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"Veritasium" (YT) - "The Big Misconception About Electricity" ?

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adx:

--- Quote from: bsfeechannel on January 03, 2022, 02:10:28 am ---The Poynting vector is weird, but it is what is really going on there. Welcome to reality.

--- End quote ---

I think you're probably right. But that's not certain, and no amount of introspection on the mathematical details of some theory is going to answer that last part.

I get it now, and I can see the attraction. Some people just want to believe.

Sredni:

--- Quote from: adx on January 03, 2022, 02:36:31 am ---
--- Quote from: Sredni on January 03, 2022, 02:12:48 am ---Enclose each resistor in a gauss surface and compute the net flux of S through that closed surface to find the power absorbed and you will see that each resistor is getting the power corresponding to V times I. ...

--- End quote ---

Do the same procedure on some space inside the loops but not where wires or resistors are. Then tell me how the result in any way supports the concept that "power doesn't flow in the wires"?

(Yes I'm aware of what will happen if you include some wire. That's not the question.)

--- End quote ---

I guess we can get to the conclusion that vacuum does not absorb energy?
(I wonder what a QFT theorist would say about that...)

bsfeechannel:

--- Quote from: adx on January 03, 2022, 02:47:01 am ---I think you're probably right. But that's not certain, and no amount of introspection on the mathematical details of some theory is going to answer that last part.

I get it now, and I can see the attraction. Some people just want to believe.

--- End quote ---

What is funny is that the Poynting theorem was independently studied by Oliver Heaviside, the same guy who developed the transmission line model, that you attempted, without success, to use to try to "debunk" Derek. His study of energy flow through fields is what made it possible for him to come up with the modern version of Maxwell's equations, without which we wouldn't have the transmission line model, nor the high frequency electronics we have today, from computers to radio.

bsfeechannel:

--- Quote from: vad on January 02, 2022, 04:12:13 pm ---[I have a question though. Consider the following experiment. Let's take a rubidium laser, shine its beam through a beam splitter, then one of the beams goes through a thick copper plate to a detector A, and another beam goes through the air unobscured directly to a detector B (sea level, 25C air temperature, 30% relative humidity). Can I assume that the probability of a photon reaching detector A (the one behind the metal plate) would be 999999 times higher than probability of reaching detector B, considering the same Coulomb's law and QED?

PS. Simplified version of this experiment can be reproduced by every member of this forum with a flashlight and a frying pan.



--- End quote ---

Your simple experiment is so brilliant that the Poynting-haters didn't even realize it.

bsfeechannel:

--- Quote from: adx on January 02, 2022, 07:22:32 am ---
--- Quote from: Sredni on January 01, 2022, 09:09:39 am ---...
Or, if you want to fly a bit lower, Kraus

John D. Kraus
Electromagnetics 2e
section 10.20 Circuit Applications of the Poynting Vector
p. 416
on p. 418, after considering a circuit with a battery (DC) and a resistors he writes:

--- Quote ---"In Fig. 10-19aflow lines of the Poynting vector (power flow lines) are shown. It is evident that the power flow is through the empty space surrounding the circuit, the conductors of the circuit acting as guiding elements. From the circuit point of view we usually think of the power as flowing through the wires but this is an oversimplification and does not represent the actual situation."
--- End quote ---

--- End quote ---

This (italics mine). Is an example of an academic sermonising scientific hypothesis as fact. It may seem harmless, but results in generations(s) of disciples believing stuff.

--- End quote ---

I will let Maxwell talk. But you can see that already in the beginning of the 19th century scientists who discovered the electromagnetic phenomenon were beginning to suspect that energy didn't flow in the wires because of experimental data, not because of some "academic sermonizing scientific hypothesis".


--- Quote ---547.] He [Faraday] observes, however, that 'the first thought that arises in the mind is that the electricity circulates with something like momentum or inertia in the wire.' Indeed, when we consider one particular wire only, the phenomena are exactly analogous to those of a pipe full of water flowing in a continued stream. If while the stream is flowing we suddenly close the end of the tube, the momentum of the water produces a sudden pressure, which is much greater than that due to the head of water, and may be sufficient to burst the pipe.

If the water has the means of escaping through a narrow jet when the principal aperture is closed, it will be projected with a velocity much greater than that due to the head of water, and if it can escape through a valve into a chamber, it will do so, even when the pressure in the chamber is greater than that due to the head of water.

It is on this principle that the hydraulic ram is constructed, by which a small quantity of water may be raised to a great height by means of a large quantity flowing down from a much lower level.

548.] These effects of the inertia of the fluid in the tube depend solely on the quantity of fluid running through the tube, on its length, and on its section in different parts of its length. They do not depend on anything outside the tube, nor on the form into which the tube may be bent, provided its length remains the same.

In the case of the wire conveying a current this is not the case, for if a long wire is doubled on itself the effect is very small, if the two parts are separated from each other it is greater, if it is coiled up into a helix it is still greater, and greatest of all if, when so coiled, a piece of soft iron is placed inside the coil. Again, if a second wire is coiled up with the first, but insulated from it, then, if the second wire does not form a closed circuit, the phenomena are as before, but if the second wire forms a closed circuit, an induction current is formed in the second wire, and the effects of self-induction in the first wire are retarded.

549.] These results shew clearly that, if the phenomena are due to momentum, the momentum is certainly not that of the electricity in the wire, because the same wire, conveying the same current, exhibits effects which differ according to its form; and even when its form remains the same, the presence of other bodies, such as a piece of iron or a closed metallic circuit, affects the result.

550.] It is difficult, however, for the mind which has once recognised the analogy between the phenomena of self-induction and those of the motion of material bodies, to abandon altogether the help of this analogy, or to admit that it is entirely superficial and misleading.
--- End quote ---

A Treatise on Electricity and Magnetism, 3d edition, J.C. Maxwell, pp 195-196.

There you have it. Maxwell is the Veritasium of the XIX century.

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