An interesting question from Veritasium on YouTube

[tech99]

It's not along the wire and not via the electron fluid but via the field, as nicely demonstrated by the simulations shown in the movie and also verified by measuring the signal of the transient state.

But would you agree that the electrons have a longitudinal motion, oscillatory for AC, in response to the fields?

 

[vanhees71]

Sure, they make up the current.

 

[bob012345]

Indeed, one should show this movie to all the "physics pedagogues" still advocating a kind of "water-pressure model" of electric circuits, which is completely wrong in many ways, particularly in the discussed issue with how energy is transported from the source ("battery"). It's not along the wire and not via the electron fluid but via the field, as nicely demonstrated by the simulations shown in the movie and also verified by measuring the signal of the transient state.

I expect Veritasium to make a video saying the battery is not the source next. :)

 

[tech99]

I expect Veritasium to make a video saying the battery is not the source next. :)

The switch is the source of the wave in a circuit.

 

[anorlunda]

The switch is the source of the wave in a circuit.

Some people will quibble over the choice of words. The switch triggers the wave, but it is not the source of power. Closing a switch in a wire with no power source, produces nothing.

 

[tech99]

Some people will quibble over the choice of words. The switch triggers the wave, but it is not the source of power. Closing a switch in a wire with no power source, produces nothing.

Yes, battery at the exchange, dial at the subscriber premises.

 

[tech99]

Sure, they make up the current.

So can we say that the electrons execute a longitudinal wave? And can we also say that they do this in response to a longitudinal, rather than transverse, electric wave?

 

[berkeman]

Closing a switch in a wire with no power source, produces nothing.

Tree, forest, no people, ...

 

[Baluncore]

By changing the voltage sources, or arrangement of the conductors, resistors and insulators, we reconfigure the electric field. Those electric fields are guided by the wires and components of our circuits.

In response to the changing electric field, a current flow is required to redistribute the charge of the circuit capacitance. That current generates a magnetic field, guided by the currents in the wires.

Changes to the electric and magnetic fields constitute a redistribution of energy in the fields. The direction of that energy flow is the (cross) product of the electric and magnetic fields, we call it the Poynting vector.

Those EM fields fill the space between the circuit elements, where changes propagate at a speed close to the speed of light. It follows that electrical energy travels to the load through the space surrounding the circuit elements, guided by, but not through, the conductive wires.

 

[hutchphd]

It follows that electrical energy travels to the load through the space surrounding the circuit elements, guided by, but not through, the conductive wires.

That is the well stated answer as reiterated several different times recently I thought we had all figured this out.

So can we say that the electrons execute a longitudinal wave? And can we also say that they do this in response to a longitudinal, rather than transverse, electric wave?

Please let's not play twenty questions. If you have a point, please make it completely.

 

[berkeman]

Old thread closed temporarily for review by the Mentors...

 

[berkeman]

That is the well stated answer as reiterated several different times recently I thought we had all figured this out.

Exactly. Thread will remain closed. Thanks everybody for an interesting thread.