The shape of a black hole

Originally posted by adam warlock
Your original quote is this: "I also see no reason why two singularities cannot orbit one another (as binary stars do) and thus have a more exotic shaped event horizon." Since you didn't provide your scenario I assumed the simplest one (no interactions) and in that scenario you can only have one singularity.

You say I misrepresent you, but English is my native language and your statement above simply does not make any sense in English. I presented a scenario in which there are two singularities orbiting one another and you claim that you assumed there were no interactions between singularities. How can two singularities be orbiting one another and not be interacting? How can you claim that the equations - when applied to a single singularity only rules out multiple singularities? It just doesn't make any sense.
You are so hung up on equations that you can seem to follow plain English.

Originally posted by twhitehead
You say I misrepresent you, but English is my native language and your statement above simply does not make any sense in English. I presented a scenario in which there are two singularities orbiting one another and you claim that you assumed there were no interactions between singularities. How can two singularities be orbiting one another and not be inte ...[text shortened]... n't make any sense.
You are so hung up on equations that you can seem to follow plain English.

" I presented a scenario in which there are two singularities orbiting one another and you claim that you assumed there were no interactions between singularities"
That's because I assumed that you meant two singularities in a BH. And that's impossible. Than you specified the conditions of two BHs interacting and that never crossed my mind. so when I said that I assumed no interactions it was about interactions between two BHs.

"How can you claim that the equations - when applied to a single singularity only rules out multiple singularities?"
When did I say that? What I said, when attempting to explain to you why two singularities are impossible in one BH, is that when one is just dealing with one BH there is only a place that can be called a singularity.
In case I didn't make myself clear I'll try to present this in another angle: looking the Schwarzschild solution to the Einstein field equations you see that only at r=0 you have a genuine singularity. But this approach is done from the beginning considering only a single BH.

When two BHs are considered I have repeatedly said that I'm not sure on what happens.

I think that maybe the problem here is the fact that you're equating a BH with the BH singularity.

"You are so hung up on equations that you can seem to follow plain English."
To that I say that you are so hang up on being right that you can't seem to read what I read.

By the way: what do you have to say to all the other things I wrote? I'm still waiting for the proof of your claims.

Originally posted by adam warlock
I think that maybe the problem here is the fact that you're equating a BH with the BH singularity.

Since we are obviously not understanding each other at all, please start by defining some terms.
What do you mean by BH. What do you mean by BH singularity.

When you say: "But this approach is done from the beginning considering only a single BH. " do you mean:
a. "one single continuous event horizon" or
b. "one singularity"?
c. something else.
If b. then my argument still holds ie if a single singularity is an assumption, to produce it as a result is ridiculous.
If a. then you cannot claim not to know what happens when two event horizons collide as there are only two possible options:
1. the event horizons combine to become a single continuous event horizon - which must necessarily contain only one singularity which means the two singularities must combine instantaneously as the event horizons touch.
or
2. they can never combine and something else will happen eg bounce or explode etc. After all if gravity is so strong that light cannot escape in one direction but is being equally pulled in the other direction (ie halfway between the two singularities) then who knows what will happen.

But now we also discover that all this time you have been preaching that equations rule yet you have been relying on the Schwarzschild solution which is an approximation with very special conditions. One of those special conditions is that the mass must not be rotating, yet in my scenario of two orbiting singularities they clearly are rotating, yet you felt it reasonable to apply your equation to my scenario.
Clearly physics is more than just equations, you need to be able to think, too.

Originally posted by twhitehead
Since we are obviously not understanding each other at all, please start by defining some terms.
What do you mean by BH. What do you mean by BH singularity.

When you say: "But this approach is done from the beginning considering only a single BH. " do you mean:
a. "one single continuous event horizon" or
b. "one singularity"?
c. something else.
I ...[text shortened]... scenario.
Clearly physics is more than just equations, you need to be able to think, too.

BH is short for black hole. And a black hole just has the normal technical meaning it has in Physics. I'm flabbergasted that you have to ask this at this point.

"But this approach is done from the beginning considering only a single BH." You consider the gravitation field created by one body of mass m and then look at the Schwarzschild solution. There are two singularities there: one at r=2m and one at r=0. After some tinkering with the coordinate system you realize that the singularity at r=2m isn't a real singularity but it's just a deficiency of the first coordinate system (kinda like the origin of a cartesian axis is a singularity when one considers polar coordinates). The r=0 singularity reveals itself to be a real singularity then.
In conclusion: one starts by analyzing a single body and concludes that it has one single singularity. That's what I meant and it's pretty straightforward for anyone that has any experience in GR and with derivations in physics.

Does this explanations fits under your a) or b) hypothesis? By the way what does a) means. I can't make anything out of it.

"If b. then my argument still holds ie if a single singularity is an assumption, to produce it as a result is ridiculous."
This just shows that you don't know what a singularity is. Nor what a BH hole is. What happens is that you start analyzing the gravitational field of a single body of mass m under certain specific conditions (the ones that produce a BH) and conclude that inside that region there is a point were derivatives can't be calculated. This is called a singularity.
So, you start with one BH (the single body of mass m that causes a region of space-time to become so curved that not even light can escape) and derive the existence of one singularity. Once again it appears to me that you don't know the difference between the two terms nor know what the derivation of a scientific result is.

"If a. then you cannot claim not to know what happens when two event horizons collide as there are only two possible options:
1. the event horizons combine to become a single continuous event horizon - which must necessarily contain only one singularity which means the two singularities must combine instantaneously as the event horizons touch.
or
2. they can never combine and something else will happen eg bounce or explode etc. After all if gravity is so strong that light cannot escape in one direction but is being equally pulled in the other direction (ie halfway between the two singularities) then who knows what will happen. "
1. Is utterly incomprehensible to me.
2. yep this an option too. And if you have read the articles I linked to you'd know that it was contemplated in them, so obviously I know about it. Here the main problem seems to be that we understand the word know differently. Of course I can give you some possibilities to what happens when two BHs collide. But that isn't knowing to me. Knowing is deriving and I can't derive what happens when two BHs collide.

