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Author Topic: Does a charged black hole emit an electric field?  (Read 9000 times)

Offline imatfaal

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Re: Does a charged black hole emit an electric field?
« Reply #25 on: 26/01/2012 13:52:05 »
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
 

Offline yor_on

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Re: Does a charged black hole emit an electric field?
« Reply #26 on: 26/01/2012 14:19:34 »
It's locally defined as you say JP. But the point with a black hole time dilation is that what you see, measuring outside its gravitational field, must be time dilated relative you. So what you see from the 'outside' should be more or less 'frozen', at least at the event horizon as I think of it, that as the BH 'gravity' will slow all interactions you observe. I think you will agree to that?

That means that what you observe at the event horizon, not that we have done so yet, will be a relation between 'frames of reference'. What that says about what you will see if 'standing' at that event horizon, instead of observing it from afar I'm not sure. If we consider the time dilation we can experimentally observe on Earth then you constantly wander 'between' different clocks relative the gravity, as observed by you comparing 'frames'.  If we could measure that electromagnetic field as we moved towards the Event Horizon we would also, relative the far observer, wander in time as the time dilation will grow as we come closer, 'slowing us down' relative that observer.

It's a interesting question.
 

Offline MikeS

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Re: Does a charged black hole emit an electric field?
« Reply #27 on: 26/01/2012 15:22:10 »
Without going into quantum field theory and virtual particles, it makes no sense to me whatsoever.
Light being sucked in can only be 'frozen' at the event horizon which happens to also be the vanishing point of light.  Seems to me that if light vanishes at the EH so must charge and magnetism. Light is electro-magnetic after all.
 

Offline JP

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Re: Does a charged black hole emit an electric field?
« Reply #28 on: 26/01/2012 22:34:18 »
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

Hah.  Well, you can do field theory over locally flat space-time and then connect patches up, I believe.  I'd guess that's what Hawking did when he came up with Hawking radiation.  Dunno much about it, though.
 

Offline imatfaal

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Re: Does a charged black hole emit an electric field?
« Reply #29 on: 31/01/2012 10:48:46 »
Mike - OK if you wanna really take your mind for a work-out on this topic then you can read up on exact electrovacuum solutions of the einstein field equations within proofs of the uniqueness theorem of black holes.  I am not sure this helps - and the maths is beyond me, but it does show that within the bounds of a general relativistic treatment of a blackhole that we do not have a situation of no charge being able to be felt o/s eh

fyi
electrovac solutions -
Quote
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

uniqueness theorem
Quote
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.
 

Offline yor_on

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Re: Does a charged black hole emit an electric field?
« Reply #30 on: 01/02/2012 10:35:29 »
Eh, photons are called 'carriers' of the electro magnetic force. It shouldn't be read as they are 'electromagnetic' in themselves although they are expected to influence electromagnetic 'fields' relative so called 'virtual photons'.

"It turns out that the photons which make up a static electric or magnetic field are "virtual" -- their energy and momentum doesn't satisfy the relationship for "real" photons -- E=p*c (E is energy, p=momentum, and c is the speed of light).

And ..

Photons, real and virtual, are emitted and absorbed by charged particles, even though they are not charged themselves. They only interact with charged particles, and not with each other. That's why photons don't interact with magnetic fields -- the photons which make up the magnetic field are not charged so other photons cannot interact with them"

Read this and ponder.

"an ordinary, free, photon has two different transverse polarization states as can be easily demonstrated by the usual crossed polarizers experiment.  An electron that interacts with this kind of photon couldn't care less where it came from.  It just scatters ala Compton.

Now in the case of when the photons are virtual, such as when two electrons are close to each other and are experiencing Coulomb-like forces, the photon has an extra, longitudinal, polarization state.  This extra state carries information as to the charge sign of its source. Hence the electron receiving the photon can decide whether to be attracted or repelled."

If that is a true description then a virtual photon should exist inside Planck time. But. I'm starting to doubt that idea, I don't trust  'virtual photons' myself. Instead I'm finding the alternative description of 'indeterminacy' more fitting to my taste.
 

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Re: Does a charged black hole emit an electric field?
« Reply #30 on: 01/02/2012 10:35:29 »

 

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