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Hundreds of Black Holes Found
eldavojohn writes "Hundreds of black holes that were thought to exist at the beginning of the universe have been found by NASA's Spitzer and Chandra space telescopes. From the article, 'The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores. For decades, a large population of active black holes has been considered missing. These highly energetic structures belong to a class of black holes called quasars. A quasar consists of a doughnut-shaped cloud of gas and dust that surrounds and feeds a budding supermassive black hole. As the gas and dust are devoured by the black hole, they heat up and shoot out X-rays. Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view.' This is pretty big, as it's empirical evidence proving the existence of objects that theoretically had to exist but could not be detected previously."
'The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.
That's funny, because I've heard the same thing about Dick Cheney.
The theory of relativity doesn't work right in Arkansas.
I was scared I might have run into one in a dark alley one night, thank goodness they have been found. On a more serious note, the article mentions that "the galaxies are 9-11 billion years old, and that they *did* exist when the universe was in it's adolescence." Does this mean they are no longer there? And if not, what would have become of the black holes?
"Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view."
pfft yea sure, i'll believe it's a black hole when i see it.
sigs... don't talk to me about sigs....
No, this just proves that, for certain empirical cases, the difference between theory and practice is smaller in practice than certain other theoretically challenged cases: in other words, this one is rather similar, while still remaining slightly different.
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
As covered by Red Dwarf... ... We've been in space for three million years and there hasn't been one! Then, all of a sudden five of them turn up at once!"
"Well, the thing about a Black Hole, its main distinguishing feature, is it's black! And the thing about space, the colour of space, yer basic space colour, is its Black! So how are you supposed to see them.
And the cause of all these black holes?
"Five specs of grit on the scanner scope....the thing is about Grit... is it's black.."
groklaw, wired and slashdot. The holy trinity of work based time wasting.
but where does that stuff come from? And how did it get there?
IANAA (I am not an astrophysicist) but I seem to remember, from the astronomy course which I took for fun in college, that stars formed out of hydrogen present after the big bang (the hydrogen formed soon after everything cooled down enough to allow protons and electrons to bind together again) which formed stars due to minute temperature variations throughout the universe (apparently if the temperature were entirely uniform then nothing interesting, including ultimately Humans, would ever have formed out of the large soup of hydrogen that was left over).
Now, depending upon the initial mass of a star and its final disposition (white dwarf, brown dwarf, neutron star, supernova, black hole) which depends upon that mass, the star creates ever heavier elements as the fusion of hydrogen into helium progresses into the fusion of Helium into Lithium and Lithium into Boron and so on all the way up to Iron (which is the heaviest element that can be produced by fusion). The elements that are heavier than Iron are produced in the massive pressure and forces generated by novas and super novas. Obviously this process has happened over and over again as matter and stars coalesced by gravitational attraction into the galaxies that we see today (lots of handwaving here, again IANAA).
Now, to answer your question, since dust is probably mostly carbon type stuff and compounds (which form pretty often in giant red stars) then over time as stars form and explode and form and explode and form and turn into black holes there will ultimately be some black holes surrounded by stray gases and dust from its own nova or surrounding novas or nearby stars over large periods of time. Lots of handwaving here, but does this answer your question?
Just because it's a black hole, doesn't mean it has to suck everything around it in. Stuff that's close enough, sure, but you can still get a stable orbit around a black hole, just like you can around any other collection of mass.
"This is pretty big, as it's empirical evidence proving the existence of objects that theoretically had to exist but could not be detected previously."
look closely
"empirical evidence proving"
should never occur in any sentence ever. By definition empirical evidence cannot prove anything. Empirical evidence lends support to inductive arguments, which don't concern themselves with proof. Only analytic statements may be proven.
Please, for the love of god remember, there are two forms of logic, inductive which has arguments from experience (physics), and deductive which has arguments from pure reason (mathematics). Only deductive arguments can be proven because you can always argue with the strength of the evidence in inductive claims. It is a fact (supported by inductive evidence and deductive proofs) that inductive claims may be false no matter how strong the evidence for them is. Thus they can never be proven, but you can say "there are strong practical reasons to believe."
