Hawking radiation

Discussion in 'Physics & Math' started by hardalee, Sep 16, 2015.

  1. sweetpea Valued Senior Member

    The other chuckle brother will probably be along soon enough...were else have these 'great minds' to go. Farsight will probably give his usual link to Einstein's 1935 paper showing time stops at the horizon, and thus showing Farsight's view that mathematical modelling also stopped in the year 1935. If I have the year wrong...then what ever year it was.
    Last edited by a moderator: Oct 18, 2015
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  3. sweetpea Valued Senior Member

    Pedantic tidy-up.
    My above post #221 should read...--- and thus showing Farsight's view that mathematical modelling also stopped from the year 1935 onwards---
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  5. paddoboy Valued Senior Member

    Now there's a contradiction in terms....Farsight and humility!

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    Again wrong, time is never seen to be stopped, and neither has light, as already explained to you. Time dilates to infinity and light is redshifted to infinity from the perspective of any remote frame of reference.
    From the local frame though, everything proceeds as per normal.
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  7. Schmelzer Valued Senior Member

    The point of the Kruskal coordinates is that they seem to show - and, in fact, show, if one accepts the spacetime interpretation and the Strong Equivalence Principle as fundamental - that there is no such stop of light or stop of clocks. In this interpretation, time is what clocks show. So, as long as there is a trajectory in some system of coordinates, and one can compute "proper time" (which is what the clocks show) along this trajectory, the clock will not be stopped.

    You have to rely on a different interpretation of GR. One where what clocks measure is not really time. Only in such an interpretation the clock can stop - without time being stopped.

    But in this case, you need some hypothesis about what is the true time. It should be some time-like coordinate. And, once it is something objective, physical, it should be connected with clock time, another physical thing, by a physical equation.

    You think Yilmaz gravity is a nice candidate, ok, your choice, but this does not make Kruskal coordinates of GR solutions a schoolboy error. It is correct in the GR spacetime interpretation.

    BTW, I think to use the harmonic equation to define an absolute time is much more natural and reasonable than Yilmaz gravity.

    Last but not least: Curvature is small, but if it would be exactly zero, the pencil would not fall down. Even in Yilmaz gravity.
  8. paddoboy Valued Senior Member

    The correct accepted interpretation of GR says that in gravity wells such as above the EH of a BH, gravitational time dilation occurs.
    That dilation covers all aspects and scenarios of time, physical, mechanical and biological. eg: If I were to reside for an extended period in a capsule just heading directly radially away from the EH of a BH, while my imaginary twin watched from a safe distance, he would notice me aging a lot slower, and my time ticking over a lot slower than his own clocks and his own aging.
    If I were to return to him at his safe distance, 12 months later according to my time when I was near the EH, I would be 12 months older while he may have aged many years.
    That's relativity.
  9. Q-reeus Banned Valued Senior Member

    Given you quoted just one person, not me, that schizophrenic piece is a little difficult to untangle. But I managed.

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    You think Schmelzer Gravity is a nice candidate, with it's absolute time and space and a freely adjustable parameter making it either functionally identical to GR, or by arbitrarily adjusting, somewhat different in strong gravity regime. 'Unfortunately', Yilmaz gravity has no such freedom to morph. Which some consider a strength - given it passes all 'acid tests' to date, and has the unique strength as per that article I linked to in #219.

    However, it may interest you to note there is at least one theory based on absolute space and time that 'reduces' to the exponential Yilmaz metric as gold standard rather than the multi-problematic SM:
    At least then one never encounters gravitationally 'stopped time' in any physical or coordinate artifact sense. [Except possibly in the physically unrealistic case collapse proceeds all the way to r = 0] And HR is not possible in principle, as is the case with 'standard' Yilmaz gravity. No bizarre -ve energy quanta streaming *into* a +ve mass BH EH, or 'firewalls' or similar exotica e.g. CTC's. Boringly normal (read: reasonable).
    Last edited: Oct 19, 2015
  10. Farsight

    If light doesn't stop there aren't any black holes. I'm happy that black holes exist. But I'm not happy with Kruskal coordinates. Like I said, I think they include a schoolbody error.

