Slashdot Mirror
Do Solo Black Holes Roam the Universe?
sciencehabit writes "Two mysterious bright spots in a disheveled, distant galaxy suggest that astronomers have found the best evidence yet for a supermassive black hole being shoved out of its home. If confirmed, the finding would verify Einstein's theory of general relativity in a region of intense gravity not previously tested. The results would also suggest that some giant black holes roam the universe as invisible free floaters, flung from the galaxies in which they coalesced. Although loner black holes may be an entity that has to be reckoned with, they would still be rare."
Ease off. That was a huge step up from our normal First Posts.
Violence is like duct tape. If it doesn't solve the problem, you didn't use enough.
It's ironic, then, that neither of you have put anything forth to foster the discussion along what you would consider "proper" lines. Oh, and you both posted as ACs, too...
For your security, this post has been encrypted with ROT-13, twice.
I find it fascinating that theories developed in the first half of the last century continue to stand up to observation. This fits the predictions of general relativity, and that is almost as exciting as if they discovered something that totally blew away the predictions. The latter would mean we go back to the cutting board, but this is, as I said, almost as exciting. It makes me wonder how much of the 'missing mass' that we lump into the dark matter bucket is actually contained in bodies like this; bodies so massive that we can barely fathom their 'size'.
You mean, by being sucked into a giant black hole? Unless you have some suggestions on how to make a giant black hole change its course, or how to move your solar system out of the way of a giant roaming black hole, that is...
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Slashdot isn't some game where you try to score the most karma points.
What? Shit, why have I been wasting all this time here if I can't win?
Ahh, yes, that lovely golden age of slashdot when first posts didn't make fun of exes, but did have recruitment statements for GNAA.
Jesus was all right but his disciples were thick and ordinary. -John Lennon
No... the stars in a galaxy are orbiting their own collective center of gravity, not the blackhole. It just so happens that this collective center of gravity often attracts enough stars that it collapses into a super massive black hole. The most likely scenario for the blackhole to lose it's galaxy is in a collision with another galaxy (although "Collision" is a bad word since nothing actually hits anything else) The center of mass of the 2 combined galaxies would radically change rather suddenly (in galactic terms) and the Super massive blackhole would begin orbiting the new center of gravity. If it's orbit is too far out, it would get flung off. In most situations stars would get flung out with it. But rarely it could shoot off on it's own.
(although "Collision" is a bad word since nothing actually hits anything else)
I like to think of it as merging.
/* No Comment */
If you were to take the 3 million solar mass black hole in the center of the Milky Way, and plop it into the solar system where the sun is, the Schwartzchild radius would be well within the orbit of Mercury. We wouldn't lose a single planet, though an earth "year" would shrink to roughly 2 hours. Hold your fist at arm's length. That's how big it would appear in the sky.
Now imagine trying to see something like that, from 4 billion light years away, moving faster than galactic escape velocity. The only reason you can see it at *all* is that it's still siphoning galactic gas into its accretion disk. Once it hits intergalactic space, you'll never see it again.
Three million solar masses sounds huge, but is a microscopic fraction of the Milky Way's total mass (1-4 trillion solar masses). Given the quantity of matter orbiting near the center of a galaxy, I'd believe it likely that even if the central black hole were ejected, a new one would form in short (cosmologically speaking) time. So core ejection may not be a one-off, but a common event during galaxy collisions. In which case, there might be enough of them to partly explain dark matter (though certainly not enough to explain it all).
We also know there is a relationship between the mass of the central black hole, and the "tightness" of the arms in a spiral galaxy. But how would core ejection affect this? Given the speed of light, the outer regions of a galaxy would be tightly wound, while the inner region would be loosely wound (after core ejection). Wouldn't that look an awful lot like a barred spiral?
So many interesting questions, so few answers...
And here I thought it was hip to be square... I guess I should stop taking life lessons from Huey Lewis :-(
if slashdot isn't a game, then what's up with the achievements? if you don't think it's a game, you are being played. the object of the game is to gain enough karma points that you can troll at will with impunity. mini-games include Make Others Look Stupid, Make Yourself Look Smart, and I'm Sofa King Funny.
insensitive clod overlords obligatory xkcd car analogy russian reversals whoosh pedant fanbois ftfy in 3...2...1..PROFIT
Honest Question here - do you really believe that the best way to foster free and open discussion is to severely limit the people that can participate?
Look at my number. It is huge. Yes, I contribute some bullshit every now and then, but I honestly try my best to contribute to this open forum. Why is my number soooo big? Because I chose to lurk first, learn the dynamics and how to do stuff (technical word there), and then post.
It's like this - you want to ride a roller coaster. So, you go to an amusement park. Then you get pissed about waiting in line with the other idiots. What are your options? (a) Build your own rollercoaster; or (b) quit bitching about the line and enjoy the pleasant conversations that do happen, when they happen.
