# Steven Crothers , against BB

Now c is also defined in free-space by c = 1/√(εμ). From above that means coordinate value of c should alter by factor 1/√(√(g_tt)/√(g_tt)) = 1. In other words it predicts c is unaffected by the metric. Doesn't look right to me. We could look at the predicted coordinate value for free-space impedance and it's implications, but finding for c is enough.
Wait, are you saying you disagree with one of the postulates of special relativity (namely, that the speed of light in a vacuum is constant)? The value of c in GR is similarly constant (and often set to 1); the choice of metric in GR has no effect on c. If you think otherwise, you're not working with SR or GR anymore, in which case that's most likely the source of the conflict between your scenario and GR.

Wait, are you saying you disagree with one of the postulates of special relativity (namely, that the speed of light in a vacuum is constant)? The value of c in GR is similarly constant (and often set to 1); the choice of metric in GR has no effect on c. If you think otherwise, you're not working with SR or GR anymore, in which case that's most likely the source of the conflict between your scenario and GR.
Would have expected you were aware that coordinate c (and I DID specify we are talking about coordinate value of c) is NOT a constant in GR! Seems not:
http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
http://www.speed-light.info/speed_of_light_variable.htm

Ah, OK, so you were talking about some non-inertial frame of reference you didn't mention, and/or some non-local values from a location you didn't mention. Got it.
Neither conclusion/inference is valid. At a guess, you mistakenly read the following sentence under 'General Relativity' in first given link in #162:
"In general relativity, the constancy of the speed of light in inertial frames is built in to the idea of spacetime being a geometric entity."
to mean a variable coordinate c in GR only applies to observers in non-inertial motion. Which inference would be flat wrong.

The unstated assumption in that above sentence in quotes is local i.e. proper measurement of c in a free-falling frame is meant. Otherwise we have nonsensical contradiction e.g. coordinate determined c for light deep in a gravitational potential will equal flat spacetime c if and only if the coordinate observer ('at infinity') is exactly unaccelerated. Nonsense. And such a mistaken conclusion would fly in the face of everything else written there and further in that 2nd linked article (and many more such is easily furnished).

What I mentioned in earlier posts not just #160 was entirely sufficient and clear enough for there to be no reasonable chance of misconstruing. In GR coordinate c is a function of gravitational potential. Period. Something you flatly denied in #161.
Are you now prepared to concede your assertion there is wrong?
Are you further prepared to concede that my claim - 2nd passage in #160 re 1:1 ratio, is correct? If not, why not?
Are you further prepared to concede my finding - 3rd & 4th passages in #160 re prediction of coordinate c unaffected by gravity. As logical consequence of applying your 'thinking out loud' thought bubble in #159? If not, why not?

And all of this is rather peripheral to challenging the central 'GR fact' that static E & B fields are supposedly unaffected at all by gravity induced metric distortions.

Neither conclusion/inference is valid.
So you claim that the speed of light in the vacuum, locally, in an inertial frame, can be different than 299,792,458m/s? Please explain to me under which circumstances this is possible.

At a guess, you mistakenly read the following sentence under 'General Relativity' in first given link in #162:
"In general relativity, the constancy of the speed of light in inertial frames is built in to the idea of spacetime being a geometric entity."
to mean a variable coordinate c in GR only applies to observers in non-inertial motion. Which inference would be flat wrong.
Your guess is wrong; I say you saying that c wasn't constant, which raised my eyebrow.

The unstated assumption in that above sentence in quotes is local i.e. proper measurement of c in a free-falling frame is meant. Otherwise we have nonsensical contradiction e.g. coordinate determined c for light deep in a gravitational potential will equal flat spacetime c if and only if the coordinate observer ('at infinity') is exactly unaccelerated. Nonsense. And such a mistaken conclusion would fly in the face of everything else written there and further in that 2nd linked article (and many more such is easily furnished).
Exactly, and that's why I wrote "and/or".

What I mentioned in earlier posts not just #160 was entirely sufficient and clear enough for there to be no reasonable chance of misconstruing. In GR coordinate c is a function of gravitational potential. Period. Something you flatly denied in #161.
No, I did not. I did not fully get you were talking about the coordinate value of c in a non-inertial frame of reference and/or non-local, because you didn't mention any of that in your original post. That part of the misunderstanding is indeed my mistake.

Are you now prepared to concede your assertion there is wrong?
I agree that my factually correct claim is not something you meant, yes.

Are you further prepared to concede that my claim - 2nd passage in #160 re 1:1 ratio, is correct? If not, why not?
No, because I have yet to dig into its details.

Are you further prepared to concede my finding - 3rd & 4th passages in #160 re prediction of coordinate c unaffected by gravity. As logical consequence of applying your 'thinking out loud' thought bubble in #159? If not, why not?
No, because I have yet to dig into its details.

And all of this is rather peripheral to challenging the central 'GR fact' that static E & B fields are supposedly unaffected at all by gravity induced metric distortions.
If that's so, then why did you bring it up in the first place?