    I rely on what Einstein said. He said the speed of light varies with gravitational potential. He didn't just say this in 1911. You can find lots of examples in the Einstein digital papers.

    I go by Einstein, and I don't agree that Kruskal coordinates are correct.

    The "spacetime tilt" causes your pencil to fall. Not the curvature. I think this paper is worth a read: http://arxiv.org/abs/physics/0204044
  11. Beer w/Straw Transcendental Ignorance! Valued Senior Member

    No, what you want is to appear the beneficial to listen to amongst the naive. It's not a passion for science, you could care less, you would much fashion yourself a some sort of guru and nothing else. You are a disgusting person to those who would want to learn.
  12. Schmelzer Valued Senior Member

    Sorry, answering Farsight I had a vague memory that in this thread there was some post in favour of Yilmaz gravity, which I have falsely attributed to him.

    Regarding Yilmaz gravity, I have found http://arxiv.org/abs/gr-qc/9504050 by Misner which starts with "Recent publications by Yilmaz [1, 2] claim that General Relativity (GR) is inconsistent and that its Newtonian limit is unsatisfactory". Misner's paper was published in Nuevo Cimento, but Yilmaz answer http://arxiv.org/abs/gr-qc/9506082 rejected, and it, indeed, contains a similar dubious claim about GR. My rough consideration of above papers gives a similar result.

    https://en.wikipedia.org/wiki/Parameterized_post-Newtonian_formalism also mentions that Yilmaz gravity has the wrong PPN parameters. So, my recommendation: Forget it.

    Once it seems to have the same form as Yilmaz gravity, one should expect the same PPN values. Thus, forget it.
  13. Q-reeus Banned Valued Senior Member

    OK then. Just clear the head before replying in future.
    I have previously remarked that both parties imo made exaggerated or outright false claims against the other. Still, it's worth noting Mizner never came back for a second try. Surprised you didn't bring up a similar exchange between Fackerell and Yilmaz-Alley, for which the same thing happened - Fackerell never attempted a comeback. Worse there, the quoted article datings are made to look like Fackerell answered finally, and years after the Yilmaz-Alley article. Actually, it was the reverse, though not years apart in actuality.
    That article was written at least in the main by the fanatical GR devotee Chris Hillman, who seems to have a sacred duty to put down all rivals to GR. And by any means - as for instance the disingenuous use of only the earlier purely scalar potential 1958 theory, not the tensor potentials 1973 one. That can be explicitly seen in the table of comparisons here:
    One suspects also done by CH. Might as well compare 1911 GR to the results in order to 'disprove' 1916 GR.

    Further, it's almost laughable that the very parameter alpha_1 quoted as 'disagrees violently with observations', has to do with orbital polarization of elliptical orbits. The crucial test being cited as lunar laser ranging. The man in charge of that project for many years - Carroll O Alley, was driven to Yilmaz gravity for precisely the reason it naturally explained the results of those measurements! Check out in particular slides 36-44 here: http://www.powershow.com/view/1bbc8-ZjhlZ/P1246341516SeoJH_flash_ppt_presentation
    What a bad joke that Wiki piece is. You should know ideological commitment, and likelihood of less than scrupulous ideologues being alive and well in GR community, is to be expected just as elsewhere.
    Try actually reading through that article by Robertson. There are currently no observations actually conflicting with Yilmaz theory.
  14. Schmelzer Valued Senior Member

    There is no reason for this. This is the rule of the game - and the point I have made. You see a bad article, you write a refutation. The author of the bad article will be, of course, one of the reviewers and gets a chance to answer in the same journal. If this results in the refutation being published, but the authors answer not, this issue is clarified. In favour of the refutation. So, coming back would be beating a dead horse.
    Naming scientists fanatical is nothing I care about.
  15. Q-reeus Banned Valued Senior Member

