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    • CommentAuthortinker
    • CommentTimeMar 21st 2016
     
    One for Andrew. Hawking radiation- made in Israel.

    http://arxiv.org/ftp/arxiv/papers/1409/1409.6550.pdf
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      CommentAuthorpcstru
    • CommentTimeMar 21st 2016
     
    Posted By: tinkerOne for Andrew. Hawking radiation- made in Israel.

    http://arxiv.org/ftp/arxiv/papers/1409/1409.6550.pdf

    Now we will have NASA not doing very well "because black hole lasers".
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      CommentAuthorTrim
    • CommentTimeMar 21st 2016 edited
     
    @tinker

    I hope Andrew appreciates you giving him such a nice one.
  1.  
    I do, and also appreciate that Mathematica has a function called InverseSeries for Kepler's equation. Anyway, nice one Tink.

    This is of course the usual grim-faced bollocks
    Posted By: pcstruNow we will have NASA not doing very well "because black hole lasers".
    based on the false assumption that I think creation and deployment of useful black holes is technically feasible at present. It isn't, and I have listed the various ways in which it isn't. But don't let me get in the way of a good whine.

    As for the practicality of this paper, it seems extremely low, even bearing in mind the technical caveats mentioned are somehow resolved. That's because useful-sized BHs (about the mass of an aircraft carrier) can't be charged and have their charge maintained for useful amounts of time. Although neutral, non-spinning useful BHs have lifetimes on order weeks to a few years, they lose any charge they originally possessed in seconds (losing spin takes somewhat longer, but it's also gone within a few percent of the total lifetime). So one has to devise a way to maintain the charge, and that is a tricky proposition, especially considering that we're talking an event horizon radius of attometres. An electron has zero dimension, you say? Well, there's a chance to test it.

    Sadly, if we want useful BHs, we are not likely to find them naturally. Stellar collapse produces monsters which take billions of years to evaporate and thus radiate totally minutely. The useful ones which may have been created at big bang / inflation times are long since evaporated. The chances of having a nearby usefully sized BH are vanishingly small, and would be because an old monster BH happened to be just reaching end of life. Nope, if we want a uBH, we will have to roll our own. The best bet seems to be grasers.
  2.  
    Speaking of appreciation, lots of that to structures for his tireless maintenance of the moletrap
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      CommentAuthorAngus
    • CommentTimeMar 21st 2016
     
    More grim-faced bollocks:

    The paper does not describe a black hole. It describes an analogue computer that sort of emulates a black hole. The analogue computer works simply because the equations that (we think) describe a black hole also happen (we think) to describe the processes in some condensed-matter systems. There are even some elements here that don't seem to have obvious correlates with what we imagine to be real black holes, for example the "inner event horizon".

    Or perhaps I'm missing something.

    So this is maybe a method of studying a system that we think is analogous to a black holes. If you want to study negative mass you can find it in a similar way. The "effective mass" of electrons in a semiconductor can be negative. It doesn't mean that you have found actual negative masses, but that the collective behaviour of everything makes it look a bit that way.

    So it's neat, but kind of a so-what? as regards firing spaceships to alpha-Orionis with black hole drives.
    • CommentAuthortinker
    • CommentTimeMar 21st 2016
     
    Posted By: AngusThere are even some elements here that don't seem to have obvious correlates with what we imagine to be real black holes, for example the "inner event horizon".


    Shirley, if something has an outside it by definition has an inside?
  3.  
    They are using real BECs at nK for real experiments, Angus.

    And speaking of onions, this is a laser which does not emit a narrow collimated beam, but rather emits isotropically, and in all directions too between two onion layers. So no recipe for a directed exhaust. Please bring your own unobtainium paraboloid.

    The double event horizon is a property of the charge. Drops out of Kerr's maths; please don't ask me to explain.
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      CommentAuthorAngus
    • CommentTimeMar 21st 2016
     
    Posted By: Andrew PalfreymanThey are using real BECs at nK for real experiments, Angus.


    I know they are. That's why I said it is an analogue and didn't say it is a thought experiment.

    And speaking of onions, this is a laser which does not emit a narrow collimated beam, but rather emits isotropically, and in all directions too between two onion layers. So no recipe for a directed exhaust. Please bring your own unobtainium paraboloid.

    The double event horizon is a property of the charge. Drops out of Kerr's maths; please don't ask me to explain.


    You are making my point for me.

    BTW lasers in the form of discs that radiate radially are a matter of current technology, though generally the light is extracted by diffraction in the orthogonal direction. I never heard of a 3D version but there would be no obvious way to make one.
  4.  
    Posted By: Andrew Palfreymanisotropically, and in all directions too
    Damn, not even a nibble
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      CommentAuthorDerrickA
    • CommentTimeMar 21st 2016
     
    Do you mean that narcissistically, and in a self obsessed way?
  5.  
    From here it's called "a bit of fun"
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      CommentAuthorDerrickA
    • CommentTimeMar 21st 2016
     
    Likewise. May the fun propagate isotropically.
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      CommentAuthorAngus
    • CommentTimeMar 21st 2016
     
    Posted By: Andrew Palfreyman
    Posted By: Andrew Palfreymanisotropically, and in all directions too
    Damn, not even a nibble


    I thought it rude to point it out in case it was an example of your thought processes.
  6.  
    Sorry but I haven't gone mad quite yet
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      CommentAuthorAngus
    • CommentTimeMar 22nd 2016
     
    Drear Mr Poultryman

    Re: The Canadian Protected Vocabulary

    We have been advised that on the twenty-second inst. you made use in a posting on the internet of the protected term 'sorry'. We wish to inform you that tbis word when used in the sense you employed is the sole property of our client. Use by others requires prior permission from ourselves, in writing. We have no record of a negotiation with you on this matter.

    If you wish to make use of this word in future the rate is $CAN 0.25 per appearance. Please be advised that 'appearance' is counted on a per-screen basis for internet use. We estimate that each use on he 'Not the [word deleted at the request of Steorn] forum will cost $CAN 0.75. Payment must be made in advance.

    Further unauthorised use will be prosecuted to the Full Extent of the Law.

    Yours sincerely

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    Babble,Brooks and Associates
    for- the Canadian Protected Vocabulary
  7.  
    Dear Anus,

    That's interesting.
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      CommentAuthorAngus
    • CommentTimeMar 22nd 2016
     
    Dear Andrew Paltryman

    Your comment is addressed to G.S.F.X.Fortinbras, I suppose. I will let him know.

    I guess I should let the trappers know that I do permit the use of my moletrap account to Crown Agencies in the service of Canadian Interests. I consider this only my civic duty.

    Sincerely

    Angus

    PS You spelled my handle incorrectly in a most offensive way. I assume this was an accident.
  8.  
    Dear Anus,

    That's interesting
  9.  
    once more and that will be anus the turd