If you are not the owner of a website, who are you to limit, or suggest a limit for that matter, on who can contribute?
Why do I love the internet, and online forums and discussion boards? Because I can hear a...n...y...t...h...i...n...g... on them. If I wanted to have a closed discussion on a topic, I'd go back to yelling at my television. It feels just as good, and is as one-sided as you make it.
In other words, sir or ma'am, I understand that you believe that there were glory days on this site. I'm sure there were. But, limiting who can speak, simply based on how old s/he is comes off as, in my opinion, utter bullshit.
In other words. Learn to ignore the shit. Look for the good. It's there, if you care to be positive. OR, instead of limiting who can post, have a system where you can register your account, but can not contribute until you reach a certain time on the site, or number of articles read paired with time spent reading, or something. I don't know, just quit complaining about it. It's just as annoying as the bullshit posts from user numbers>1,000,000, and contributes nothing to the discussion.
But that is all my opinion. Thank you.
The theoretical evaporation of black holes is an incredibly slow process; a black hole the mass of the sun would only evaporate after some 10^67 years. which considering the age of the universe is 13x10^9 years (or about 6000 if you're a creationist) means it won't disappear any time soon.
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
then black holes can be too. We have observed almost a score of so of stars with the 2 million MPH velocity required to escape from a galaxy, which they probably got from proximity to a black hole. There is no reason not to think that a black hole could have the same close orbit. Just much much, rarer.
Some guy makes a witty crack, 1 simple, single sentence post.
Then 4000 neckbeards get all pissy about it and chime in to complain about the S/N ratio.
This sig is not paradoxical or ironic.
more like a brief merging of heavenly bodies followed by a massive ejection of.. um. stars.
sorry, i was trying to make it filthy but failed to find a plausible way to refer to stars as fluids. i guess they can be modelled as such...
how am I supposed to parse that?
As a joke - albeit one that pointed out that H2 in voids, given our current understanding of course, isn't a candidate for dark matter. Not enough mass, not in the right place, and interacting using photons being three of the main problems with it.
The first one would be (10^6)*(10^9)*(10^12), which is a shitload of tons. The mass of the universe is roughly 3*10^52 to 3*10^54 kg given 1 ton is ~10^3 kilograms that would put that hydrogen as roughly half the mass of the observable universe.
3+6+9+12=30 - so 10^30 kg of H2, or about half of the sun's mass. That's 22 orders of magnitude short, given your own numbers, of being 'half the observable universe' - i.e. not even a rounding error.
They are finding additional %s. Brown dwarfs, extra H2 in the voids etc.
Right, but none of them have the right properties (no EM interactions, etc) to be dark matter, not to mention that their mass is trivial compared to the amount required.
Anything is possible, especially something based on 'finaglers constant' (FC=answerwant/answergot) like dark matter.
We're a little past that stage. For example, we have observed galaxies colliding in ways that separate the visible mass from the non-visible mass - i.e. the stars, gas etc, interact via EM and slow down, while the majority of the mass (inferred through gravitational lensing) continues on as if it's affected only by gravity. It's hard to ascribe that kind of behavior to dim stars or extra-galactic H2.
You obviously don't understand that 10^30 is nowhere near 1/2 of 10^52. It's practically nonexistent on that scale.
"Educate the mind but never at the expense of the soul."~Blessed Basil Moreau
My point is that 1 million is just as arbitrary as 100k.
Jesus was all right but his disciples were thick and ordinary. -John Lennon
Not to interrupt yer moral soapbox special feelings or anything, but my slider to the right says I'm a third down the page and none of you sister boys has said a damn thing pertaining to black holes, galactic feces being flung about, Lawyers, NASA or nothing.
So with that outa the way, I'll introduce a recentish occurence, http://photojournal.jpl.nasa.gov/catalog/?IDNumber=PIA13455. I figure if you can venture a ratio of black holes to stars you can figure odds of being affected by one coming our way.
No fear, have a beer. Don't let my low number fool ya baby, No Viagra needed here.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
I can remember worse than this. You gotta figure the number of usual probable participants occupied with "Venus Transit" events, parties and swap meets.
Relax, beer is good, they'll be back.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
It was actually shortly after I joined that I started noticing the downward spiral in comments.
So it was YOU?!
There have been too many "First posts" and racist rantings
Honest question: Were you reading Slashdot during the GNAA days?
Honestly, the signal to noise ratio is very good. Trouble is that the signal is no longer tech, but politics. Ever since coverage of 9/11 the community visibly changed. YRO is where all the views are, with tech-oriented articles hardly gets any comments.
Post first and post often.
I've found that often, no matter how insightful or thought-provoking an FP is, some dufus will mod it "offtopic," "troll," or (hilariously) "redundant." I try to avoid first posts, just because if the first two mods are the "FP always modded down" type, nobody is likely to even see it. What's the point of making a comment if you're going to be at -1?
Free Martian Whores!