What keeps an electron from skipping over one another?

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Dnkldorf

Senior Member
If an electron is being forced to occupy another electrons space, by voltage, and this in turn forces this electron to move into anothers space.......electron flow......what keeps the first electron from skipping it's place and jumping over the next electron?

Or do they just bang into each other like kinetic energy balls?
 

charlie b

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Nothing requires an electron to move from one atom to the next atom in line. It might skip by two or three atoms, before settling into its next temporary home. And as to bumping into each other, I once developed an electrical theory 101 presentation, and I did some math in preparation for it. I am working from memory now, so I might not have this quite right. But I remember tellling my class that if you used a basketball to represent the nucleus of a hydrogen atom (i.e., a single proton), the single electron associated with that atom would be the size of a single grain of salt, and it would be in an orbit around the basketball at a distance of about ten miles. "Solid matter" is mostly empty space! I might conclude that the notion of electrons bumping into each other is not a likely event.
 

Mr. Bill

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Location
Michigan
This is a deep question. I'm sure there have been a few thesis papers written on the subject. I think it is easiest to just visualize the electrons skipping along like water flowing thru a river. I don't know if we can visualize it in a truely accurate manner. Very few can even visualize an electron "orbiting" around the nucleus. (It's not really an orbit like the planets, more of a cloud area that the electron is in somewhere.)

Then current is not always equal in the cross section of the wire. High voltage can push the current to the skin of the wire.

Then there's hole theory which says the electrons do not create current but the gap of electrons which does.

Please google the subject and search physics forums. I'm sure there's lots of intersting info out there. Share what you find.
 

Dnkldorf

Senior Member
Tranfer of energy, like balls on a billiards table.

That's what I was thinking. The pool cue initiates the force, and the energy is passed along kineticly. So, in theory.....the cue ball can jump over other balls, striking a different one, and therby passing along what energy is left.

It would waste X amount of energy, passing by other balls.

But what would happen if moving electrons along by force, was replaced by moving them along by vaccum?

You remove one, and another automatically takes it's place by magnetic vaccum, not magnetic force.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
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But what would happen if moving electrons along by force, was replaced by moving them along by vaccum?

You remove one, and another automatically takes it's place by magnetic vaccum, not magnetic force.
Well, the theory that electrons move from an abundance of electrons to a dearth of them does suggest that.

I guess one could say that electron flow sucks. :roll:
 

charlie b

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That's what I was thinking. The pool cue initiates the force, and the energy is passed along kineticly.
If you hit the cue ball with the cue stick, the nearest other ball is likely no more than eight feet away. If you think of an electon being the size of a cue ball, and you are playing pool in Seattle, then the nearest other electron will also be the size of a cue ball, but it will be in Tacoma.
But what would happen if moving electrons along by force, was replaced by moving them along by vaccum? You remove one, and another automatically takes it's place by magnetic vaccum, not magnetic force.
The force that gets electrons moving is electrostatic (along the lines of "like charges repel" and "opposite charges attract"), not magnetic, and it is a push, not a pull.
 

nakulak

Senior Member
its nice that everyone is trying to provide an explanation as to how charged particles (assumption) move through conductors, but I'm wondering if this thread shouldn't be moved to the Hack quantum mechanics forum section :grin:
 

zog

Senior Member
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Charlotte, NC
its nice that everyone is trying to provide an explanation as to how charged particles (assumption) move through conductors, but I'm wondering if this thread shouldn't be moved to the Hack quantum mechanics forum section :grin:

May I recommend "The Dancing Wu Li Masters", perhaps the greatest book I have ever read.
 

zog

Senior Member
Location
Charlotte, NC

If you hit the cue ball with the cue stick, the nearest other ball is likely no more than eight feet away. If you think of an electon being the size of a cue ball, and you are playing pool in Seattle, then the nearest other electron will also be the size of a cue ball, but it will be in Tacoma.

Yes but there are millions of other ones out there, so any shot will hit something. Even if you miss there are millions of other cue balls being shot at not only the one in Tacoma but all of the other ones too.

In a nuclear reactor the odds of a nuetron becoming thermalized and therefore craeting heat (To heat water, to make steam , to turn a turbine, to make power) are about a million to one yet somehow nuclear reactors make heat. Why, because thee are a billion nuetrons to thermalize.

Or another concept. sperm, what are the odds of a sperm cell fertiliting that egg? Not good, yet somehow you got here :)
 

charlie b

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I don?t have a copy of my paper, ?Concepts of Reactor Physics, Without the Mathematics? (IEEE Transactions on Nuclear Science, 1992) handy with me at the office. But from what I recall, it reports that the odds that a neutron will slow down without leaving the vicinity of the operating reactor that sent it flying in the first place, and further that the neutron will eventually hit a uranium atom, and still further that this collision will result in a new fission, are collectively better than 40%. It is absolutely not a million to one shot. And the reason reactors can operate is not that there are plenty of neutrons flying about, but rather that each neutron has a reasonable chance of causing another fission.

By contrast, electrons simply don?t collide with each other, because there is simply too much empty space out there for them to hit instead.
 

zog

Senior Member
Location
Charlotte, NC
I don?t have a copy of my paper, ?Concepts of Reactor Physics, Without the Mathematics? (IEEE Transactions on Nuclear Science, 1992) handy with me at the office. But from what I recall, it reports that the odds that a neutron will slow down without leaving the vicinity of the operating reactor that sent it flying in the first place, and further that the neutron will eventually hit a uranium atom, and still further that this collision will result in a new fission, are collectively better than 40%. It is absolutely not a million to one shot. And the reason reactors can operate is not that there are plenty of neutrons flying about, but rather that each neutron has a reasonable chance of causing another fission.

