MrRB said:1. If the source mechanism of the magnetic field is a current, would you call the field itself "current", say where it extends external to the magnet body?
2. If that external magnetic field passes through another object, would you say there is "current" flowing between the 2 objects?
Ok, I've been thinking about this, if I look at a single wire and cut it flat with little or no metal burs extending around it. Holding it with the tip up in front of you then, spin it in your fingers
Then apply voltage, the static EM field should be from 0 to 180° in all directions; with no field around the wire just at the end (Should their be current that would change). However, the field strength should extend out on "y" axis which would mean the field strength is shorter at the center and longer at the edges.
Now I have 2 Plates with edges. Parallel to each other, each having surface area toward each other and a small surface area around the edges.
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If a voltage is applied you would get field that might behave like the wire and would have field strength at the edges and those fields would couple with little or no field at the center of the plates facing each other? Could this allow tunneling?
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As a rise of charge and EM builds it would begin to stack the force between the plates "attracted to the lower charge at the center Plate B" if a rise in EM around it push's in the stack of force finally reaches Plate B which is slowly exited until it suddenly discharges and the fields collapse.
If the sudden charge moves, it would cancel the field around the edges momentarily with a radiating EM just like a wire with current flowing. This would continued with AC sin.
Hi,
I dont know if we can talk classical and quantum in the same sentence. I seriously doubt tunneling is in effect here though.
The only thing that 'flows' is energy, and even that is hard to believe because the energy is stored.
So far, i havent found anything that we can say that 'flows'. Charge doesnt flow, field lines dont flow, just about the only thing we can say that flows is the flow field, which is still not considered to be anything physical like the fluid flow we all know about in pipes. In a water pipe the water (obviously) flows, but in the capacitor the flow field is just a concept, not a reality like the water is.
It is often said in classrooms that the "displacement current" flows, but that's just a concept too like the flow field, and if we dont know what displacement current is really made up out of, then we still dont know what it is (if anything) that is really flowing. We're trying to figure out the essence of nature here, not the behavior so to speak, but im sure you realize this already.
It gets even stranger when we think about radio waves, which would have a 'displacement current' associated with them too. We know that the fields reach an antenna somewhere off in the distance, but does it really help to think about a current of some type also reaching that antenna? I have no problem believing that a current is developed in the antenna once the waves reach it, but that's a little more obvious.
Protons aren't normally released in a capacitor. That is an achedemic question, not to be taken too literally.
What is the proton doing in the Cap.
A proton is released from rest at the positive plate of a parallel-plate capacitor.
There is a 90° electron motion.
A proton is released from rest at the positive plate of a parallel-plate capacitor.
Hi again,
I was trying to get that point across (the electron, not the proton) earlier in this thread. the electron sort of turns 90 degrees once it gets inside the cap. Supposedly (i say that because you dont know what to believe these days on the web) there is X ray proof of this, with the electrons turning as they enter the plate and distributing across the plate. I would assume that on the other plate the electrons are exiting by the same means, turning 90 degrees more or less just before they enter the wire on that side of the cap. This is what brought about the transmission line model, because if we look inside the cap we see charge flowing parallel to each other in the opposite direction, exactly what happens in a transmission line. This isnt my theory either, it's someone else's and i just read about it so i dont want to take credit or blame (depending on how you look at it ha ha) for this theory. The first guy to publish a paper on this was Catt, which i think you can find on the web.
I dont think the protons move do they? The nucleus may move very slightly in a dielectric, but not very far, and the protons are bound up in the nucleus right? We might think of protons moving just out of convenience perhaps.
This is the thread from hell, but I can't help myself.. I just have to post this here.
I fail to see how "that guy is cool" :/
Doesnt he state that the so called displacement current is an "equivalent" current?
When you say the displacement current (the way we take it here to be an equivalent thing) is small, that's only in the wire outside of the cap. Inside the cap other professors show it to be equal to the current in the wire during the time the field is changing and that can be large.
It's a shame we have to call this current "it" sometimes, just because it was once declared a real thing. But we often call imaginary things "it" as well.
Also, nit picking on whether or not current "flows" is not going to get you anywhere because it's an accepted way to describe it as i am sure you know.
Same with "capacitor charges up". It's acceptable.
The guy is cool because he does not give a rat-**** what you or anyone else thinks about his videos. Good or bad, it is his way. Mostly good.
Then there are a lot of "cool" people in this world
No.I guess that makes most criminals "cool cats", right?
misterT,
Summary: He uses false facts and imprecise terminology to explain them.
Ratch
+1 for that.
My 2c
Saying current flows in a capacitor is like saying current flows via magnetic fields from the primary to secondary in a transformer. Current (charge) flows in to one plate and opposing current (charge) flows out from the other plate. The electric field generated from the charge seperation moves the energy across the physical dielectric, not flowing but changing (linear polarization in a dielectric) fixed atomic structures (or nothing in vacuum ) to the other side. If you see a capacitor as a black box as is common in circuit theory it's understandable because it greatly simplifies the math but it's just an imposter and a illusion with a name called (whatever) current because we are measuring the conduction current in the wiring. Displacement current was a mathematic tool invented by Maxwell to model the flow on energy in space (vacuum) in EM far-field plane waves. The meaning of the term has actually change since then from Maxwells physical molecular vortex model to the dualist theory of charges, currents , electric and magnetic fields as fundamental per Lorentz so what is happening is not a current but a displacement field generating a magnetic field while transporting energy. It is common to use "Displacement current" when talking about capacitors and displacement fields in vacuum but it's usual meaning in this context is different from the original meaning used by Maxwell.
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