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Warning: If you fall into a black hole, you will die. You will not go through a wormhole to another time and place.

Would anyone who believes that the internal charge of a black hole can be felt outside the event horizon please suggest by what mechanism they believe this can happen. Personally I don't see any mechanism that could allow it to happen.

JPNice site.It does raise a question in my mind.It seems the gravitational effects of a black hole can be explained in two ways.1) Light can not escape because space itself is falling into the black hole at the speed of light (similar to a light-speed waterfall.2) The geometry of space-time around the black hole is so highly curved (warped) that light follows the curvature and can not escape. Both scenarios have the same result but presumably only one can be correct. Which one?Or may be they are the same thing but we just can't visualise it.Either way I don't see how electrical charge, that presumably can not travel faster than light, could break free. The same goes for magnetism.

Quote from: MikeS on 20/01/2012 09:18:47Would anyone who believes that the internal charge of a black hole can be felt outside the event horizon please suggest by what mechanism they believe this can happen. Personally I don't see any mechanism that could allow it to happen.I've heard of 2 methods, but I haven't seen them stated rigorously or in a scientific text, so I'm unsure. The first is that matter falling into a black hole will appear to take forever to cross the event horizon, so the field from that matter will last forever outside of the black hole. The problem with this is that the field will get weaker and weaker and this doesn't account for black holes that aren't sucking in charged matter.The second is that on a more rigorous, quantum level, virtual particles carry the electrostatic force and virtual particles can escape the black hole.

There have been a few questions about charged black holes lately, but I think this very basic question about them hasn't been answered yet. Will a charged black hole (let's say non-rotating for simplicity) emit an electric field and why/why not? (I'm talking about the black hole itself, not any field that might be emitted by infalling matter).The second is that on a more rigorous, quantum level, virtual particles carry the electrostatic force and virtual particles can escape the black hole.

Quote from: MikeS on 20/01/2012 10:28:14JPClipone thought - if we feed a blackhole an electron diet, which it can continue to take cos of the intransmissibility to EM force of the EH then we have removed a certain amount of negative charge from the universe to beyond the EH. When the universe cools enough for the BH to evaporate, the radiation that slowly denudes the mass of the blackhole is clearly chargeless; this evaporation will continue at a higher and higher rate till the blackhole melts away in a flash of radiation. Where has all the charge gone? We have a firm position on conservation of charge - yet we seem to have lost a bunch. (I guess this might be the reason behind the white hole theory on the site JP mentioned - which I still havent got around to reading)Good point.The black hole is slowly radiating away energy via Hawkin Radiation. Of every pair of particles produced just outside the event horizon lets assume that one is sucked in and the other escapes. It is supposedly a random process as to which particle is sucked in. Let's assume that all the particles that get sucked in (or a majority) are electrons. The black hole will gradually acquire a negative charge. When it eventually evaporates where did the charge go?

JPClipone thought - if we feed a blackhole an electron diet, which it can continue to take cos of the intransmissibility to EM force of the EH then we have removed a certain amount of negative charge from the universe to beyond the EH. When the universe cools enough for the BH to evaporate, the radiation that slowly denudes the mass of the blackhole is clearly chargeless; this evaporation will continue at a higher and higher rate till the blackhole melts away in a flash of radiation. Where has all the charge gone? We have a firm position on conservation of charge - yet we seem to have lost a bunch. (I guess this might be the reason behind the white hole theory on the site JP mentioned - which I still havent got around to reading)

The original question contains a totally fundamental error that is very common in questions of this type and may even be in the minds of some of those who are replying. Particles do not emit fields they possess them. An electron has an electrical field, a magnetic field and also a gravitational one. it is only when a great many particles are lumped together to form a planet or a star that the gravitational field is noticeable. Now matter in large quantities is mostly electrically neutral but can be electrically charged and in some cases magnetically polarised and these fields are well known and obvious in all the simple science experiments.A black hole has a strong gravitational field because it contains a lot of material in a small volume. It is very likely to be electrically neutral but if it had an electrical field or a magnetic one (more likely) it would exist outside the event horizon because it does NOT emit it it possesses it as an inherent property of the object. To that extent it is nothing more or less than a very large heavy particle no different from an electron.

A field can only extend out indefinitely if the particle has been around indefinitely. Otherwise you violate causality since the front of the field propagates faster than c. Of course, you can argue that all matter/energy has existed in some form since the big bang, which may essentially be indefinite in terms of how far the fields can go. I don't know enough cosmology to address that. What I do know is that if you move a charged particle, that motion generates a "kink" in the EM field, which propagates away at the speed of light, which seems to argue to me that the field is being emitted from the particle. At any rate, whether you like the word "emit" or not, I think I understand how a charged black hole can imprint its charge onto the event horizon, since the electric field associated with matter creating the black hole is "frozen" on the event horizon, and the electric field is going to extend continuously out from the horizon.

As the star collapses into a black hole, the field doesn't disappear. We can't see the charges anymore, since they've fallen into the black hole, but the electric field lines still lead to the event horizon. Since that's the case, since the field as you move away from the event horizon is related to the field at the event horizon, you can get a field coming out of the black hole.This seems pretty much the same as how a black hole can generate a gravitational field. As a star collapses into a black hole, its gravitational field remains at the event horizon, even though we can't peek inside. Since gravity at a point is related to gravity at neighboring points, the event horizon field is sufficient to describe the field away from the event horizon.I see how this related to SS's argument about a black hole "possessing" rather than emitting a field as well. The fact that there was a field before matter fell into a black hole is sufficient to maintain a field after it became a black hole. The field doesn't disappear just because we can't see the source anymore.

JP - when you have a great of idea of how the two work together can I come and applaud in Oslo? I think I understand your field explanation and it make sense to me

In general relativity, an electrovacuum solution (electrovacuum) is an exact solution of the Einstein field equation in which the only nongravitational mass-energy present is the field energy of an electromagnetic field, which must satisfy the (curved-spacetime) source-free Maxwell equations appropriate to the given geometry. For this reason, electrovacuums are sometimes called (source-free) Einstein-Maxwell solution

One of the most intriguing outcomes of the mathematical theory of black holes is the uniqueness theorem, applying to the stationary solutions of the Einstein–Maxwell equations. Asserting that all electrovac black hole space-times are characterized by their mass, angular momentum and electric charge, the theorem bears a striking resemblance to the fact that a statistical system in thermal equilibrium is described by a small set of state variables as well, whereas considerably more information is required to understand its dynamical behavior.