After
Posted on 05/03/2011 12:23:32 PM PDT by Red Badger
If the Universe expands and contracts in cycles of Big Bangs and Crunches, some black holes may survive from one era to the next, according to a new analysis
Black holes are regions of space in which gravity is so strong that nothing can escape, not even light. Conventionally, black holes form during a gravitational collapse, after a large supernova for example.
But there is another class of objects called primordial black holes that cosmologists think must have formed in a different way. These are essentially leftovers from the hugely dense ball of stuff from which the universe expanded, some parts of which must have been dense enough to form black holes.
These primordial black holes would then have been widely dispersed as the universe expanded.
Primordial black holes are very different beasts to the ones that form when stars die, in particular because they ought to be much smaller.
Although nobody has yet seen a primordial black hole, our knowledge of them comes from thinking about the processes that must have occurred shortly after the Big Bang.
In recent years, however, cosmologists have begun to think seriously about processes that occurred before the Big Bang. One idea, is that the Universe may eventually collapse leading to an endless cycle of Big Bangs and Crunches.
Today, Bernard Carr at Queen Mary University of London, UK, and Alan Coley at Dalhousie University in Canada, ask what might happen in such a universe in the moments before a crunch.
By some accounts, a Big Crunch generates a singularity that ought to cause everything in the Universe to merge. But Carr and Coley say that in some circumstances, 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.
That leads to a problem, however. Coley and Carr say that since the mass of primordial and pre-crunch black holes is similar, they will be very difficult to tell apart.
Nobody has yet seen a primordial black hole, although efforts are underway to search for the telltale signatures they ought to produce.
Small black holes ought to evaporate away in relatively short period of time, finally disappearing in a violent explosion of gamma rays. The hope is that observatories such as the Fermi Gamma Ray Space Telescope will see such events. Indeed, some cosmologists say this thinking might explain the gamma ray bursts that we already see from time to time.
What all this means, of course, is that there may be objects in our Universe that predate the Big Bang. And if we can somehow find a way to distinguish them from primordial black holes, we may yet be able to observe these most ancient of objects.
Ref: arxiv.org/abs/1104.3796 : Persistence Of Black Holes Through A Cosmological Bounce
Careful! You’re just asking for a HT Pic!..............
So they are saying there was a hole in the doughnut before there even was a doughnut?
Which came first? The donut or the hole?..............
Maybe if it had a Pancake......
Wrong. It is a graph of WalMart’s sales following a new moon.
In recent years, however, cosmologists have begun to think seriously about processes that occurred before the Big Bang.
I’ve always thought about this, but obviously before
there were Bangs there were Frizzies and Split Ends.
I thought the entire universe grew out of the “singularity” with the expansion we call the “Big Bang”.
Which means until the “Big Bang”, there was no universe, just the singularity.
So if these primordial black holes were not incorporated into the singularity, and there wasn’t any universe yet because the “Big Bang” hadn’t happened, where the heck were these primordial black holes supposed to be living?
I’m beginning to like the “brain” (membrane) theory.
After
Of course there is ...
When you put the first lot of doughnuts in the oil, do you see anything on the plate? Of course not! That's where all of the holes are!
Obviously the “singularity” was getting some on the side.............
Our Universe?
How many other universes are there, and who owns the other ones?
“By some accounts, a Big Crunch generates a singularity that ought to cause everything in the Universe to merge. But Carr and Coley say that in some circumstances, 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.”
Does this “thinking about the process” require new ideas about space and time as well. When the universe in a “big crunch” condenses to a single massive “singularity”, WHERE are any surviving, left over small singularities - to be called “primordial” in the next cycle?
Are they inside of or outside of the singularity crunched together in the “big” crunch?
Could they actually “survive” as an independent singularity inside the “big crunch” singularity?
No? Then what is “space and time” of “the universe”. Is it “divided” between the singularity crunched together in the “big crunch” and the “primordial” singularities that remain outside of it?.
Or is “the universe”, and “space/time” independent of and more than the mere experience of “space/time” to any occupants of any of those singularities?
Is there “space/time” BEYOND ANY material/energy expression of “the universe”?
Just questions.
Sorry to be picky but there are four Maxwell equations
THERE MAY BE ONLY ONE PHOTON IN THE UNIVERSE!
You see, a photon travels at the speed of light...duh!
And at the speed of light...time stops (maybe more accurate..does not exist). Thus, a photon is every where...all at once. Weird...but TRUE! Go ahead..
ask your physics professor.
That has absolutely nothing to do with my comment, or the article.
"Nobody said anything about faith."
"Believing that something exists without any objective proof requires faith."
Nobody is talking about belief. Read the headline again. "Some Black Holes May Pre-Date The Big Bang, Say Cosmologists"
"Why should I believe that "primordial black holes" even exist if none have been observed?"
Nobody in the article said what you should believe.
"Even if all the "evidence" points to such things existing, we could say that there's a ton of evidence that Bigfoot exists as well, even though no one has seen Bigfoot."
Saying it doesn't make it so. If you really did have a ton of evidence and no contrary evidence, then it would perfectly logical to think Bigfoot probably exists.
"This piece honestly reads like bad fiction. Perhaps these scientists should wait until they have observed something before they speculate as to whether or not it exists."
No it doesn't. You just have a too narrow definition of what scientists do. Coming up with creative ideas is part of the process. It's not just about measuring things. There's nothing wrong with a scientist saying something may have happened or might happen. The only thing wrong would be saying it did, without evidence. "Faith", as you said. But this article never suggests that they are doing that. Instead it is quite clear that this is speculation. Which is fine.
Right, got it.
Well.... maybe in this Universe.
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