Recent content by dllahr

Nope. I asked if the charge was located at the apparent center. I asked where the charge was located. Really simple if you stop arguing at straw men.

Nope; apparently you didn't read my whole post, and just fired that off. Or my other posts. I've posited repeatedly that I'm making measurements from outside the outer event horizon, so sphere's do have a center. Why are you arguing against things I'm not saying? I never said I cared where...

Yes it is. The Reissner-Nordstrum metric has a spherically symmetric horizon. Bingo, center of that sphere. Easy. All of my questions - in this thread and the other - have focused very specifically on making measurements outside the horizon. The horizon that is spherically symmetric. And...

Center of the black hole is a pretty obvious concept, I'm not sure why you're trying to obfuscate it. Regardless of the level of the discussion, it serves as a good starting point. I'm not sure exactly what l-level means; I'd be happy to move the discussion elsewhere if that's going to be a...

Where do the static electric field lines appear to originate from a charged black hole, non rotating, Reissner–Nordström metric? I've had a number of qualified physicists say they appear to come from the center of the black hole, but people on these forums have said that doesn't make sense...

So I guess the equation is wrong?

So this is much simpler than @PeterDonis is making it. The charge in the Reissner–Nordström metric is located at the singularity: https://en.wikipedia.org/wiki/Reissner%E2%80%93Nordstr%C3%B6m_metric#Charged_black_holes In the section above, the electromagnetic potential is defined: So yes...

I don't think you're being reasonable and I think this discussion has become unproductive, so I'm going to stop. I think I've hit a nerve because this isn't something with a well defined answer.

Does the Reissner-Nordstrom metric apply when a single charged particle falling past an event horizon? I don't think it does - it is a static solution to the Einstein-Maxwell field equations, which corresponds to the gravitational field of a charged, non-rotating, spherically symmetric body of...

Assume time long enough that there is no measurable change - e.g. it's finished falling.

Thank you all for the discussions and explanations, @PeterDonis thank you for taking the time to explain in detail and with great heuristics. I have a follow up question - based on your discussion of the light cone of the event, assume for simplicity a single charged particle has fallen into a...

Thanks for posting - my question was, if gravity waves propagate at the speed of light, how does the expansion-contraction of the Alcubierre metric travel faster? It seems they are not consistent with each other.

Are you aware of the photoelectic effect and the relationship between intensity and number of photons? Are you aware that you can change frequency independent of the intensity / number of photons? Does any of this really matter to the original point? No. Edit: at the end of the day, you...

# photons is directly proportional to intensity, no? This is minor semantics at best. Is it really critical to be re-phrased on a discussion forum to say "the intensity observed on the other side of the glass" instead of the intensity transmitted? Really? really? The "more complicated"...

assume / given: * the train is moving at 0.5*c * the light source is stationary in the train frame of reference * in the train frame of reference the light is incident perpendicular to the plane of the glass * the light is s-polarized with respect to the direction of motion of the train * glass...