"Some Black Holes Existed Prior to the Big Bang"
Cosmologists have begun to think seriously about processes that occurred before the Big Bang. Alan Coley from Canada's Dalhousie University and Bernard Carr from Queen Mary University in London, have theorized that some so-called primordial black holes might have been created in the Big Crunch that came before the Big Bang, which supports the theory that the Big Bang was not a single event, but one that occurs over and over again as the Universe crunches down to a single point, then blows up again. In some circumstances, they say, black holes of a certain mass could avoid this fate and survive the crunch as separate entities. The masses for which this is possible range from a few hundred million kilograms to about the mass of our Sun.
An artists impression of a Supermassive Black Hole
The theory is based on the fact that the Earth, and the rest of the known Universe is occasionally bombarded with unexplained bursts of gamma rays -- something that could, according to Coley and Carr, be the result of primordial black holes running out of energy and disintegrating. These small black holes ought to evaporate away in relatively short period of time, finally disappearing in a violent explosion of gamma rays. Some cosmologists say this thinking might explain the gamma ray bursts that we already see from time to time.
Primordial black holes are thought to be of a different type than the regular kind that are formed when a supernova occurs but rather formed in the first “moments” after the Big Bang. Primordial black holes would be smaller and created by the energy of the Big Bang itself and would then have been widely dispersed as the Universe expanded. In their theory, however, Coley and Carr suggest that some of these black holes, if they actually exist, might have been created by the collapsing Universe as part of the Big Crunch, and then somehow escaped being pulled into the pinpoint singularity comprised of everything else. And then, after the Big Bang, they simply assimilated with the newly formed Universe.
A key problem they agree on is that it would likely be impossible to tell the difference between pre- and post Big Bang primordial black holes.* The theory raises major questions for cosmologists: if the Universe contracts, then blows up, over and over, has this gone on forever? Or is it possible that our view of the Universe is so limited that we’re only seeing one tiny fraction of it, and thus, any theories or explanations we offer, are little more than guesses.
Image at the top of page shows co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant Universe. In their final stages the mergers are expected to be intense sources of gravitational waves. http://www.dailygalaxy.com/my_weblog/2012/07/some-black-holes-existed-prior-to-the-big-bang-were-assimilated-into-newly-formed-universe-todays-mo.html#more
More information: Persistence of black holes through a cosmological bounce, B. J. Carr, A.A. Coley, arXiv:1104.3796v1 [astro-ph.CO] http://arxiv.org/abs/1104.3796
The Daily Galaxy via MIT Technology Review
Scientists gear up to take a picture of a black hole
"Black holes are the most extreme environment you can find in the universe," Doeleman said. The field of gravity around a black hole is so immense that it swallows everything in its reach; not even light can escape its grip. For that reason, black holes are just that –emitting no light whatsoever, their "nothingness" blends into the black void of the universe. So how does one take a picture of something that by definition is impossible to see? "As dust and gas swirls around the black hole before it is drawn inside, a kind of cosmic traffic jam ensues," Doeleman explained. "Swirling around the black hole like water circling the drain in a bathtub, the matter compresses and the resulting friction turns it into plasma heated to a billion degrees or more, causing it to 'glow' – and radiate energy that we can detect here on Earth." By imaging the glow of matter swirling around the black hole before it goes over the edge of the point of no return and plunges into the abyss of space and time, scientists can only see the outline of the black hole, also called its shadow. Because the laws of physics either don't apply to or cannot describe what happens beyond that point of no return from which not even light can escape, that boundary is called the Event Horizon. "So far, we have indirect evidence that there is a black hole at the center of the Milky Way," Psaltis said. "But once we see its shadow, there will be no doubt." Even though the black hole suspected to sit at the center of our galaxy is a supermassive one at four million times the mass of the Sun, it is tiny to the eyes of astronomers. Smaller than Mercury's orbit around the Sun, yet almost 26,000 light years away, it appears about the same size as a grapefruit on the moon.
