Electrons are round!

[aetherist]

Once again, if electricity “hugs the surface” of a wire, then why does the DC conductance (reciprocal of resistance) scale with the cross-sectional area, not the circumference?

Let's keep in simple: because when enough time is provided, the electricity penetrates inside, to make more intimate bond with the wire.

Yes, i like that. U of course are referring to the standard AC explanation, & i suspect that Tim's original linked table is for AC.
But i am liking your explanation in regard to my hugging elekton elekticity. Bearing in mind that i agree that there is an electron electricity in a wire (which i describe as hugging elektron elektricity)(here hugging the nuclei).
But i did not intend to say any more re my hugging elektons. But then i saw your comment which is in line with my thinking, that (fast) elekton elekticity is "when enough time is provided" "penetrates inside" to give us (slow) elektricity.

And, re other comments re the correctness of present engineering equations etc, i am happy with present equations, my ideas dont change any of that.
But, our present equations are simply simple models, that give good numbers -- they dont explain anything.

[aetherist]

Don't rely on the headline.
The actual research result involved an upper limit on the dipole moment of the electron.
"Roundness" is not a real technical term in particle physics.

I'm confused.  How could the electron have a dipole moment?  It consists of no constituent parts.  It is a primitive particle.  To have a dipole moment, it would need two opposite charges, separated by a distance.  Is someone proposing the electron is not primitive?

The currently accepted theory, known as the standard model, postulates that the electron is an elementary particle without any internal constituents. The experiment have confirmed this theory on a smaller scale than ever before.

Whether the standard model is accurate, and whether elementary particles lack a geometric shape at even smaller scales is unknown. Alternative theories might surface if future experiments reveal finer structures within elementary particles.

Physics differs from climate “science”. In physics, room for doubt exists, and there are always alternative theories. Experimental physicists always try to find anomalies that cannot be explained by theories.

Its simple. All is photons, the elementary quasi particle.
Photons make elementary particles.
But, in an atom, we dont have elementary particles orbiting a nucleus -- we have photons orbiting the nucleus.
Photons have mass. Photons have momentum. Photons have inertia. And so do orbiting photons in an atom.
And, orbiting photons have all of the qualities of the (silly) orbiting electrons.

[TimFox]

How do the orbiting photons in your model (not yet substantiated) explain the Zeeman and Stark effects of external magnetic and electric fields on the atomic spectra?

(BTW, I haven't done the calculations yet but I guess that the erroneous wire table I linked was in terms of mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.)

[aetherist]

How do the orbiting photons in your model (not yet substantiated) explain the Zeeman and Stark effects of external magnetic and electric fields on the atomic spectra?

(BTW, I haven't done the calculations yet but I guess that the erroneous wire table I linked was in terms of mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.)

I  am an Engineer not a physicist, & i dont know enuff about that kind of stuff.
I go along with most of what physicist JG Williamson says -- he says that photons orbit a nucleus.
A hugging photon has charge & orbit etc etc, like a (silly) electron.  Hence i dont see how orbiting photons should have any special problem (compared to silly electrons).

Light is photons confined in one dimension -- no nett charge (in the far field).
Elekticity is photons confined in two dimensions -- have negative charge.
Elektrons is photons confined in three dimensions -- have negative charge.

[vad]

Its simple. All is photons, the elementary quasi particle.
Photons make elementary particles.
But, in an atom, we dont have elementary particles orbiting a nucleus -- we have photons orbiting the nucleus.
Photons have mass. Photons have momentum. Photons have inertia. And so do orbiting photons in an atom.
And, orbiting photons have all of the qualities of the (silly) orbiting electrons.

Nay, atoms are made of cheese. Lighter atoms are made of fresh, unprocessed varieties, such as ricotta. Atoms of heavier elements up until iron are made of stretched curd varieties, such as mozzarella. The heaviest atoms are made of Swiss-type cheese.

[gnuarm]

Ok, i have the correct results. I got my results from the link provided by TimFox.
A 1.0 mm Cu wire 1000 m long has a resistance of 35 ohm
A 10.0 mm Cu wire 1000 m long has a resistance of 3.6 ohm.
A 10.0 mm wire has a Xsectional area 100 times that of a 1.0 mm wire.
Hence the resistance of a 10.0 mm wire should be 0.35 ohm based on Xsection area.
And the resistance of a 10.0 mm wire should be 3.5 ohm based on circumference.
So, my circumference theory has an "error" of 0.1 ohm.
But your area theory has an error of 3.15 ohm.

good lord, heaven knows how I correctly worked out harness lengths in my previous career particularly when I had to calculate the length of cable required to supply a load that was more sensitive than most to voltage drop on a 24V system. I must have been on magic mushrooms at the time and was obviously helped by the fairies..... Or I used my understanding of current and correct physics.

