Electrons - when they move from Atom to Atom - where do they end up?

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ggunn

PE (Electrical), NABCEP certified
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Austin, TX, USA
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Excellent!

But the furnace, that which we called the 'EB', didn't have a tungsten filament. It had a thing like this:

View attachment 7025

Our first design we considered a success (this was 1980). We were easily melting titanium with it. So, what did the titanium do with those electrons??

One day a bunch of military types came in and told us we had to up the power to many times what we had designed. So, months were spent tearing this huge vacuum furnace apart and installing bigger 'guns'. When we were done, the furnace would easily boil titanium. The military types came back, saw the boiling titanium and said it was good. Much hand shaking and back slapping ensued with a five star tour of the rest of the plant to follow. That was on a Friday. When I got back on Monday, the entire unit was gone.

Well, all gone except for the hopper that the engineers told us was used to feed the EB with powdered electrons. That was still there and looked strangely like some sort of sand blasting equipment.
Powdered electrons, eh? Just add water? :D

Seriously, the electrons for all these devices come from a power supply that basically pumps them around in a circle. You don't need a "supply" of electrons; they are lying around everywhere.

Electron guns are just glorified incandescent light bulbs. They run a current through a piece of metal (the cathode) heated to the point where the electrons are loosely bound to the metal and put a highly positively charged grid nearby. The attractive force of the grid extracts electrons from the cathode. Many get captured by the grid, but the ones that are on a path through the center of a hole in the grid get through and they are traveling very fast. Their kinetic energy is converted to heat when they strike the titanium in your furnace, which melts and eventually boils it.
 
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K8MHZ

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Michigan. It's a beautiful peninsula, I've looked
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Powdered electrons, eh? Just add water? :D

Seriously, the electrons for all these devices come from a power supply that basically pumps them around in a circle. You don't need a "supply" of electrons; they are lying around everywhere.

Electron guns are just glorified incandescent light bulbs. They run a current through a piece of metal (the cathode) heated to the point where the electrons are loosely bound to the metal and put a highly positively charged grid nearby. The attractive force of the grid extracts electrons from the cathode. Many get captured by the grid, but the ones that are on a path through the center of a hole in the grid get through and they are traveling very fast. Their kinetic energy is converted to heat when they strike the titanium in your furnace, which melts and eventually boils it.

Well, thank you, but I guess my sarcasm was wasted.

The part I left out was that I was a research and development tech, not an electrician, while I was at the facility. The place makes hot stage jet engine parts out of exotic alloys and various crystalline structures, including single crystal. We had lasers, plasma guns, EDMs, EBs, induction vacuum furnaces, and a plethora of other things to play with in the lab.

Last I heard they were making parts for the Raptor.

Believe it or not, being an electrician pays better than being an R&D tech in an aerospace research facility.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Well, thank you, but I guess my sarcasm was wasted.
Well, that's the problem with communicating in text, isn't it? When you converse with someone face to face, there are all sorts of cues whereby true intent can be conveyed, but with mere text... not so much. I once went to a seminar on communication where they told us that in a face to face conversation, 75% of the information transferred is passed nonverbally via body language, voice inflection, etc..

Anyway, I'm SO sorry I missed your sarcasm. That's sarcasm, BTW. :D
 
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mivey

Senior Member
B=I*u/2*3.14*r (See page no.143 of the paper under dispute http://stc.huji.ac.il//staff_h/Igal/Research Articles/Pointing-AJP.pdf )
I guess you take issue with the very next sentence where they state "E=RI/L"? Would E=V/L satisfy your needs?

But for ideal conductors, the assertion was made.
So what? We have already covered that there is no axial component of the electrical field in the ideal conductor because otherwise the zero resistance would yield infinite current.

The point that is shown by the Einstein's equation is the energy acquired by the electron from the power source is attached to it in the form of increase in its mass and moves with it wherever it goes until there occurs any conversion of it.
Can't be so because the energy propagates faster than the electron.

