Hawking radiation

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

  1. Farsight

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    3,492
    No it isn't. Hawking has never ever been associated with any physics that has ever been proven to be correct. If you beg to differ, list his achievements. He's a media darling, but amongst the physics community he is not nearly as popular as he is in the popscience press.

    But GR does have a lot to say about gravitational time dilation, which goes infinite at the event horizon. That means events down there take an infinite coordinate time to occur. So they haven't occurred yet, and they never ever will. Hawking radiation totally ignores this.
     
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  3. OnlyMe Valued Senior Member

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    First you complain that nothing Hawking has been associated with has been proven, debatable itself.., depending on what you define as proof and what you include as being associated with....

    Then.......
    ... you use reference to an unproven prediction to support your position?

    Farsight, you have the right to believe anything you like, that does not make anything you believe, true and an accurate description of reality.
     
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  5. Schmelzer Valued Senior Member

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    Ether theory or not is a question of interpretation. In the spacetime interpretation, it is not an ether theory. An ether-theoretic interpretation is possible. But this is not exactly GR, because it excludes some GR solutions (like those with nontrivial topopoly as well as with causal loops), even if it preserves the Einstein equations. So, in particular, it also does not contain the part behind the horizon.

    I'm not sure what they think about the trans-Planckian problem, they may, of course, simply ignore it.

    Another nice quote: http://arxiv.org/abs/1109.3593
     
    Last edited: Oct 16, 2015
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  7. paddoboy Valued Senior Member

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    Oh yes it most definitely is!
    You mean as opposed to your own baseless, misinterpreted, taken out of context and just plain outright lies that you fabricate to impress people?

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    While you as a nobody in the scientific community, with your only "infamy" being in regards to science forums such as this, and resting on outrageous, unevidenced claims and accusations, perpetuated by your self delusion opinions of grandeur concerning yourself.
    The way of most alternative hypothesis pushers I might add.
     
  8. Farsight

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    3,492
  9. paddoboy Valued Senior Member

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    27,543
    Light does not "stop"...period! As explained to you before, from a local frame of reference, it crosses the EH with no problem, unless and except when it is emitted directly radially away.
    From a remote frame of reference, light is gravitationally time dilated and red shifted to infinity...It is never seen to cross the EH, simply and gradually fading from view.
    Both frames though, as determined by relativity, is as valid as the other.
     
  10. sweetpea Valued Senior Member

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    Paddo, do you remember when farsight had to admit that Prof. Don koks does not agree with him.
    http://www.sciforums.com/threads/qm-gr-black-holes-cannot-exist.142658/page-34#post-3240400
    Farsight said...
    Prof. Koks said...
    http://www.sciforums.com/threads/qm-gr-black-holes-cannot-exist.142658/page-34#post-3240241
    So, nothing unusual to be happening there and the speed of light is c in local frame even at the horizon.

    The other one farsight usually pulls up is the space in the room is not curved...remember thanks to Tashja we had this from Prof. Baez ...
    http://www.sciforums.com/threads/qm-gr-black-holes-cannot-exist.142658/page-33#post-3239077
    Thanks to Tashja for contacting BOTH Profs. back then.
     
    Last edited by a moderator: Oct 16, 2015
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  11. paddoboy Valued Senior Member

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    27,543
    Thanks sweetpea for resurrecting all that.....nice to see and be reminded about how delusions of grandeur can absolutely blind some to reality and fact.
    Remember, Farsight also is one of four posters in my time here, that claims to have a TOE...

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    [Although its hard to get him to discuss it in recent times]
     
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  12. Schmelzer Valued Senior Member

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    The coordinate speed in one particular direction - backward - is zero. Which is not a really important point. If the Strong Equivalence Principle would be really a fundamental principle, this would be completely irrelevant. It would be no more than about a particular irrelevant choice of coordinates. By the way, to have a link to digital papers is nice, but the Leyden lecture I have read before and know what is claimed there, and what was the point of linking this particular page is beyond me.

    The problem with Hawking radiation is that it requires that this Equivalence Principle remains valid even for time dilation of factor \(10^{100 000}\) even if one wants to predict it for 1 second after the collapse itself. Which is simply nonsensical.
     
  13. sweetpea Valued Senior Member

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    well, it getting near christmas and his self published book needs pushing, he needs the web presence to show him as some kind of expert, that's for anyone googling his name to find more about him when thinking about buying his book.

