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Thread: Could a black hole's electric charge exceed its gravity?

  1. #1 Could a black hole's electric charge exceed its gravity? 
    Time Lord
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    Is it possible for that to happen? A black hole gains an electric charge so great that it exceeds the force of its gravitation?


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  3. #2 Re: Could a black hole's electric charge exceed its gravity? 
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    Quote Originally Posted by kojax
    Is it possible for that to happen? A black hole gains an electric charge so great that it exceeds the force of its gravitation?
    http://thunder.pa.uky.edu/magnetic/program_final.htm


    that link has a list of pubs from people all over the world based on this theme

    “If nuclear and gravitational forces were the only forces at work in the universe, the broad pattern of cosmic evolution would be one of gradual thermal degradation punctuated by occasional explosive events. The cosmos would resemble the serene and monotonous heavens of classical conception. There is, however, a cosmic agitator: the magnetic field. Although only a small part of the available energy in the universe is invested in magnetic fields, they are responsible for most of the continual violent activity of the cosmos, from auroral
    displays in the earth's atmosphere to stellar flares and X-ray emission, and the massing of clouds of interstellar gas in galaxies.”

    E. N. Parker, Scientific American (August 1983)

    it was a 4 day event in early 08 and all their pubs with all their work coming together because of the very kind of idea you are inquiring upon


    enjoy the ride


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  4. #3  
    Time Lord
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    Well, magnetism is just moving electric charges, so it seems better to just keep things simple and focus on the electric effect itself.

    The reason I originally asked this question is because we know the electric effect is much stronger than gravity, but most of the time you have a good enough balance of charges so that the amount of positive charge cancels the negative charge. So, what I'm wondering is what potential exists for a black hole to build up a strong electric charge?

    Intuitively, it makes sense to expect that equal amounts of positive and negative charges would be absorbed over time. However, I think it's possible to imagine a few scenarios where charge could play a role.

    1) - Electrons falling between the cracks of the larger protons and neutrons might get pulled more closely to the innermost part of the singularity, leaving a more positive charge along the outer surface?

    As the electrons get further away from them by moving closer to the center, the protons in the outer layer would start to feel each other's repulsive force stronger than the electrons' attractive force... maybe?

    2) - Maybe one or the other of the elementary particles (proton or electron) is being formed from absorbed energy, but not the other? Or maybe the internal crushing of matter into a smaller area changes some of its charge???

    3) - Maybe free electrons in space are randomly more likely to fall into a black hole than free protons? Or vice versa?
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  5. #4  
    Forum Radioactive Isotope MagiMaster's Avatar
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    I'm reasonably sure you can at least discount #1. I don't think the mass inside a black hole resembles ordinary matter enough to get protons and electrons. (Of course, no one knows for sure what it does resemble.)
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  6. #5  
    Moderator Moderator Janus's Avatar
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    I'm going to have to say no.

    Think of this way:

    You have the charge of the Black hole, and since like charges repel each other this is trying to push the BH apart.

    You have gravity holding the Balck hole together.

    If the former exceeds the later, nothing can prevent the black hole from fling apart. In fact, it could never form in the first place.

    If you start with a noraml black hole and start pumping charged particles into it, before you get to the point where the electrostatic force exceeds the force of gravity, the you won't be abel to pump any more in.
    In the meantime, the BH will be drawing in any particles of opposite charge and neutralizing its charge.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  7. #6  
    Time Lord
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    Quote Originally Posted by Janus

    If you start with a noraml black hole and start pumping charged particles into it, before you get to the point where the electrostatic force exceeds the force of gravity, the you won't be abel to pump any more in.
    In the meantime, the BH will be drawing in any particles of opposite charge and neutralizing its charge.
    Ah. So before it would allow any like charges to escape, it would just stop drawing like charges in first? (And only draw in opposite charges for a while). Or probably not stop altogether. Just draw more of the opposite for a while. I hadn't thought of that. Seems it would be randomly very improbable for that to happen, then.

    So another question:

    Is there any reason that the anti-particles from Hawking radiation would tend to annihilate one of the elementary particles more often than the other? Or, would that also tend to balance out over time? I hope that I'm understanding this process right.

    Quote Originally Posted by wiki
    A slightly more precise, but still much simplified, view of the process is that vacuum fluctuations cause a particle-antiparticle pair to appear close to the event horizon of a black hole. One of the pair falls into the black hole whilst the other escapes. In order to preserve total energy, the particle that fell into the black hole must have had a negative energy (with respect to an observer far away from the black hole). By this process, the black hole loses mass, and, to an outside observer, it would appear that the black hole has just emitted a particle. In reality, the process is a quantum tunneling effect, whereby particle-antiparticle pairs will form from the vacuum, and one will tunnel outside the event horizon.
    http://en.wikipedia.org/wiki/Hawking_radiation
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