    That hardly fits the character of that particular exchange imo. Mizner was refuted in methodical fashion. It would be natural for him to return fire, especially given his icon status within GR community. Similarly with Fackerell exchange, although not such an icon in that case. There are numerous examples where a whole series of exchanges take place. If an explicit concession is not made by one party, and things have not degenerated to just abusive polemic, the usual assumption is the last respondent wins by default.
    OK, I ammend to 'imo fanatical'. Anyway, the substance of it is the material by Alley re lunar laser ranging gives a very different picture to that in the two Wiki articles.
  16. Schmelzer Valued Senior Member

    This is IYO. I have not checked the formulas, too lazy, but my superficial impression is the same as of the referees. What was decisive here for me is that the answer contains a claim that a standard established mathematical result - the Newtonian limit of GR - is wrong. For such a claim you need really strong arguments.

    Once a refutation to an own published paper is rejected, it makes no sense for a scientist to care more about this refutation. This would be a loss of time. I behave in the same way: My refutation of a paper of some Schulz http://arxiv.org/abs/0910.4740 has been published. He has also written an answer to this refutation which was not published. You can find his answer on arxiv.org too, if you like, but I will no longer care about this.
    Not exactly. The last published wins by default. Preprints on arxiv.org, once peer-review has not accepted it, do not count.
  17. paddoboy Valued Senior Member

    Interesting discussion/exchange between you two......seriously, no pun intended.
    Please note I also don't pretend to understand all of what either of you claim/interpret, but of course I still have my usual observations/objections/fault finding criticisms of the gist of what all this is about.

    Having crossed swords with both of you at different times, I'm sure you can guess what my observations are.
    In my more than two years on this forum, we have had four claims from four posters claiming to have formulated the holy grail of physics, a TOE...one of those was our friend Farsight.
    Both of you, and Farsight, all seem to have variations of your interpretations of GR. The three of you, all claim validity of your own interpretation and are of the opinion that what is generally accepted by mainstream is wrong.
    The three of you all cannot be correct.
    Farsight sees himself as aligning totally with Einstein, while refusing to recognising the fact that GR has progressed somewhat over the last 100 years.
    And of course we do have others on this and other forums, which likewise offer even more questionable supposed criticisms directed at SR/GR and present day cosmology. I don't believe their issues are worthy of discussion here.
    Schmelzer seems to have had some success with published papers with reputable publishers, and which I have congratulated him for in the past, Q-reeus I'm not sure of.
    On that point itself, and which I did argue with Schmelzer on, many papers are purely hypothetically theoretical as opposed to scientifically theoretical as accepted by the definition of a scientific theory. I see a difference there and I hope that difference is clear.

    As a lay person interested in cosmology and just as interested in the best derived reality or model of present day cosmology, I am put in a rather difficult position.
    I can imo claim that generally speaking, and on average, the majority is far more likely to be correct than individuals like yourselves.
    That of course leads me open to criticism that I'm a sheep and follow without understanding properly.
    But as a sheep, I also need to make a decision in my own mind and to the best of what I do understand.
    I see some criticism from both of you on Charles Misner.
    Never read him but I have a book by Thorne called "Black Holes and Time Warps"
    I mention this because I see claims that final replies and refutations denote winners and/or losers.

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    Less said about that claim the better.

    I don't hold onto conspiracies that mainstream science is tainted, or indulge in conspiracies to shut out independent thinking, and independent scientists as Schmelzer says he is. At least not on any scale to be really worried about. Nothing is perfect though. And If that were the case and was as widespread as both of you at times seem to insinuate, then we would certainly be in deep shit.
    The scientific method and associated peer review is not perfect but again it is the best we have.