People getting basic logic wrong has led to a lot of poor decisions in our society lately, so please do not contribute to the problem by adding to confusion over terms.
google example Replace the mass with any interesting value.
Fnord.
Like these?
No one has ever "seen" a black hole, they are seeing effects that can be explained by black hole theory. A subtle but perhaps important difference.
IANAAP, but on the surface of it, ECOs are interesting because they do not involve a singularity.
A house divided against itself cannot stand.
Interesting Google calc link. In a related vein, a black hole with the mass of Pluto would have an event horizon (Schwartzchild radius) of only 20 microns, or about the width of a hair on your arm. If it were somehow accelerated to a relativistic speed (> 0.95c), such a black hole could theoretically impact a star/planet/moon and pass right through. The only damage would be the curious 20 micron wide tunnel that suddenly appeared in the celestial body. All other matter on the planet would not be sucked in, although any inhabitants might experience some strange gravitational effects. My first-year college physics professor was a big fan of exotic astronomy, and we did several projects involving similar scenarios.
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
Well, the Earth is pulling the moon towards it too, and yet we still have a moon after all these billions of years. The Sun is pulling the Earth towards it, but, funnily enough, after all these billions of years we're not quite there yet.
In a sense, the Hitchhiker's guide got that right: ""There is an art to flying, or rather a knack. It knack lies in learning to throw yourself at the ground and miss. Clearly, it is this second part, the missing, that provides the difficulties."" We keep falling in an almost circular orbit around the Sun and ending up (almost) where we started.
What I'm trying to say is that those super-massive black holes obviously do suck everything towards them. But the rest of the galaxy sees it as centripetal force and rotates around them.
The problems with a black holes are at closer ranges.
For a start, if you do get closer to it than its event horizon, then you're properly fucked. There is no way to get out of there, not even theoretically. Not even light can get out of there. Hence, the name black hole.
However, I'll return to the analogy with the solar system. With the Sun's massive gravity well, it's damn near impossible to hit it, even if you wanted to. If you dropped a big rock right at it, even the slighest deviation or initial speed sideways (like would happen if you dropped it from Earth), would cause a clean miss and you'd just get that rock in some kind of orbit around it. The only way to actually hit the sun would be if that orbit was flattened enough that it passes through the sun.
And the same problem applies to black holes too. Remember that it's a more massive gravity well _and_ the "bullseye" is much smaller, at least in relation to the gravity well. As you fall even a little off the centre, your speed would increase enough so at one point the centrifugal force (yes, I know it doesn't even exist, but it makes the explanation easier) just flings you clean around it.
There's even at least one theory that nothing ever finishes falling into a black star. Although there is energy loss due to that X-ray emission and all, basically matter just spirals closer and closer to the event horizon without ever reaching it. Think an asymptotic decay. It gets closer and closer and closer over time, but never quite reaches it.
The second problem is, well, tides. If you get close enough to the centre of a gravity well, say, looking at the centre, then your front is pulled towards it much stronger than your back is.
This is actually true for any gravity well, and, again, you can see it in action in the solar system too. That's why the moon is tidal-locked with the Earth and you always see the same face of it.
But for a massive enough gravity well, the force difference gets larger and can rip a star or a planet apart. That's how stars and black holes end up occasionally peeling another star apart, pretty much syphoning its outer layers.
So basically you could be past the event horizon and still be properly fucked, in slightly different way.
But even that only extends so far. IIRC there are stars orbitting the centre of a galaxy with a period measured in hours. Admittedly, that's not as close as it might suggest, again because of the massive gravity. Even with that angular speed, you still need a heck of a radius to stay in orbit there. But, still, if those survive just fine, then you can probably see how the rest of the galaxy is safe.
A polar bear is a cartesian bear after a coordinate transform.
Noone has ever "seen" an atom either, or a bunch of molecules.
What did you think you were seeing but incoming photons triggering electrical pulses to your brain?
Makes you think how little we do "see"..
http://www.debunkingskeptics.com/