Maxwell's equations are not independent of its source – electron.
Maxwell's equations depend on an electron.
Maxwell's equations isn't isolate system.
There isn't Maxwell's theory without SRT and vice versa.
Source .
Max Abraham's work is almost all related to Maxwell's theory and electron.
FitzGerald light contraction is effect of light's motion.
Henri Poincaré' On the dynamics of the electron'
H.A.Lorentz 'Theory of electrons '
Einstein : "On the Electrodynamics of Moving Bodies",
====================..

Maxwell's equations are about charges and fields. You don't need electrons. A pure proton beam generates EM waves and fields nicely. Most people don't own a particle accelerator so proton current is not the 'normal' electricity we all use and study but it's positive charge is equal to that of an electron and in the right conditions behaves in an equivalent manner as a charge carrier.

 

WOW, how did I miss this....Good read

 

socratus, now that you are actually listening to what others post and responding we can have a useful discussion.

That is much much better than continues preaching.

socratus post#68
Electron is a dynamic particle. This means it cannot “rest “

studiot post#69
Why (not) ?

Your statement is nearly true but your 'proof' was not valid.

The truth is known as Earnshaw's theorem and follows from Gauss's Law, which Maxwells second equation is a form of.

"A charged particle cannot rest in stable equilibrium in an electric field, when the only forces acting are electric ones."

Note the conditions under which the statement is true, it does not apply in the absence of and electric field and it must be in stable equilibrium. A charged particle may come to rest, for an indefinite period, in unstable or metastable equilibrium or it may rest in stable equilibrium when there are other forces acting as inside the nucleus.

We can dig further into understanding the derivation, if you wish.

 

While researching something else I found this about electron speed in wiring.

http://webcache.googleusercontent.c...+&cd=6&hl=en&ct=clnk&gl=us&client=iceweasel-a

Wouldn’t it be fantastic if we could travel at the speed of an electron? Imagine a trip from The Dalles, Ore., to Los Angeles in the blink of an eye on the 846-mile Electron Express known as the Pacific DC Intertie.
Unfortunately, you would be in for a disappointingly long ride.

 

While researching something else I found this about electron speed in wiring.

http://webcache.googleusercontent.c...+&cd=6&hl=en&ct=clnk&gl=us&client=iceweasel-a

An example that I find sometimes makes something click is to use a audio analogy. When you talk to someone, that sound travels between you and them because of the motion of air molecules. The speed of sound is around 1100ft/s or around 750mph (at around room temperature). Clearly the air is not moving from you to them at 750mph! Thus the movement of sound energy and the movement of air molecules are two very different things. Similarly, the movement of electrical energy and the movement of electrons are two very different things.

 

While researching something else I found this about electron speed in wiring.

http://webcache.googleusercontent.c...+&cd=6&hl=en&ct=clnk&gl=us&client=iceweasel-a

Interesting, but I'm pretty sure this:

their motion is impeded because of repeated collisions with individual atoms that make up the wire

, while it makes a tiny contribution, is not the predominant factor causing the 'slow' drift velocity. The previous calculation I made is quite accurate, yet has no dependance on collisions (or what we'd call resistance). The enormous number of available free electrons in a metal matrix is the main reason that the flow rate is so low.

 

Agreed. And the argument falls apart completely if you look at the case of a superconductor.

 

An example that I find sometimes makes something click is to use a audio analogy. When you talk to someone, that sound travels between you and them because of the motion of air molecules. The speed of sound is around 1100ft/s or around 750mph (at around room temperature). Clearly the air is not moving from you to them at 750mph! Thus the movement of sound energy and the movement of air molecules are two very different things. Similarly, the movement of electrical energy and the movement of electrons are two very different things.

But in this case the air molecules are moving at around the speed of sound (from memory the rms speed is 30-40% bigger than the speed of sound). They have to, after all it is only the movement of the air molecules that can convey the sound across the fluid, so the velocity of many has to be at least the speed of sound. Of course each molecule only travels a few hundred nanometers or so before colliding, so the molecules stay local (their drift velocity is low).

 

We are talking about drift velocity.

 

We are talking about drift velocity.

The point I was making is that in the conductor case, the EM fields move at the speed of light and it is these fields that promote the much slower movement of the electrons. In typical cases, no physical particle moves at anything like the speed of light.

In air, the actual disturbance is propagated by movement - and collision - of the air molecules, which move roughly at the speed of sound. If the air molecules moved slower than the speed of sound then it wouldn't work.

 

Interesting, but I'm pretty sure this:

, while it makes a tiny contribution, is not the predominant factor causing the 'slow' drift velocity. The previous calculation I made is quite accurate, yet has no dependance on collisions (or what we'd call resistance). The enormous number of available free electrons in a metal matrix is the main reason that the flow rate is so low.

Agreed, the information was from a handout to non-technical staff at the plant but it does clearly make the point that even at very high levels of power (3,100 megawatts total capacity) flow the electron speed is still at a snails pace.

 

Interesting about the sound, but slightly disagree...

The wave moves at the speed of sound. The individual air molecules move back and forth to form the crests and valleys, the compressions and vacuums that exist in a single wave of a sound. This movement is at the speed of sound, but the total movement averages out to nothing. The energy is in the waveform.

Otherwise it would be wind.

 

I saw a lecture on pbs where a phycisist was saying that electrons dont move in streight ines, they jump around, dissapear, and reapear randomly. if so, how does a crt work? if you cant get electrons to the phospor screen where you want them, what does get there and light up the screen.

 

Sheep or cows don't naturally move in straight lines. They jump or wander around although they don't disappear and reappear, but neither do electrons.

But sheep and cows can be herded in straight lines and so can electrons.

 

I saw a lecture on pbs where a phycisist was saying that electrons dont move in streight ines, they jump around, dissapear, and reapear randomly.

...it sounds like this description might have been for semiconductor physics - electron-hole pairs can be generated and recombine due to influences of random processes. These electrons move about the crystal lattice.

No electron travels in a straight line, especially in solids. The best we can do to get electrons to move in a general, net direction.

 

...it sounds like this description might have been for semiconductor physics - electron-hole pairs can be generated and recombine due to influences of random processes.

But the electrons still exist!

There are quantum processes that create so called virtual particles that have a very short existence. There are also quantum electron/positron pair production processes.

But neither are part of everyday human physics.

 

But the electrons still exist!

There are quantum processes that create so called virtual particles that have a very short existence. There are also quantum electron/positron pair production processes.

But neither are part of everyday human physics.

True. I should have stated that I was referring to electrons available for conduction.