    My other point as I have mentioned many times, in reality, not too many professional experts indulge in science forums such as this, for what I believe are obvious reasons.
    We had a Professor Bennett Link for a little while, until he decided he had had enough. We certainly also have other qualified people, and without pissing into either of your pockets, both you are probably of that ilk.
    But not all professional people are correct....

    Anyway, I said my piece, and will now leave you two to your devices.
  18. Q-reeus Banned Valued Senior Member

    And all that in turn IYO. Fact of the matter remains that Misner, an icon in GR community with a reputation to defend, was unprepared to come back and defend against a very thorough, point-by-point - and then some - demolition job done by the trio in http://arxiv.org/abs/gr-qc/9506082
    They went far beyond a mere refutation in fact. Feel free to point to any actual 'glaring errors' in their presentation. Misner never did. Ditto for Fackerell here:

    My own particular discovery related to metric matching across a thin spherical shell. Gr's SM is shown to be unphysical on a number of counts. Yilmaz metric on the other hand gave a completely self-consistent picture. Just that was enough for me. I had however made a silly error when comparing standard SM to the so-called Isotropic SM (ISM). It seemed at the time they were as usually claimed, physically equivalent. A correct analysis showed otherwise, but I have yet to clean up such and a few other matters, but will eventually get round to having such published. But not any time soon.
  19. Schmelzer Valued Senior Member

    Of course, everybody who proposes an own theory or interpretation does this because he thinks it is better than the actually accepted one. Else, there would be no point proposing it.

    So, this is a quite meaningless point. What makes sense is to compare how GR and its spacetime interpretation are criticized. The typical crank criticism of "logical errors of Einstien" is one thing, standard criticism accepted by the mainstream like incompatibility with QT, unaviodable singularities, conflict with realism because of the violation of Bell's inequalities, closed causal loops are a different thing.
    Big news. Have any of us made such a claim?
    Yes, it is clear, this difference is completely your own invention, not based on any sound scientific methodology, and, therefore, completely irrelevant.

    Scientific theories are always hypothetical and theoretical. To become empirical theories, they have to make empirical predictions. This is known as Popper's criterion. The theories I have proposed make such predictions.
    Of course, this is indeed difficult.
    You mingle here two things. It is one thing to simply follow the mainstream, as a layman. This is a decision you have to make for yourself. And I have exactly no problem with this decision. But it is another thing to participate in a discussion, and to take sides in such a discussion, and having your personal decision to follow the mainstream as the only argument.

    In fact, modern physics is too complex to read and check everything, so even professionals are not much better than laymen in many questions outside their own specialization. And, essentially, they usually also have to make this choice for themself, to accept the mainstream position without carefully checking it. I have to do the same, and in fact I usually accept the mainstream, and even without much checking - the time for checking is my own lifetime. In particular, I have decided to ignore Yilmaz without checking all formulas in the disputes which have been considered here. I have seen the major arguments, made some expectations about the plausibility of these arguments, and made my decision.

    But, you may note, I do not argue that Q-reeus is stupid or so if he likes Yilmaz. I have explained him my decision, that's all.
    I also don't believe into any conspiracies.

    What I criticize in actual science is not the scientific method in general, and not peer review (even if it is prejudiced against things outside the mainstream, but this is a general human weakness, where I also do not see a way to make it better). My main criticism is about a point which can be made better, even easily, and which has been made better in the past, and even in otherwise stupid communists states. It is about the organization of science, with young scientist being extremely insecure, much more insecure than everybody else, with the exception of maybe professional criminals. Give young scientists badly paid but secure jobs, and the problem disappears. Good scientists are in some sense fanatics, they do not care about how much they get paid - if they can do what they like to do, they are happy enough. But they need some basic security, enough to live a modest life and to have a family, even if they disagree with the mainstream. Today they know - if they disagree with the mainstream, they will be out of job after the actual grant is finished. So they have to follow the mainstream. This is simply stupid, and this is a stupidity one has to be worried about, and it is a stupidity which one could easily avoid.

