Question: Just to clarify, Hawking’s radiations takes place simultaneously to the black hole growing? and, then becomes dominant once the black hole stops growing? Further, having depleted with a final outburst/explosion leaving behind ” nothing ” – to what level is this “nothingness” defined? No mass,no energy,no waves, no “quantum fluctuations”?..no dark matter, no dark energy? It seems to be that it is becoming increasingly difficult to define ” nothing “?! – Simon
Answer: As you have said, “Hawking Radiation” is the theoretical process by which black holes that spin lose energy (and, therefore, mass). For black holes that lose more mass than they gain (i.e. those that do not collect a lot of mass due to accretion), in theory a black hole can lose all of its mass and “vanish”. This means that all matter associated with the black hole has been emitted as energy.
Question: Does a black hole move through spacetime or does it draw spacetime to “it” giving the illusion its moving? – Nigel
Answer: Black holes move through spacetime just like any other object in the universe. It is true, though, that black holes “warp” spacetime more than other objects due to their extremely intense gravitational field.
Question: I don’t understand this:
I read somewhere (and this isnt a quote but its close enough) that
….the gravitational pull of a black hole is so great that nothing can escape from it – not even light ( thats what makes them black).
I also read that its the general scientific concensus that nothing can go faster than light ( or else some law is getting broken or something like that)…..so doesn’t this mean that the stuff in the jets escaping out of black holes is going faster than light can go ,cos light cant get out? – Nigel
Answer: The matter that we observe as jets emanating from a black hole are not actually coming from the black hole itself. The jets are composed of matter which is escaping from the accretion disk which surrounds the black hole. Although the mechanism by which the jets are produced is not completely understood, the process likely involves the acceleration of matter near the poles of the black hole and an interaction with the tangled magnetic field in the region near the poles of the accretion disk. The material in the jets is measured to be travelling at less than the speed of light.
Question: My partner was driving home yesterday night ( 29 june 2015) listening to the radio, they were talking about a black hole that they realised had came back to life again. Would you know specific black hole they talking about? Or what constellation its near to. Like i said my partner was hearing it on the radio on the 29 june 2015. – Pete
Answer: I suspect that the story you heard was about V404 Cygni, which is a black hole and star system in our galaxy, in the direction of the constellation Cygnus, which has recently “flared”, or produced an outburst of energy at xray wavelengths. Although the specific mechanism by which black holes flare is not entirely understood, it likely has something to do with the amount of matter being fed to the black hole (by, in this case, the nearby star that is gravitationally coupled to the black hole).
Question: Do dimensions really exists? [Also,] are the black holes really or possibly portals leading to different dimensions (like a whole new universe or a totally different universe)? [Also,] right now I read in the blog about like the diameter of universe being 96 billion light years (in other sense the universe being confined within these 96 billion light years diameter) so what lies beyond that diameter? – Pravesh
Answer: One can speculate or theorize as to what exists beyond that which we can measure, but that is, strictly speaking, not science. What scientists do is make observations of the universe and apply the laws of physics to those observations to interpret what they observe. As there are no actual observations which can tell us what lies beyond a black hole or the edge of the universe, we can only speculate or theorize as to what might lie beyond what we observe. To my knowledge there are no theoretical predictions which are based on physics which predict what lies beyond black holes or the edge of the universe, which leaves us only speculation, which is not science. So, a scientist would answer that there is no information to tell us what lies beyond a black hole or the edge of the universe.
Question: Can a black hole become unstable and cause a “small bang”? Creating parallel universes? – Raoule
Answer: I don’t believe that there are any reliable theoretical calculations that produce this series of events. In fact, I don’t believe that “unstable” black holes lead to explosions of any kind.
Question: It is a challenging research topics to search how supermassive black holes formed at the early epoch. I am very much interested to do my future research on this topic. Could how please tell me what can be possible solution for this problem? How can SMBH formed at early epoch? – Anirban
Answer: The discovery of a supermassive black hole (SMBH) in a quasar (a special kind of galaxy) which is at a redshift which places it at an age of only about 900 million years after the Big Bang certainly pushes the theory of the formation of SMBHs. One of the most popular theoretical scenarios associates the first massive black holes with the remnants of the first generation of stars in a galaxy. I believe, though, that the discovery of this very young SMBH means that the formation of black holes must happen over a much shorter timescale than previous believed.
Question: Can black holes swallow planets and moons? – Chandi
Answer: Black Holes swallow anything that gets trapped in its voracious gravitational pull. Stars, gas, dust, planets, moons, etc. can all be swallowed by a Black Hole.
Question: On a recent visit to the Very Large Array we saw a radio image of a black hole with two streams of gas and dust being ejected from the area. Is this essentially the EXIT for matter from the black hole? Is this what is taking place at the center of our universe and if that hypothesis were correct, would there most likely be two universes? Thank you in advance. – Andy
Answer: The two streams of matter that are ejected from a galaxy which contains a black hole are due to the energy balancing process for matter which is being swallowed by a black hole. As matter spirals into the center of a galaxy which contains a black hole it loses energy, this lost energy has to go somewhere, and a method for allowing that energy to be released is provided by jets which propagate outward from a black hole along the poles of its axis of rotation. These jets are in fact what we measure at radio wavelengths. This process of energy balance in black holes, though, is unrelated to the structure of our universe.
Question: Ok so say the universe gets to a point where every black hole consumes everything including each other until your left with a single black hole. Or would this not be possible due to the universe ever expanding and just the vastness of the universe ? Just a thought. – Danny
Answer: Space is actually a pretty empty place on average. The WMAP cosmic microwave background probe measurements indicated that there are on average about 6 protons per cubic meter in the Universe. I believe therefore that the possibility of black holes even interacting with each other is pretty small.