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  14. Farsight

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    Sweetpea: it hasn't been for sale for years. Apart from a few second-hand copies at silly-money prices that are nothing to do with me.
     
  15. Farsight

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    Schmelzer, trust me, it's really important. If the coordinate speed of light did not vary in the room you're in, your pencil would not fall down. See the Einstein digital papers:

    "Second, this consequence shows that the law of the constancy of the speed of light no longer holds, according to the general theory of relativity, in spaces that have gravitational fields. As a simple geometric consideration shows, the curvature of light rays occurs only in spaces where the speed of light is spatially variable.''

    Particles popping into existence like magic is nonsensical. Negative-energy particles are nonsensical.
     
  16. Schmelzer Valued Senior Member

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    5,003
    Farsight, as if I would not know this.

    Particles do not simply pop into existence. But if the gravitational field changes, this change may lead to some particle creation. This effect happens during the BH collapse, but will probably stop after a short time after the collapse. At least this is what one would guess if one relies only on reasonable assumptions about what we know and what we don't know.
     
  17. paddoboy Valued Senior Member

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  18. Farsight

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    Do you know about Freidwardt Winterberg's firewall? I'm pretty sure it's right.

    No problem.
     
  19. brucep Valued Senior Member

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    And he bases all this bullshit on the belief that Schwarzschild remote bookkeper coordinates are preferred over the local proper coordinates Professor Koks mentions in shooting down Farsight and his sidekick RJBerry.
     
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  20. Q-reeus Banned Valued Senior Member

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    Surprised you would say that. Coordinate speed in all directions is zero at supposed EH. It tends to zero faster in radial direction than transverse as EH is approached, but must be zero in all directions at EH for the simple reason sqrt(g_tt) is zero there. Of course proper value is always c for an infalling observer, but for a hovering observer, in GR the proper value is effectively directional if measurement is, as in practice it must be, over a finite distance. Something well known that I brought up in another thread.
     
  21. Schmelzer Valued Senior Member

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    There is a whole light cone, which, in non-degenerated coordinates, looks like a normal, non-degenerated light cone.

    That you cannot use the Schwarzschild metric itself at the horizon, because it is degenerated there, is well-known. You can argue that I should have guessed that he means coordinate speed in Schwarzschild coordinates, and, therefore, should have objected in a different way, namely that these coordinates are invalid at the horizon. But I have interpreted the original claim without making this hypothesis about the particular coordinates. There are other, non-degenerated choices of coordinates near the horizon, say, with a time coordinate which becomes proper time for some infalling observer. And, whatever non-degenerate coordinates you use, you will never have a light cone degenerated into a line, which would correspond to zero light speed in all directions.
     
  22. Q-reeus Banned Valued Senior Member

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    It was assumed you were taking your context as consistent with that given in both #201 and #205, where it's clear Schwarzschild coordinates are implied. And it's the 'natural choice' since it's in a sense at least comparing apples with apples - relative determinations of two static observers at different gravitational potentials. The other 'charts' (apart from the so-called isotropic SM which again gives c -> 0 at EH) afaik all compare oranges with apples, which 'trick' thereby makes SM seem sensible at the assumed EH.

    And btw I very much like that Stanley Robertson, who had much earlier seemingly abandoned interest in Yilmaz gravity, has returned to it with a a new powerful array of arguments in it's favour: http://arxiv.org/abs/1507.07809
    No need to worry about 'degenerate coordinates' in that theory - there are none - just one chart consistently covers all situations.
     
  23. Farsight

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    3,492
    Maybe I should discuss that with him.

    This is misleading. Your pencil falls down because of the "spacetime tilt", not because of the spacetime curvature. That's to do with the tidal force. It isn't detectable in the room you're in. But your falling pencil is. If you doubt me, go and ask John Baez. Mention my name.

    Schmelzer/Q-reeus : when light stops, you have no coordinate system. In my humble opinion Kruskal-Szekeres coordinates make the schoolboy error of putting a stopped observer in front of a stopped light-clock and claiming he sees nothing unusual, and instead sees the light-clock ticking normally "in his frame". He doesn't. The clock is stopped, and so is he. He doesn't see nothing unusual. He sees nothing.
     
    Last edited: Oct 18, 2015

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