Nature of the Coulomb force

[Abeer Arora]

Can charges collapse under coulomb attraction like charge-less matter does under gravity? In a way it's similar to asking about the lower limit of coulomb force if there is any. Also, does Pauli exclusion principle save the day just as in the case of gravity?

 

[vanhees71]

Why should any charge distribution collapse under the Coulomb force? Like-sign charges repell each other, and thus any non-zero charge distribution rather flies appart under the influence of the repulsive Coulomb force. Indeed you need the strong force to hold atomic nuclei together against the Coulomb repulsion of the protons. That's why for larger nuclei you need more and more neutrons to stabilize them against Coulomb repulsion.

 

[Abeer Arora]

I mentioned coulomb attraction for unlike charges. Say, if two unlike charges were held at a distance away from each other and then left to themselves what would happen after they get very close to each other?

 

[mfb]

They form a bound state, emitting one or more photons on the way, and/or react with each other in some way (e.g. annihilation for particle/antiparticle pairs).

 

[Abeer Arora]

And what's a bound state-with less technical details pls.

 

[mfb]

Something like a hydrogen atom for example. A positive particle (a proton) and a negative particle (an electron) bound together.

 

[Abeer Arora]

Consider the case where there's a head on collision between the two( impact parameter=0) giving the electron no reason to orbit around the proton. What sort of bound state would be formed then?

 

[mfb]

What do you mean by "reason"?

The ground state of hydrogen has no angular momentum.

Every bound state of a proton and an electron is a hydrogen atom, if it is not in the ground state it is in an excited state (or a superposition of that and the ground state).