Capacitor Controversy: Debunking the Conventional Theory

  • Thread starter Thread starter EEngineer91
  • Start date Start date
  • Tags Tags
    Capacitor
Click For Summary

Discussion Overview

The discussion centers around the functioning of capacitors, specifically challenging the conventional theory that charge is stored on the metal plates. Participants explore alternative interpretations, referencing historical perspectives from Charles Steinmetz and experimental observations, particularly from a MIT physics demonstration.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants argue that the absence of a spark when metal plates touch suggests that the glass dielectric is storing electrical energy, rather than the plates themselves.
  • Others reference Steinmetz's critique of the conventional understanding of electrostatic charge on conductors, suggesting that this view complicates the understanding of dielectric fields.
  • A participant questions the validity of using a YouTube video as a source for technical discussions, emphasizing the importance of peer-reviewed literature.
  • Some express skepticism about the reliability of the MIT demonstration, while others defend its credibility based on the institution's reputation.
  • One participant points out that the lack of a spark when the plates are held by a person is consistent with orthodox theory, as any potential difference would be equalized.
  • Another participant notes that the energy stored in the dielectric can exceed that stored in the charge separation of the plates, leading to sparks upon discharging the dielectric polarization.
  • There is a mention of the need to reconcile observations with mainstream physics and electrical circuit theory, indicating a desire for a coherent explanation that aligns with established knowledge.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of charge storage in capacitors, with no consensus reached on the validity of the conventional theory versus the alternative interpretations presented.

Contextual Notes

Some participants highlight the limitations of relying on non-peer-reviewed sources for technical discussions, while others emphasize the historical context of the theories being debated. The discussion reflects a mix of contemporary and historical perspectives on electrostatics and capacitor functionality.

EEngineer91
Messages
38
Reaction score
0
Hi,


Please watch the following video:




If the capacitor did store charge on metal plates, like we believe today, in opposition to Steinmetz, how come no spark was produced when the metal plates touched? This must mean the glass is storing electrical energy, and that the metals do not carry an electrical charge! The more I read on electrical phenomenon, the more Steinmetz makes sense!

To quote:

"Unfortunately, to large extent in dealing with dielectric fields the prehistoric conception of the electrostatic charge (electron) on the conductor still exists, and by its use destroys the analogy between the two components of the electric field, the magnetic and the dielectric, and makes the consideration of dielectric fields unnecessarily complicated."

Steinmetz continues, "There is obviously no more sense in thinking of the capacity current as current which charges the conductor with a quantity of electricity, than there is of speaking of the inductance voltage as charging the conductor with a quantity of magnetism. But the latter conception, together with the notion of a quantity of magnetism, etc., has vanished since Faraday's representation of the magnetic field by lines of force."
 
Last edited by a moderator:
Engineering news on Phys.org
EEngineer91 said:
Hi,


Please watch the following video:




If the capacitor did store charge on metal plates, like we believe today, in opposition to Steinmetz, how come no spark was produced when the metal plates touched? This must mean the glass is storing electrical energy, and that the metals do not carry an electrical charge! The more I read on electrical phenomenon, the more Steinmetz makes sense!

To quote:

"Unfortunately, to large extent in dealing with dielectric fields the prehistoric conception of the electrostatic charge (electron) on the conductor still exists, and by its use destroys the analogy between the two components of the electric field, the magnetic and the dielectric, and makes the consideration of dielectric fields unnecessarily complicated."

Steinmetz continues, "There is obviously no more sense in thinking of the capacity current as current which charges the conductor with a quantity of electricity, than there is of speaking of the inductance voltage as charging the conductor with a quantity of magnetism. But the latter conception, together with the notion of a quantity of magnetism, etc., has vanished since Faraday's representation of the magnetic field by lines of force."


I don't watch YouTube videos when I'm at work. Can you please link to the peer-reviewed journal article that you are quoting from?
 
Last edited by a moderator:
berkeman said:
I don't watch YouTube videos when I'm at work. Can you please link to the peer-reviewed journal article that you are quoting from?

It is a MIT physics demo, not sure I can find a peer-reviewed journal article specifically about their demostration. Do we not trust that the MIT grads did it correctly or are being deceitful?
 
As for the Steinmetz quote, I can, give me a moment please.

Charles Steinmetz - Elementary Lectures on Electric Discharges, Waves and Impulses
 
EEngineer91 said:
It is a MIT physics demo, not sure I can find a peer-reviewed journal article specifically about their demostration. Do we not trust that the MIT grads did it correctly or are being deceitful?

We don't use YouTube videos as the source for technical discussions here on the PF. It's important that the concepts being discussed appear in peer-reviewed journal articles or in standard mainstream textbooks.

EEngineer91 said:
As for the Steinmetz quote, I can, give me a moment please.

Charles Steinmetz - Elementary Lectures on Electric Discharges, Waves and Impulses

Is there a textbook that goes with the lectures? I'll try to do a little searching...
 
I'm not sure I understand the objection. I am simply showing an experiment done by MIT physics department and how it relates to electrostatic charge on conductor. As for Steinmetz, yes it is an older book, but he had very advanced knowledge too.
 
EEngineer91 said:
Hi, Please watch the following video:

If the capacitor did store charge on metal plates, like we believe today, in opposition to Steinmetz, how come no spark was produced when the metal plates touched? This must mean the glass is storing electrical energy, and that the metals do not carry an electrical charge!


You seem to be stuck on that quote.
http://en.wikipedia.org/wiki/Leyden_jar#Storage_of_the_charge
http://www.sis.org.uk/bulletin/99/mills.pdf
This is why videos can be deceiving.
 
Last edited by a moderator:
I am stuck on the quote, and if you do not understand the significance, I can explain.

