Question

black hole concepts Right or wrongs​

Answer 1

The black hole mystery. What is wrong with the following argument? If a black hole is formed by gravitational collapse, as most are believed to, then to an outside observer the relativistic time dilation of the event means that it reaches its Schwarzchild limit (and becomes an actual black hole) after an infinite amount of time. Therefore it is impossible for an observer to see any effects of a black hole unless he is part of it. The only alternative seems to be that all black holes are created in the big bang.

Ian King, Westbury on Severn, UK

By their very nature, black holes do not directly emit any signals other than the hypothetical Hawking radiation; since the Hawking radiation for an astrophysical black hole is predicted to be very weak, this makes it impossible to directly detect astrophysical black holes from the Earth. A possible exception to the Hawking radiation being weak is the last stage of the evaporation of light (primordial) black holes. The supermassive black hole in the center of our galaxy (4.5 ± 0.4 million solar masses) constitutes observationally the most convincing evidence for the existence of black holes in general. It is thought that large black holes like these don't form directly in one collapse of a cluster of stars. Instead they may start as a stellar-sized black hole and grow larger by the accretion of matter and other black holes.In quantum mechanics, subatomic positive particles and negative antiparticles pop into existence all the time. If these particles and antiparticles came into existence right next to a black hole something different happens around it. The idea is that particles and antiparticles may not be able to automatically cancel each other out because the black hole's gravity pulls the negative antiparticle into black hole-oblivion. This process leaves the positive particle alone and "uncancelled," making it "real." These positive particles then, are emitted from the black hole.The black hole would then lose the rest of its mass in a short amount of time as abrupt explosions—we can detect these explosions as gamma ray bursts. In quantum mechanics, loss of information corresponds to the violation of vital property called unitarity, which has to do with the conservation of probability. It has been argued that loss of unitarity would also imply violation of conservation of energy. Over recent years evidence has been building that indeed information and unitarity are preserved in a full quantum gravitational treatment of the problem.

Goteti MVSR Krishna, Tadepalligudem,Andhra Pradesh India

Besides, no-one sees a black hole, because no-one needs to. All you can see is the conspicuous gap where nothing is and nothing can be seen through or behind it.