Large Black Hole?

I'm going to pour myself a drink and hope that Jorrie notices this thread.

I did not see a question. What is your question?

One observation, the event horizon of a black hole is simply the point of no return near a black hole where even light can not escape the grasp of the black hole. The event horizon is not velocity dependent, but dependent on the gravitational magnitude.

As to what exactly is the terminal point of a black hole, where there are two competing theories where one is a singularity and the other dictates that a black hole is just very small.

Ok, the event horizon gets larger with a more massive black hole, so that implies a geometrical limit for space time curvature, does it not?If there was no limit, the hole would become infinitely deep, and the event horizon would collapse in on itself, or become minuscule.

No. The event horizon is not a thing to object that has mass. It is a description of a point (or points) in space relative to the center of a black hole.

As the black hole gains mass, the event horizon increases.

The event horizon simply marks the point where light and all other matter and energy can not return once it passes that boundary. It has nothing to do with the gravitational gradient, but the magnitude of gravity surrounding the singularity.

When the magnitude is great enough it will capture everything that passes by and nothing escapes.

I realize that the event horizon is merely a description of space curvature, and not an object,with mass, per se.But the shape and size of this set of points is determined by the mass,spin,charge and density of the black hole.Assuming a density limit,the singularity would grow in physical size as more matter was added.If there is no limit to the density, the mass entering would never reach the singularity.The "tube" of curved space time might even collapse at some point, like a vortex will sometimes do.The result may be a spin-off of another dimension that would expand rapidly after being released from the gravitational compression of it's parent black hole.Another big bang, perhaps?

Maybe space-time as we know it is still rebounding from the crunch of the "big crunch" before the big bang, and space time is merely trying to achieve a natural state of non-compression.Thus, the expansion of our universe.

I know that is stretching my ignorance to the limit, but it sounds no more ridiculous than P Branes,etc.

10-50 billion solar masses? What percentage of the mass of the Universe is that?

An itty, bitty, enie, benie, tiny, wenie, bit.

Now we are getting way out to the edge, but some calculations estimate the universe weighs in at 2 × 10^53 to 2 x 10^55 kgs.

1 solar mass is 2 x 10^30 kgs.

Part of the problem with determining the mass of the universe is the observable size (radius of 14 bly) is smaller than the actual believed radial size of 45 bly. We can only assume what we can't observe is not really different than what we can observe.

I am reading an interesting book by Brian Greene called Hidden Realities where he postulates that the real universe is infinite and our universe is but one universe bubble amongst an field of infinite bubbles. The distances from bubble to bubble are vast and therefore outside the horizon of observation.

It is an interesting postulate, but I still have not been convinced of the probability or even possibility of this model. Greene has not adequately explained that, at least not yet. However, if true, this model raises some interesting ideas.

One is, since there is a finite amount of particles in our bubble universe and there is an infinite number of bubble universes, then statistically there must be bubble universes that mirror our own (both exactly and others that are somewhat different). Essentially, all possibilities exist since because there is a finite amount of matter to our bubble universe and therefore a finite number of ways that the universe can be arranged.

Interesting reading, but not much different than science fiction at this point.

It's roughly 0.1 x the mass of a galaxy (a galaxy contains ~ 10¹¹ stars) and there are ~ 10¹¹ galaxies in the universe, so it's 10^-12 x mass of the universe. Not a lot!

Codey

I understand what you are saying, but the Schwarzschild radius allows a body of any mass to become a black hole if sufficiently dense(of course he was referring to a non rotating, zero charge body).He defined the radius as the hypothetical point at which the "escape velocity exceeds the speed of light".This allows the possibility of micro-sized black holes,that probably would have evaporated very soon after their creation due to Hawking Radiation.Perhaps a few are presently produced by super nova explosions, black hole collisions, or during the unknown titanic explosive forces that produce the mysterious cosmic rays that seem to come from everywhere.

If the singularity is infinitely small and dense, then the mass has been separated from the gravity at this point, and only the gravity is left in our universe.

Perhaps discovery of the Boson will help define if they are indeed separate constituents of matter.

Glad to see you back and thanks for the post!

Hi Jorrie

That must be close to Paradise?

GM (Good Move) as long as you don't contribute to the pollution in the lagoon.

Hi Jorrie,

Good to hear from you again. Hope you are enjoying your adventure. I give you and AH a GA each.

-S

No such entity exists.

http://www.ptep-online.com/index_files/2006/PP-05-10.PDF

http://www.sjcrothers.plasmaresources.com/Unicorns.pdf

http://www.sjcrothers.plasmaresources.com/Gillessen.html

First, I think the author of the last two links misunderstood the reply from Gillessen. I don't believe Gillessen denies the existence of black holes.

Second, the idea of black holes having an escape velocity is more of a construct than an absolute. Black holes are an intense gravity well.

Even light will fall into a gravity well. The effects of gravitational lensing are well documented. Gillessen even makes note that the example of an escape velocity is just a construct.

So, I don't see the last two links as a serious challenge to the existence of black holes.

The first link I just did not had time to digest.

However, we have ample evidence of supermassive objects in the universe that span a very short volume of space. These are much, much larger than neutron stars, so the concept of a black hole is probably real. Just because we don't understand the physics inside the event horizon does not make it unreal.

The escape velocity is determined by the curvature of space time.

Is this true? It seems that a galactic size black hole would have less curvature than a stellar size black hole. Yet at the event horizon the escape velocity of both is equal to the speed of light.

"It seems that a galactic size black hole would have less curvature than a stellar size black hole."

This is correct, if you mean spacetime curvature at the Schwarzschild radius, because curvature is associated with tidal gravity, a value that depends on the mass of the hole.

According to general relativity, it is at the central singularity that the spacetime curvature of all black holes diverge to infinity. Quantum gravity may however tell us something different in the future...

Hi HTRN,

I am no expert on black holes, but found some interesting links. This one talks about upper mass limits and the many BHs found buried under gas and dust by the Chandra X-ray Observatory. Spinning BHs are talked about here, and may be the source of the cosmic rays you mentioned. The most informative link is called Inside a Black Hole. I hope this answers some of your questions, but will probably create others.

I have a question. Do all the supermassive BHs discovered by the Chandra X-ray Observatory eliminate the need for dark matter?

-S

Well the funny thing is we know that a plasma torus lies at the center of our milky way, we have imaged it. We know Birkeland currents connect our Sun to the earth and also extend light years out from the Sun. The thing about plasma and electrical forces is they produce synchrotron radiation, x-rays, gamma rays, all the things you attribute to these never seen Black Holes, and we have laboratory experiments that prove plasma does this. How many experiments do you have that show Black Holes do this? We are discovering magnetic fields in space everywhere, and as all of you should know without electrical forces you have no magnetic fields.

Astrophysicists that have never taken a course in electrodynamics or plasma physics see things they cant explain and automatically label them Black holes. This is strange since 99.999% of the universe is in a plasma state, and one would think one or two courses in plasma physics might be a good idea if you are going to study something that is 99.999% plasma in nature. That would be like me never having taken a course in geology describing how the tectonic plates work. Absurd!

http://www.thunderbolts.info/thunderblogs/archives/solar08/062308_milky_way_birkeland_current.htm

http://www.thunderbolts.info/tpod/2011/arch11/110801kinked.htm

http://www.nasa.gov/mission_pages/themis/auroras/northern_lights.html

http://www.thunderbolts.info/webnews/121707electricsun.htm

Are not we as scientists supposed to be open minded and consider all the possibilities? Open your minds, see the true nature of the universe.