Gravitational waves from black hole merger

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Plazma Inferno!, Feb 10, 2016.

  1. Schmelzer Valued Senior Member

    Messages:
    3,603
    This is a loss of energy not of the black holes themself, but of the whole two-body system. This energy of the gravitational field you have already in the Newtonian theory, even if you have two point masses with fixed mass. In the Newtonian theory, this energy would not radiate away in a two-body system, because you have an exact stable solution - Keplerian ellipses - there, but no gravitational waves. But even in these ellipses you get higher velocities (higher kinetic energy) if the two bodies are closer to each other.
     
    danshawen likes this.
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. hansda Valued Senior Member

    Messages:
    2,191
    The merged entity is also a Black Hole. It is no longer a two-body system after its merger.
     
    danshawen likes this.
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. danshawen Valued Senior Member

    Messages:
    3,942
    Interesting. Many of you and also this grand experiment now seem to be saying that the largest impulse of gravity wave oscillation / emission is at the very end of the merger. I agree. Why is that, exactly?
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. danshawen Valued Senior Member

    Messages:
    3,942
    Not at all. But you'd be surprised how often the wrong compromises are made in real life engineering. The Concorde's tires and the Shuttle's many problems with ceramic tiles and Morton Thiokol's gaskets, and Perkin-Elmer's fiasco with the first Hubble optics are all something that shows just how easy it is to mess up when the pressure is on and the stakes are high.
     
    hansda and Little Bang like this.
  8. Schmelzer Valued Senior Member

    Messages:
    3,603
    Correct. But most of the gravitational energy radiating away comes from the period where they have yet been a two-body system. This is what has been seen by LIGO - the oscillations during this last time before the merger.
     
    danshawen likes this.
  9. Schmelzer Valued Senior Member

    Messages:
    3,603
    If they are far away, the Newtonian approximation is better because the gravitational fields are weaker. But in the Newtonian theory itself, the Keplerian orbits are completely stable. The GR effects become more powerful in stronger gravitational fields. That's why it was the Mercury whose orbit was most distorted by GR effects so that the error of Newtonian theory was seen there first.
     
    danshawen likes this.
  10. hansda Valued Senior Member

    Messages:
    2,191
    deleted
     
  11. billvon Valued Senior Member

    Messages:
    12,725
    Because before the merger you had two ultramassive objects moving at relativistic speeds approaching each other more and more closely. That generates a lot of gravitational modulation. After the merger you had none; it was a static black hole. That discontinuity is what was so noticeable. In addition, the strongest signal came when the two were going at the maximum speed relative to each other - i.e. right before collision.
     
  12. hansda Valued Senior Member

    Messages:
    2,191
    If a mass falls into a Black Hole, it is absorbed completely. Instead of the mass, if a Black Hole falls into another Black Hole, how only some mass can be lost? Is there any ratio for this mass loss ?
     
  13. hansda Valued Senior Member

    Messages:
    2,191
    When two masses collide, it is broken into pieces if some mass is lost from the original bodies. How in this case, there is no broken piece of mass if some mass is being lost from the original bodies?
     
  14. billvon Valued Senior Member

    Messages:
    12,725
    Right - that's normal masses. Black holes do not "break into pieces."
    Mass is only being lost through radiation.
     
  15. hansda Valued Senior Member

    Messages:
    2,191
    What is the ratio, for this mass being lost? Is this radiation same as "Hawking Radiation" ?
     
  16. billvon Valued Senior Member

    Messages:
    12,725
    Depends on a great many things. In black holes that size, Hawking radiation is minimal as a percentage of total mass. I don't know how much mass is lost as a result of gravitational radiation.
     
  17. hansda Valued Senior Member

    Messages:
    2,191
    Are "Hawking Radiation" and "Gravitational Radiation" different?
     
  18. billvon Valued Senior Member

    Messages:
    12,725
    Yes. One comes from "conventional" radiation from just above the event horizon, the other comes from moving massive bodies.
     
