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Let's change this a little bit. We have observed specific phenomena but not that which created such phenomena. As far as "Black Holes" as per theoretical desc

Let's change this a little bit. We have observed specific phenomena but not that which created such phenomena. As far as "Black Holes" as per theoretical descriptions are concerned, they cannot exist in a finite time universe as far as we (the observers) are concerned. The theoretical models used all have as a basic assumption that increasing gravity (whatever that may be) will cause a slow down in time as observed at distances away from such increase. As such, all phenomena involved in the creation of such entities will slow to a complete stop as far as we are concerned. Hence, if the universe is of any finite duration, we will not have seen the creation of even 1 black hole of any kind. On the other hand, if the universe has existed eternally, it is still likely that these entities are still in the process of formation and not yet in existence. I don't doubt we are seeing some interesting phenomena, but not the entities called "Black Holes". The argument for the creation involves changing perspective to some observer who is falling into or through the event horizon (choose which one of these you want, as there are apparently a couple of choices here in the theoretical models). Since we are not such observers, that perspective is actually irrelevant to us. What is relevant is what we observe in the universe at large. The basic problems (irrespective of mathematical assumptions) with the processes of "Black Hole" generation relate to non-uniformity of compression, time dilation and other basic assumptions for the "Black Hole" models. I find the reasoning used for the existence of "Black Holes" in our universe to be lacking in logical rigour and appears to have a lot of hand-waviness to it. I am currently reading the documentation for the Metamath system and there are some quite enlightening comments in that about mathematics and those who study it. Especially as it relates to us who are not mathematicians as our career. One of these relates to the amount of "faith" we have to exhibit when trusting that specific "proofs" are in point of fact true. Even mathematicians who are not in that specific speciality do not have the necessary background to verify any proof outside of their own mathematical area. Mathematics is a profoundly useful tool but as we have seen in the past and we will see in the future, it has problems (like all areas).

InclinedPlane 8y ago
We have observed matter falling into a black hole. We've watched "hot spots" in orbit of a black hole in the accretion disk shine their light at us as they orbited the black hole. We've watched as the orbit got tighter and tighter and the light was dimmed by gravitational red shifting, then we've watched the light blink out and disappear as the blob of gas fell below the event horizon. The evidence for the existence of black holes is incredibly strong at the moment. In fact in some ways it's stronger than the evidence for the existence of atoms about a century ago. Nobody except cranks or extreme contrarians seriously disputes the theory these days.
- roywiggins 8y ago
  I believe the argument is that event horizons exist but inside is not a singularity, but an eternally collapsing mass of the original star. From the point of view of the star, it does collapse all the way, but from our point of view that final singularity collapse is in the indefinite future. https://en.m.wikipedia.org/wiki/Magnetospheric_eternally_collapsing_object https://en.m.wikipedia.org/wiki/Magnetospheric_eternally_col...
  - roywiggins 8y ago
    Update: I am mistaken. The classic GR black hole behaves this way. MECOs supposedly never fully collapse into a singularity, even for infalling observers. That's the difference. I rather think we'd have noticed the difference from LIGO gravitational wave measurements of BH mergers, but maybe not?
- perl4ever 8y ago
  From your point of view, if so-called black holes are "fuzzballs"[1] is that a vindication or a refutation of the existence of black holes? Without a deep understanding of physics, I have the general attitude that infinities must be a mathematical error, and therefore something must stop black holes from collapsing totally, but whether they "exist" is only a matter of definitions. [1]https://en.wikipedia.org/wiki/Fuzzball_(string_theory) https://en.wikipedia.org/wiki/Fuzzball_(string_theory)
  - roywiggins 8y ago
    I tend to agree with you. Are mathematical singularities physical? We just don't know. I think probably not on philosophical grounds. But we can't peek inside an event horizon to find out, and these event horizons seem to exist, so whatever the structure of the insides of them are, they're still black holes.
- TeMPOraL 8y ago
  Then there's this video ESO's Very Large Telescope shot[0], of stars orbiting something that's a) very massive, and b) invisible. Does that constitute a direct observation of a black hole? -- [0] - https://www.youtube.com/watch?v=TF8THY5spmo https://www.youtube.com/watch?v=TF8THY5spmo
AgentME 8y ago
Black holes may not form true singularities in any finite amount of time, but event horizons that are indistinguishable from the outside can be formed.
- oldandtired 8y ago
  It is the event horizon that never forms. The problem that is never dealt with is that when the density of material goes up, gravity goes up, time dilation throughout all the affected material increases. From our perspective, everything throughout the affected material and region slows down - that includes any compression effects to increase the density. There is no opportunity for the effects to generate an event horizon to occur in finite time. If the event horizon cannot form then you can forget about any singularity ever forming. It is just assumed that the event horizon and all of the associated effects will occur in finite time. It is taken as a given that "Black Holes" exist without questioning all of the assumptions being made regarding these entities. When anyone questions this view, the amount of disdain and ridicule expressed to them is just ridiculous. Those expressing such disdain and ridicule do not even attempt to answer the questions - it is immediate ad hominen attack. This is the attitude that encouraged me to investigate the matter further and the conclusion is that those experts who support the idea of "Black Holes" have a mindset of "we are the authority and who are you to question us". They are so blinded by there own brilliance that they cannot see the forest because they have their noses up against the ground. It is a sorry state of affairs when dogma gets in the road of investigation. There are no stupid questions, ever. However, there are many non-answers given.
  - AgentME 8y ago
    The event horizon might never "complete" in finite time either, but from the outside it can become increasingly indistinguishable from a complete event horizon over time as the black hole's mass compresses along the surface of the event horizon. Light escapes from the mass less and much less often over time. Black holes were originally often called "frozen stars" to emphasize how from our point of view, the mass never quite made it into the interior of the event horizon. Relevant: https://astronomy.stackexchange.com/a/14239 https://astronomy.stackexchange.com/a/14239. It seems like you're just placing restrictions on the term "black hole" that no one else is.

