The only way to cancel the natural internal EMF of a metallic crystal lattice is to cool it. As you cool it, there will be a temp. where all of the free electrons return to a home atom. Only then will the lattice not have an internal EMF. As you warm the lattice up...one electron will be freed. As soon as the first free electron starts moving about the lattice, you have an internal EMF.

As I understand things they don't work like that.

The 'natural' thermal movement is randomly oriented so that, over time, there is no preferred direction of drift or build up.

If however you introduce a preference/selection mechanism then you will introduce a concentration gradient which produces a voltage.

This can apply to random drift phenomena in general such as osmosis not only to electric phenomena such as semiconductor junctions, electrophoresis, electro-osmosis , the Hall effect and others.

 

As I understand things they don't work like that.

The 'natural' thermal movement is randomly oriented so that, over time, there is no preferred direction of drift or build up.

If however you introduce a preference/selection mechanism then you will introduce a concentration gradient which produces a voltage.

Correct, it's rather like the old electric football sets with a harmonic vibrator on the play surface. By adjusting the base prongs you create a mechanical vibration preference that will cause the base to move.

 

When the second electron is freed.......one electron will go to one surface end and one electron will go to the opposite surface end of the conductor. When you add a third, it will go to the middle surface. As more electrons are freed....they distribute evenly on the surface. This causes a EMF between the surface and the center. All metallic free electron conductors are naturally polarized. There is no drift unless there is an external field or a temp. change.

When you add a voltage across the conductor, the surface electrons do not move straight down the conductor. They spin around the outside surface of the conductor. This rotating electric field causes a magnetic moment in the center of the conductor. These magnetic field lines traveling longitudinally thru the center of the conductor is what REAL current is.
The reason that drift current is so slow is not because it is slow. It's because it spins around the wire....not down it.
Real current is not the electron flow......it's the magnetic flow thru the conduit that we call a conductor.

This is why elections can only flow a quarter of an inch.......but the effect is almost instantaneous at the other end.

This is the longitudinal force that Ampere was trying to explain.

 

This is the longitudinal force that Ampere was trying to explain.

Very interesting... and I had thought that I had nothing to learn from this thread!
Thanks for the explanation...

 

 

Now you're talking!

 

When the second electron is freed.......one electron will go to one surface end and one electron will go to the opposite surface end of the conductor. When you add a third, it will go to the middle surface. As more electrons are freed....they distribute evenly on the surface. This causes a EMF between the surface and the center. All metallic free electron conductors are naturally polarized. There is no drift unless there is an external field or a temp. change.

Mostly at AAC I exhort folks to avoid quantum explanations. This is a practical forum for practical folks.

However what you say above is classical and definitely does not happen.

The conduction band (band is a quantum word) electrons are delocalised. But the band can only exist by virtue of the immovable metallic positive matrix.

I haven't studied spook's post, his are usually more spooktacular than mine, but I expect that is what is says.
Edit.
The whole point is that 'free' electrons are not detached from their nucleii, they have simply moved into another energy band called the conduction band. This takes next to no energy with metals. Your explanation is equivalent to saying that the free electrons are fred as a result of ionisation, which implies the huges energy changes of thermionic emission, where they are ionised.

 

This is the mathematical approach and not the cognitive or how things really work. Just like the chemist ( I don't mean a pharmacologist) who uses oxidaton-reduction rules (numbers if you like) to explain redox reactions (redox is short for oxidation - reduction reactions).

In other words, the assignment of oxidation numbers ( a classical example of chemical sophistry) in order to explain certain reactions.

Likewise, a mathematician is interested in explaining phenomena through numbers, this is what the videos show.

However, they do not explain what takes place in reality.

Above, I had given an example how an emf is produced in a rod moving in a magnetic field because it happens to fit the model (the way, we think about it, in order to help us understand the situation), however, this may not be the way, the emf is generated.

I had come across a thesis by some French researchers, which contradicted that electricity is caused by electron flow, if only I could remember the title.

 

This is the mathematical approach and not the cognitive or how things really work.
...
Likewise, a mathematician is interested in explaining phenomena through numbers, this is what the videos show.
However, they do not explain what takes place in reality.

Math is a descriptive language that can be used to produce models that don't resemble reality but so can the English language. That's not the case here, we can verify the mathematical results by experiment. Simply, because you fail to understand how it works does not make it false. If we can build devices like the LHC using these theories I think they match reality fairly closely. The ultimate reality of 'electricity' might be flowing unicorn tears but that still won't make current theories wrong, just incomplete.

 

Math is a descriptive language that can be used to produce models that don't resemble reality but so can the English language. That's not the case here, we can verity the mathematical results by experiment. If we can build devices like the LHC using these theories I think they match reality fairly closely. The ultimate reality of 'electricity' might be flowing unicorn tears but that still won't make current theories wrong, just incomplete.

Agreed.... ever heard of mathematical reality?

 

Post # 88.
The reason that you will get many different answers to your questions and
that none of them can clearly show you the answer is........THEY DON"T KNOW HOW IT WORKS.

Modern science today insist on magic and the metaphysical. Only the
enlightened can understand the true workings of matter and the universe.

Sounds like a religion to me. You must know the secret handshake.....QM or you can't get in.

It's been over 100 years now......can modern science tell you what an electron is?

Why not?

When you listen to a science that ignores cause and effect, denies that
matter has structure, and says that random chance, statistical probability, and
virtual particles popping in and out, ....control the universe, what do you expect?

With those premises and a little creative math as evidence, you can now "prove" anything you want. But the best part is, if there are any anomalies in the experiment, it was because of randomness, or probability, or a quantum effect. What a gig!

But what really gets me is that so many educated people except this as science.

You or anyone else will never understand the universe by this process.

Fortunately for us(or at least for me)....the universe is very severely ordered and obeys simple laws. Anyone can understand how everything works because of this.

It is so simple, many may not be able to except it.

When you understand what a particle is and how they combine to make atoms and matter, you will understand that the mystery isn't about how it works, the true mystery is the beauty and elegance of the device.

 

It's been over 100 years now......can modern science tell you what an electron is?

Why not?

You tell us what an electron is.

 

how about heating above the Currie point? no magnetic field to induce electron flow.

 

No... this is not off-topic at all... see, we're talking about a bunch of fantasy impossible things here... we might as well talk about how many angels can dance on a pin-head... and still be on-topic in this thread...

Except that question has a correct answer: "all of them".

Bob

 

how about heating above the Currie point? no magnetic field to induce electron flow.

A very interested explanation of how the magnetic field of the earth is generated, given that metal looses its magnetism when heated above the so called Currie point.

http://physics.aps.org/story/v19/st3