  19. origin Trump is the best argument against a democracy. Valued Senior Member

    Messages:
    9,831
    deleted
     
    Last edited: Feb 16, 2016
  20. Schmelzer Valued Senior Member

    Messages:
    3,603
    There is a lot of radiation from infalling matter. There is no fixed ratio for this, if, say, something neutral would fall directly into the black hole there would be no such radiation, but the usual way to fall inside is much longer. Usually matter rotates a lot of time around the BH in some accretion disc, similar to the ring of Saturn.

    But all this is the long way from far away toward the BH horizon. Nothing special, in principle this is similar for matter falling into the Sun or on Earth. The role of the atmosphere of the Earth, which transforms the invisible meteorites into fireballs before they reach the surface can be played by this accretion disc.

    And, the more close to the horizon, gravitational waves become more and more important for the loss of energy.
     
  21. paddoboy Valued Senior Member

    Messages:
    21,225
    Where? In relation to your credentials? OK, then what are your credentials? Certainly I have the right to ask that, as you seem to be alleging that this whole magnificent effort in detecting gravitational waves is fraudulent. You said it also about GP-B.
    And of course you also have the right to refuse to answer my questions and ignore them if you wish, but then naturally that conjures up images of you being fraudulent yourself, and not wanting to reveal your total inexperience and lay person status.
    That's nothing to be ashamed of.If you were more up front about your claims and accusations, by answering all criticisms of your claims by myself and others, it wouldn't be so bad. But you ignore the overwhelming evidence supporting mainstream cosmology and fabricate and conjure up some supposed anomaly that in near all cases with your general opposition to all things mainstream, does not hold water, and inevitably is shown to be wrong.

    Perhaps it irks you that those excited by cosmology are singing the praises of this great discovery so loud?
    Perhaps its because this discovery has also validated further the existence of BH's?

    If that is the case, I would suggest then that any problems lay within yourself, and only yourself can handle that and/or modify your apparent fervent unethical behaviour to legitimate science.
    All the best with that.
     
    krash661 likes this.
  22. paddoboy Valued Senior Member

    Messages:
    21,225

    Bingo also!
     
  23. paddoboy Valued Senior Member

    Messages:
    21,225
    Your final paragraph is correct and as obvious as dog balls.
    Critical analysis sure! That's what science is all about...Genuine critical analysis that is! But what if that critical analysis is actually driven by some agenda, or some medical condition like delusions of grandeur?
    What if that person although being unqualified, sees himself as some sort of expert due to such delusions of grandeur? What if that person is driven by a religious agenda to try and deride and refute science whenever possible, due to the fact that the same science has driven any need for any deity into near oblivion? What if that person has had his attempts at maths shown to be in total disarray in the past? What if that person has had his fabricated interpretations as to the data received by our cosmologists, totally refuted and shown to be in error?
    Where does your so called critical analysis stand then?Critical analysis and criticism just for the sake of it?

    Please Register or Log in to view the hidden image!



    My dear Dan, do you really believe that anyone [including yourself and I] is really going to invalidate these findings from a science forum, open to all?

    Please Register or Log in to view the hidden image!


    What access to LIGO, Swift, or any of the other myriad of ground based and space based state of the art scientific equipment do you or any of these posters with their critical analysis have?


    There have been quite a few papers posted that show how all contingencies were catered for with this superb discovery. Yet they are summarily ignored by these so called "on line" critics. So tell me Dan, how is that "sensible critical analysis" that you seem to be praising others for?
    Perhaps it was embarrassing for you to have to admit you were wrong and accept these findings. Cudos though for at least doing that.
    But perhaps others are more affected, or driven by a religious agenda, or suffering from a far more serious bout of delusions of grandeur then you do.
    The point is, and as you have recognised, these findings are magnificent and will probably be awarded this year's Nobel.
    The critical analysis are not. At least certainly not in this case.
    And please don't give me a "like" on this as I think you really have shown how you are absolutely abusing this system just as at least one other nut was doing.
     
    Last edited: Feb 16, 2016

Share This Page