Understanding Charge: A Brief Explanation

[icvotria]

What actually is charge? Hmm, I'm trying to think of a way to elaborate the question to make myself sound a bit more intelligent but I can't so I'll have to just live with ignorant and curious

 

[JamesU]

I also wonder about this and no it does not sound stupid.

 

[dextercioby]

For a 13-yr old,i guess there's nothing more to say than:"along with rest/invariant mass and spin,one of the fundamental properties of matter".

Daniel.

 

[quasar987]

Hmm, I'm trying to think of a way to elaborate the question to make myself sound a bit more intelligent

So yes, charge seems to be amongst the most fundamental properties of matter. And by that it is meant that we can't deny its existence*, yet there is no explanation for it in terms of other concepts. It's fundamental.

*Take 3 objects, A, B and C. If A & B repulse each other and A & C attract each other, then invariably, we observe that B & C attract each other. From there, you can derive the notions of 'positively charged' and 'negatively charged'.

 

[dextercioby]

For the record,there is a reasonable explanation for the existence of charge.Electric charge,that is.Within the SM of particles and interactions,of course.I don't know how particle electric charge emerges from string vibrations,i have a hunch there is a way...

Daniel.

 

[roger]

For a 13-yr old,i guess there's nothing more to say than:"along with rest/invariant mass and spin,one of the fundamental properties of matter".

Daniel.

Isn't she 23 ?

In the standard model, why is the electron referred to as a point charge ? Doesn't the electric field lines converge to give an infinite energy density ?

When we take the vector product of velocity and flux density,(of charge) why is the magnetic intensity equal to this ?

 

[dextercioby]

Of course,i meant "Yo,mamma!".He's 13.

There's no problem with that.There's no such thing as "field lines" at quantum level.Incidentally,the energy of the electron field vacuum is taken to be zero in the theory of the Dirac field and in QED,the electron self-energy diagrams are renormalized.

As for the second,could u ascribe an equation to it ?

Daniel.

 

[roger]

Of course,i meant "Yo,mamma!".He's 13.

There's no problem with that.There's no such thing as "field lines" at quantum level.Incidentally,the energy of the electron field vacuum is taken to be zero in the theory of the Dirac field and in QED,the electron self-energy diagrams are renormalized.

As for the second,could u ascribe an equation to it ?

Daniel.

What did you mean there's no such thing as field lines at quantum level ?

H=vector product v *d(flux density vector)

Also, why do we assign epsilon0 permittivity to vacuum, ? what is there to resist flow of charge ?

And how does the electric potential exist in the vacuum ? it can be measured..


Roger

 

[~()]

hmmmm,
a charge quantised by QM illustrates an assembly of photons...

Is the charge around a electron a constant cloud, does it emit from the electron itself, does there need to be a picture for energy conservation ?


How do particles - the fields of EM actually work? How and why is charge able to attract - to repel, does this mean a special case for gravity since it can only attract ?

All interesting queries...

 

[roger]

What did you mean there's no such thing as field lines at quantum level ?

H=vector product v *d(flux density vector)

Also, why do we assign epsilon0 permittivity to vacuum, ? what is there to resist flow of charge ?

And how does the electric potential exist in the vacuum ? it can be measured..


Roger

Could someone try to answer please ?

thankyou

 

[marlon]

What actually is charge? Hmm, I'm trying to think of a way to elaborate the question to make myself sound a bit more intelligent but I can't so I'll have to just live with ignorant and curious

in most general terms, charge is a measure of how strong two charged particles interact with each other via the Electromagetic forces, like the Coulombforce for electrical charges.

So charge not only says that a particle will interact via EM-forces, it also gives an idea of how strong this interaction will be

regards
marlon

 

[quasar987]

in most general terms, charge is a measure of how strong two charged particles interact with each other via the Electromagetic forces, like the Coulombforce for electrical charges.

Socrates is probably cursing in his grave right now.

 

[icvotria]

hmmmm,
a charge quantised by QM illustrates an assembly of photons...

Is the charge around a electron a constant cloud, does it emit from the electron itself, does there need to be a picture for energy conservation ?


How do particles - the fields of EM actually work? How and why is charge able to attract - to repel, does this mean a special case for gravity since it can only attract ?

All interesting queries...

That's what I meant to say

 

[Haelfix]

Charge is an interesting topic. I recall there being papers in the 60s (Wheeler I think) where he tried to relate charge to geometric configurations of defects (little 'effective' black hole configurations). I think there were problems with the model, does anyone know the details?

Magnetic charge (both Dirac, Polyakov and T'Hooft monopoles) of course is completely determined by the geometry within gauge fields. They are pure topological solutions (related to the first chern class), and incidentally if observed, would imply electric charge quantization (a really cool, simple result with the so called Dirac string accessible to undergrads).

In the literature you sometimes come across various different types of electric charge. The localized, non gauge invariant quantized versions. Nonlocal, gauge invariant unquantized versions, and nonlocal, gauge invariant quantized ones.

 

[marlon]

Socrates is probably cursing in his grave right now.

I see your point . You are indeed correct

marlon

 

[marlon]

Magnetic charge (both Dirac, Polyakov and T'Hooft monopoles) of course is completely determined by the geometry within gauge fields. They are pure topological solutions (related to the first chern class), and incidentally if observed, would imply electric charge quantization (a really cool, simple result with the so called Dirac string accessible to undergrads).

Quite right. For the Dirac string thing and quantization of both magnetic and electric charge, check out the zip-file in post nr 20 of https://www.physicsforums.com/showthread.php?t=43685&page=2&pp=15

regards
marlon

 

[cefarix]

In the Standard Model the how and why of charge aren't defined...it's just an intrinsic property like spin and mass, without any cause to it. My theory does give the cause of charge, spin, and mass, but that's beyond the scope of this post of course :)

 

[cefarix]

1 eV = 1.6 x 10^-19 Joules

This is the energy imparted to a charge of 1.6 x 10^-19 Coulombs by an electric field as it moves from a point that has an electric potential of 1 Volts to an point which has an electric potential of 0 Volts.

The natural unit of electric charge is 1.6 x 10^-19 Coulombs. This is the magnitude of the charge on the proton and the electron.

 

[quantumdude]

I've pruned the little sideshow out of this thread. Everyone at PF should keep in mind that when someone asks a question that it is safe to assume that that person is looking for a cogent, correct answer from a qualified person. If that does not apply to you then you should resist the urge to post your answer to the question.