Let's see how this comes up.
Black holes are not black, they are actually invisible and the only way to "see" one is to look at how the stars around it shift.
Let me explain
A black hole bends any light that gets near it. If light from a star behind it is bent, it would appear as if the light came from a different direction. That change would make the black hole disapper hence, black holes are invisible.

Rather than the black hole disappearing (tha's its irrevocable state) the star would appear to experience erratic proper motion as it is occulted by the black hole as seen from earth (or anywhere else). Also the likelihood of gravitational lensing may make the star appear brighter for a short interval of time.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

h34r: Well how about the alternative theory that Black Holes are really high-speed tunnels to another Universe? This theory says there are many Universes, but we cannot see them unless we zip through a Black Hole.

Related to this is Dark Matter which we are seeing splattered around our Universe. Actually under the theory above, these are exit points of Black Holes from other Universes.

We will know all of this is true when finally an alien in his space ship is deposited in our Universe. He was on his way to a frapple game (something like soccer) when he got nailed by a BH. By the way, he thinks we are really funny looking.

setiman

The opinion has been expressed by Einstiein and others that the concept of motion, although applicable molecular and corpusular fluids, is not applicable to a homogeneous and structureless medium asthe ether.
So-Called Blackholes

Any medium that is capable of supporting wave motion, should be capable of supporting vortex motion, and it seems inconsistent after recognizing light as wave motion in the medium, to refuse to regonize the elementary particles of matter as vortex motion in the same medium.

A medium that is capable of moving would necessarily have inertia, although usually refered to as a property of matter, is a primary propery of motion.

Inertia means continuity of motion, and all motion necessarily has continuity as long as the motion contiues.

If the motion is rotation, as in a closed circuit, as in the case of vortex motion (Black Holes), then the motion will be localized inertia, or momentum.

The distinguishing characteristic of all elementary particles is their localized persistense of individuality,and this is the distinguishing characteristic of vortex motion.

Wave motion is not localized like elementary particles of matter, nor does it have individuality in the full sense of the term.

As an example, a wave that is distorted, will not of its own accord revert to its originalform, but will travel in the direction normal to the new wavefront; there being no persistence of indiduality, or memory of the original waveform.

On the other hand, if a vortex ring (Black Hole) is distorted from the circular or elliptical form, it will spontaneously revert to the original form.

The Black Hole Vortex therefore does have persistencew of individuality, or memory of its original form.

Prime

One thing I've wondered about related to black holes is this:
What happens to the Heisenberg Foam inside the Schwarzchild Radius?
Does it get swept away somehow, leaving some kind of null space?

If so, what happens during that brief moment when two black holes merge, and there is a space in between them where gravity balances out, making non-collapsed space again? Could a photon or other particle travel through this space?

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Ah ha, a worm hole!

:unsure: Seriously, until we understand more about the force of magnetism, we are speculating. Called the weakest force, it certainly appears not to be so within the context of black holes.

setiman

That's true setiman. Not just magnetism, either... we need to know about:
- magnetism and the mechanisms supporting it [my understanding is that all magnetism associated with a black hole must be from outside the surface].
- angular momentum inside these things, and frame dragging
- gravity [saturated Higgs field?]
- other physics in the extreme.

To have a good model for what's happening, we need to build some super instruments and measure the details of what's happening around some known black holes. Until we do that, we're spinning theoretical wheels.

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Is there anyone out there that thinks that black holes are not singularities and not the collapsed cores of stars?
Cheers.

I am not convinced that a rotating object can collapse to a singularity. Perhaps they eventually use up their rotational inertia through frame-dragging or something, but I don't picture them as singularities. [Note well: My knowledge of simple physics goes out the window inside the Schwartzchild radius].

I suspect that the supermassive black holes in the centers of galaxies never had to go through a stage of being a star, but may have piled up matter so fast that they collapsed faster than light could escape.

Aside from that, I think stellar-mass black holes are collapsed cores of stars.

Are you looking to see if people think they may have a more spiritual nature?

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I hear my teacher once talk about this thing(BH) before, he said, there are 2 different type of BH, one was a collapse core, and another one was huge nature form BH... e.g the one that once in our Milky Way galaxy.. err am I am wrong again?