I once worked at a place where there were rumors of a guy who not only was stupid, but had no idea just how stupid he was.  This was a beltway bandit, where we would either build systems for the government, or sometimes simply provide direct support. 

The story of this guy goes that he was in a meeting where they were picking the location of new antennas to be installed.  Different people gave a few opinions.  Then this guy, we'll call him Floyd, chimes in that we should put the antenna at the bottom of the hill.  Everyone had a laugh, then Floyd continued.  He said the antenna should be a the bottom of the hill, so that they would collect the electrons as they ran down the hill.  Another good laugh.  But, Floyd wasn't laughing!  He was being serious! 

Another time, Floyd and some other guys were doing a facility survey to prepare for installation of equipment in a room.  It's basically measuring the space, making sure there was enough AC, electricity, etc.  One of the team members was calculating the floor area, length times width.  Floyd said he was doing it wrong.  It's length divided by width.  The guy asked him what he was talking about.  Floyd's reasoning was, "How many quarters in a dollar?  How many quarters in two dollars?  See?" 

It's hard to argue with someone like that.

[TimFox]

It's like playing chess with a pigeon:  First, he flaps his wings and knocks over the pieces, then he takes a dump on the board, finally he flies home and brags that he won the game.

[coppercone2]

[EPAIII]

Actually, since electrons are best described by quantum theory which uses what is called a wave function that describes the probability of finding any individual electron at any given point in the universe and since that implies that each individual electron can actually and truly be at any given point in the universe when that wave function is made to collapse, then the shape of an electron, if it can indeed be said to have any shape at all, would be the shape of the universe itself.

And since we don't actually know what the shape of the universe itself is, we do not know what the shape of an electron is. Not really!

[Nominal Animal]

I haven't done the calculations yet but I guess that the erroneous wire table I linked was in terms of mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.

It matches the \$R(\ell, A) = \ell \rho / A\$ exactly, when "gauge" is area in square millimeters, \$\ell\$ is length in meters, and resistivity were \$\rho = 35.2 \text{ n}\Omega \cdot m\$.

It seems the table has several errors, not just using "gauge" and "mm" for cross-sectional area.  For example, the resistivity of copper is around \$\rho = 17 \text{ n}\Omega \cdot m\$ (depends on the copper alloy and structure, hardened/non-annealed copper tends to have a slightly higher resistivity/lower conductivity), so it looks like the author erroneously halved the area, as in "\$A = \pi r^2 / 2\$" –– which is a common error when confusing radius and diameter \$D = 2 r\$ and thus \$A = \pi r^2 = \pi (D/2)^2 = \pi D^2/4\$.

Understandable errors, but horribly annoying when taken as correct.  I, too, were bamboozled for a second, before I checked some of the stated resistances (which obviously did not match the known correct and measured values).  And the edits to this post were because I was again bamboozled when investigating how the factor of 2 error came to be.

[Psi]

This seems relevant.

[Nominal Animal]

I'm sad, because there are no Pallas cats in Pallas, Finland.  None at nearby Ylläs, either.

I will now get my coat (it's still hanging at the bar), and go ask if I can has Cheezburger.

[Simon]

How do the orbiting photons in your model (not yet substantiated) explain the Zeeman and Stark effects of external magnetic and electric fields on the atomic spectra?

(BTW, I haven't done the calculations yet but I guess that the erroneous wire table I linked was in terms of mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.)

I  am an Engineer not a physicist, & i dont know enuff about that kind of stuff.

OK, so we are done, you say you don't know what you are talking about but keep talking....

[Simon]

Ok, i have the correct results. I got my results from the link provided by TimFox.
A 1.0 mm Cu wire 1000 m long has a resistance of 35 ohm
A 10.0 mm Cu wire 1000 m long has a resistance of 3.6 ohm.
A 10.0 mm wire has a Xsectional area 100 times that of a 1.0 mm wire.
Hence the resistance of a 10.0 mm wire should be 0.35 ohm based on Xsection area.
And the resistance of a 10.0 mm wire should be 3.5 ohm based on circumference.
So, my circumference theory has an "error" of 0.1 ohm.
But your area theory has an error of 3.15 ohm.

good lord, heaven knows how I correctly worked out harness lengths in my previous career particularly when I had to calculate the length of cable required to supply a load that was more sensitive than most to voltage drop on a 24V system. I must have been on magic mushrooms at the time and was obviously helped by the fairies..... Or I used my understanding of current and correct physics.

I once worked at a place where there were rumors of a guy who not only was stupid, but had no idea just how stupid he was.  This was a beltway bandit, where we would either build systems for the government, or sometimes simply provide direct support. 