No. After moving through a resistance, there is a loss of potential energy of the electrons, which reappear as heat in the resistance.
Which resistance are you discussing, the resistance in the wire or the resistance of the load?
 

mivey

Senior Member
True. But you can't prove or disprove a theory by experimenting within limited conditions. The equations are designed to describe the physics within those limits. And that's all the peeps in your articles did - experiment within the conditions and proclaim it therefore works everywhere.
A theory proved is not a theory. A theory not disproved by experiment is a valid theory. Feynman said that no experiments have proven the Poynting Theory wrong. He said that even though Poynting Theory can defy normal intuition, he felt it was probably perfectly right and that our intuition is wrong. Experiments have supported that as well.

Charge is a measurement of the intensity of the energy present. Not a thing unto itself.
Again, you mistake a measurement of energy for a thing. Charge is a measurement of energy. If there is no energy then there is no charge.
From http://hyperphysics.phy-astr.gsu.edu: "Electric current is the rate of charge flow past a given point in an electric circuit"

Um, actually, lots of people have said the electrons don't travel in the wire but rather oscillate near place.
The lower the frequency, the more they travel. Tell me who has said otherwise.
 

__dan

Senior Member
quote_icon.png
Originally Posted by T.M.Haja Sahib
The point that is shown by the Einstein's equation is the energy acquired by the electron from the power source is attached to it in the form of increase in its mass and moves with it wherever it goes until there occurs any conversion of it.


Can't be so because the energy propagates faster than the electron.

I recall the thread where it was argued the photon gets heavier when it acquires more energy. Which cannot be so because the photon has no mass. Photon energy varies with the frequency.

Single electron effects are denied by the Heisenberg Uncertainty Principle, despite being observed experimentally. As far as I know HUP states all of the physical properties of the electron are either undefined or unknowable for the single unit at the specific instant. The dilemma is resolved statistically, with probability distributions, rather than deterministically, with acknowledgement of knowable physical properties of the single electron.

It seems well understood that the bound electron changes energy level by absorbing and emitting photons, so no mass change. Feynman models the atomic structure as a spherical cavity resonator and Randel Mills models the bound electron as a great circle that changes radius with photon absorbtion / emission.

I would love to see the arguement over if the electron is / is not a point charge. The point charge electron model has properties that are either undefined (HUP), resolve to infinite quantities when examined mathematically, or violates Maxwell's equations (The bound point charge would radiate and be unstable when it moves in orbit. Stability and non radiation is what is observed).
 
T

T.M.Haja Sahib

Guest
Single electron effects are denied by the Heisenberg Uncertainty Principle, despite being observed experimentally. As far as I know HUP states all of the physical properties of the electron are either undefined or unknowable for the single unit at the specific instant. The dilemma is resolved statistically, with probability distributions, rather than deterministically, with acknowledgement of knowable physical properties of the single electron.
An electron should be imagined as a definite point charge particle somewhere inside the atom. It should not be imagined as a wave just as a sound wave or electromagnetic wave is. An electron wave is a probability wave stating where the electron may be found. So the Einstein equation is applicable to individual electrons just as it is applicable to energy release in splitting up of atoms.
It seems well understood that the bound electron changes energy level by absorbing and emitting photons, so no mass change.
Here discussion is about free electrons roaming inside any metal and not about bound electrons in the atoms..
 

__dan

Senior Member
An electron should be imagined as a definite point charge particle somewhere inside the atom. It should not be imagined as a wave just as a sound wave or electromagnetic wave is. An electron wave is a probability wave stating where the electron may be found. So the Einstein equation is applicable to individual electrons just as it is applicable to energy release in splitting up of atoms.

You are making my point for me.

If the electron is imagined as a point charge inside the atomic radius, the question is, does it move from point A to point B inside the radius, in orbit? This is where the point charge model fails. A point charge that moves would radiate, which is not observed. Radiation would imply energy loss and instability.

The convention is to state that either the electron appears statically 'by the process of observation' or only has a probability of being found in a distribution. No mention is made of the electron dynamically moving (if it moved, it would radiate). Determining the electron's location and momentum are mutually excluded by the uncertainty principle.

