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Thread: Is the viewing of the SMBH really a null hypothesis test?

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    Is the viewing of the SMBH really a null hypothesis test?

    I think that the pictures of Sagaterius a will look as expected, but I don't think that means the hypothesis is true. I started a thread years ago asking if there would be an observable difference between an event horizon bh, and other types of bh, like an object just larger than the event horizon that would behave just the same.
    Maybe the information loss paradox acts as a force that keeps the object from forming a bh?...or some other force......I gather the time dilation would be similar for an object just bigger than the EH.
    waits for 01101001 to dig up my old threads.....but there is the experiment coming up this month.
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    Maybe while he's at it he can also dig up all the links you've already been given, explaining that an event horizon is observationally distinguishable from a surface. Here's one. Here's another.

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    Maybe while he's at it he can also dig up all the links you've already been given, explaining that an event horizon is observationally distinguishable from a surface. Here's one. Here's another.

    Grant Hutchison
    What size of object were they testing for in the second link? How much bigger than the EH were they assuming?
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    It doesn't really matter. The farther in stuff falls, the hotter and more energetic is the impact if it hits a surface.

    ETA: There's discussion, specifically in relation to Sgr A*, here.

    Grant Hutchison
    Last edited by grant hutchison; 2017-Mar-05 at 01:52 AM.

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    Quote Originally Posted by Frog march View Post
    ....[any] observable difference between an event horizon bh, and other types of bh, like an object just larger than the event horizon that would behave just the same [?]
    As I've read, there are no stable objects with masses between neutron stars and black holes....
    Everyone is entitled to his own opinion, but not his own facts.

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    Quote Originally Posted by Cougar View Post
    As I've read, there are no stable objects with masses between neutron stars and black holes....
    Yes, I think the idea of a "null hypothesis" doesn't apply much outside the formalism of statistical hypothesis testing. What science generally does is seek to falsify the predictions of an existing hypothesis. We are seeking to be persuaded that the existing hypothesis is not true. So rather than rejecting a catch-all null hypothesis ("no event horizon") and being persuaded to a defined alternate hypothesis ("event horizon"), we seek to go in the opposite direction (by falsifying a prediction made using the event horizon model), and if we fail we accept that as evidence to support the existence of event horizons.
    In that model, anyone who wants to propound some sort of magic levitation that prevents an event horizon forming and instead creates a surface just outside the Schwarzschild radius has to come up with a detailed justification and some falsifiable predictions. Just saying, "But what if a miracle occurs in this step?" doesn't prevent any observation consistent with an event horizon being understood as support for the idea of an event horizon.

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    Yes, I think the idea of a "null hypothesis" doesn't apply much outside the formalism of statistical hypothesis testing. What science generally does is seek to falsify the predictions of an existing hypothesis. We are seeking to be persuaded that the existing hypothesis is not true. So rather than rejecting a catch-all null hypothesis ("no event horizon") and being persuaded to a defined alternate hypothesis ("event horizon"), we seek to go in the opposite direction (by falsifying a prediction made using the event horizon model), and if we fail we accept that as evidence to support the existence of event horizons.
    In that model, anyone who wants to propound some sort of magic levitation that prevents an event horizon forming and instead creates a surface just outside the Schwarzschild radius has to come up with a detailed justification and some falsifiable predictions. Just saying, "But what if a miracle occurs in this step?" doesn't prevent any observation consistent with an event horizon being understood as support for the idea of an event horizon.

    Grant Hutchison
    yes, but wouldn't it be dangerous to assume that there is an event horizon? If 50 years of science is then built on the assumption that that enterpretation of relativity is correct, and then it turns out not to be.....then that may be 50 years down the drain. I'm sure that it will appear to have an EH....
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    Quote Originally Posted by Frog march View Post
    yes, but wouldn't it be dangerous to assume that there is an event horizon? If 50 years of science is then built on the assumption that that enterpretation of relativity is correct, and then it turns out not to be.....then that may be 50 years down the drain. I'm sure that it will appear to have an EH....
    Wouldn't it be dangerous to assume that fairies don't intervene to create antigravity during the collapse of massive stars?
    Or perhaps invisible unicorns capable of faster than light travel are mischievously interfering with our quantum mechanics experiments.

