Why is electrical conductivity denoted by G?

[falsepromises]

TL;DR

I couldn't find a co-relation of G and Electrical Conductivity. I know it's denoted by sigma as well.

I did search Wikipedia and other science related websites, couldn't find an answer. Let me know if anyone knows the story behind G.

 

[Baluncore]

It may have been chosen because G was available, or possibly after Luigi Galvani who studied galvanic conduction, and had the galvanometer named after him by Ampere.
https://en.wikipedia.org/wiki/Luigi_Galvani
I could ask why current is I, inductance L, and charge is Q?
Z = R + jX ; Why is impedance Z, and reactance X?
Y = 1 / Z ; Why is admittance Y?
Y = G + jB ; Why is conductance G, and Susceptance B?

 

[anorlunda]

Z = R + jX ; Why is impedance Z, and reactance X?

Don't forget why $j$ is $\sqrt-1$?
That one is most contentious because everyone else calls it $i$.

 

[falsepromises]

It may have been chosen because G was available, or possibly after Luigi Galvani who studied galvanic conduction, and had the galvanometer named after him by Ampere.
https://en.wikipedia.org/wiki/Luigi_Galvani
I could ask why current is I, inductance L, and charge is Q?
Z = R + jX ; Why is impedance Z, and reactance X?
Y = 1 / Z ; Why is admittance Y?
Y = G + jB ; Why is conductance G, and Susceptance B?

I= intensity of current, Q= quantity of charge (C taken as the unit as in Coloumb), Inductance as L because I was taken, so they just took the relating scientist name ( I forgot who he was). Rest I need to research into, but I'm pretty sure there is some logic (or illogical stuff) behind the names. Cause the scientists understand more than us and there must be a story behind every name.

 

[Baluncore]

I= intensity of current, Q= quantity of charge (C taken as the unit as in Coloumb), Inductance as L because I was taken, so they just took the relating scientist name ( I forgot who he was). Rest I need to research into, but I'm pretty sure there is some logic (or illogical stuff) behind the names. Cause the scientists understand more than us and there must be a story behind every name.

Can you please provide a solid reference for any of those assertions.

 

[Baluncore]

Don't forget why j is √−1 ?
That one is most contentious because everyone else calls it i.

I don't question that because I know the answer. i is used in mathematics, while j is used in electronics, because i is used for instantaneous current.

Multiplying by j just means turn left, do it again and you will be going back the way you came.
So j⋅j = j ² = –1; please don't scare beginners unnecessarily with the square root of a negative number.

x + j y uses the j to prevent beginners immediately adding the x and y, before they have time to realize x and y are orthogonal. x and y are in different dimensions, but use the same units.
So j is used in electronics as a mathematical insulator.

 

[falsepromises]

Can you please provide a solid reference for any of those assertions.

Most of them are on Wikipedia, I'm not going to do your research for you. If you can't find it on Wikipedia then ask me I will give you sources.

 

[falsepromises]

There is a story behind everything, even if the story is "I don't care what I'm going to call it so let me pick any word" mood of the related people. Needless to say, this doesn't happen 99% of the cases. Thanks for the inputs as well.

 

[davenn]

Can you please provide a solid reference for any of those assertions.

They are readily available online

 

[Baluncore]

They are readily available online

Then you should be able to produce a link to a reliable reference.
Reference books are available in libraries, but it helps to know which one to look at.

 

[davenn]

Then you should be able to produce a link to a reliable reference.

I'm sure you are capable of doing some basic research

 

[Baluncore]

I'm sure you are capable of doing some basic research

Reading wikipedia does not constitute basic research.
I looked at the pre-1900 references and it appears that the capital letter symbol used to represent a circuit parameter is a historical convention. It is not named after the inventor, or in any way related to the SI units employed.

 

[falsepromises]

Reading wikipedia does not constitute basic research.
I looked at the pre-1900 references and it appears that the capital letter symbol used to represent a circuit parameter is a historical convention. It is not named after the inventor, or in any way related to the SI units employed.

So what if two thing's name starts with the same letter? It has happened a lot of times and they do use invertor's name as an alternative. Also, wikipedia doesn't make things up, they have reference list at the end of the pages. Be sure to check that out.

 

[Baluncore]

Be sure to check that out.

I did, it went to two other articles without references. No original reference.

I picked on L for inductance.

Where did the L used for self inductance originally come from; maybe the alphabet, Lagrange, Lorentz, Laplace or Lenz? Wikipedia says it is Lenz. But I believe that was attributed after the event, as an excuse, or educational mnemonic.

J. C. Maxwell used L, M and N in his 1865 paper “A Dynamical Theory of the Electromagnetic Field”. L and N were what became known as self inductance, M was the mutual inductance of L with N. Maxwell's use of N for an inductance suggests L was not in standard use at that time.
By the time Andrew Gray produced “Absolute Measurements in Electricity And Magnetism” in 1893, L had become L1, N became L2 and we see the form used today.
Both of those texts based the analysis on an electrical analogue of Lagrange's equations of motion.

 

[falsepromises]

I did, it went to two other articles without references. No original reference.

I picked on L for inductance.

Where did the L used for self inductance originally come from; maybe the alphabet, Lagrange, Lorentz, Laplace or Lenz? Wikipedia says it is Lenz. But I believe that was attributed after the event, as an excuse, or educational mnemonic.