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We come without a thing and gone without a thing. We need simple life. A cup of teas and a couple of meals per day, that is good enough. And this is my standard of living.

h34r: It is very easy to assign sinister-like behavior to Black Holes and see them as the end points of the Universe. I look at the complexity of living organisms which are essentially fashioned to be self-sustaining. I think this same kind of interactivity exists in the Universe. We see a continual renewal going on some of which is brought about by the action of Black Holes. So like I sort of facetiously wrote earlier, who is to say that BHs are not vital energy transformers that contribute to the shape and vitality of the Universe.

I am not a cosmologist so I can stupidly say that I do not believe our Universe to be self-destructive. I think the contrary applies, we have just not found out how that works yet. by the way, the most significant thing cosmoslogist say about this in a finite way is - they shrug their shoulders!

:blink: Do you know that much of what we say here has been asked, answered and argued over at the very beginning of human life on this planet? Our advantage is we have more tools to use to tease our minds. Think of Gallileo's mind when he looked through the first telescope and saw the craters on the moon? Do you suppose he envisioned a Moon Mars Mission?

Ain't this fun!?!

setiman

Nope, my question is meant to remind us that we know very little about these black holes. They emit X-rays and they can be found al over the Universe and some are at the centre of galaxies. Stars seem to behave strangely around these high-energy sources, but basically that's it. All the rest is pure math and conjecture. Nothing wrong in itself, but it can be very misleading to believe that what formulae tell us has anything to do with reality. We should be aware that science is a long way off from really understanding the Universe. There's a lot that remains to be explained, like how jets form and why we haven't seen any stars being swallowed up.
We should be looking at ways to recreate the X-rays and try to find ways to explain (and experimentally verify) the jets. As I said in another thread, computer modelling is a dangerous tool so we're basically out on a limb and the problem is that some people think that everything is already explained and nailed down to within a margin of error of 1%.

Cheers.

Well said, VanderL. I think it was President Calvin Coolidge who stated that all that will ever be invented has been invented. He was President from 1923-1929. Thanks heavens nobody believed him!

setiman

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<span style='font-family:Arial'><span style='font-size:8pt;line-height:100%'><span style='color:blue'>setiman
If I had a cousin, his name would be Yoda.</span></span></span>

Black holes are not completely invisible, black holes also release energy acording Hawking Radiation. So they are technically not invisible, but they don't emit enough to be detected by anthing but very sensitive equipment.

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We have to differentiate between the real black holes and the theoretical explanation of black holes. Real black holes are very visible, they are X-ray sources (Chandra and XMM images are full of them) and emit all sorts of radiation and jets. If we are looking for the theoretical constructs or "naked singularities" they are indeed practically invisible. Which is the real problem here, first we had the theory predicting singularities and next we could identify objects that might fit this theoretical model. Nowadays every strong X-ray source is equated with a black hole (or it's little brother the neutron star), but we still have to prove that these extremely strong gravitational fields really exist.Our mathematical approach and the theories that followed (Einstein in front) are way ahead of the parade in my opinion.

Cheers.

I agree with vanderL, except for this:

Our instruments are detecting emissions from the effects of the real black holes, yes; but we do not know if there are black holes out there which are not part of multiple star systems, and which are simply floating around no longer collecting significant amounts of matter, and no longer blasting lots of X-Rays.

We can detect these only by their gravitational lensing. I recall reading that a few of the microlensing events seen against the LMC were thought to be 3 to 5 solar masses, and therefore likely to be quiet balck holes. [sorry for not looking up the story, I have a deadline on something else today.]

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Just to point pout a few descepancies.

Yes we have, see this: http://www.esa.int/export/esaCP/SEMUPO1PGQ...QD_index_0.html

According to the Theory of Relativety, yes they are singularities. They can form from massive enough stars, but these do not account for the mid or supermassive sizes ones.

Why? Why would rotation have any effect on something that massive? Or more precisely, how could rotation prevent its collapse in the face of such overwhelming mass.

Yea, same with most of us I would have to say!

Yes, and there is evidence to suggest that they were the catalyst for galaxy formation. See this: http://www.space.com/scienceastronomy/blac...y_030128-1.html for example.