The story of this guy goes that he was in a meeting where they were picking the location of new antennas to be installed.  Different people gave a few opinions.  Then this guy, we'll call him Floyd, chimes in that we should put the antenna at the bottom of the hill.  Everyone had a laugh, then Floyd continued.  He said the antenna should be a the bottom of the hill, so that they would collect the electrons as they ran down the hill.  Another good laugh.  But, Floyd wasn't laughing!  He was being serious! 

Another time, Floyd and some other guys were doing a facility survey to prepare for installation of equipment in a room.  It's basically measuring the space, making sure there was enough AC, electricity, etc.  One of the team members was calculating the floor area, length times width.  Floyd said he was doing it wrong.  It's length divided by width.  The guy asked him what he was talking about.  Floyd's reasoning was, "How many quarters in a dollar?  How many quarters in two dollars?  See?" 

It's hard to argue with someone like that.

Point taken,

[gnuarm]

Actually, since electrons are best described by quantum theory which uses what is called a wave function that describes the probability of finding any individual electron at any given point in the universe and since that implies that each individual electron can actually and truly be at any given point in the universe when that wave function is made to collapse, then the shape of an electron, if it can indeed be said to have any shape at all, would be the shape of the universe itself.

And since we don't actually know what the shape of the universe itself is, we do not know what the shape of an electron is. Not really!

Maybe I missed an important post somewhere, but my understanding is an electron is a fundamental particle.  That means it can have no structure.  How would it have any shape, other than a point? 

If you wanted, I suppose you could make an argument that it's an infinitesimally small sphere.  But as soon as you do that, you could extrapolate it to be shaped like a chair or anything else. 

What's wrong with just saying it's a point with no particular shape?  Did someone already mention this?

[gnuarm]

How do the orbiting photons in your model (not yet substantiated) explain the Zeeman and Stark effects of external magnetic and electric fields on the atomic spectra?

(BTW, I haven't done the calculations yet but I guess that the erroneous wire table I linked was in terms of mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.)

I  am an Engineer not a physicist, & i dont know enuff about that kind of stuff.

OK, so we are done, you say you don't know what you are talking about but keep talking....

That's very rude.  He is saying that he doesn't understand all the details, but he believes what he reads of what others say about the subject.  Is that ok with you?

[radiolistener]

mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.

cross section area in mm² is commonly used for high power electricity, such as mains lines, power cable between mains socket and high power equipment, etc. When you deal with more precise electronics, for example hand made RF inductors, transformers, in these area diameter in mm is commonly used...

For example bobbins with copper wire for inductors and transformers are marked with mm diameter. I don't remember bobbins which was marked with cross sectional area in mm^2.

[gnuarm]

mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.

cross section area in mm² is commonly used for high power electricity, such as mains lines, power cable between mains socket and high power equipment, etc. When you deal with more precise electronics, for example hand made RF inductors, transformers, in these area diameter in mm is commonly used...

For example bobbins with copper wire for inductors and transformers are marked with mm diameter. I don't remember bobbins which was marked with cross sectional area in mm^2.

I can't recall specifics, but when I look for info on wires, I seem to recall the use of terms which are not properly electronic.  It's as if the electrical world tossed out all the info on units and just invented their own.  So, I think there is a unit they use for area, which reads like a linear unit, circular mils, perhaps?  This gets shorted to just mils in tables.  Maybe that's also true for mm?

[TimFox]

Actually, since electrons are best described by quantum theory which uses what is called a wave function that describes the probability of finding any individual electron at any given point in the universe and since that implies that each individual electron can actually and truly be at any given point in the universe when that wave function is made to collapse, then the shape of an electron, if it can indeed be said to have any shape at all, would be the shape of the universe itself.

And since we don't actually know what the shape of the universe itself is, we do not know what the shape of an electron is. Not really!

Maybe I missed an important post somewhere, but my understanding is an electron is a fundamental particle.  That means it can have no structure.  How would it have any shape, other than a point? 

If you wanted, I suppose you could make an argument that it's an infinitesimally small sphere.  But as soon as you do that, you could extrapolate it to be shaped like a chair or anything else. 

What's wrong with just saying it's a point with no particular shape?  Did someone already mention this?

Yes, the usual understanding is that the electron is a fundamental particle with no structure.
The experiment discussed in the ill-titled article is testing that understanding, and reported an upper bound to the dipole moment, meaning that they found zero moment (as expected) and that their experiment could be quantified by that bound.

[TimFox]

mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.

cross section area in mm² is commonly used for high power electricity, such as mains lines, power cable between mains socket and high power equipment, etc. When you deal with more precise electronics, for example hand made RF inductors, transformers, in these area diameter in mm is commonly used...