InclinedPlane 8y ago

We have observed matter falling into a black hole. We've watched "hot spots" in orbit of a black hole in the accretion disk shine their light at us as they orbited the black hole. We've watched as the orbit got tighter and tighter and the light was dimmed by gravitational red shifting, then we've watched the light blink out and disappear as the blob of gas fell below the event horizon. The evidence for the existence of black holes is incredibly strong at the moment. In fact in some ways it's stronger than the evidence for the existence of atoms about a century ago. Nobody except cranks or extreme contrarians seriously disputes the theory these days.

roywiggins 8y ago
I believe the argument is that event horizons exist but inside is not a singularity, but an eternally collapsing mass of the original star. From the point of view of the star, it does collapse all the way, but from our point of view that final singularity collapse is in the indefinite future. https://en.m.wikipedia.org/wiki/Magnetospheric_eternally_collapsing_object https://en.m.wikipedia.org/wiki/Magnetospheric_eternally_col...
- roywiggins 8y ago
  Update: I am mistaken. The classic GR black hole behaves this way. MECOs supposedly never fully collapse into a singularity, even for infalling observers. That's the difference. I rather think we'd have noticed the difference from LIGO gravitational wave measurements of BH mergers, but maybe not?
perl4ever 8y ago
From your point of view, if so-called black holes are "fuzzballs"[1] is that a vindication or a refutation of the existence of black holes? Without a deep understanding of physics, I have the general attitude that infinities must be a mathematical error, and therefore something must stop black holes from collapsing totally, but whether they "exist" is only a matter of definitions. [1]https://en.wikipedia.org/wiki/Fuzzball_(string_theory) https://en.wikipedia.org/wiki/Fuzzball_(string_theory)
- roywiggins 8y ago
  I tend to agree with you. Are mathematical singularities physical? We just don't know. I think probably not on philosophical grounds. But we can't peek inside an event horizon to find out, and these event horizons seem to exist, so whatever the structure of the insides of them are, they're still black holes.
TeMPOraL 8y ago
Then there's this video ESO's Very Large Telescope shot[0], of stars orbiting something that's a) very massive, and b) invisible. Does that constitute a direct observation of a black hole? -- [0] - https://www.youtube.com/watch?v=TF8THY5spmo https://www.youtube.com/watch?v=TF8THY5spmo

AgentME 8y ago

Black holes may not form true singularities in any finite amount of time, but event horizons that are indistinguishable from the outside can be formed.

oldandtired 8y ago
It is the event horizon that never forms. The problem that is never dealt with is that when the density of material goes up, gravity goes up, time dilation throughout all the affected material increases. From our perspective, everything throughout the affected material and region slows down - that includes any compression effects to increase the density. There is no opportunity for the effects to generate an event horizon to occur in finite time. If the event horizon cannot form then you can forget about any singularity ever forming. It is just assumed that the event horizon and all of the associated effects will occur in finite time. It is taken as a given that "Black Holes" exist without questioning all of the assumptions being made regarding these entities. When anyone questions this view, the amount of disdain and ridicule expressed to them is just ridiculous. Those expressing such disdain and ridicule do not even attempt to answer the questions - it is immediate ad hominen attack. This is the attitude that encouraged me to investigate the matter further and the conclusion is that those experts who support the idea of "Black Holes" have a mindset of "we are the authority and who are you to question us". They are so blinded by there own brilliance that they cannot see the forest because they have their noses up against the ground. It is a sorry state of affairs when dogma gets in the road of investigation. There are no stupid questions, ever. However, there are many non-answers given.
- AgentME 8y ago
  The event horizon might never "complete" in finite time either, but from the outside it can become increasingly indistinguishable from a complete event horizon over time as the black hole's mass compresses along the surface of the event horizon. Light escapes from the mass less and much less often over time. Black holes were originally often called "frozen stars" to emphasize how from our point of view, the mass never quite made it into the interior of the event horizon. Relevant: https://astronomy.stackexchange.com/a/14239 https://astronomy.stackexchange.com/a/14239. It seems like you're just placing restrictions on the term "black hole" that no one else is.