See this: http://news.bbc.co.uk/1/hi/sci/tech/779707.stm
Or this: http://space.mit.edu/~hermanm/ss433/AASPre...sConference.pdf
Or this: http://www.space.com/scienceastronomy/blac...ics_021111.html
Or this: http://www.nrao.edu/pr/1999/m87/

There are lots of other sites regarding the formation of black holes, their detection, how they cause weird things like gravitatinal lensing, x-ray emission, frame dragging, etc.

I like the theory of black holes because it is simple (as compared to other theories trying to explain the same phenomenum), it is observable, and it is re-creatable. Just because a theory is hard to understand doesn't mean it is wrong. If you have evidence that fits the picture of what is known already better, then present it.

A naked sigularity would be an amazing thing indeed, in a universe filled with matter. Yet it is postulated that such a thing might arise right here on earth--if a giant super-collider is built, the crashing togeather of atomic nuclei might impart enough energy to create one for a few billionths of a second.

It is very easy to say "thats wrong". Thats what everyone told Columbus, and Gallileo, and Newton, and Planck, and Darwin, etc etc, ad infinitum, ad nauseum. Which is fine, as far as it goes. Scientists should be made to explain themselves. But if you are going to say "thats wrong", then come up with at least some reason why.

As for black holes, I think that there is plenty of observational data to support their theoretical existance. Plug the words "black hole" into your favourite search engine and start reading.

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Humanity must rise above the Earth, to the top of the atmosphere and beyond, for only then will we fully understand the world in which we live.~Socrates, 500 B.C. ~

Let every man judge according to his own standards, by what he has himself read, not by what others tell him. ~Albert Einstein~

My concern about rotation and singularities is that I have a belief I'm having trouble ignoring in the conservation of angular momentum, and this is at odds with the apparent need for faster-than-light instantaneous velocities inside the Schwarzchild radius.

I suppose, since all bets on physics are off inside there, it could simply ignore conservation and just collapse.

Regardless of what I think about rotation and singularities, you and I are both on the same page about it being a good clean way to test general relativity. The day is coming when we'll be able to observe some of these objects in enough detail that we will better know how physics is changed in their vicinity.

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And I'm apparently on a different page, because there still is no direct evidence (direct, as in measuring in situ, or recreating the same conditions in a laboratory)of high gravity fields. And the star that was swallowed up wasn't directly imaged, there was just a (yes, indeed) blast of X-rays detected.
The jets are only modelled on computers (which can generate anything you want it to) and there is a lot of data unexplained in even the best fitting models. It would be nice to have a better term than "black hole" because this way it looks as if there is no doubt on what it consists of, and there are other models that are trying to explain what makes an object act like a black hole, but it isn't proven yet. So in the end we need to be careful when we make statements based on mathematical concepts, it could very well be different in reality.
Cheers.

Not true. See this: http://www.aas.org/publications/baas/v32n3...ead2000/332.htm
Or this: http://arxiv.org/abs/astro-ph/9911273
Or this: http://science.msfc.nasa.gov/newhome/headl...st24mar97_1.htm
or this: http://hubblesite.org/discoveries/10th/vau...lackholes.shtml
or this: http://www.sns.ias.edu/~dpsaltis/ASTRO541/oct2.pdf

I could list a dozen more if you like.

Well ok. Hmm lets see, they have not seen the nucleus of an atom. Does that mean it's not there? They haven't seen an asteroid strike on any terrestrial planet. Does that mean they don't happen? The star involved was approximately 1 solar mass at a distance of some millions of light years. Notwithstanding that distance, the tidal disruption of the star behaved in exactly the way it was predicted. How is that for observation matching theory?

Again, not true. See this: http://universe.gsfc.nasa.gov/press/2002/021003a.html

I agree, but not for the reasons you state. The name came from someone trying to explain the phenomenum to a layperson (I can probably find the name, but I don't have the time right now) and the name "black hole" was so compelling, it stuck. And there is no doubt of what it consists of, the doubt is what happens to the material that it is made up of once the mass necessary to trap light was exceeded.

String theory is starting to unravel even that mystery. While there is certainly more to be learned about black holes, if the evidence for or against their existance was presented to any reasonable jury anywhere, it would easily be found that the preponderence of the evidence would support the premise that they exist.

I agree! But having said that, when the overwhelming bulk of evidence supports in reality was has been postulated in theory, then you have to consider that the theory was correct. The fact that our knowledge in incomplete is what drives the continued research. If we knew everything, we wouldn''t have to look anymore.

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