If the bound electron inside the atomic radius does not move, how does it get from point A to point B, or have physical properties like momentum and spin ?

If the electron has a shape other than a point charge, do you think that shape changes substantially from the bound to the free state?
 
T

T.M.Haja Sahib

Guest
Dan,
There is a difference between free electrons and bound electrons in a metal. The bound electrons as long as they are in their stable orbits do not radiate, a principle of quantum mechanics. But when energy in specific amount is given to them, the bound electrons change to higher unstable orbits and returning back to stable orbits radiate specific amount of energy.
Contrary to above, the free electrons can receive any amount of energy and radiate any amount of energy and can move any where in the conduction band of the metal and with sufficient energy outside the metal!
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
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the question is, does it move from point A to point B inside the radius, in orbit?

They don't really move from one energy level to another, they 'leap'. That is different from the 'movement' of an electron in orbit.

But hey, I am just parroting what I have read. This all may be ancient lore in a century so I don't have much faith in today's theories. They are interesting though.

I graduated from high school with the 'knowledge' that there were three elementary particles. Now look. And those graduating from high school this year will experience the same thing 40 years from now.
 

pfalcon

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Location
Indiana
A theory proved is not a theory. A theory not disproved by experiment is a valid theory. Feynman said that no experiments have proven the Poynting Theory wrong. He said that even though Poynting Theory can defy normal intuition, he felt it was probably perfectly right and that our intuition is wrong. Experiments have supported that as well.
Feynman said the Poynting Vector equation stood up contrary to our intuition. He said the theory extended from the equation was nuts and did not attach it to intuition.

From http://hyperphysics.phy-astr.gsu.edu: "Electric current is the rate of charge flow past a given point in an electric circuit"
Current = velocity of charge; Charge = magnitude of electrical energy. Ergo "Current = velocity of charge" is functionally correct but imprecise. "Current = velocity of electrical energy" is more precise.
 

ggunn

PE (Electrical), NABCEP certified
Location
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Electrical Engineer - Photovoltaic Systems
Current = velocity of charge; Charge = magnitude of electrical energy. Ergo "Current = velocity of charge" is functionally correct but imprecise. "Current = velocity of electrical energy" is more precise.

Consider 10A in a conductor of arbitrary diameter. Now consider the same current in a conductor of double that diameter. The "velocity" of the charge in the second case is half what it is in the first although the current is the same. It seems to me that "velocity" is more analagous to voltage than to current.
 

pfalcon

Senior Member
Location
Indiana
... So what? We have already covered that there is no axial component of the electrical field in the ideal conductor because otherwise the zero resistance would yield infinite current.

Can't be so because the energy propagates faster than the electron. ...

Near absolute-zero temperature conductors have near zero resistance and do not generate currents that approach infinity. This is similar to extending Maxwell's base gravity equation to near-zero radius and getting a black hole. Maxwell's base electromagnetic equation also produced infinite energy at near-zero radius for the electron. Testing proved that electrons have finite energy. Maxwell then created a second equation for near-zero radius calculations. In short, a lot of equations that work for real world conductors fail when applied to ideal conductors.

Current theories that I've seen hold that the energy transfers from electron to electron rather than being carried by the electron. Sort of like Newton's Cradle. Depending on your favorite theoretical physicist the transfer mechanism is slightly different.
Particles with fields (Popular electron model); Non-particles with extended fields (Einstein); Standing waves with resonant coupling (Wolff).
 

mivey

Senior Member
Feynman said the Poynting Vector equation stood up contrary to our intuition. He said the theory extended from the equation was nuts and did not attach it to intuition.
You have to read the lectures to get the context of what Feynman was saying and recognize his "tongue in cheek" expressions. Then you will understand his use of "nuts" and crazy" is taken to mean in comparison to normal intuition and was the point he was making through this sequence of lectures.

