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Veritasium "How Electricity Actually Works"

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rfeecs:

--- Quote from: electrodacus on May 01, 2022, 07:34:42 pm ---
--- Quote from: rfeecs on May 01, 2022, 07:06:35 pm ---Apparently you mean current, not energy.

--- End quote ---

If there is no current there is no energy.


--- End quote ---

So there is no energy in electromagnetic waves?

There's no energy in a laser beam?

No energy in sunlight?

Then how does solar energy work?  You seem to be in that business.

rfeecs:

--- Quote from: SiliconWizard on May 01, 2022, 06:28:07 pm ---While the new video is a good effort and gets into a lot more details than the initial one, there still are points that are definitely not addressed.
Some of them come from - as was mentioned in the other thread early - a chicken-and-egg problem.

--- End quote ---

Something like do moving charges cause fields or do fields cause charges to move?

Perhaps he addressed that in saying electrons don't push each other.

He comes down on the side of fields cause charges to move.

rfeecs:
I don't think he adequately debunks the idea that charges gain potential energy (V) and then that potential energy is converted to kinetic energy.  The P=IV model.

He doesn't mention potential energy, just kinetic energy.  He argues that the electrons drift too slowly to carry the energy.

But the (retarded) potential moves at the speed of light.

I imagine he didn't want to mention potential because it introduces another concept that might be complicated to explain.

electrodacus:

--- Quote from: rfeecs on May 01, 2022, 07:43:03 pm ---So there is no energy in electromagnetic waves?

There's no energy in a laser beam?

No energy in sunlight?

Then how does solar energy work?  You seem to be in that business.

--- End quote ---

The resistor (lamp) is not powered by lasers or sunlight.  Such a lamp powered by laser or sunlight will be a a mirror.

A capacitor and an inductor are energy storage devices.
Storing energy is not the same with using energy to do work (convert one type of energy in to another).

If the ends of that loop in Derek's video where open then whose long parallel wires will only be a capacitor so when switch will have been closed that capacitor will have charged the exact same way it happened with the closed loop tested.
The difference will have been that after those few ns of charging this capacitor there will be no current flow thus no voltage drop on that 1.1kOhm resistor and so no power available for the resistor/lamp thus no energy.
The capacitor will have remained charged so if you look at the balance of energy you will see this

Energy delivered from battery =  IR loss on the internal battery ESR + IR loss in wires + IR loss in the 1.1kOhm resistor + energy stored in the capacitor made by the parallel wires.

rfeecs:

--- Quote from: electrodacus on May 01, 2022, 08:23:26 pm ---
Energy delivered from battery =  IR loss on the internal battery ESR + IR loss in wires + IR loss in the 1.1kOhm resistor + energy stored in the capacitor made by the parallel wires.

--- End quote ---

You are using a lumped model that is not adequate.

This circuit is three dimensional.  There is a one meter gap between the switch and the load.  You haven't explained how energy gets across that gap.

You can look at the simulation in the video.  When the switch is closed a spherical wave propagates out in all directions.  It should be very clear that some of that energy is going out away from the bulb.  Some of the energy is lost.  Your model doesn't account for the energy radiated away.

Consequently your equation is wrong.

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