Astronomers Find Gas Cloud About To Fall Into Black Hole 94
First time accepted submitter pigrabbitbear writes "Black holes are basically celestial Cookie Monsters, gobbling anything and everything in sight. But because that appetite includes light itself, it's incredibly rare for us to actually see a black hole suck back an interstellar treat. Astronomers using the European Southern Observatory's Very Large Telescope have found just that: a mysterious, giant gas cloud that's rapidly been pulled into the maw of a supermassive black hole. The researchers, led by Reinhard Genzel of the Max-Planck Institute for Extraterrestrial Physics in Germany, discovered the cloud as part of a now 20-year ESO program tasked with tracking stars as they whirl around the supermassive black hole, known as Sgr A*, at the center of our galaxy."
Re: (Score:1)
Just a thought - it would be nice that once an AC post reached troll -5 score, IP and related details (ISP, geograpgical location, anything available from HTTP headers) of the poster is added to his post.
Maybe it would discourage some of the trolls.
Re: (Score:3)
Just a thought - it would be nice that once an AC post reached troll -5 score, IP and related details (ISP, geograpgical location, anything available from HTTP headers) of the poster is added to his post.
That would be a good idea right up to the point where it was realised that such a technique could be used to harass, intimidate and silence any user expressing an unpopular opinion. Or, at least, any opinion likely to be unpopular with 5 or more users of the type who are happy to abuse the mod system to attack those they disagree with.
If you extended it to logged-in users, it could be used to give strong evidence as to a given account's true identity. In either case, it wouldn't even need much coordinatio
Re: (Score:2)
Abuse the moderation system? Hell, most of the comments I've seen in this thread are offtopic, yet they get modded up anyway.
I wish they'd bring the old metamoderation system back.
Re: (Score:1)
I felt stupid reading that without my 1 year old grandson setting on my lap.
Stupid...
Re: (Score:2)
It is a quote from TFA...
Re: (Score:1)
Really? A black hole at the center of our galaxy? Who'd have thunk it.
Re: (Score:3, Funny)
What an honour. (Score:5, Interesting)
To see this cosmic event happening before our eyes. I know that it has already happened and we are seeing the light from the event finally reaching our eyes or CCDS, but this is an awesome event to watch and shows how incredible the universe around us truly is.
It is humbling to think that it could be our solar system spiraling into the black hole, but we could save Earth if we had 6*6*6 levels of energy, we could keep Earth poised next to the black hole and watch everything else fall in. Until the Doctor opens the Satan pit that is...
Re: (Score:1)
>To see this cosmic event happening before our eyes.*
*For certain values of "see", "happening", "before" and "eyes".
Re: (Score:2)
Until the Doctor opens the Satan pit that is...
Don't be silly....
That was Cthulhu in the pit (strongly psychic alien taking over people's minds with squid faced minions.)
Seriously people, get it right! :P
Re: (Score:2)
To see this cosmic event happening before our eyes. I know that it has already happened and we are seeing the light from the event finally reaching our eyes
But that's no different than seeing anything else. You cannot see the present, you can only see the past. That sunset? Eight minutes old. That red dot in the sky they call Mars? It's ten to twenty minutes in the past. That coffee cup you're reaching for? It's the image of that cup from the tiniest fraction of a second ago.
Seeing that event that happened
Re: (Score:2, Interesting)
It's worse than that.
The impulses and other interactions that make up your neural activity aren't instantaneous either. One clump of your brain is humming along in total ignorance of what is even at that moment occurring on the other side. The delusion of "now" is even more insidiously false than mere travel time of a light beam to your eyes. Your brain is about as synchronized and contemporary as an easy chair thrown into a wood chipper: it's all over the place all the time. Consciousness is the sheerest c
Re: (Score:2)
The entire concept of "now" is pure fiction. Neurologically, physically, metaphorically and scientifically.
Nah; that's only true if you don't understand (or refuse to deal with) concepts like "digits of precision" or "error bars" or "resolution limit", which are used all over the place in scientific and engineering circles.
If you understand those concepts, then it's fairly trivial to define "now" internally to your brain and/or body; it's just the time interval that your mental processes can resolve. This interval differs for different people, of course. It's generally greater than a millisecond for humans,
Re: (Score:2)
To see this cosmic event happening before our eyes. I know that it has already happened and we are seeing the light from the event finally reaching our eyes
But that's no different than seeing anything else. You cannot see the present, you can only see the past. That sunset? Eight minutes old. That red dot in the sky they call Mars? It's ten to twenty minutes in the past. That coffee cup you're reaching for? It's the image of that cup from the tiniest fraction of a second ago.
Seeing that event that happened so long ago is no different than seeing the sun from eight minutes ago, or the coffee cup from a tiny fraction of a second ago.