    And, again, it is not at all a conspiracy. It is an economic problem. You want independent judges? Give them a safe job, a job where they cannot be dismissed for unpopular decisions. You want independent scientists? Give them a safe job, where they cannot be dismissed for developing unpopular theories. You want to be able to control judges? Make the job of the judge unsafe. It does not even matter what is the procedure to get rid of a recalcitrant judge, it matters that his job is not safe. Even better is if they have only temporary jobs. They will care automatically about what the powers who decide about jobs want. Same for science. If you want a politically controllable science, which follows some mainstream without questioning it, give scientist only temporary jobs. Then they automatically will start to follow the mainstream, whatever it is. Not because they conspire, but because they want to get paid in future too.

    Conspiracy can start only after this. Only if you have an organization of science where they all automatically follow the mainstream, you can start to try to manipulate the mainstream, for example, by influencing the distribution of grants and so on. This is something one has to care about in sciences related with big money, like climate science or medicine. But it seems irrelevant for physics.
  20. Schmelzer Valued Senior Member

    Sorry, no, he was not unprepared. He was uninterested. Because there was no demolition. At least in the opinion of the peer reviewers of the journal where above papers were considered, Misner's refutation accepted, and the answer not.
    Indeed, they have made the claim "With the correct premise the conclusion of the article regarding the absence of gravitational interactions applies to general relativity and not to the Yilmaz theory." Which means, translated, that GR is BS because it has an invalid Newtonian limit. Which puts Yilmaz into the class of deniers of elementary GR mathematics. Of course, the math here is a little bit more sophisticated than that of the usual "logical refutation of SR" cranks, but this is nonetheless nothing I'm ready to spend my time.
  21. paddoboy Valued Senior Member

    You seem to have missed the point. Any Tom, Dick, or Harry can propose what he likes. [Do you remember constant theorist?...or jcc?] And again, leaving aside those ratbags and just considering the three more credible I originally spoke of in this thread, not all can be correct. This is where the scientific method and peer review must maintain some sensibility and decorum.

    Not at all as explained. Which leads to my other point. If any professionals have any beef with SR/GR in any way shape or form, and have the necessary observations, experiments, or mathematical prowess to support their claims, they would not be here.
    Thank you, but I can't take credit for it. The rest of your stuff is incorrect.
    And I know you as a scientist know that most assuredly. Which tells me just as I have inferred about you in the past, that you seem blinded by your agenda.
    Scientific theories while not 100% certain, are the best descriptive explanation we have of any particular scenario, which has been supported by repeated experiments and observations and continue to make correct predictions.
    While scientific theories do gain in certainty over time, they remain scientific theories. Your confusion with hypotheticals probably stems from your own hypothetical paper.
    It's a decision I make based on common sense and logic, and for the reasons that I have already stated.
    Good for you. And while your decisions as a professional in accepting what you have, may hold more credibility than my own per se, the overall decisions or acceptance of mainstream science, most definitely over rides your own personal acceptance.
    And that must remains subordinate to the mainstream accepted science, until you have shown otherwise.
    Which leads me again to my other point, that if you did have anything of any concrete nature to invalidate or falsify present accepted cosmology or GR, would you really be here?
    And perhaps examining our past exchanges, if you had of not confused some of your insulting remarks to me for daring to disagree as a lay person, with what you saw as "legitimate criticism", while at the same time confusing my genuine criticism of you, as insults, then we may have got onto a better footing.
    With all due respect, I'm not sure how I can except that, taking into account what you say as follows......
    What you have claimed on this forum both politically and scientifically are your own thoughts Schmelzer.
    And again, while the scientific methodology and peer review may not be perfect, and taking into account some of the reality you speak of, it is the best there is and generally works OK.
    Your choice to be independent is your choice.
    Just as it is your choice to voice your scientific and political views on forums such as this.
    But in any democracy [forgoing the fabricated conspiracies you have listed] you can also voice those political and scientific views through more appropriate channels.
    Last edited: Oct 20, 2015
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  22. Q-reeus Banned Valued Senior Member