For example bobbins with copper wire for inductors and transformers are marked with mm diameter. I don't remember bobbins which was marked with cross sectional area in mm^2.

From a table posted by a wire manufacturer:  "The most common method of referring to conductor sizes uses the cross-sectional area, expressed in mm². The following AWG metric conversion table converts AWG to mm and inches, and also lists the cross sectional area (mm2)."
https://www.elandcables.com/the-cable-lab/faqs/faq-what-is-the-conversion-between-awg-and-the-metric-system 

[TimFox]

mm², the common wire size in metric-speaking countries, rather than mm diameter, since I have had technical conversations with foreign engineers who used "mils" or "mm" as an abbreviation for area.

cross section area in mm² is commonly used for high power electricity, such as mains lines, power cable between mains socket and high power equipment, etc. When you deal with more precise electronics, for example hand made RF inductors, transformers, in these area diameter in mm is commonly used...

For example bobbins with copper wire for inductors and transformers are marked with mm diameter. I don't remember bobbins which was marked with cross sectional area in mm^2.

I can't recall specifics, but when I look for info on wires, I seem to recall the use of terms which are not properly electronic.  It's as if the electrical world tossed out all the info on units and just invented their own.  So, I think there is a unit they use for area, which reads like a linear unit, circular mils, perhaps?  This gets shorted to just mils in tables.  Maybe that's also true for mm?

An American conventional unit (inch based) for wires is the "circular mil", which is defined as the area of a circle that is one mil in diameter, where one mil = 0.001 inch.
It is often found in design rules or rules-of-thumb for recommended current density in transformer windings, etc., in amperes per circular mil.
The American "AWG" gauges for wires, typical for "gauges", is a logarithmic measurement rather than linear measurement, where a difference of 3 in AWG is close to a factor of 2 in area: AWG 20 is 1,022 cir mil and AWG 17 is 2,048 cir mil in area.
My mnemonic is that AWG 10 is 0.1019 inch diameter, close to 1/10 inch.
For very large wires, larger than AWG 0 (sometimes called 1/0) = 0.3249 inch diameter or 106,000 cir mil area, the conventional series proceeds to multiple 0's: 00 (2/0), 000 (3/0), and 0000 (4/0).
Thereafter the amusing abbreviation "MCM" for "thousand circular mils" (as in the ancient Roman numeral M = 1000, not the modern mega).
I first ran into this when observing the installation of a new electrical box fed by "250 MCM" wire (0.5 inch diameter), the next size up from AWG 0000 at only 212,000 cir mil area.
Now, the skin depth of copper at 60 Hz is approximately 8.5 mm = 0.335 inch (depending on alloy), so one reaches diminishing returns in AC resistance per price of copper for solid copper wires above that diameter.
I believe that the maximum copper wire diameter in that series is 2000 MCM (1.414 in = 36 mm diameter).

[AVGresponding]

There's a certain laziness in referring to the size of cables in mm² by just using "mils". I have to confess I am sometimes guilty, as are all my colleagues, from time to time...

[TimFox]

There's a certain laziness in referring to the size of cables in mm² by just using "mils". I have to confess I am sometimes guilty, as are all my colleagues, from time to time...

As I have mentioned elsewhere, I fell into a technical misunderstanding when a UK engineer asked me if "4 mil" wire were adequate for a power connection, and I thought he meant 4 mm diameter instead of 4 mm². 
I did a rough calculation based on my mnemonic that AWG 10 was 0.1 inch diameter, knowing that the current rating of AWG 10 is 30 A.

edit:  corrected typo

[radiolistener]

Yes, the usual understanding is that the electron is a fundamental particle with no structure.

in reality no one knows what is electron and if it exists at all, we just using different physics models that can predict behavior in some cases, but there is no model which explains all details about electron. Some models represents electron as particle, some model represents it as wave, but we don't know what is it exactly

[TimFox]

I have had experience with electrons in vacuum (CRTs, particle accelerators, vacuum tubes, radioactive beta decay) and know that they exist.
In my view of physics, "particle" and "wave" are mathematical descriptions of the behavior of entities, analogous to billiard balls and ocean waves in much larger macroscopic contexts, that quantum mechanics' rules dictate how to calculate their properties and motion.
Note that "model" and "theory" are not bad things (like in the vulgar usage "just a theory") in science.
In this particular discussion, the experiment is testing models that assume no structure (zero moment).
In another recent experiment, measurement of (g-2) in muons (heavier leptons with short lifetime) tests if the currently accepted "standard" model accurately models the interaction of the muon with a host of other particles (real and virtual) buzzing around it.