Electricity flows in an open circuit, too

andrewmm

Joined Feb 25, 2011
1,612
"The metal box system only acts as a shield when it redirects or converts energy by absorption the vast majority of energy directed at it."

read up on faraday shields,

If a lightning strike hits a car or a plane , it has millions of watts of power, the object would vaporise. Its self evident they dont, it highlights that current flows around the outside of the metal box

putting the "receiver" in a sealed metal box, to see if it still worked or not, would indicate if the power is being conducted over "air" or not,

Though I agree with you re metal and frequency, we are talking about the frequency the user is using which should be known and I doubt its high enough to penetrate an likely metal box

https://www.britannica.com/video/185595/physics-lightning-strikes-channel-Faraday-cages-objects

 
Last edited:

Yaakov

Joined Jan 27, 2019
3,316
If this was true, many things that now work properly and according to the laws of physics as worked out by many brilliant people over many years would not work.

That things do work now are enough evidence to know that the explanation given here is not correct.

On its face, electricity cannot flow without a circuit, electricity flowing is proof there is a circuit.
 

Delta Prime

Joined Nov 15, 2019
1,051
If a lightning strike hits a car or a plane , it has millions of watts of power, the object would vaporise. Its self evident they dont, it highlights that current flows around the outside of the metal box
A newly recognized type of discharge called fast positive breakdown, and the data suggests that this same discharge initiates most or even all of the lightning flashes typically seen in thunderstorms speeds that are fast even for lightning—around 10 to 100 million meters per second—and produce very powerful radio frequency (RF) radiation as high as a few megawatts, making them the strongest natural sources of RF radiation on Earth. But here's the kicker.Currently, the largest electric fields that have been measured inside thunderstorms are several times weaker than what is needed to break down cloudy air and initiate lightning.
Therein lies the phrase Naturally Occurring Phenomenon.
 

nsaspook

Joined Aug 27, 2009
8,504
"The metal box system only acts as a shield when it redirects or converts energy by absorption the vast majority of energy directed at it."

read up on faraday shields,

If a lightning strike hits a car or a plane , it has millions of watts of power, the object would vaporise. Its self evident they dont, it highlights that current flows around the outside of the metal box

putting the "receiver" in a sealed metal box, to see if it still worked or not, would indicate if the power is being conducted over "air" or not,

Though I agree with you re metal and frequency, we are talking about the frequency the user is using which should be known and I doubt its high enough to penetrate an likely metal box

https://www.britannica.com/video/185595/physics-lightning-strikes-channel-Faraday-cages-objects

OMG
We have the case of Faraday cage with static or quasi-static fields like the lightning DC component than moves charge to create a equal-potential space inside. This is the classic simple physics model for a Faraday cage.
https://forum.allaboutcircuits.com/...hield-helps-reducing-noise.109271/post-840972

Then we have the Faraday cage electrodynamics boundary condition model between free space and a good conductor providing shielding for most of the RF frequency range and the high frequency component of a lightning strike.
That's what's being talked about here.
https://forum.allaboutcircuits.com/...t-like-with-van-de-graaff.177500/post-1610162


If the object in the direct path of the lightning strike current presented a significant impedance in the discharge circuit you can bet it would be vaporized from the vector product of the voltage (electric field energy) across the impedance and the current flow (magnetic field energy) with the KE of the actual charged particles (ions) thrown in as good measure.

https://www.flightglobal.com/pictur...elevator-after-lightning-strike/79694.article

lufty-737-445_22235.gif
 
Last edited:

andrewmm

Joined Feb 25, 2011
1,612
OMG
We have the case of Faraday cage with static or quasi-static fields like the lightning DC component than moves charge to create a equal-potential space inside. This is the classic simple physics model for a Faraday cage.
https://forum.allaboutcircuits.com/...hield-helps-reducing-noise.109271/post-840972

Then we have the Faraday cage electrodynamics boundary condition model between free space and a good conductor providing shielding for most of the RF frequency range and the high frequency component of a lightning strike.
That's what's being talked about here.
https://forum.allaboutcircuits.com/...t-like-with-van-de-graaff.177500/post-1610162


If the object in the direct path of the lightning strike current presented a significant impedance in the discharge circuit you can bet it would be vaporized from the product of the voltage (electric field energy) across the impedance and the current flow (magnetic field energy) with the KE of the actual charged particles (ions) thrown in as good measure.

https://www.flightglobal.com/pictur...elevator-after-lightning-strike/79694.article

View attachment 240937
Thank you

All very interesting,

Not certain how that relates to the OP post though
 

nsaspook

Joined Aug 27, 2009
8,504
Thank you

All very interesting,

Not certain how that relates to the OP post though
It's was a response to your "What's all the fuss about?" The 'Fuss' is the OP was looking at information that was misleading and incorrect. Your answer IMO confused the matter instead of providing clarity on the physical nature of 'Electricity' vs electrical energy in an 'open' circuit. Unfortunately it's necessary to be fundamentally precise and brutally honest when dealing with things like 'New theories about electromagnetism' when a person asks about it.

https://www.physicsclassroom.com/cl...on-Misconceptions-Regarding-Electric-Circuits
Electric circuits are all about energy, not charge. The charge is simply the medium which moves the energy from location to location. The batteries or other energy source does work upon the charge to supply it with energy and place it at a high electric potential. Charge at high electric potential will spontaneously begin its very slow migration towards the low potential terminal of the cell. Charge everywhere within the circuit moves together, like soldiers marching in step. As an individual charge moves through circuit elements such as light bulbs, its electrical energy is transformed into other forms of energy such as light energy and thermal energy. With many, many charges moving through the light bulb at the same time, there is a significant transformation of electrical energy to light energy to cause the light bulb filament to noticeably glow. Upon passage through a light bulb filament, an individual charge is less energized and at a lower electric potential. The charge completes its slow migration back to the low potential terminal where the electrochemical cell does work upon the charge again to move it back up to high electric potential. Once at high potential, the charge can begin its loop again through the external circuit.
http://web.archive.org/web/20080730.../school/curric/stage6/phys/stw2002/sefton.pdf
As Arnold Sommerfeld (1952) has pointed out, metals are good conductors of current but nonconductors of energy. Metals conduct current but space conducts energy and the best conductor of electromagnetic energy is the vacuum!
Many text and syllabus writers like the motto “Keep it simple ...”. Although that is an admirable aim it can conflict with scientific validity. Do we really want to teach stuff that is wrong just because it is simple? I don’t think so. One source of wrong or misleading ideas is the use of inappropriate analogies. Various attempts to make analogies between circuits and water flowing in pipes come to mind. You should be able to see from the account in this article that using water as an analogy for charge does not make much sense. Stories about water and little gremlins carrying buckets of stuff called energy are all best forgotten.

An initial reaction to the story in this article may be that it is too difficult. I would argue that the basic ideas are no more difficult than the concept of field, which already occurs in various schoollevel courses. In any case field is such a fundamental concept, even more basic than energy, that it is hard to imagine how one can learn any serious physics without it. The arguments about circuits should be no more difficult to grasp than the better known stories told about electromagnetic waves and light – because the basic physics is the same in both cases. I think it is reasonable to expect that high school physics students can grasp the essence of the conceptual framework outlined here.
 
Last edited:

click_here

Joined Sep 22, 2020
256
If that were true the SPDT switch would be useless.

If a SPDT switch did not work when both sides were connected to large metal objects, don't you think that it would be known by now?

Instead of claiming that they have discovered a new thing, perhaps it would be better to explore how the results fit in with what's already known
 
Top