You see, if you were to enter any physics course concerning capacitors, you would find the notion of electrostatic charge on conductors to explain it. This experiment shows that interpretation is false! Yet, universities all over the world still use this concept! Like I said, the dielectric field has been forgotten, and misinterpreted.
 
  • #10
It sounds like you are trending away from mainstream science in your posts in this thread. Thread is closed for Moderation.

I will watch the YouTube video from home over the weekend, and decide if there is a basis for a valid scientific discussion on your questions/assertions.
 
  • #11
EEngineer91 said:
I am stuck on the quote, and if you do not understand the significance, I can explain.

You see, if you were to enter any physics course concerning capacitors, you would find the notion of electrostatic charge on conductors to explain it. This experiment shows that interpretation is false! Yet, universities all over the world still use this concept! Like I said, the dielectric field has been forgotten, and misinterpreted.

I have watched the video, and it is indeed weird at the end where the 2 plates of the Leyden jar do not generate a spark when brought together, but do generate a spark when put back together in the jar. I would have expected sparks from both contacts (due to the residual charge effect linked to by nsaspook).

I will re-open the thread for now, but do not continue to make statements that current electrical theory is wrong. There is an explanation to this that conforms to mainstream physics and electrical circuit theory. We just need to figure it out in our discussion.
 
  • #12
Notice that the two plates that do not produce a spark when touched together are BOTH being held in the person's hands. Thus any potential difference between the two plates has been equalized by the conductivity of the person holding them; we shouldn't expect any spark. This is not mysterious; it's perfectly in accord with orthodox theory.

The glass has a dielectric constant larger than free space, so the energy stored in the polarization of the glass is much larger than stored in the charge separation of the two plates alone. We get a big spark when we discharge that polarization.

Does this make sense?
 
  • #13
The Electrician said:
Notice that the two plates that do not produce a spark when touched together are BOTH being held in the person's hands. Thus any potential difference between the two plates has been equalized by the conductivity of the person holding them; we shouldn't expect any spark. This is not mysterious; it's perfectly in accord with orthodox theory.

The glass has a dielectric constant larger than free space, so the energy stored in the polarization of the glass is much larger than stored in the charge separation of the two plates alone. We get a big spark when we discharge that polarization.

Does this make sense?

Perfect, thanks! I missed the part that they were holding both plates. Duh. :biggrin:
 
  • #14
I had a discussion with the OP via PMs. These links should answer the question.
http://amasci.com/emotor/cap1.html

On Wimshurst machines and capacitors:

Do you believe that the energy in a capacitor is trapped permanently in the dielectric? Many people do. Their belief is caused by a famously misleading experiment called "Dissectable Leyden Jar." It's an experiment which involves high voltage and corona discharge. The effect it purports to prove does not occur in capacitors at lower voltages.

First charge up a Leyden jar using a Wimshurst Machine (or other source of high voltage.) Now, carefully remove the inner metal from the jar. Now remove the outer metal. Discharge everything, then hand the parts around the classroom. Next, put the parts together again, connect the two metal cylinders, and BANG!, there is a loud discharge.

Doesn't this prove that the energy in a capacitor is stored in the dielectric? No.

A thin film of water (a poor conductor but not an insulator) is on the surfaces of the glass from atmospheric water vapor where charge is transferred by corona discharge from the metal plates to the surface water layer. So when you removed the metal plates you still have a capacitor (and it's electric field) with the glass as the insulator. When reassembled the charge transfers back to the metal plates to be discharged later.
 
  • #15
First of all, present theory suggests conductor holds charge, if this were true, the metals would have discharged. ..therefore charge on conductors is rules out...that is all I am saying. ..yes it is explained only using dielectric field...the water vapor explanation makes no sense...neither does the hands touhing the metal. ...it just proves you cannot use charge on conductor as an answer...the argument is the concept of charge developing on conductors is a misconception, yet still used!

As for the dielectric difference of air and glass, this contradicts again the idea of conductor carrying charge like I said...so this supports my claim...I get two different explanations yet this is orthodox theory. ...
 
  • #16
EEngineer91 said:
First of all, present theory suggests conductor holds charge, if this were true, the metals would have discharged. ..therefore charge on conductors is rules out...that is all I am saying. ..yes it is explained only using dielectric field...the water vapor explanation makes no sense...neither does the hands touhing the metal. ...it just proves you cannot use charge on conductor as an answer...the argument is the concept of charge developing on conductors is a misconception, yet still used!

As for the dielectric difference of air and glass, this contradicts again the idea of conductor carrying charge like I said...so this supports my claim...I get two different explanations yet this is orthodox theory. ...

No, you are just whining pseudo-science, and refusing to read the good explanations of the past few posts. This thread is done.
 

Similar threads

What explains the current flow in a LC circuit?
  • · Replies 4 ·
Replies
4
Views
2K
Understanding Capacitor Behavior for Noise Filtering?
  • · Replies 15 ·
Replies
15
Views
4K
How does a Permanent capacitor motor actually work?
  • · Replies 7 ·
Replies
7
Views
2K
Parallel Plate Capacitor Design
  • · Replies 3 ·
Replies
3
Views
3K
Steady state boundary conditions between metal/dielectric?
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Electrostatic charge or dieletric field?
  • · Replies 10 ·
Replies
10
Views
5K
Undergrad Magnetic field when the area of the plates of a capacitor increases
  • · Replies 7 ·
Replies
7
Views
2K
Questions about a parallel plate capacitor apparatus for lab experiments
  • · Replies 9 ·
Replies
9
Views
3K
A few questions about capacitors
  • · Replies 17 ·
Replies
17
Views
3K
Electric Field in Capacitors and Diodes
  • · Replies 3 ·
Replies
3
Views
3K