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Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes — as they are popularly portrayed — as being true for black holes which are not rotating and which have no charge. I don't understand the role rotation does play, but at least because it has to do with the motion of massive bodies, I can understand why it could play an important role. But I have no such intuition for electrical charge.

How does charge change the behaviour of a black hole, aside from the obvious role of electrostatic force? (It will preferentially attract particles of the opposite charge, obviously.) But it would seem that charge plays a more intriguing role than just this.

The current status of the Wikipedia page on black holes claims that you can theoretically avoid the singularity of a charged black hole. It also describes there that there is a theoretical upper bound on the charge/mass ratio of a black hole: that any would-be black hole exceeding it (which is generally thought to be impossible — see this related question on trying to force saturation of the charge/mass ratio or black holes) would lack an event horizon (and therefore presumably not be a black hole). Why should that be? Furthermore: from this other related question on repulsion of pairs of charged black holes (and from Willie Wong's comment, below), ir seems that the size of the event horizon may change depending on how close it is to being extremal! Why would the event horizon of a highly charged black hole be different than the event horizon of a neutral black hole, of similar mass?

Is there a clear reason for such an interplay is there between electrodynamics (aside from local Lorentz invariance) and general relativity that bring these things about?

Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes — as they are popularly portrayed — as being true for black holes which are not rotating and which have no charge. I don't understand the role rotation does play, but at least because it has to do with the motion of massive bodies, I can understand why it could play an important role. But I have no such intuition for electrical charge.

How does charge change the behaviour of a black hole, aside from the obvious role of electrostatic force? (It will preferentially attract particles of the opposite charge, obviously.) But it would seem that charge plays a more intriguing role than just this.

The current status of the Wikipedia page on black holes claims that you can theoretically avoid the singularity of a charged black hole. It also describes there that there is a theoretical upper bound on the charge/mass ratio of a black hole: that any would-be black hole exceeding it (which is generally thought to be impossible — see this related question on trying to force saturation of the charge/mass ratio or black holes) would lack an event horizon (and therefore presumably not be a black hole). Why should that be? Furthermore: from this other related question on repulsion of pairs of charged black holes (and from Willie Wong's comment, below), ir seems that the size of the event horizon may change depending on how close it is to being extremal! Why would the event horizon of a highly charged black hole be different than the event horizon of a neutral black hole, of similar mass?

Is there a clear reason for such an interplay is there between electrodynamics (aside from local Lorentz invariance) and general relativity that bring these things about?

Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes — as they are popularly portrayed — as being true for black holes which are not rotating and which have no charge. I don't understand the role rotation does play, but at least because it has to do with the motion of massive bodies, I can understand why it could play an important role. But I have no such intuition for electrical charge.

How does charge change the behaviour of a black hole, aside from the obvious role of electrostatic force? (It will preferentially attract particles of the opposite charge, obviously.) But it would seem that charge plays a more intriguing role than just this.

The current status of the Wikipedia page on black holes claims that you can theoretically avoid the singularity of a charged black hole. It also describes there that there is a theoretical upper bound on the charge/mass ratio of a black hole: that any would-be black hole exceeding it (which is generally thought to be impossible — see this related question on trying to force saturation of the charge/mass ratio or black holes) would lack an event horizon (and therefore presumably not be a black hole). Why should that be? Furthermore: this other related question on repulsion of pairs of charged black holes claims that black holes which are nearly 'extremal' (have nearly the maximum charge/mass ratio) have event horizons diverging to infinity! Why would the event horizon of a highly charged black hole be larger than the event horizon of a neutral black hole, of similar mass?

Is there a clear reason for such an interplay is there between electrodynamics (aside from local Lorentz invariance) and general relativity that bring these things about?

Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes — as they are popularly portrayed — as being true for black holes which are not rotating and which have no charge. I don't understand the role rotation does play, but at least because it has to do with the motion of massive bodies, I can understand why it could play an important role. But I have no such intuition for electrical charge.

How does charge change the behaviour of a black hole, aside from the obvious role of electrostatic force? (It will preferentially attract particles of the opposite charge, obviously.) But it would seem that charge plays a more intriguing role than just this.

The current status of the Wikipedia page on black holes claims that you can theoretically avoid the singularity of a charged black hole. It also describes there that there is a theoretical upper bound on the charge/mass ratio of a black hole: that any would-be black hole exceeding it (which is generally thought to be impossible — see this related question on trying to force saturation of the charge/mass ratio or black holes) would lack an event horizon (and therefore presumably not be a black hole). Why should that be? Furthermore: from this other related question on repulsion of pairs of charged black holes (and from Willie Wong's comment, below), ir seems that the size of the event horizon may change depending on how close it is to being extremal! Why would the event horizon of a highly charged black hole be different than the event horizon of a neutral black hole, of similar mass?

Is there a clear reason for such an interplay is there between electrodynamics (aside from local Lorentz invariance) and general relativity that bring these things about?