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Veritasium "How Electricity Actually Works"
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Naej:

--- Quote from: Alex Eisenhut on May 27, 2022, 03:35:01 am ---So how does energy transfer from side of a vacuum tube diode to the other?

--- End quote ---
I thought that energy was supposed to flow around the vacuum tube?
Alex Eisenhut:
Terry Bites:
Some time back Dave pointed out that for most practical engineers it doesn’t matter. I'd agree with that. But it may or may not matter, it depends on the situation. It matters very much to ic designers and semiconductor physicists.

Its ok to believe in little green men, it doesn’t affect satelite launches. (or does it....)

If the electrons move under influence of the potental difference they would have only Vbat electon volts of energy and get bounced back by the first atoms in the condcutor.
It is the bounce that is observed to travel in a conductor not particles. There is the drift velocity of notional charge carriers- thats really slow. It would take at least a decade or ten before the power got from the power plant to your home using that mechanism. Whats moving in the drift are electronic irregularities in the condcutors crystal lattice. "Things" in the convential sense are not going anywhere.

The thing and the name of a thing are not the same thing.








electrodacus:

--- Quote from: Terry Bites on June 05, 2022, 04:55:01 pm ---Some time back Dave pointed out that for most practical engineers it doesn’t matter. I'd agree with that. But it may or may not matter, it depends on the situation. It matters very much to ic designers and semiconductor physicists.

Its ok to believe in little green men, it doesn’t affect satelite launches. (or does it....)

If the electrons move under influence of the potental difference they would have only Vbat electon volts of energy and get bounced back by the first atoms in the condcutor.
It is the bounce that is observed to travel in a conductor not particles. There is the drift velocity of notional charge carriers- thats really slow. It would take at least a decade or ten before the power got from the power plant to your home using that mechanism. Whats moving in the drift are electronic irregularities in the condcutors crystal lattice. "Things" in the convential sense are not going anywhere.

The thing and the name of a thing are not the same thing.

--- End quote ---

I think it matters even for the practical engineer.  Like for example shielding a circuit from electric fields.
I explained how a simple shield that removes that small current through the lamp/resistor in Dereks experiment.
It is also important to understand that energy flows through a conductor and not outside of it. So in case of a capacitor being charged energy flows into capacitor and not through capacitor.
That old vacuum diode someone used as an example is good for visualization. If the filament on that is not working it acts as a capacitor but having the filament heater it allows electrons to travel through that vacuum from one plate to the other and they (electrons / charged particles) are what transports energy.
There are no electrons traveling through that 1m of air between wires in Derek's experiment  meaning no energy travels from source to lamp/resistor outside the wire.  All energy both in transient/AC and DC phase travels through wire in Derek's experiment while he claims the opposite with zero proof.

What he claims as proof is that small current in the first 65ns that is due to energy being stored in the transmission line. Adding the electric shield I mentioned will get rid of that and yet after 65ns there will be energy flowing through lamp/resistor and obviously trough wire which is also a resistor. 
TimFox:
Yes, that which we call Ohm's Law is a result of the scattering of electrons by lots of things in a conductor, so that they do not achieve a high velocity from the voltage gradient along the wire.
An example calculation in  https://www.macmillanlearning.com/studentresources/college/physics/tiplermodernphysics6e/classial_concept_review/chapter_10_ccr_10_mean_free_path.pdf   gives a mean free path between scattering events for electrons in copper as 0.39 nm.
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