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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

[aetherist]

New measurements on roundness of electrons.
https://www.sciencenews.org/article/electron-round-new-measurement-matter-physics

An electron in an atom is a photon orbiting/hugging the nucleus. Best call this an elektron.
We dont know the 3D size/shape/dimensions of a photon(s).
And, an elektron would form a loop (the head chasing its tail). And, the loop would trace out a spherical path over time (as the loop wanders), but i daresay that-there sphere might not have a single fixed radius, it might be a fuzzy sphere.

[CatalinaWOW]

Interesting how the dipole moment is conflated with physical shape.  I have no idea if an electron has a physical shape, but just for a thought experiment can any of you imagine a perfect sphere of alnico or other magnetic material.  In spite of its sphericity it has a strong magnetic dipole.

[TimFox]

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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

Edit:  please ignore the chart in that file, and consult the one cited below.

[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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

[Simon]

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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!

the area of a circle is r^2*pi
the circumference is r*2*pi

Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!

You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.

Now measure them and tell us your results.

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

[DavidAlfa]

C'mon it's not that hard 

[Simon]

I'm referring to his claim that resistance is proportional to circumference rather than area. No I don't want his explanation, we know it will be bollocks! He has to prove it, in real life, the hard way. That's how scientists do it when they want to defy current understanding, unless of course you just messed up in your latest discovery of a super conductor!

[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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!

the area of a circle is r^2*pi
the circumference is r*2*pi

Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!

You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.

Now measure them and tell us your results.

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

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.

[2N3055]

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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!

the area of a circle is r^2*pi
the circumference is r*2*pi

Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!

You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.

Now measure them and tell us your results.

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

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.

That table is simply wrong. Here is one that is correct:
https://www.engineeringtoolbox.com/copper-aluminum-conductor-resistance-d_1877.html

Resistance scales with cross section area. That is not some stupid theory, that is proven fact. If you don't trust scientists, follow the money.
Copper is sold by weight which is a cross section area x length x specific weight of copper.  People would be VERY UNHAPPY with the price of cables if the current capacity was linear with diameter....

[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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!

the area of a circle is r^2*pi
the circumference is r*2*pi

Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!

You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.

Now measure them and tell us your results.

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

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.

That table is simply wrong. Here is one that is correct:
https://www.engineeringtoolbox.com/copper-aluminum-conductor-resistance-d_1877.html

Resistance scales with cross section area. That is not some stupid theory, that is proven fact. If you don't trust scientists, follow the money.
Copper is sold by weight which is a cross section area x length x specific weight of copper.  People would be VERY UNHAPPY with the price of cables if the current capacity was linear with diameter....

Yes, that  table says that resistance/area is constant -- for DC i suppose, solid circular.
And for sure that is a problem for my elekton (photon) elekticity (hugging the surface of a wire).
But i did not want to argue about elektons.
I didnt even want to argue about electrons -- ie re the topic that electrons are round.
I wanted to point out that there is no such thing as a hard little nutty electrons orbiting a nuclei -- i reckon that what we have is photons (elektrons) orbiting & hugging nuclei.
And leave it at that. Bearing in mind that the nature of the atom & electrons has a long history of contrary ideas.

[TimFox]

Sorry about the wrong values in the table I linked (one of many that pops up on Google).
I was looking for one in straight metric units, without practical wire gauges, and did not re-calculate the values myself.
Note that no one holds the "solar system" model of the atom to be appropriate any more, except graphic artists.
Quantum mechanics is a difficult topic, but it is past the "hand waving" state.
In atoms, spectroscopy is an advanced and accurate field of study:  the early successes of quantum theory explained the spectra of light interaction with atoms.
Further work in quantum electrodynamics included the incredibly accurate calculation of the Lamb Shift, which gives the "fine-structure constant" to within 1 ppm of the measured value.
Since the Lamb Shift in hydrogen is a microwave frequency, it can be measured with high precision.
Trigger warning:  heavy mathematics.  https://en.wikipedia.org/wiki/Lamb_shift

If you want to contribute to a field where there are still unsolved questions, look at recent (g-2) measurements for the muon.

