Black Hole in Search of a Home 115
jose parinas writes "Interesting news from the ESO observatory on Paranal about black holes that travel. From the article: 'For 19 of [the low redshift quasars], they found, as expected, that these super massive black holes are surrounded by a host galaxy. But when they studied the bright quasar HE0450-2958, located some 5 billion light-years away, they couldn't find evidence for an encircling galaxy. This, the astronomers suggest, may indicate a rare case of collision between a seemingly normal spiral galaxy and a much more exotic object harbouring a very massive black hole.'" More from the article: "Has the host galaxy been completely disrupted as a result of the collision? It is hard to imagine how that could happen. Has an isolated black hole captured gas while crossing the disc of a spiral galaxy? This would require very special conditions and would probably not have caused such a tremendous perturbation as is observed in the neighbouring galaxy. Another intriguing hypothesis is that the galaxy harbouring the black hole was almost exclusively made of dark matter." Update: 09/17 00:15 GMT by Z : Edited for clarity.
Shiznit (Score:1, Insightful)
Re:Shiznit (Score:1)
Re:dark matter (Score:2)
Re:dark matter (Score:3, Funny)
Hello? (Score:3, Insightful)
20 20 sounds like the results of an eyesight test, and ' found that for 19 of them, they found,' - what?
Re:Hello? (Score:1, Funny)
Re:Hello? (Score:1, Funny)
Re:Hello? (Score:1)
Re:Hello? (Score:3, Funny)
An international team of astronomers [1] used two of the most powerful astronomical facilities available, the ESO Very Large Telescope (VLT) at Cerro Paranal and the Hubble Space Telescope (HST), to conduct a detailed study of 20 low redshift quasars. For 19 of them, they found, as expected, that these super massive black holes are surrounded by a
adoption (Score:5, Funny)
*rolls up newspaper* but if it starts behaving badly, we're gonna have a problem.
Re:adoption (Score:2, Funny)
Sounds a lot like an ex-girlfriend.
Re:adoption (Score:1)
Weapons of Mass Annihilation (Score:2)
This black hole will bite the hand that feeds it.You are 0wn3d say big black letters for infinite amount of time. Can you imagine what will happen if such a rogue elephant comes wandering in our backyard? We will have much bigger problems to worry about.
Re:Weapons of Mass Annihilation (Score:2)
Re:Weapons of Mass Annihilation (Score:1)
Re:adoption (Score:1)
My plan is absolutely flawless.
On another note, how on earth does Zonk get work on this site? Is he sucking off the owners?
Re:adoption (Score:1)
I must point out that time is relative and (from our perspective) time appears to slow around a black hole. Would that not drastically reduce the usable amount of power for those away from the blackhole?
So am I.
-Kruton
Re:adoption (Score:2)
You're absolutely correct. The time distortion does reduce the available power. The sheer magnitude of the forces, however, makes up fantastically for the temporal effect. In fact, tidal forces at decent proximity to the event horizon will make protons and neutrons flow like water (the quarks and gluons i
Re:adoption (Score:2, Informative)
Only for sufficiently small black holes. There is nothing locally special about a region near the event horizon. If the BH is big enough, 100M solar masses say, the tidal forces at its event horizon are small enough to let an astronaut pass through it without ill-effect. The same can not be said of the experiences encountered much closer to the s
Re:adoption (Score:1)
Stephens theories,.... (Score:2, Interesting)
Re:Stephens theories,.... (Score:3, Informative)
Re:Stephens theories,.... (Score:2)
Re:Stephens theories,.... (Score:2)
Re:Stephens theories,.... (Score:2)
Re:Stephens theories,.... (Score:2)
I'll never sleep again (Score:5, Funny)
This brings Uhura's "exotic" dance in Star Trek V to mind.
Oh sure.... (Score:5, Funny)
Re:Oh sure.... (Score:4, Funny)
That was quick. (Score:1)
Well, it's nice to see Slashdot editors actually implementing one of the community's ideas [slashdot.org]. Some suggested that submitting test phrases to /. would be the way to get started; it's only been two days, and already the software seems to be going into production. Of course, it'll be awhile before the program gets out o
Article summary (Score:2, Insightful)
Definitely a case of grammatical structure in search of a home!
i for one... (Score:1, Funny)
its all fun and games untill someones galaxy gets hit with a black hole...
