connected at points D and A.

So we use the in-plane lead orientation to measure the pd across both resistors, once without the decoupled leads connected between points D and A, and once with. We could do this 3 times each to get an average reading for both scenarios.

If the total pd is the same or within a few percent between each scenario, one with the decoupled leads, and one without, then we can say that the decoupled lead measurement DOES NOT have an appreciable effect on the total induced emf. Therefore, the decoupled measurement technique can be approved as a valid method to measure across any two points on the loop.

What do y'all think?

Of course this will only go forward if WW agrees that using the in-plane measurement isn't going to skew or throw off the actual induced emf in the loop.

What do you say WaveWatcher?

There is restriction to this method. 

The resistor length must be as close to zero as possible.  Otherwise, you will subject to the sector measurement as we have already demonstrated. 

   

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It's not as complicated as it may seem...
There is restriction to this method.  

The resistor length must be as close to zero as possible.  Otherwise, you will subject to the sector measurement as we have already demonstrated.  

Sorry, I don't follow your reasoning. I don't know what a "sector measurement" is.

The in-plane measurement is what Lewin uses. Are you forgetting that when using the in-plane measurement, the length of the resistor isn't critical? Remember that this measurement produces virtually identical results when the probes are directly across the resistor OR across points D and A.


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Let's look at this picture.  The measurement decoupled at point 0b and 1a is .06V .  What would the in plane measurement for these two points?  The in plane measurement would give the voltage across the resistance of that wire segment... which is about 0V (we'll ignore the loop size effect).  Do you agree?  If you have 100 Ohms with the length of that segment, the in plane would gives say .1V, but the decoupled would reads .1V+.06V.    So we ask what is causing the .06V?  Hope I didn't lost you.





   

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It's not as complicated as it may seem...
Let's look at this picture.  The measurement decoupled at point 0b and 1a is .06V .  What would the in plane measurement for these two points?  The in plane measurement would give the voltage across the resistance of that wire segment... which is about 0V (we'll ignore the loop size effect).  Do you agree?  
Yes.

Quote
If you have 100 Ohms with the length of that segment, the in plane would gives say .1V, but the decoupled would reads .1V+.06V.    So we ask what is causing the .06V?  Hope I didn't lost you.
The in-plane measurement would give 0.1V (assuming the measurement is taken from the left side), and the decoupled measurement would ALSO give 0.1V, assuming the measurement is taken directly across the resistor element, with no wire segment in between the measurement probes.

You're trying to re-write Ohms law too I see.  >:-)


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The in-plane measurement would give 0.1V (assuming the measurement is taken from the left side), and the decoupled measurement would ALSO give 0.1V, assuming the measurement is taken directly across the resistor element, with no wire segment in between.

So you think even if the resistor is as long as the segment, the measurement is still .1V?  The length of the resistor is also a wire.  So the decoupled measurement would be resistance + length. 
   

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It's not as complicated as it may seem...
So you think even if the resistor is as long as the segment, the measurement is still .1V?
Yes. You can't break Ohms law this way.

Quote
The length of the resistor is also a wire.  So the decoupled measurement would be resistance + length.  
The resistor is not equivalent to a wire, and much less emf will be induced in them as a result; the ratio being:

emf(wire)/emf(resistor) = R(resistor)/R(wire) (for approx. same length resistor & wire)

There are far fewer free electrons in a resistor compared to a wire, and it is the free electrons that become "induced" into moving due to the electric field. So, fewer free electrons, less induced emf. The vast majority of the emf is induced in the wire segments.


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There is an easy way to test this.

Let's insert 100Ohms into segment 0b-1a.  Let's say the segment is 4 inches long.  A typical resistor is .5 inch long after clipping the leads off.  We can join 8 resistors together with 12.5 Ohms each resistor.  Now we have 100 Ohms resistor with 4 inches long (no leads).  Is this fair?  Will the measurement the same in plane and decoupled? 

   

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Of course this will only go forward if WW agrees that using the in-plane measurement isn't going to skew or throw off the actual induced emf in the loop.

What do you say WaveWatcher?

I don't know how another statement from me should matter. I was waiting to see what method you would invent that didn't change the Gaussian surface area and also not change the quantity of such areas. The method you describe will do one, the other or both. It doubt it will change the actual emf induced in the loop under test. That isn't the point. If that was understood you probably wouldn't bother the proposed test.

Please continue, anyway. I'm hoping that at some point you will discover what I'm talking about on your own. It will make more sense that way.


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"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality." - Einstein

"What we observe is not nature itself, but nature exposed to our method of questioning." - Werner Heisenberg
   

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It's not as complicated as it may seem...
There is an easy way to test this.

Let's insert 100Ohms into segment 0b-1a.  Let's say the segment is 4 inches long.  A typical resistor is .5 inch long after clipping the leads off.  We can join 8 resistors together with 12.5 Ohms each resistor.  Now we have 100 Ohms resistor with 4 inches long (no leads).  Is this fair?  Will the measurement the same in plane and decoupled? 

