Back hole in Cygnus X-I
Posted: Sat Sep 03, 2011 6:01 pm
What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?
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There is no such thing as an unstable black hole (except possibly for the hypothetical class of microscopic black holes). When a black hole absorbs anything- be it dust or be it a star- it increases in mass by that amount. The other conserved properties are angular momentum and electric charge. That's it.babaonet wrote:What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?
Jets, accretion discs, and all the other active phenomena we see around black holes have nothing at all to do with black hole physics as such. They are all the indirect result of the mass, charge, and rotation of the black hole. This is why we see similar phenomena around other objects with those properties, like protostars and neutron stars.babaonet wrote:Thank you Peterson, but what you think about the powerful gamma jet radiation during feeding, Such as in SW 1644+57?
They don't, because the jets were never inside the black hole. As I said before, everything we see around black holes is caused by their influence on the environment around them. Jets are produced outside the black hole, so there is nothing preventing their radiation and material from escaping the region.babaonet wrote:One more question please, as we know nothing can escape from black hole, even light too. But how those gamma ray jets manage to escape from black hole?
They do exactly what any two objects do: depending on their initial velocities, they either end up in a closed orbit or they swing past each other and never come back together. There are many multiple (two) black hole systems, which commonly occur when galaxies collide.ErnieM wrote:What happens when a black hole gets close to another black hole? Is there such a phenomena as multiple black holes system?
Black holes in orbit about each other eventually collide because they lose energy to the surrounding medium, and their orbits decay. When they collide they merge into a single, more massive black hole. It is hypothesized that many (or all) supermassive black holes formed from a string of black hole mergers. Whether a merged black hole will have jets, however, depends on the medium around it. If there isn't enough material to support an accretion disc, there won't be any jets. Even if one or both had accretion discs before the merger, the collision itself could disrupt or even absorb that material, which would actually shut off any jets that were present.If black holes eventually eat each other, then one can imagine a single super massive black hole with two opposite super long and expansive jet streams.
Anything is conceivable. I don't think there is anything to support this idea, however. At the least, you'd need to allow for the fact that the number of dimensions that define the Universe is at least one greater than the number that define a jet.Is it inconceivable to imagine that this is the shape and geometry of our expanding "universe" (and others as there could be than one) and we presumably "live" in one of the Picard horn shaped jet stream?
The universe is mostly dark matter and dark energy in comparison to visible matter and visible energy. Then it is only logical to assume that most of the medium around a black hole are dark matter. Would this not result in a "dark jet stream" being present but not yet detectable by our instruments?Whether a merged black hole will have jets, however, depends on the medium around it. If there isn't enough material to support an accretion disc, there won't be any jets. Even if one or both had accretion discs before the merger, the collision itself could disrupt or even absorb that material, which would actually shut off any jets that were present.
No, for two reasons. Jets require an influx of material from a disc structure, that is then caught up in strong magnetic fields and ejected along the rotation axis. Dark matter doesn't form discs, but rather it forms halos (you need fluid dynamic processes to form a disc, and that isn't possible if the material doesn't interact with itself or other matter), and dark matter isn't influenced by magnetic fields. Dark matter may fall into a black hole, or orbit a black hole, both of which are purely gravitational effects. But there is no mechanism for dark matter to be ejected from the region around a black hole, other than the trivial (and non-relativistic) ejection of material via injection into hyperbolic orbits by angular momentum transfer processes.ErnieM wrote:The universe is mostly dark matter and dark energy in comparison to visible matter and visible energy. Then it is only logical to assume that most of the medium around a black hole are dark matter. Would this not result in a "dark jet stream" being present but not yet detectable by our instruments?
Probably. That scenario provides the best fit to observational data.babaonet wrote:Is there a black hole in Cygnus X-I?
There are elements in that article that make me skeptical, particularly the rather bizarre mix of Eastern philosophy with science. There are also factual errors, such as the suggestion that WMAP data leads to the conclusion that the Universe is 12.73 billion years old (the actual WMAP value is 13.69±0.13 billion years).ErnieM wrote:Full article: http://knol.google.com/k/shape-of-the-universe#
I don't follow your suggestion that the change in ratios of the components of the total energy budget carries an implication that dark matter influences itself. By direct observation we know that dark matter gravitationally influences itself; other mechanisms are currently unknown, and largely speculative. Any mechanisms behind the conversions are also largely speculative. Dark matter is simply another form of energy, so the mass-energy equivalence is present- an assumption that is fundamental to cosmological theory.The estimated changes in the make up of the universe, specifically the reduction of dark matter and the increase of dark energy, implies that dark matter is influenced by itself (internally) or by other "matters" (externally) through gravity and other phenomena.
How is dark matter converted into dark energy? Does dark matter follows Einstein's E = mc2?
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I don't follow your suggestion that the change in ratios of the components of the total energy budget carries an implication that dark matter influences itself. Nobody knows if all matter decays (not sure why you qualify this with "organic"). The paper you reference isn't useful, and much of Kapp's science-philosophy is demonstrably false. It is certainly possible that the proton decays, which is pretty much the same thing as saying matter has a half-life, although with a much larger value than Kapp proposed. But the question remains unsettled. And nobody knows much about dark matter, other than the broad suggestion that it is probably non-baryonic.ErnieM wrote:It has been suggested that all organic matter decays and have a half-life. Does this decay process(es) apply to dark matter?
DM and DE are not necessarily correlated, at least in the sense the one is, or can be, converted to another. Keep in mind that DM and DE are apparent entities that are not understood, but manifest themselves in comological observations and supported by GR (Lambda-CDM) model. Also, the concept of an expanding Universe was a direct consequence of GR, whence the origin of Lambda (Λ) the cosmological constant. It is interesting that DE and GR have an apparently intrinsic connection, but DM is not born from GR. Thus it seems reasonable, today, that DM and DE are viewed as distinct, uncorrelated, entities despite not knowing what they really are.ErnieM wrote: How is dark matter converted into dark energy?
Does dark matter follows Einstein's E = mc2?
babaonet wrote:What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?