So you claim that the speed of light in the vacuum, locally, in an inertial frame, can be different than 299,792,458m/s?...
???!!! Where did you pull that one from? If this is to be the level of continued misunderstanding/misrepresentation - and I charitably include the first option there - it's pointless continuing any dialogue here. I would have similar remarks for your further inaccurate statements in #165, but continuing with time-wasting ping-pong is just not worth the effort.

Bottom line: either you recognize the standard GR position re static E & B fields is nonsensical, or you accept it coz it's mainstream and all those highly qualified authorities backing/'deriving' that standard viewpoint can't all be wrong. Personally, I don't give a shit how many authorities back/'derive' whatever - if it's inconsistent nonsense, then that's how it is.

Up to you to pursue this matter in your own time and way, or not.

???!!! Where did you pull that one from?
Post #160: You are talking about a non-constant c.
Post #162: You respond by linking to a text that writes: "In general relativity, the appropriate generalisation is that the speed of light is constant in any freely falling reference frame (in a region small enough that tidal effects can be neglected)."
Post #163: I say: "Ah, OK, so you were talking about some non-inertial frame of reference you didn't mention, and/or some non-local values from a location you didn't mention."
Post #164: You respond with: "Neither conclusion/inference is valid."

In post #164 you thus claim that you were talking about the local value of c being non-constant in an inertial frame, which, according to your own link, is wrong. That is where I got my conclusion in post #165 from: you.

If this is to be the level of continued misunderstanding/misrepresentation - and I charitably include the first option there - it's pointless continuing any dialogue here. I would have similar remarks for your further inaccurate statements in #165, but continuing with time-wasting ping-pong is just not worth the effort.
If you don't point out my "inaccurate statements", how can I correct them?

Bottom line: either you recognize the standard GR position re static E & B fields is nonsensical, or you accept it coz it's mainstream and all those highly qualified authorities backing/'deriving' that standard viewpoint can't all be wrong.
Or, you accept that your argumentation is wrong. I mean, that is a third option, isn't it?

Personally, I don't give a shit how many authorities back/'derive' whatever - if it's inconsistent nonsense, then that's how it is.
True, but that goes for your derivation and argumentation as well.

Up to you to pursue this matter in your own time and way, or not.
I already am, but unfortunately I don't have as much spare time to spend on this as I'd like.

In post #164 you thus claim that you were talking about the local value of c being non-constant in an inertial frame,...
Wrong. If you can't ever get to figure what I actually write - and there has NEVER been any contradictions/shifts in my position, then it is hopeless to continue discussion.

Wrong. If you can't ever get to figure what I actually write - and there has NEVER been any contradictions/shifts in my position, then it is hopeless to continue discussion.
If you cannot point out where I am apparently misinterpreting what you are saying, then it is indeed hopeless to continue this part of the discussion.

Wrong. If you can't ever get to figure what I actually write - and there has NEVER been any contradictions/shifts in my position, then it is hopeless to continue discussion.

I felt hugely disturbed by his word manipulations. Schemelzer also gave up on him, and now you too.

If you can't stand the heat, stay out of the kitchen.

If you can't stand the heat, stay out of the kitchen.
I will not take sides but perhaps consider the concerns others express.
It is a pity that these intetrestimg discussions will close because a matter of communication can not be addressed.
Alex

I will not take sides but perhaps consider the concerns others express.
I am considering them, and in a very few cases I indeed have accidentally misinterpreted what they have said whilst I should have known better. When this was pointed out to me, I have apologized. But in many cases, I do not see e.g. how my pointing out sloppy wording (sloppy enough that it could lead to nonsensical conclusions) is "word games"; I would in fact argue it's the other person (unintentionally?) engaging in such activities. I've been accused by multiple people of trolling, word games, manipulation, etc., but I have yet to receive even a single infraction for any of those. Apparently, the accusations were too weak to stand up to scrutiny.

I am not denying I may have an abrasive (online) personality, but it seems that only a certain kind of people encounter this abrasive side, and it's only those people that are accusing me of things. If you (or anybody else) thinks I'm going too far, please have the moderators tell me so, and I will adjust.

It is a pity that these intetrestimg discussions will close because a matter of communication can not be addressed.
True, but if one party simply walks away because things aren't going their way, there's very little one can do.

I'm going too far, please have the moderators tell me so, and I will adjust.
I think it is not a case of needing moderation.
Even I can rub folk up the wrong way and that is never my intention.
I just ask you and others to be more flexible so these wonderful discussions can continue.
You have brought something to the site and that is wonderful.
Anyways I hope the great discussions continue.
All the best.
Alex

I think it is not a case of needing moderation.
Even I can rub folk up the wrong way and that is never my intention.
Same here. It always saddens me to see people accuse me or others of all kinds of things, and thereby shutting down the discussion and closing themselves off from valid criticism. Progress unfortunately often gets hampered when ego's are bruised.

