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> Huh? Where are you getting this from? From the physicists themselves. Public discussions on their respective blogs. >Nope. The event horizon is a null surfa

> Huh? Where are you getting this from? From the physicists themselves. Public discussions on their respective blogs. >Nope. The event horizon is a null surface--it is "made" of outgoing light rays. The concept of "time" does not apply to light rays. Are you then saying that all the physicists who say time stops here as viewed from outside are wrong? > > The underpinnings of "black holes" requires an eternal universe > No, they don't. An "eternal" black hole is an idealization, but a real black hole does not have to be exactly the same as the idealized model. I mentioned numerical simulations in another post down-thread; any realistic black hole cannot be exactly described by closed form equations, it needs to be simulated numerically. Numerical simulations make predictions that match what we see, and show how realistic black holes can form by gravitational collapse of stars and star systems. The theoretical basis for "black holes" is an eternal universe with a single mass in it. There are many things that can be numerically simulated. However, one must be very careful what you are simulating and on what basis the simulation exists. The "black hole" is a solution from a specific model and that model does not match the real universe as we observe it. I have no issue with there being large gravitational entities. i do however have an issue with the declarations that said entities are "black holes". We do not know what they are. You cannot in any way "prove" that they are "black holes", no matter what level of consensus you display. We observe by proxy, we are at this point unable to directly test what we see. All one can say is that there is a model that is believed to be appropriate to explain the phenomena observed. I'll put it this way by example. We observed an entity that we call and electron that has various observable attributes and we use a variety of models to describe theoretically that entity. Are those models correct. Well, no. They are what we use to try and predict further tests and outcomes that we expect to find. We get some approximate closeness and then move forward. At no point, are the models "fully correct" or "truth", there are still anomalies found between theory and experimentation. When we forget that our models and theories are only approximations to reality and fall into the trap that they are reality itself, then we will become incapable of actually advancing our understanding. > I don't know what assumptions you're talking about. Single mass existing only, asymptotically flat universe are just two of the fundamental assuptions required. > I don't know what discrepancies you're talking about as far as black holes are concerned. We are not in a position to directly observe any such entity. The number of times that scientists have declared that we have now seen for the first time a "black hole" over the last how many decades. that alone says that each previous declaration has been a furphy. > You can't effectively disagree with the consensus view if you don't understand it. You clearly don't understand the consensus view of black holes. I am simply trying to point out incorrect things you are saying about that view. When simple questions are raised against the model and are not answered by those who lead the charge for the model and when their responses amount to "you don't understand the model, so go away", then you can quite rightly take the view that they themselves don't have a clue about what they are agreeing with. I have yet to see a clear exposition of why such entities such as "black holes" should exist in our universe and answer the various simple questions that arise in opposition. If such an explanation was to be given in a logically clear manner, then yes, we could then put "black holes" back on the table.

pdonis 8y ago
I have been tied up myself and am only now able to respond. > From the physicists themselves. Public discussions on their respective blogs. Physicists will say all kinds of things in a popular forum. Do you have any references to textbooks or peer-reviewed paper? Even on physicists' blogs, I have never seen any reference to three different event horizons, so if you have any specific ones you can point to, it would really help me to understand what you are talking about. > Are you then saying that all the physicists who say time stops here as viewed from outside are wrong? If any of them actually are saying that, yes, they're wrong. But I doubt you'll be able to find any textbooks or peer-reviewed papers that say that. I don't care what pop science sources say; they're not valid sources for learning the actual science. > The theoretical basis for "black holes" is an eternal universe with a single mass in it. No, it isn't. You are confusing an idealized model used for pedagogy with actual models used to make predictions about actual objects observed by astronomers. > I have no issue with there being large gravitational entities. i do however have an issue with the declarations that said entities are "black holes". If you want to be very careful, you could say that black holes are the only entities consistent with our current theories that these "large gravitational entities" could be. It is true that our current theories are incomplete, and it could be true that a more complete theory would tell us that these entities are not anything like our current model of black holes. But even if that happens, it won't be for any of the reasons you are giving. > Single mass existing only, asymptotically flat universe are just two of the fundamental assuptions required. Again, you are mistaking an idealized model used for pedagogy with the real models used to make predictions about real observations. The latter do not depend on any such assumptions for the universe as a whole. They only require that a suitable region of spacetime around the object being studied contains only that object (or objects--models of this sort are used to make predictions about multi-object systems such as binary pulsars, for example, as well as black holes) and becomes flat enough at its boundary for asymptotic flatness in the model to be a reasonable approximation. These conditions are certainly met by the objects and systems to which the real models in question are applied.

pdonis 8y ago

I have been tied up myself and am only now able to respond. > From the physicists themselves. Public discussions on their respective blogs. Physicists will say all kinds of things in a popular forum. Do you have any references to textbooks or peer-reviewed paper? Even on physicists' blogs, I have never seen any reference to three different event horizons, so if you have any specific ones you can point to, it would really help me to understand what you are talking about. > Are you then saying that all the physicists who say time stops here as viewed from outside are wrong? If any of them actually are saying that, yes, they're wrong. But I doubt you'll be able to find any textbooks or peer-reviewed papers that say that. I don't care what pop science sources say; they're not valid sources for learning the actual science. > The theoretical basis for "black holes" is an eternal universe with a single mass in it. No, it isn't. You are confusing an idealized model used for pedagogy with actual models used to make predictions about actual objects observed by astronomers. > I have no issue with there being large gravitational entities. i do however have an issue with the declarations that said entities are "black holes". If you want to be very careful, you could say that black holes are the only entities consistent with our current theories that these "large gravitational entities" could be. It is true that our current theories are incomplete, and it could be true that a more complete theory would tell us that these entities are not anything like our current model of black holes. But even if that happens, it won't be for any of the reasons you are giving. > Single mass existing only, asymptotically flat universe are just two of the fundamental assuptions required. Again, you are mistaking an idealized model used for pedagogy with the real models used to make predictions about real observations. The latter do not depend on any such assumptions for the universe as a whole. They only require that a suitable region of spacetime around the object being studied contains only that object (or objects--models of this sort are used to make predictions about multi-object systems such as binary pulsars, for example, as well as black holes) and becomes flat enough at its boundary for asymptotic flatness in the model to be a reasonable approximation. These conditions are certainly met by the objects and systems to which the real models in question are applied.