I was thinking the other day about the supposed Black holes which reside in the center of the Galaxy. It suddenly occured to me that if a Black Hole became so immense that it began to digest other Black Holes perhaps this Mother of all Black Holes might eventually swallow everything in space.
My convoluted thought process then imagines this gigantic Hoover Vacuum bursting and vomiting all the matter it has ingested. Could this be an eternal cycle, perhaps many Big Bangs have occured?
in theory a black hole could not explode because space and time is bent.it would only expand.what may happen could be the proverbial snake eating its tail effect.it may grow and bend so much devouring all the known universe that the tail ends up in the mouth.hence time and matter then being eternal.where does that leave us as a race.
Actually, it is possible for a black hole to consume too much matter too rapidly and remanifest in our reality. This is probably accompanied by some rather spectacular fireworks.
There is also a significant difference between a black hole and the universal singularity. It is quite common for black holes to radiate matter. This is know as Hawking Radiation (named for Stephen Hawking). This radiation commonly manifests as “cosmic jets” that spew material from the polar nodes of a black hole for many light years.
Cosmic jets are formed when material that collects in the accretion disc surrounding a black hole is crushed. When you talk about crushing entire stars or multiple stars you also must account for their magnetic fields. The magnetic repulsion of these monster fields actually drives matter back over the event horizon.
The universal singularity is another matter entirely. As much as it seems similar to a black hole, the matter contained therein was in an altogether different state. The Relativistic Heavy Ion Collider at Brookhaven is currently investigating this state of matter known as the “quark-gluon plasma”. Please click over to this site for more information.
I am currently working on a pet theory that involves strings as the initial form of “Hawking Radiation” that came from the universal singularity and led to the destablization that we call “Big Bang”. (You heard it here first.)
Uncle Cecil raises the possibility that we’re inside a huge black hole now in this column:
What would happen if you were swallowed by a black hole?
Apparently incredibly massive black holes are less dense (according to the column) than smaller black holes. I presume that means a black hole is less dense within the event horizon, as a singularity is infinitely dense, as it is a point.
Hope this isn’t a hijack but I’ve wondered the same thing too. If a black hole is so strong that light cannot escape, then wouldn’t it start pulling in local matter, in turn making the grav pull stronger pulling in even more matters (stars?) creating even more gravity and so on until, finally, everything was sucked in?
This is not quite correct. Hawking radiation is not the cause of the polar jets. Hawking radiation is more of a slow leak from the entire surface of the black hole. The more massive the BH, the less Hawking radiation it gives off. The BH’s in the center of galaxies are extremely massive, ranging from 2 million to 3 billion times the mass of the sun, so their Hawking radiation is virtually nil.
Again not quite correct. There’s no magnetic field strong enough to push matter out of a BH. The magnetic fields channel some of the matter in the accretion disk in a vertical direction and that makes the polar jets.
According to most physists, matter in the universe is too far apart and moving away from other matter too rapidly for the an ultimate black hole to appear and swallow all the matter in the universe.
If the total amount of matter in the universe exceeded the critical value for expansion to stop, then a giant black hole would be the eventual fate of all the matter in the universe. However, it appears the universe has nowhere near that amount.
We covered this topic (sorta) in this there here
I seem to remember reading about “cosmic strings” floating around the universe in Omni magazine, or some such place. Something about imploding the Earth should one pass through it, or something like that.
What are “strings”?
Take a trip at The Official String Theory Website. You can find a short and fairly non-technical introduction to strings under the “Basics”, and then the “So what is string theory, then?” link.
The “cosmic strings” from Omni magazine are probably different than the strings from string theory. It’s unfortunate that the two used the same word to label the different ideas since it’s probably caused much confusion among non-initiates.
Cosmic strings are long, massive, two-dimensional things. The idea was that the early universe underwent one or more phase transitions which could have left some discontinuities, known as cosmic strings, in the fabric of space-time.
I’m afraid I can’t find a good web site about them that is aimed at the interested layperson.
Black holes typically don’t swallow everything around them, because at any significant distance from the hole, the gravity of the hole is essentially identical to that of any other object with the same mass. If the Sun were instantaneously replaced with a Solar-mass black hole, we’d just keep orbiting it in the same way we do now.
2nd Law, the density referred to there is the mass divided by the volume contained in the event horizon. Since the radius of the event horizon is proportional to the mass, and the volume is proportional to radius cubed, this means that the density of a black hole is proportional to the inverse square of its mass.
dtilque, you meant to say, of course, that cosmic strings are one-dimensional, not two, unless you’re counting time. They are, indeed, completely unrelated to the strings of String Theory.
As to the OP, even if it is possible for a black hole to become a new Big Bang (we would need a theory of quantum gravity to be able to say that definitively), we can’t necessarily that that was the origin of our own Bang. Before t=0, we can know exactly zilch about our Universe, assuming that “before t=0” even has any meaning.
IBBen, what you’re describing is known as “The Big Crunch.”
I don’t know enough about it to give you a correct answer as to what it is, but I know enough to BS my way through it. So here goes:
Basically, after the Big Bang, everything spewed out all over the universe in every direction. A huge, ever expanding game of tiddly winks. But, the objects could be slowing down. Very very very gradually, but what did you expect on a cosmic scale? In a couple hundred billion trillion years (i.e. a lot of zeros), they might be moving backwards in respect to the direction they’re headed now. This depends on whether the total mass of the universe is so large, it overcomes the acceleration of the individualized objects scurring about. If so, it’s a big party and we’re all invited. If not, we keep going on our happy little way.
Someone else wanna fill in the details I’ve ever so conveniently left out?
Then there’s Lee Smolin’s musings (not theory, since it’s just speculation) that every black hole creates a new universe. And each universe created would have new physical laws. But if the new universe’s physical laws are such that stars cannot form, then that universe will have no black holes…and it cannot reproduce. Therefore, universes which create stars have a reproductive advantage. If they can pass on this ability to the baby universes, we have an explanation for why our physical laws are what they are…cosmic natural selection!
First, I just want to concur with dtilque’s corrections of Zenster’s post. Nothing exits the event horizon & the jets are from the accretion disk, not the black hole itself. I’ll also agree with Chronos, that a black hole is not like a vacuum cleaner…its gravity is just like everything else and you can have a safe orbit around one. It’s just that there’s no escape once you get too close.
In a “closed” universe, like Enderw23 said, there would be enough matter to stop the expansion of space (which started at the Big Bang) and bring everything back into a Big Crunch. For such a case, some people have speculated that this could lead to another Big Bang (or an eternal cycle of Big Bangs & Big Crunches). But it is not known if this is possible.
Current evidence shows that our universe is “flat” and will, therefore, expand forever.
The singularity of a black hole is still a scientific mystery. Modern physics cannot describe this situation in spacetime. Some scientists are working on a Theory of Quantum Gravity (which would combine the large-scale Relativity with the small-scale Quantum Mechanics). Others are working on String Theory.
So, maybe the black hole is a dead-end (it sure seems to be and it certainly is for all practical purposes…nothing can escape it) or maybe there’s more to it. It just isn’t known.
argh. sorry about the bolding…I didn’t preview :o
Of course, string theory is a theory of quantum gravity, among other things. Unfortunately, it’s got too many free paramaeters, and not enough exiperiments (as of right now, exactly none) to try to fix the values of those parameters, so we can’t yet use it to make any sort of predictions.
Current thinking is that not only is the Universe going to expand forever, it’s actually accelerating, due to the cosmological constant. It’s gonna get mighty cold, eventually.