J. C. Maxwell used L, M and N in his 1865 paper “A Dynamical Theory of the Electromagnetic Field”. L and N were what became known as self inductance, M was the mutual inductance of L with N. Maxwell's use of N for an inductance suggests L was not in standard use at that time.
By the time Andrew Gray produced “Absolute Measurements in Electricity And Magnetism” in 1893, L had become L1, N became L2 and we see the form used today.
Both of those texts based the analysis on an electrical analogue of Lagrange's equations of motion.

It all depends how much evidence do you need. Will you believe if it's printed on a book or a scientist comes up to you and says that's what happened or do you need a professor to tell you. Because, most of the sources are credible it's just not enough to satisfy everyone. I can't give you video evidence of them naming inductance after
"Heinrich Friedrich Emil Lenz's Initial "L"
Everyone is lying and conspiring only you are correct.

 

[anorlunda]

This thread is heating up. Let's try to keep it cooler. (use C for cool).

 

[Gordianus]

Since I'm an old guy, I've read old books and I clearly remember the reference to "Quantity of electrical charge" and "Intensity of electrical current".
Unfortunately, I can't remember the authors.

PS: We only have 26 letters (52 if we add the Greek alphabet) to name quite a lot of concepts.

 

[Baluncore]

I've read old books and I clearly remember the reference to "Quantity of electrical charge" and "Intensity of electrical current".

I agree that is how students have been taught to remember or think of it.
But I do not believe it explains the origin of the use of those symbols.

As a scientist I need to follow the references all the way back to the original use.
Does the “Q” come from the English word “Quantity”, from the latin “Quantitas”, or from some other, probably Latin based, language? Who first used Q? When? Did they say why?

Wikipedia says “In modern practice, the phrase 'amount of charge' is used instead of 'quantity of charge'.” But then wiki reverts back to using quantity. https://en.wikipedia.org/wiki/Electric_charge#Units

 

[Baluncore]

As this thread states; Resistance, with symbol R, and units of ohms, has a reciprocal term, conductance, with symbol G, that had units of mho, but now has units of siemens, S, named in memory of, or after Ernst Werner von Siemens. (Note that units are not pluralised, nor the initial letter capitalised when spelt out. An initial is capitalised only when used alone, and then only if the unit is named after a person).

Like resistance has conductance, capacitance, C, with units of farad, F, has a reciprocal capacitance called elastance, with the symbol D, and units of daraf. That unit appears not to have been replaced like the backward mho.
Does the D symbol for elastance come from alphabetic order …CD…, or maybe from the first letter of daraf, = last letter of farad, or from somewhere completely different?

It all depends how much evidence do you need. Will you believe if it's printed on a book

No, not unless that book has a reference that can be traced back to the original definition.

or a scientist comes up to you and says that's what happened

I am a scientist. I always doubt everything. Maybe that is just an example of the Impostor Syndrome. The Dunning-Kruger effect is an interesting parallel.

or do you need a professor to tell you.

I would not trust a professor's word unless they could point me to a reference chain of evidence that concluded in proof.

Because, most of the sources are credible it's just not enough to satisfy everyone.

They may seem credible, but are they traceable back to consistent evidence.
It is necessary to apply critical thinking skills and research into the original literature, to work out which came first, the chicken or the egg. We live in a postmodernist world, where everyone has their own truth, many of which differ.

I can't give you video evidence of them naming inductance after "Heinrich Friedrich Emil Lenz's Initial "L"

If you gave me video evidence I would know that it was certainty fake. Video was invented more than 50 years after the conventional use of L for inductance.

Lenz's work on forces between magnets and currents was first published in 1834. Lenz died in 1865. But Lenz is not referenced with regard to self inductance in articles from the 1860s that I have seen using L for inductance. The attribution of L to Lenz must date from after his death and after the first use of L.

Everyone is lying and conspiring only you are correct.

I am happy that you agree with me.
This is not a rhetorical blog. These Physics Forums are concerned with evidence based science, NOT with popularity poles, or group-think-i-pedia.

 

[sophiecentaur]

It may have been chosen because G was available,

There's your answer.

 

[Baluncore]

Extracts from: LORD KELVIN his influence on electrical measurements and units' by Paul Tunbridge, 1992.

“In 1861, Sir Charles Bright and Mr Latimer Clark proposed the names of;
galvat for current,
ohma for electromotive force,
farad for quantity, and
volt for resistance.”
Reference; Electrician, vol 1, p 3, 9.11.1861."

Which is as close as Galvani came to G for conductance, with G for galvat for current.
Note; "Quantity" is now called "charge" and measured in coulombs.

"Varley's new proposal was as follows: Latimer Clarke and I the same evening, and Fleeming Jenkin and I the next evening, discussed the matter. Latimer Clarke proposed the following:
[Variable; 1 unit, 1 million units]
Potential; Galvad, Gaboon
Resistance; Ohmad, Ohmon
Current; Voltad, Volton
Quantity; Farad, Faron
“...Jenkin objected to both, and one objection is a good one (and will apply to me and to you) viz: he writes so badly that if the magnitude be expressed by a termination, Ohmad and Ohmon will be confounded in indiscreet writing...I should like to introduce a French name into the list. We have Germany, England, and Italy represented: suppose Ampere were used to represent the magnetic pole, viz the unit pole?...I should like to have seen Weber's or your name [Thompson] introduced, attached to the unit of potential and have suggested it: fear has been expressed lest we should use any name on the committee and so give opponents an opportunity of saying the "unpleasant". I object to Galvad because Galvani discovered next to nothing,...”

When the game of musical chairs stopped, things were different.