0

Well I read this article https://en.wikipedia.org/wiki/Abhas_Mitra

and he has claimed that "The so-called massive Black Hole Candidates (BHCs) must be quasi-black holes rather than exact black holes"

Yet people tell that the wave detected was due to the joining of 2 black holes.

So are there black holes or not?

Any comments?

Sidarth
  • 999
  • 7
  • 17
  • Of course, I would not be asking this if his reputation was questionable but it does not seem to be so. – Sidarth Feb 25 '16 at 05:01
  • 2
    Physics doesn't run on reputation but on observation... let us know when we have observational evidence for "quasi-black holes". – CuriousOne Feb 25 '16 at 05:07
  • but what about this statement "His peer reviewed paper published in Journal of Mathematical Physics of the American Institute of Physics supports this contention by showing that Schwarzschild black holes have M = 0." @CuriousOne – Sidarth Feb 25 '16 at 05:08
  • Possible relevant comment in another thread: http://physics.stackexchange.com/questions/238801/can-we-make-any-implications-about-the-internal-structure-of-black-holes-from-th/238883#comment521864_238883 – dmckee --- ex-moderator kitten Feb 25 '16 at 05:12
  • There are no such things as Schwarzschild black holes. That's an unphysical corner case. – CuriousOne Feb 25 '16 at 05:17
  • do you ever give a proper answer@CuriousOne your answers are always vague and its difficult for a person to understand anything at all.. – Sidarth Feb 25 '16 at 05:21
  • The words "unphysical corner case" are quite obvious, aren't they? Schwarzschild black holes do not exist and nobody ever assumed that they do. Indeed, physicists spent a lot of time and effort on finding solutions to Einstein's field equations that are actually physical. – CuriousOne Feb 25 '16 at 05:25
  • " Schwarzschild black holes do not exist" how do you say that? – Sidarth Feb 25 '16 at 05:29
  • Hi Sidarth. There are some related points in my answer to So Black Holes Actually Merge! In 1/5th of a Second - How? – John Rennie Feb 25 '16 at 07:00
  • 1
    Why was this a wikipedia page? Self-written I presume. – ProfRob Feb 25 '16 at 07:49
  • @JohnRennie so real black holes don't exist after all huh??Thanks for the link..:) and btw, this answer in combination with anna v 's answer worked for me:) – Sidarth Feb 25 '16 at 10:07

1 Answers1

2

What LIGO experiment observed are two very dense and heavy celestial object collide and thus giving ripples in space-time, known as gravitational waves. Abhas Mitra's claim doesn't get forfeited by it. Even if the objects were not black holes but rather Eternally Collapsing Objects(ECO's) as Dr. Mitra claims, they would still give you same wave structure detected. The difference between the two theories are completely about the internal structure of black holes and has nothing to do with their external behaviours i.e. creating gravity waves and so on.

Ari
  • 2,841
  • then why is it being propagated by the media that it was due to "black holes" ...even the scientists tell that in the interviews... – Sidarth Feb 25 '16 at 05:10
  • If you take the standard accepted theory, they were black holes. It means that it can't be any other object like quasars or big stars. But whether they are real black holes or quasi-black holes are not verified obviously. – Ari Feb 25 '16 at 05:14
  • what about neutron stars? – Sidarth Feb 25 '16 at 05:23
  • 1
    @Sidarth read this: https://briankoberlein.com/2016/02/20/gravity-wave-grb/ . This is considering the FERMI gamma ray burst.:"From its apparent peak brightness we can calculate its peak luminosity. It turns out the peak luminosity of this event is an order of magnitude dimmer than any previous short GRB event. This would support the idea that it was not caused by a neutron star collision." – anna v Feb 25 '16 at 06:58
  • @Ari It certainly can't be "big stars" or quasars that orbit each other in 0.01 s before merger. – ProfRob Feb 25 '16 at 07:45
  • @sidarth The frequency behaviour was all wrong for neutron stars. – ProfRob Feb 25 '16 at 07:51
  • @annav what an exact answer to my comment. thanks anna....is there any other object which has the power to cause this? – Sidarth Feb 25 '16 at 09:52
  • @RobJeffries you mean the signal predicted by GR for neutron stars is different right? – Sidarth Feb 25 '16 at 09:53
  • Yes, though what I really mean is that the signature seen was that of merging $30 M_{\odot}$ compact objects. GR (and other considerations) says that these cannot be neutron stars. – ProfRob Feb 25 '16 at 10:08