"But now we also discover that all this time you have been preaching that equations rule yet you have been relying on the Schwarzschild solution which is an approximation with very special conditions. One of those special conditions is that the mass must not be rotating, yet in my scenario of two orbiting singularities they clearly are rotating, yet you felt it reasonable to apply your equation to my scenario. "
It took all this time to realize to what solution I was referring to (by the way I never preached that the equations rule. One more baseless categorical affirmation). I ostensibly said numerous times that my first comment was made in relation to a non moving BH. And that's just what the Schwarzschild solution is about. You really don't read what I've been writting do you? And the Schwarzschild solution isn't an approximation. It is an exact analytic solution to a very hard differential equation under certain boundary conditions. In case you don't know, every differential equation solution has to be computed under boundary conditions in order for it to have any physical meaning.
After you proposed the colliding scenario I ostensibly said that in that case I didn't know what would happen to the singularities, thus I have never applied that particular solution (not an equation as you erroneously say) to your colliding scenario.
Just get this under your skull. There was a comment made by me when I didn't factor you collision scenario, and there were a lot of comments made by me after that scenario (I feel I'm saying this for the zillionth time). By the way the Schwarzschild solution is about the whole BH not rotating, it isn't just the singularity not rotating. Here it seems that that error of yours is creeping in once again.

"Clearly physics is more than just equations, you need to be able to think, too."
LOL. The coup de grace: The ad hominem attack. Here's one for you too: I'm beginning to think you are a crackpot.
I've been saying this all along. You need the equations, you need the solutions, and you need to interpret the equations and the solutions. Are you reading anything of what I write or just go knee-jerk replying to all of my comments?

I'm still waiting for you answer to most of my points in the fifth post of the fifth page.

I really find it humorous that a person that doesn't know what is a black hole, what is a singularity, doesn't know the Einstein field equations, doesn't understand normal procedures of solving differential equations, doesn't know the difference between an equation, and a solution of it, doesn't know what a derivation is, finds the time to lecture me in GR and Physics. This thread really is a keeper.

Originally posted by adam warlock
BH is short for black hole. And a black hole just has the normal technical meaning it has in Physics. I'm flabbergasted that you have to ask this at this point.

So what is the 'normal technical meaning it has in Physics'? You may be flabbergasted, but unless we understand what you mean by BH, there is no way we can communicate. It is not at all clear from your usage thus far whether it refers to a singularity alone or the phenomenon of a singularity with an event horizon. I must note here that there may exist what are called 'naked singularities' which are singularities without event horizons. Are they BH's or not?
I also don't know whether it is possible to have an event horizon without a singularity - again, I don't think physics yet has an answer.

Edit: I see that later in the post you define BH as "a single body of mass m that causes a region of space-time to become so curved that not even light can escape".

Originally posted by twhitehead
So what [b]is the 'normal technical meaning it has in Physics'? You may be flabbergasted, but unless we understand what you mean by BH, there is no way we can communicate. It is not at all clear from your usage thus far whether it refers to a singularity alone or the phenomenon of a singularity with an event horizon. I must note here that there may ex ...[text shortened]... that causes a region of space-time to become so curved that not even light can escape".[/b]

twhitehead: "I also don't know whether it is possible to have an event horizon without a singularity"

Let's define an 'event horizon':

"An 'event horizion' is a surface where information can only go in one direction."

Is this a good definition?

Originally posted by adam warlock
BH is short for black hole. And a black hole just has the normal technical meaning it has in Physics. I'm flabbergasted that you have to ask this at this point.

"But this approach is done from the beginning considering only a single BH." You consider the gravitation field created by one body of mass m and then look at the Schwarzschild solution. Ther ...[text shortened]... re me in GR and Physics. This thread really is a keeper.

It's round case closed

Originally posted by FabianFnas
When you see a black hole from a distance, then you don't actually see the black hole itself but only the agregation disc around the hole, and the jets of matter. The actual hole is so small you cannot see it from that distance.

A black hole, or rather it's event horizon sphere is sperical. Or if it's rotating perhaps flattened a little, I don't think you can see the flattening thou.

Wouldn't the area inside the event horizon be spherical and the stuff outside the event horizon be a disc or even a disc with spiraling arms? Wouldn't this disc make the black hole appear to be a disc as it is all we can see?

Originally posted by joe beyser
Wouldn't the area inside the event horizon be spherical and the stuff outside the event horizon be a disc or even a disc with spiraling arms? Wouldn't this disc make the black hole appear to be a disc as it is all we can see?

No.

Originally posted by FabianFnas
No.

You could have at least said nope.

Originally posted by joe beyser
You could have at least said nope.

Well, if that would please you: Nope.
On what ground do you think an event horizon could be shaped as a disc with spiraling arms. I cannot find any reason that makes any sense.
Therefore my short answer: No. Sorry, nope.

Originally posted by FabianFnas
Well, if that would please you: Nope.
On what ground do you think an event horizon could be shaped as a disc with spiraling arms. I cannot find any reason that makes any sense.
Therefore my short answer: No. Sorry, nope.

The event horizon would not be disc shaped. Just the stuff outside of it. Say maybe a galaxie or something.

Originally posted by joe beyser
The event horizon would not be disc shaped. Just the stuff outside of it. Say maybe a galaxie or something.

Sorry. Your reasoning is a bit thin. I still say : Nope.