I've seen something like this... (Score:2, Funny)
If it's anything like my uncle, it doesn't capture gas, it releases it... in large quantities...
Re:Gotta say ... (Score:5, Funny)
Re:Gotta say ... (Score:2)
Re:Gotta say ... (Score:1, Funny)
Which one's? I prefer Zeus!
Just not in my neighborhood. (Score:1)
Re:Just not in my neighborhood. (Score:1)
Believe it or not, Jay Leno just mentioned this story on his late night show (9/16). Astronomy is not his usual subject matter, to say the least.
Michael
Why couldn't it have (Score:5, Interesting)
Re:Why couldn't it have (Score:3, Insightful)
Re:Why couldn't it have (Score:2)
Re:Why couldn't it have (Score:1, Funny)
Bloody EPA gets everywhere!
Re:Why couldn't it have (Score:2)
Re:Why couldn't it have (Score:2)
Re:Why couldn't it have (Score:3, Informative)
Is the gravity of the sun not enough to get the earth moving towards it? Is the gravity of the earth not enough to get the moon moving towards it?
Same thing. If there is non-zero angular momentum then gravity does not cause things to fall in, it causes them to orbit. Orbits can only decay and "fall in" if you find some way to bleed of the angular momentum. For exa
Re:Why couldn't it have (Score:2)
However, if perigee of the orbit is within the Schwarzchild radius of the hole, then the star will never come out again. The orbit does not have to decay; the angular momentum is conserved and is added to the angular momentum of the hole itself.
Re:Why couldn't it have (Score:1)
The gravity of a black hole *IS* inverse-square law.
As long as you are outside the event horizon then a black hole really isn't particularly different from a Really Big Star. Stars of a galaxy will orbit a giant black hole just like planets orbit a sun in a solar system.
-
Re:Why couldn't it have (Score:1)
Maybe. :)
Uh oh (Score:1)
Re:Uh oh (Score:1)
Chiral Dark Matter Galaxies (Score:3, Funny)
Scientists are baffled as to how the different handed socks ended up in completely separate galaxies. However, some have stated that the apparent long-range transport phenomenon does provide hints for the mechanisms behind unexplained sock behaviors in this part of the universe.
Re:Chiral Dark Matter Galaxies (Score:1)
So THAT'S where the holes in my underwear came from!
Re:Chiral Dark Matter Galaxies (Score:2)
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Dark matter? (Score:5, Interesting)
A reasonable person might well consider an explanation that included the natural evolution of advanced technological civilizations before they resorted to the invention of new particles and laws of physics (as is typically a requirement as soon as you mention 'dark matter').
It is useful to keep in mind that several papers by Charley Lineweaver's [anu.edu.au] group document that ~70% of the "Earth's" in our galaxy are significantly older than ours (perhaps billions of years older). It would not be that unexpected that from time to time we might encounter a galaxy where advanced civilizations had placed *all* of the reasonably available matter and energy "under management". (For the purposes of discussion we will assume that black holes do not constitute a "reasonably available" useful resource despite proposals from time to time that require rather creative physics to make them "useful".)
Re:Dark matter? (Score:1, Insightful)
Surely such an advanced civilization wouldn't let all the energy (and it would be quite a lot of energy if we can detect it all
Re:Dark matter? (Score:2)
by bradbury (33372)
You might have a low ID, but I'm guessing you're not Ray Bradbury. (Not that argumentum to eminentum authoritum or argumentum againstum hominem are worth anything, though, but it's still funny.)
And the reference to some dude at the Bogatonic SETI conference over thirty years ago has a disturbing resemblance to the infamous "Proof by reference to inaccessible literature" found on the classic joke proof list (including such items as "Proof by vigorous hand
Re:Dark matter? (Score:4, Interesting)
Dyson had made a set of points, one of which was:
"Point 3. If a society is very highly developed technologically, it must emit intense infrared radiation, not necessarily a planetary spectrum, but necessarily a large intensity of infrared radiation, whether or not this society wishes to communicate. Consequently, we should use infrared radiation, as a signpost indicating priority areas toward which we should direct searches by radio and other techniques."