Yes, this could be done, but it would not likely work as you envision. A segment of wire even 0.1mm long is most likely going to produce more emf than the resistor material.

Perhaps we can simply find a long non-inductive resistor, and use that? Even one inch would be sufficient I believe. I will look and see what I have.


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Yes, this could be done, but it would not likely work as you envision. A segment of wire even 0.1mm long is most likely going to produce more emf than the resistor material.

Perhaps we can simply find a long non-inductive resistor, and use that? Even one inch would be sufficient I believe. I will look and see what I have.

Poynt,

The result over the entire length (say 100mm) just wire alone is .06V.  What would .1mm length contribute? 

.06V/100mm = ?V/.1mm

V = .006/100 = .00006V 

So .1mm length contribute .00006V to the measurement.  It's negligible.

   

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It's not as complicated as it may seem...
I don't know how another statement from me should matter. I was waiting to see what method you would invent that didn't change the Gaussian surface area and also not change the quantity of such areas. The method you describe will do one, the other or both. It doubt it will change the actual emf induced in the loop under test. That isn't the point. If that was understood you probably wouldn't bother the proposed test.

Please continue, anyway. I'm hoping that at some point you will discover what I'm talking about on your own. It will make more sense that way.
WW, unless you can produce a test that accomplishes what's needed, then it's relatively easy to rest on the notion that the decoupled leads are tainting the experiment, isn't it? What do you suggest then as a means to determine this?

Anyone????

Are you resting "your case" on this WaveWatcher? I'd guess you're pulling out of the debate then. How unfortunate if you're content leaving it inconclusive... for you that is.


Let's summarize where we are at this point, regarding the Lewin experiment according to WW:

1) All the measurements I've taken on my apparatus are invalid, notwithstanding the non-ideal solenoid. This, despite close correlation with a simulation of the experiment.

2) Lewin's in-plane measurements are invalid.

3) An in-plane measurement of pd's in the experiment invalidates the emf measurement.

4) It is beyond practical means to design and implement a test to quantify the true induced emf in Lewin's experiment.

5) Regardless if induction does not occur in the measurement leads, the measurement taints the experiment nonetheless.

6) We are to take WW's word for the above, even though he has not shown any proof, nor confirmed anything by experiment.

 C.C



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It's not as complicated as it may seem...
Poynt,

The result over the entire length (say 100mm) just wire alone is .06V.  What would .1mm length contribute?  

.06V/100mm = ?V/.1mm

V = .006/100 = .00006V  

So .1mm length contribute .00006V to the measurement.  It's negligible.

Gibbs, either you're not following along, or you didn't understand.

It has little to do with length. It has ALL to do with free electrons. This should hopefully make it clear:

Imagine part of a loop is composed of nichrome wire that is 9 inches long. That 9 inches of nichrome wire has a resistance of 100 Ohms. Attached to this to complete the loop is one inch of solid copper wire. Guess where 99.9999999999999999999999999% of the induced emf is going to appear? Across that one inch of copper wire.


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Okay,

Let's approach this from another angle.   Again, measurement is being decoupled at point 0b-1a.  It is being read .06V.  Now we decrease the height of decoupling.  Voltage starts to drop down and as the height reach 0, voltage reads zero.  Decoupled is decoupled, why does this happens? 

   

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It's not as complicated as it may seem...
Unfortunately Gibbs, I won't be able to perform either of these two experiments (I know you want me to prove the 9 inch nichrome, 1 inch copper thing) for a number of days, as I'm going in for a hernia repair surgery in the morning.  :'(


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Unfortunately Gibbs, I won't be able to perform either of these two experiments (I know you want me to prove the 9 inch nichrome, 1 inch copper thing) for a number of days, as I'm going in for a hernia repair surgery in the morning.  :'(

I'm sorry Poynt.  I did not want you to perform those experiments.  I rather experiment is the last thing we do.  Hernia is bad enough, let's not get a stomach ulcer because of worry.  We all hope you well.

   

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The way this device/system works is conclusive for me and I urge anyone in doubt to perform the experiments themselves. Don't take my word for it

I could be and probably am wrong on some points. In the end, the opinions of those I repeat, from those with far more expertise than I could claim, mean nothing when you can only relate your observations to what you know.

Faraday was a genius at visualizing what happened in his experiments. He went overboard on more than one occasion. Thanks to him we think we have wave-particle duality, spooky action at a distance, Einstein spending his last years trying to convince people he had some of his ideas wrong and who knows what else.

Number 1 is incorrect. There doesn't seem to be anything wrong with the measurements.

Number 2 is incorrect. Lewin's in-plane resistor measurements weren't resistor measurements and I'm sure he knew it. His purpose was to demonstrate non-conservative fields and related issues. He succeeded.

Number 3 is not precise. Any measurement will display the view of the observer (the meter or scope) not the loop.

Number 6 is incorrect. I almost never take the word of another when it comes to experimental observations. Why should anyone take the word of Faraday, Lorentz, Gauss, other well known names or even little 'ol me?
 
I'm sure the functions demonstrated have made some good money for a few. Others just have to work with it every day. The majority will never see an example in front of them or when they do, they will think it is something else.