    It's your assumption Misner was uninterested, but yes a fact Il Nuovo Cimento refused to publish their rebuttal. And, considering your many complaints here about how unfair mainstream scientific process can be, it's taken for granted in this case that everything was perfectly above board and impartial? Whatever.
    "...deniers of elementary GR mathematics..."? Sure about that? Maybe an actual careful read of their rebuttal would cause a change of mind. To each their own. A pity definitive observational evidence is still an indefinite time off.
  23. Schmelzer Valued Senior Member

    Your thought remains completely unclear. Science needs different theories, because even falsified theories play an important role in science - it shows which alternatives are not viable. And alternative theories are also a necessity - without them, there would be no chance to find a better theory. So, this is a necessary part of the scientific method. And it is certainly not the job of peer review to find out if such an alternative theory is a true one - what has to be excluded are unprofessional theories.
    Your notion about certainty of scientific theories is completely unprofessional. And scientific theories are always hypothetical, and remain hypothetical forever - except they become falsified, then there will be a certainty that they are false. This is elementary Popperian fallibilism.

    This is the other problem I have with you - you repeat your own unprofessional nonsense, even after you have been told that it is nonsense, and have been referred to professional mainstream literature about scientific methodology. You should understand that scientific methodology is also a scientific discipline, also with established mainstream theories, and in this case it would be much better if you would behave as usual and accept the simple mainstream position. It is, in this case, much easier to learn and understand for a layman.

    Instead, in the domain of scientific methodology you behave completely similar to a classical ether crank who claims that Einstein has made logical errors in SR. You don't know standard mainstream scientific methodology, which is Popper's fallibilism, use your own inventions, fantasies about certainties of physical theories, in a situation where every professional physicist knows that GR is false, and not more than an approximation.
    Why not? And, again, GR is known to be false - because of its incompatibility with QT, because of its singularities, so that there is not even a necessity to falsify it. It is only an approximation. A good one, but only an approximation. My ether theory of gravity is also only an approximation, namely a large distance limit, it fails to describe the atomic structure of the ether.

    And if you think I have been insulting, I would recommend you to care more about your own postings. I have usually pointed out that you often use ad hominem, which is something different from insulting. Ad hominem =/= insulting.

    And conspiracy is something different from economic theory. It requires that several people with dubious aims conspire, thus, act in some hidden way to reach their dubious aims which they prefer to hide. Have you identified anything of this type in my description of what I find objectionable in the modern organization of science?

    Thanks for not inventing theories that my mind is controlled by aliens or so, so that I present here my own thought. Any idea what is wrong with these thoughts?

    Learn to read, I have not questioned at all nor mainstream scientific methodology nor peer review. There is nothing in peer review, nor in the scientific method, which requires to give scientists only short term grants and therefore extremely dependent and forces them to follow mainstream fads to have a hope for a new grant.
    Sorry, but there are no appropriate channels for independent scientists which I would not use. I have no money to attend conferences - participation is expensive, but paid by institutes, I have enough to live, but not enough to travel around the world and pay fantasy prices for conference participation usually taken from taxpayers. This also closes for me the channel of publishing in conference proceedings. What remains is to write papers and to submit them to journals for publication, and this is something I'm doing.

    The problem of short term employment I have described, which leads to scientists following a few mainstream fads instead of developing different independent ideas is not my problem. Because I live on my own money, thus, I'm not depending on any grants, and I probably would reject today even grants for ether theory research if they would be offered to me. (15 years ago I would have accepted such a thing, today I'm no longer interested.)

    And, of course, to publish anarchistic ideas there is anyway only the web. I'm using it.

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