By contrast, electrons simply don?t collide with each other, because there is simply too much empty space out there for them to hit instead.

Um, thermalization of nuetrons has nothing to do with fission. 2 completely different events. I don't want to get this thread too far off topic and get into the nuetron life cycle with you, lets stick to the topic at hand.
 

__dan

Senior Member
paradigms

paradigms

mmm ...

You're thinking in three dimensions, having an effect or traveling in space or position. You are neglecting movement in a fourth dimension, one of energy, the electron change in energy.

The Mars lander transmits to an orbiting relay satellite that retransmits to earth. The electrons in the transmitting antenna never leave the metal, they also do not move much in the antenna itself. Movement would cause I*I*R resistive power losses in the antenna. It would lose power as heat. If the electron movement in the antenna were marginally random, the movement would create noise along with the signal.

Electrons in the transmitting antenna have their potential energy "raised" or "shaken" by the impression of a RF transmitting voltage on the antenna. RF transmission is not executed by losses due to heat or noise, nor by conduction. The effectiveness and economy of one electron coupling electrostatically to another is such that an infinitesimal quantity in the transmitting antenna can impress their potential energy on a like quantity in the receiving antenna, so that enough power is coupled into a usable signal that can be amplified into information.

Power transmission has a similar paradigm. Throw a switch in New York that is wired to a lamp in Washington. Closing the switch imposes the change in potential energy (voltage) on the local electrons. The lamp lights after the propagation delay for voltage carried by electrons, which is the speed of light. In the seconds it takes for the voltage to travel to DC, the local electrons travel on the order of ten feet (have not done the math on this).

The transmission of voltage, a change in the electron potential energy, at the speed of light, everywhere on the connected system, causes local current flow at the subject equipment or circuit.
 

steve66

Senior Member
Location
Illinois
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Engineer
If an electron is being forced to occupy another electrons space, by voltage, and this in turn forces this electron to move into anothers space.......electron flow......what keeps the first electron from skipping it's place and jumping over the next electron?

Or do they just bang into each other like kinetic energy balls?

If you are talking about electron flow through a metal, like copper, the electrons are very loosely bound in their atoms. In fact, the electrons are so loosely bound, for the most part, its impossible to say which electron goes with which atom. You wind up with a "sea of electrons" that are pretty much free to just wonder around the conductor.

(As is that weren't enough, I think the current consensus is that an electron is a "probability wave". It has a 50% probability of being here, and 25% of being there, and another 10% of being somewhere else. So, not only do you not know what atom the electron belongs to, the electron doesn't even have a definite position until someone tries to actually find or measure its position.)

Given that, the thermal motion of the electrons is much larger than their flow due to an electric field. So if you could actually track and watch all the electrons moving, you would see they are moving in all different directions. But overall, a few more electrons would be moving in the direction of current flow, and a few moving that direction might be going a little faster.

It's a very gradual "electron drift" in the direction of current flow that would be hard to see within the general chaos of other motion.

So my vote is for lots of skipping and collisions, and general chaos, and even lots of electrons moving in the wrong direction. If you could plot the positions of the electrons vs. time, the actual current flow would still not be obvious.

Steve
 
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Dnkldorf

Senior Member
If you are talking about electron flow through a metal, like copper, the electrons are very loosely bound in their atoms. In fact, the electrons are so loosely bound, for the most part, its impossible to say which electron goes with which atom. You wind up with a "sea of electrons" that are pretty much free to just wonder around the conductor.

(As is that weren't enough, I think the current consensus is that an electron is a "probability wave". It has a 50% probability of being here, and 25% of being there, and another 10% of being somewhere else. So, not only do you not know what atom the electron belongs to, the electron doesn't even have a definite position until someone tries to actually find or measure its position.)

Given that, the thermal motion of the electrons is much larger than their flow due to an electric field. So if you could actually track and watch all the electrons moving, you would see they are moving in all different directions. But overall, a few more electrons would be moving in the direction of current flow, and a few moving that direction might be going a little faster.

It's a very gradual "electron drift" in the direction of current flow that would be hard to see within the general chaos of other motion.

So my vote is for lots of skipping and collisions, and general chaos, and even lots of electrons moving in the wrong direction. If you could plot the positions of the electrons vs. time, the actual current flow would still not be obvious.

Steve




Kudos.

It can leave its atom then, but another one has to takes it's place? No.

If too many electrons leave it's atom, wouldn't the structure of the metal change?
 

steve66

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Illinois
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Kudos.

It can leave its atom then, but another one has to takes it's place? No.

If too many electrons leave it's atom, wouldn't the structure of the metal change?


Picture 10 atoms squished together in 3 dimensions, and then picture 10 electrons that are all kind of inbetween these atoms. Its already impossible to say what electron goes with which atom. Instead, you have 10 electons that are each shared with 10 atoms.

Now imagine all the electrons are moving around (thermal motion). Now its even harder to pair electrons with its atom.

Its kind of like kids and parents that walk into a fenced-in playground. As they walk in, its easy to say which parents go with which kids. But once the kids start running around while the parents stand there, nobody knows which kids came in with which parents.

Finally, think of the electrons position not as a point particle, but as a cloud or probability on where the electron might be. Even less clear which electron goes with which electron.

So the electrons that conduct electricity don't just jump from atom to atom - they are free to just wonder around the metal. That's really what makes a conductor a conductor in the first place.

It doesn't change the structure of the metal. Its only the outter valiance electrons that are free to move about. And since the atom is sharing other electrons, its kind of like its not really loosing anything.
 
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