I just ask you and others to be more flexible so these wonderful discussions can continue.
I will take your advice to heart. If an adjustment to my style and demeanor will increase my effectiveness in communicating my thoughts and criticisms, then that's what I'll work on.

You have brought something to the site and that is wonderful.
Thank you; I appreciate that!

Anyways I hope the great discussions continue.
I have no intention of doing otherwise.

All the best.
Alex
Same to you!

...But in many cases, I do not see e.g. how my pointing out sloppy wording (sloppy enough that it could lead to nonsensical conclusions) is "word games"; I would in fact argue it's the other person (unintentionally?) engaging in such activities....
Actually, apart from the evasive dodging of my three perfectly clear 'Are you' questions in #164, it was YOU that used sloppy language and logic, e.g. on various occasions carelessly referring to light speed c without tying down to particular context or specifying whether proper or coordinate c was meant. Failing such encouraging confusion - or allowing obfuscation. Won't bother citing posts and lines now - check back and they are there. That issue was a fork off a fork and I won't waste further time over such matters.

To everyone else here with some interest left:
The key issue re static E & B fields in GR can be summarized very simply. They don't respect gravitational metric fields at all. So for instance the radial field lines of a point charge in flat spacetime will continue to be detected by a distant observer without any distortions, were a massive object to be placed in the vicinity but not coincident with the charge. Yet a point light source at the same location as the charge will be received with various amounts of redshift and angular deflection - depending on the particulars of relative location of point source and gravitating mass. And similarly for anything else that has to traverse distorted spacetime - except, magically, static E & B fields!

Which should tell anyone with a sense for logical consistency the standard GR formulation of 'EM fields in curved spacetime' is whacky.

One more consideration to leave you all with. Getting back to the extreme case of 'charged BH', an oft quoted go-to article that claims to qualitatively justify the notion is:
https://facultystaff.richmond.edu/~ebunn/ajpans/ajpans.html

Skipping past the unconvincing classical EM argument, the quantized aka QED 'resolution' boils down to claiming there is a 'sufficient flux' of 'infinitely fast virtual photons' that can cross the BH EH with ease and continue to mediate the external static E field.
There are two gaping holes in that argument.

1: Given the infalling BH charge is not statically located but in free-fall, a continuous back-and-forth exchange of 'virtual photons' is required on that perturbative picture. But coordinate time stands still at the EH. Any 'photon exchange machinery' there is frozed solid wrt the outside. Hence it doesn't matter if one allows 'infinite speed' of individual virtual photons - the rate of exchange to the outside is zero. There can be no logical exemption to that. Bummer.

2: The notion of 'infinie speed' of virtual photons comprising static E & B fields is itself quite easily disproven. A well verified fact is that all 3 possible components of the E field of a Hertzian dipole oscillator are operated on by the same phase factor exp(-jkr) - see e.g. (19) here: http://www.waves.utoronto.ca/prof/svhum/ece422/notes/05-dipole.pdf

If you don't know how to read that equation I'll just say it shows the so-called quasi-static near field - corresponding to 'virtual photon mediated' - is limited to propagating at speed c just like ordinary radiation is. Otherwise, someone would have long ago been offering superluminal relay communications lines. Another bummer.

I raised both above points and earlier ones mentioned this thread with 'top-notch' physics buffs way back at PhysicsForums. Only response was stony silence. No surprise.

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System issue meant double post.

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Actually, apart from the evasive dodging of my three perfectly clear 'Are you' questions in #164,
I did not dodge those questions; I refused to answer them because I currently have no answer to them.

it was YOU that used sloppy language and logic, e.g. on various occasions carelessly referring to light speed c without tying down to particular context or specifying whether proper or coordinate c was meant.
Something you did as well, as I pointed out in post #163. And I’ve already apologized for my mistake.

Failing such encouraging confusion - or allowing obfuscation. Won't bother citing posts and lines now - check back and they are there. That issue was a fork off a fork and I won't waste further time over such matters.
Fine with me; that issue was already resolved earlier anyway.

...Something you did as well, as I pointed out in post #163...
Believe that if you wish - that particular issue is dusted and done as far as I'm concerned.

Q-reeus:

The key issue re static E & B fields in GR can be summarized very simply. They don't respect gravitational metric fields at all. So for instance the radial field lines of a point charge in flat spacetime will continue to be detected by a distant observer without any distortions, were a massive object to be placed in the vicinity but not coincident with the charge.
Can you please point me towards a post where you established the truth of this claim, or to some other reference that verifies it? I am coming to this discussion later, and admittedly have not read the entire thread.

At first glance, it seems to me that the electromagnetic field tensor transforms just like any other tensor in curved spacetime. Why would it not respect the metric?

My second inquiry is: supposing you are correct, and E and B fields don't "respect gravitational metric fields at all". Would that have any practical or experimentally-verifiable implications? If so, can you direct me towards experimental results which confirm your claim?

Thanks.