BTW:

The resistor length doesn't matter. The same amount of emf is induced on the closed loop no matter the resistor value or length. Since potentials across sections of the loop are meaningless I suggest not wasting much time on inventing a zero length resistor.

I'm still working on 'my version' when time permits.

.........Re: The hernia stuff

OUCH! I just read that and felt a sharp pain where I went through that. 

Take the good drugs while you can get them  O0


---------------------------
"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality." - Einstein

"What we observe is not nature itself, but nature exposed to our method of questioning." - Werner Heisenberg
   

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It's not as complicated as it may seem...
Okay,

Let's approach this from another angle.   Again, measurement is being decoupled at point 0b-1a.  It is being read .06V.  Now we decrease the height of decoupling.  Voltage starts to drop down and as the height reach 0, voltage reads zero.  Decoupled is decoupled, why does this happens? 

Gibbs,

Why do you say this happens?

If all you are doing is shortening the leads down to practically zero height above the loop, the leads are still normal to the loop, AND they are not in-plane. The indicated voltage would still be 0.1V. In order to measure 0V, the leads would have to approach from the side, in-plane with the loop.


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It's not as complicated as it may seem...
The way this device/system works is conclusive for me and I urge anyone in doubt to perform the experiments themselves. Don't take my word for it
I've done them. You seem to refute my results.

Then you say there isn't anything wrong with my measurements:
Quote
Number 1 is incorrect. There doesn't seem to be anything wrong with the measurements.
It's difficult to understand where you're coming from WW. I would very much like if you could try to clarify your main point, as it seems to have gone unnoticed, or been misunderstood.


Quote
.........Re: The hernia stuff

OUCH! I just read that and felt a sharp pain where I went through that.  

Take the good drugs while you can get them  O0

Thanks guys  :) Hopefully they give me some good stuff.


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Never let your belligerence get in the way of your brilliance!
   
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Gibbs,

Why do you say this happens?

If all you are doing is shortening the leads down to practically zero height above the loop, the leads are still normal to the loop, AND they are not in-plane. The indicated voltage would still be 0.1V. In order to measure 0V, the leads would have to approach from the side, in-plane with the loop.

Okay, I think this approach is good.  Actually, the voltage is not constant .1V as you travel the height.  But let's not use that.  Use the .06V in your experiment.  It's the wire length from 0b-1a.  As you travel to 0 height, it measured just the wire length resistance which is virtually 0 V.  I hope you're not arguing it's still .06V.

   

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.99,

I must agree with your measurements. I disagree with your conclusions.

My main point? Wow! Maybe a drawing will help.


Gibbs,

If I understand your method, zero volts should be expected when the meter and probes are on the inside and in-plane with the loop while connected across the diameter of that loop. Also, the measured emf should increase as the meter and probe leads extend above the loop - up to a point.



---------------------------
"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality." - Einstein

"What we observe is not nature itself, but nature exposed to our method of questioning." - Werner Heisenberg
   
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Gibbs,

If I understand your method, zero volts should be expected when the meter and probes are on the inside and in-plane with the loop while connected across the diameter of that loop. Also, the measured emf should increase as the meter and probe leads extend above the loop - up to a point.



WaveW,

I can't really answer your comment because I do not know exactly the setup you describe.  If the meter and probes are across the diameter and the resistance is equal on both sides or zeros, then the voltage is zero.  Yes,the measurement should increase as decoupling go higher up (except in the case of directly across the diameter, it does nothing).  

   

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It's not as complicated as it may seem...
Okay, I think this approach is good.  Actually, the voltage is not constant .1V as you travel the height.  But let's not use that.  Use the .06V in your experiment.  It's the wire length from 0b-1a.  As you travel to 0 height, it measured just the wire length resistance which is virtually 0 V.  I hope you're not arguing it's still .06V.
Sounds confusing Gibbs. I'm not sure what you mean.

If all you are doing is lengthening or shortening the decoupled leads, then the measurement will remain constant, no matter what length they are. This holds for a measurement across a resistor and across a wire segment. Maybe you need to make a diagram to make it more clear?


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It's not as complicated as it may seem...
.99,

I must agree with your measurements. I disagree with your conclusions.
Yes, the measurements will be correct, but you disagree that the measurement leads are non-intrusive to the experiment, correct? I hope that makes sense. In other words, "garbage in, garbage out", is what you mean right? Kinda like Rosemary's measurements.  :D

I'm looking forward to your conclusions and explanations that refute my own.


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Never let your belligerence get in the way of your brilliance!
   
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If all you are doing is lengthening or shortening the decoupled leads, then the measurement will remain constant, no matter what length they are. This holds for a measurement across a resistor and across a wire segment. Maybe you need to make a diagram to make it more clear?


Ahah, yes, all I'm doing is lengthening or shortening the decoupled leads.  However, .06V won't be constant across that wire segment.  If you see it carefully, when you shorten decoupled leads to zero height for segment 0b-1a, it will indeed reads 0V instead of .06V. 

   
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