There was some discussion which eventually led to the following exchange:
OLIVER: Why do you suggest civilizations must of necessity produce large amounts of infrared radiation? It seems to me that the infrared radiation that would be produced by even a very much farther advanced civilization than ours would be negligible compared to their primary star. For example, in California, which has a very high usage of electricity, the power generation at the present time is only 0.1 percent of the sunlight falling on the state.
DYSON: What I am saying is that the civilizations which are observable to us will have this character.
OLIVER: But you are suggesting, are you not, that the infrared emission will be an observable characteristic? I am suggesting it is far down in the stellar noise.
DYSON: No, I am saying that the generation of large amounts of infrared radiation is not necessarily an accompaniment of a high civilization at all. Only if it occurs is it something we can see.
MINSKY: Since radiation at any temperature above 3K is wasteful and a squandering of natural resources, the higher the civilization, the lower the infrared radiation. We should look for extended sources of 4K radiation. There should be very few natural such sources.
DYSON: I don't quite go along with this but to some extent you are right.
The reason that Dyson didn't go along with this is because he still tended to view "advanced" civilizations as those operating on the basis of "biological" systems (remember this is 1971!) rather than engineered computational systems which can function at a much wider temperature range (in fact Likharev's "Rapid Single Flux Quantum Logic [sunysb.edu]" (based on Josephson junctions) *have* to operate at temperatures much closer to those Minsky suggests). Thus AIs constructed of such devices would emit IR at a temperatures much lower than "primitive" civilizations (i.e. "wet" brain based) which function at the liquid water temperatures that Dyson tended to prefer.
The theories behind Matrioshka Brains are in large part based on Minsky's observation, which are in turn related to Dyson's perspective reagarding Dyson "spheres" (really shells). They are however updated to recognize the fact that computational architectures which can support intelligence (and therefore advanced civilizations) can operate over a much wider temperature range (both higher and lower) than liquid water can provide.
The complete proceedings from the conference [amazon.com] can be purchased from Amazon for $3-7.
Re:Dark matter? (Score:1, Interesting)
Bullshi*hey, hang on a sec*
At ~1% of c, we're talking 500 years to Alpha Centauri. (400 years of
Re:Dark matter? (Score:2)
If people multiplied like rats I could see the colony time being every 1000 years or so, but most lik
Re:Dark matter? (Score:2)
Re:Dark matter? (Score:2)
We detect quasars because they emit so much damn radiation. We assume this is from the accretion disk around a black hole. Why would such an advanced civilization put out so much usable energy?
Because you have no clue what you're talking about.
Re:Dark matter? (Score:1)
Re:Dark matter? (Score:2)
Re:Dark matter? (Score:2)
You must be new around here. Intelligent Design is rather out-of-vogue around here right now.
Wouldn't it be interesting ... (Score:1)
Update: 09/17 00:15 GMT by Z : Edited for clarity (Score:1, Funny)
G f'n D - Hell finally froze over!
In a police search a black hole was discovered in (Score:2, Funny)
I can imagine the scenario:
Man: Don't go in there officer, trust me!
Officer: Are you trying to hide something boy?
Man: No, it's just that, umm...
Officer: Well we'll just see about what's behind this door, shall we?
Re:In a police search a black hole was discovered (Score:2)
ZAP BRANNIGAN: Gravity, you win again!
Blackhole... (Score:1)
Love slashdot, but digg.com is going to suck this user base dry.
Not only is this and many other stories old news, you get too much Gay Nigers of America and First Post crap.
Mod me down, but we are getting to a point of critical mass here.
Looks like somebody was playing.... (Score:2, Funny)
It's that simple. (Score:3, Interesting)
Re:It's that simple. (Score:2)
Re:It's that simple. (Score:1)
"Complete disruption of a galaxy?" (Score:1, Interesting)
The artilce mentions that there is eveidence that a companion galaxy has collided witht the quarsar withing the last 100 million years or so (relative to the observation).
If so, when the collision occured and provided material to feed the quasar, the polar jets would have plowed right into the parent galaxy, and perhaps blowing away the gas in the disk over that 100 million year period.
Any
And the sixth day... (Score:1)
Re:And the sixth day... (Score:1)
Edited... (Score:1)
Hey, Slashdot has a tradition to uphold!
Or actually... A reputation to improve!
Google sky? (Score:1)