General > General Technical Chat
"Veritasium" (YT) - "The Big Misconception About Electricity" ?
aetherist:
--- Quote from: penfold on March 15, 2022, 05:19:10 pm ---
--- Quote from: aetherist on March 15, 2022, 11:12:49 am ---[...]I am fairly sure that i/we have already looked at the catastrophe of old (electron) electricity, ie that drifting electrons can't possibly be responsible for the speed of electricity being nearly the speed of light.
If everyone agrees that drifting electrons don’t play a part in the speed of electricity then that removes that catastrophe (but it might of course create others).
But i am pretty sure that everyone can't agree that electron to electron bumping duznt play a part in the speed of electricity. Which puzzles me.[...]
--- End quote ---
Drifting electrons and bumping... I think I see your point now, with mean free paths ~10^-9 m, collision rates ~10^12 Hz should mean velocities circa 10^3 m/s: much slower than the e-field, therefore, bumping collisions don't convey momentum fast enough? And if they did they couldn't also transfer energy to the lattice in ohmic losses?
In a non-rigorous sense, the E-field (internal to the conductor) due to compression and rarefaction in an electron gas can travel fast... (I don't have the numbers to hand) and electric fields externally can also travel fast and can travel ahead of the electron wave-front, but also bare in mind that it's just a big set of differential equations so nothing is just happening without cause and consequence causing further consequence. The weakness in such a simplistic explanation is that it doesn't cover even a fraction of what's going on inside a metal and you very quickly need to either back-track into viewing the current as a smooth J component in Maxwell or proceed down the mystical path of quantum.
--- End quote ---
I think that the speed of light in Cu is 10 m/s for DC, & say 3 m/s for AC. I don’t know what that means.
But that duznt necessarily mean that the speed of em radiation in an atom is 10 m/s. Nor that em radiation tween adjacent atoms is 10 m/s. Or 10 m/s tween molecules.
It suggests that the speed of em radiation in Cu is less than the speed of sound in Cu. So, something must be wrong here.
If drifting electrons had zero mass (ie zero inertia) then they could i suppose provide a speed of electricity no faster than the speed of light in Cu. But, electrons do have mass (the mass of the free conduction electron gas in Cu is i think 0.17 kg/m3), hence the speed of their electricity would be much less than that there 10 m/s. But as i said something must be wrong with this kind of analysis.
I did attempt to do an excel for the wavefront of electron to electron bumping along a Cu wire/pipeline, last year, but i didnt finish it.
aetherist:
--- Quote from: bsfeechannel on March 15, 2022, 11:46:51 am ---The only catastrophe here is your huge ignorance of electromagnetism. No big deal. Most people don't understand it anyway. But if you really want to understand it, you have to first get rid of all the analogies you are used to. Trust me.
--- End quote ---
List of things we don’t understand.
Electrons.
Photons.
Atoms.
Charge.
Magnetism.
Electricity.
Gravity.
Aether.
Length contraction.
Ticking dilation.
Women.
List of things we understand.
Beer.
Football.
Money.
penfold:
--- Quote from: aetherist on March 15, 2022, 09:29:27 pm ---I think that the speed of light in Cu is 10 m/s for DC, & say 3 m/s for AC. I don’t know what that means.
[...]
I did attempt to do an excel for the wavefront of electron to electron bumping along a Cu wire/pipeline, last year, but i didnt finish it.
--- End quote ---
Right, yes, I see your point. Interesting. Yeah... that's tricky. First off... avoid Wikipedia, the definitions and interpretations are a bit poor. I'd recommend H. E. Hall's Solid State Physics, and Mandl's Statistical Physics (hopefully there'll be some pdfs available)... they were, at least in the first editions, very evidence-based, don't depend on maths as an explanation, quite approachable... not a beginners guide to physics, but much more dependable than the same topics on Wikipedia. Better for definitions and where they arise from at least.
I can see how confined photons in an aether would produce a satisfactory explanation... without actually disputing observations and measurements... intriguing... maths time.
SiliconWizard:
--- Quote from: aetherist on March 15, 2022, 10:18:24 pm ---List of things we understand.
Beer.
Football.
Money.
--- End quote ---
You can cross off "money", for the most part. Many of us do not understand much about it.
aetherist:
--- Quote from: penfold on March 15, 2022, 11:40:59 pm ---
--- Quote from: aetherist on March 15, 2022, 09:29:27 pm ---I think that the speed of light in Cu is 10 m/s for DC, & say 3 m/s for AC. I don’t know what that means.[...]I did attempt to do an excel for the wavefront of electron to electron bumping along a Cu wire/pipeline, last year, but i didnt finish it.
--- End quote ---
Right, yes, I see your point. Interesting. Yeah... that's tricky. First off... avoid Wikipedia, the definitions and interpretations are a bit poor. I'd recommend H. E. Hall's Solid State Physics, and Mandl's Statistical Physics (hopefully there'll be some pdfs available)... they were, at least in the first editions, very evidence-based, don't depend on maths as an explanation, quite approachable... not a beginners guide to physics, but much more dependable than the same topics on Wikipedia. Better for definitions and where they arise from at least.
I can see how confined photons in an aether would produce a satisfactory explanation... without actually disputing observations and measurements... intriguing... maths time.
--- End quote ---
I didn’t use aether (i don’t know how aether could help)(unless the problem needed aetherwind).
And i didn’t use any kind of length contraction or ticking dilation.
And i used c, ie the full speed of light, i didn’t use the slower speed of light actually found in Cu.
And i used a drift speed of zero mm/s (not important).
I pushed an electron into the end of a wire (at constant speed). I used 1 conduction electron per Cu atom. I assumed that electrons could repel electrons up to 3 atoms ahead. I used the standard electron charge & mass etc.
I don’t know why i got stuck. It might have been koz i had trouble getting excel to do circular iterations. But this duznt usually give me much trouble.
Last time i looked i couldn’t follow my method. I might have another look one day, & finish the job.
I expect to get a wavefront propagating at say c/10 (just guessing)(whereas old electricity says that slowly drifting electrons can give almost c/1).
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