    You can always invent something else that matches any experimental evidence. But it's pointless - the simplest model that is consistent with all observation is the one that's easiest to use in order to make predictions about what the Universe will do next.
    If you want to invoke levitating fairies as part of the scientific model, then you need to provide a test that allows us to distinguish levitating fairies from event horizons. Otherwise, it's safe for us to ignore the levitating fairies hypothesis, and no amount of saying "But what if it's wrong?" will make the current model any less effective. It'll be wrong when we encounter an observation that falsifies the model.

    Grant Hutchison

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    Well I personally doubt that the surface is levitating, but I won't go into my ATM idea at the moment. Yeah it may not matter if the enterpretation of relativity is wrong; I'm sure it will still provide results.
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    Quote Originally Posted by Frog march View Post
    yes, but wouldn't it be dangerous to assume that there is an event horizon?
    There is a century of evidence that GR is correct, e.g. the recent detection of gravitational waves consistent with merging back holes.
    GR and other physics says that black holes are inevitable and thus the reasonable assumption is that event horizons exist.
    You also know about the physical evidence collected over several decades that stellar and supermassive black holes have no surface.
    Thus it is very likely that we will soon detect the effects of an event horizon at Sgr A.

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    How will an event horizon be detectable?
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    Quote Originally Posted by Frog march View Post
    How will an event horizon be detectable?
    Do you look at the links we give you? All the information is there.
    A surface is detectable, because infalling material releases massive amounts of energy when it's brought to a halt. So when we don't see that energy, we are observing something with no surface.

    Grant Hutchison

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    Quote Originally Posted by Frog march View Post
    Well I personally doubt that the surface is levitating, but I won't go into my ATM idea at the moment. Yeah it may not matter if the enterpretation of relativity is wrong; I'm sure it will still provide results.
    The word is interpretaion, not en-.

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    Quote Originally Posted by John Mendenhall View Post
    The word is interpretaion, not en-.
    'interpretaion'?
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    Oh well I hope they don't see what they expect to see, but they probably will.

    Are they going to look for very redshifted radiation?
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    Quote Originally Posted by Frog march View Post
    Oh well I hope they don't see what they expect to see, but they probably will.
    So my question to you is, why do you hope that? Why is it so important to you that black holes don't exist?

    For myself, I think that the evidence that the massive compact objects we see are actually black holes as described by general relativity seems pretty compelling. The observations that tipped me over (from thinking it reasonably likely to being nearly certain) were precisely the ones linked, that show these objects acting very differently from similar compact objects that have a surface. But honestly, even if someone managed to demonstrate that there was some other type of compact object that would explain the evidence, and further observation showed that this alternate explanation made predictions that matched observations better, so that the whole scientific community turned around and decided that black holes with event horizons don't exist, I wouldn't be upset by that. Surprised, perhaps, but not personally bothered by the fact.

    Similarly, when new evidence showed that, contrary to all our expectations, the rate of expansion of the universe was accelerating rather than decelerating, cosmologists didn't react with dismay that all their previous work was for nothing. Instead, they were fascinated and excited, and immediately turned to figuring out how models could be adapted (or new models created) to account for these new observations.

    So why are you so bothered by the notion of black holes that you're constantly "rooting against them", and hoping for some kind of evidence that they don't exist?
    Conserve energy. Commute with the Hamiltonian.

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    Well I believe they probably don't exist, but that the evidence they get soon will make it look like they do. I thinkBHs are just eternally collapsing objects, and that any infalling matter will just fall upon a collapsing heavily time dilated surface, but it will just make it look like there is an EH. I think that the idea that space can be so warped that light can't escape is a bad meme, a dangerous, and incorrect meme that leads some people astray...in their understanding.....and the EH idea is just plain scary..
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    Quote Originally Posted by Frog march View Post
    Well I believe they probably don't exist, but that the evidence they get soon will make it look like they do. I thinkBHs are just eternally collapsing objects, and that any infalling matter will just fall upon a collapsing heavily time dilated surface, but it will just make it look like there is an EH. I think that the idea that space can be so warped that light can't escape is a bad meme, a dangerous, and incorrect meme that leads some people astray...in their understanding.....and the EH idea is just plain scary..
    Frog march,

    Q&A is not for your unsubstantiated fears and beliefs. You are welcome to believe whatever you like, but you cannot express it here. You can ask questions about mainstream science, but if you wish to propose alternatives, start a thread in ATM.

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