[aetherist]

Sorry about the wrong values in the table I linked (one of many that pops up on Google).
Note that no one holds the "solar system" model of the atom to be appropriate any more, except graphic artists.
Quantum mechanics is a difficult topic, but it is past the "hand waving" state.
In atoms, spectroscopy is an advanced and accurate field of study:  the early successes of quantum theory explained the spectra of light interaction with atoms.
Further work in quantum electrodynamics included the incredibly accurate calculation of the Lamb Shift, which gives the "fine-structure constant" to within 1 ppm of the measured value.
Since the Lamb Shift in hydrogen is a microwave frequency, it can be measured with high precision.
Trigger warning:  heavy mathematics.  https://en.wikipedia.org/wiki/Lamb_shift

If you want to contribute to a field where there are still unsolved questions, look at recent (g-2) measurements for the muon.

The atom is unsolved (but my  elektrons help). Electricity is unsolved (but my elektons help). Quantum theory is a model -- & we need good models -- but models dont explain anything -- models give us numbers only.

[T3sl4co1l]

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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

It does -- at AC.

Wait, you again?  God damnit.

Well, Tim has his answer at least.  You were never looking for answers so it doesn't matter.

Tim

[Nominal Animal]

That table is simply wrong. Here is one that is correct:
https://www.engineeringtoolbox.com/copper-aluminum-conductor-resistance-d_1877.html

Agreed.  And that table is easily reproduced using the simple steady-state DC conductor model, where resistance \$R\$ is a function of length \$\ell\$ and cross-sectional area \$A\$ at conductivity of \$\sigma = 58 \text{ S}/\mu\text{m} = 58 \times 10^6 \text{ S}/\text{m}\$ or equivalently resistivity \$\rho = 1/\sigma = 17 \text{ n}\Omega \cdot \text{m}\$ (for soft solid copper),
$$R(\ell, A) = \frac{\ell}{\sigma A} = \frac{\ell \rho}{A}$$
or for a round single-strand wire of radius \$r\$,
$$R(\ell, r) = \frac{\ell}{\sigma \pi r^2} = \frac{\ell \rho}{\pi r^2}$$
where the unit \$S\$ refers to siemens, \$[ \text{S} ] = [ \Omega^{-1} ]\$.

One way to verify this in practice would be to measure the resistance of different shapes but constant amounts of liquid mercury.  Its conductivity is only about a sixtieth of that of copper, but that just means you don't need stupid amounts of mercury or an unrealistically precise ohmmeter.  You do need to control the temperature precisely, because that significantly affects the conductivity.

For solids, one could use gallium, which melts at a very low temperature, but is a bit more conductive than mercury.  Melt it to reshape it, then cool down to the precise measurement temperature (for example, at freezing point of water at a constant atmospheric pressure), to get each data point.  An important point to remember is that even trace amounts of certain elements will significantly change the conductivity, so mixing the shapes instead of going from one extreme to the other is important to alleviate the drift in the results because of contamination.

Of course, all that has already been done by many, many people, and the results are in agreement with the above model.

[TimFox]

In lieu of a model (for systems too small or too large for direct observation) that gives quantitative results which can be compared with experiment, one could use the method used by Muppet Laboratories (on an ancient episode of The Muppet Show).
https://muppet.fandom.com/wiki/The_Germ
Since germs are too small for humans to examine directly, instead of using a microscope to visualize the germ the lab used a drop of "germ enlarger" to increase the size of the germ to roughly human size, whereupon it decided to examine Beaker, the long-suffering lab assistant.

[Njk]

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.

[TimFox]

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.

Even simpler:  at DC the charge carriers move through the entire cross section of the conductor.

[gnuarm]

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?  Or do I misunderstand what a dipole moment is?

[TimFox]

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?  Or do I misunderstand what a dipole moment is?

In the basic models, the electron’s dipole moment is zero, but more complicated models suggest a very small moment.  Recent experiments are looking for a tiny moment to test these theories, which could indicate a less primitive particle.  In the popular press, this was called “roundness”.
When looking for very small possible effects such as this, a negative result is usually expressed as an “upper limit”:  the effect must be smaller than this value.

[Simon]

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?

Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?

One of a myriad of sources for resistance of copper wire:  do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg

I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.

I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!

the area of a circle is r^2*pi
the circumference is r*2*pi

Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!

You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.

Now measure them and tell us your results.

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

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.

[vad]

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.

[T3sl4co1l]

WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!

So.... we're waiting

Tim

[SiliconWizard]

Damn, I woke the beast!

Entertaining though.

[BILLPOD]

New measurements on roundness of electrons.
https://www.sciencenews.org/article/electron-round-new-measurement-matter-physics

  And Pie R Squared.

Pie R Round, Cake R Square