Current = velocity of charge; Charge = magnitude of electrical energy. Ergo "Current = velocity of charge" is functionally correct but imprecise. "Current = velocity of electrical energy" is more precise.
The units do not match.
Given
charge in coulombs (C)
current in amps (A)
voltage in volts (V)
time in seconds (s)

following the units:
A = C / s
and
C = J / V
thus
A = J / (V * s)

So current is proportional to energy per volt-second (or energy per volt per second), NOT energy per second.
 

mivey

Senior Member
Near absolute-zero temperature conductors have near zero resistance and do not generate currents that approach infinity. This is similar to extending Maxwell's base gravity equation to near-zero radius and getting a black hole. Maxwell's base electromagnetic equation also produced infinite energy at near-zero radius for the electron. Testing proved that electrons have finite energy. Maxwell then created a second equation for near-zero radius calculations. In short, a lot of equations that work for real world conductors fail when applied to ideal conductors.
So no current near infinity. Not even near light speed. So you would agree with my point that we do not have an axial component of the electrical field in the ideal conductor.

Current theories that I've seen hold that the energy transfers from electron to electron rather than being carried by the electron. Sort of like Newton's Cradle. Depending on your favorite theoretical physicist the transfer mechanism is slightly different.
Particles with fields (Popular electron model); Non-particles with extended fields (Einstein); Standing waves with resonant coupling (Wolff).
I suspect none of the current theories say that the energy traveling to the load, by whatever transfer mechanism they want, travels inside the metal conductor.

If they did, it would be pretty easy to show by experiment that the propagation of energy mostly depends on the distance between the conductors and the material between the conductors. Using your logic from an earlier post, since the energy propagation depends on the configuration outside the metal and the stuff outside the metal, the energy must be traveling outside the metal.
 

pfalcon

Senior Member
Location
Indiana
... The units do not match.
Given
charge in coulombs (C)
current in amps (A)
voltage in volts (V)
time in seconds (s)

following the units:
A = C / s
and
C = J / V
thus
A = J / (V * s)

So current is proportional to energy per volt-second (or energy per volt per second), NOT energy per second.

work in joules (J)
thus
current is proportional to work per volt-second. NOT energy per volt-second.

J = kg*m*m/s/s
V = kg*m*m/C/s/s

Coulomb is the base unit for the magnitude of energy not joules. Joules and Volts are derived measurements of behaviour.
 

pfalcon

Senior Member
Location
Indiana
So no current near infinity. Not even near light speed. So you would agree with my point that we do not have an axial component of the electrical field in the ideal conductor.
Those near-zero conductors have a measurable finite current. The near-zero resistance results in near-zero energy lost in heat. Certainly seems to support that conclusion.

I suspect none of the current theories say that the energy traveling to the load, by whatever transfer mechanism they want, travels inside the metal conductor.

If they did, it would be pretty easy to show by experiment that the propagation of energy mostly depends on the distance between the conductors and the material between the conductors. Using your logic from an earlier post, since the energy propagation depends on the configuration outside the metal and the stuff outside the metal, the energy must be traveling outside the metal.
I'm not sure you said what you meant to say in that first sentence.

How to say this without a paragraph?

Electromagnetic energy is a field with a nominal center. The nominal center rests on the electron. The electrons emit and receive the center similar to a bucket brigade. The center moves within the metal not so much because it's in the metal but because the next electron in line is in the metal. It's the interaction of the electromagnetic fields that cause the forward transfer. The interaction is typically the most dense in the metal because that's where the field center is located. But it doesn't have to interact inside the metal or at least the interaction can be balanced within the metal incurring the same result. Sort of like the beads on an abacus you don't have to push on the center to make it move down the wire but it's still constrained to the wire, the center still rests in the wire, and the field density is greatest in the wire.

Thus in the ideal conductor there is no apparent axial component. But the theory is that there is an actual axial component with equal positive and negative magnitudes. In short, balanced field interactions from both directions. With no unbalanced force the current neither increases or decreases.

Guess I lost that paragraph bet. :( Anyhoot. To say any of the above is any more than one of many theories on electromagnetic energy would be presumptious.

So Yes. There is no known unbalanced axial component in an ideal conductor.
 
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