The misunderstanding is that there is something like synchronicity between places -- there isn't! You learn that in distributed systems as well as in special relativity. The only synchronicity that makes sense is to connect places by light rays. So you can say, something you see happens right now, as now is the light-cone you receive.
Black Holes aren't hard to see because the suck up (Score:5, Interesting)
... light. They are hard to see because there aren't very many of them.
They are the residue left over by the death and subsequent collapse of particularly massive stars. Such stars can take other courses during their death throes, such as ejecting their mass all over the neighborhood in a supernova.
It is thought that at the center of our own galaxy and many other galaxies there are black holes that are the result of the particularly plentiful gas and dust there, but they are hard to see because they are surrounded by more of that gas and dust.
While we cannot see what is inside the event horizon of a black hole, we certainly can see what is just outside the even horizon. It's not just that there is an incredibly strong gravitational field there, but the gradient of that field is quite steep, that is, as one gets ever closer to the event horizon, the field gets increasingly stronger quite quickly.
The result is that any particle bound states such as atoms, molecules, atomic nuclei, or even nucleons such as neutrons and protons are torn apart because the particles that are closer to the event horizon are accellerated inward much faster than the more distant particles, despite the distance between all of the particles in that bound state being no more than the distance of an electron from the proton in a Hydrogen atom.
The result of all that tearing apart of bound particles, as well as the particles colliding with each other, charged particles interacting with the magnetic fields of rotating black holes and so on, is that the region just outside of the even horizon emits particularly intense, high energy, short wavelength X-Rays.
Those X-Rays are so bright that we can see them, if I understand correctly, being emitted from the material falling into black holes located in other galaxies.
I'm not really a software engineer; I only play one on the Internet. But I really am an astronomer.
Re:Black Holes aren't hard to see because the suck (Score:5, Interesting)
Wouldn't that mean black holes aren't necessarily rare, but only that black holes near gas clouds are rare? There could be millions of them in the interstellar void, but with no gas to form an accretion disk, they would be completely invisible. And lensing effects would be incredibly difficult to detect. In fact, I thought that we only really detected most black holes if they were part of a binary system (which gives plenty of matter for x-ray radiation).
And, of course, it is absolutely impossible to see something that emits no radiation (ignoring the possibility of Hawking radiation, which is too weak to see in most cases anyways), so technically black holes aren't hard to see: they are impossible to see. We can only infer it's presence through the effect it has on matter outside the black hole itself. The x-ray radiation is not technically from the black hole itself, but rather from the effect that it's gravitational field has on incoming matter.
I'm not an astrophysicist... but I'm working on changing that.
Re: (Score:2)
Wouldn't that mean black holes aren't necessarily rare, but only that black holes near gas clouds are rare? There could be millions of them in the interstellar void, but with no gas to form an accretion disk, they would be completely invisible.
But if a star formed there, then shouldn't there be plenty of matter hanging around? Of course, if millions of black holes sucked up everything in the void... Nah, millions of black holes => a lot more stuff in the void. It just seems unlikely. Say, what happens when two black holes collide?
Two black holes colliding would be quite cool (Score:5, Interesting)
Because if they did, quite likely they would emit some gravitational waves that we might be able to detect with optical interferometers here on earth.
Einstein's general relativity predicts such waves theoretically, but because gravity is such a weak force - consider that an object with the mass of the earth is required to make you feel your own mass bearing down on the soles of your feet - even the gravitational waves emitted by the objects in our own solar system are too weak to detect.
Gravitational waves are only emitted from asymmetric motions of large amounts of mass. The explosion of a supernova, while not perfectly symmetric, is close enough to symmetric that it doesn't emit detectable waves.
I would expect that two black holes orbiting close to each other at very high radial velocity, or just two very massive stars, would emit waves we would eventually be able to detect here on earth.
We have yet to find any exceptions to the theoretical predictions of Einstein's theory of general relativity, but there are a number of things that it predicts that we are as yet technologically unable to confirm either through experiment or astronomical observation.
A few years ago, someone measured the speed of gravity by observing the effect of Jupiter's gravitational field on the apparent position of a bright radio source, but their precision was so poor that if the speed of gravity is significantly different than the speed of light, their measurement was unable to distinguish it.
Re: (Score:3)
Say, what happens when two black holes collide?
When I'm curious about something I google it. [universetoday.com]
I expect that you are correct, however... (Score:5, Interesting)
... because most black holes are formed from the remains of particularly large stars, and such stars are formed from the gravitational collapse of large gas and dust clouds, one would expect most black holes to be close to regions where lots of stellar formation has taken place. Such places would quite likely still have lots of gas around.
However a black hole could have formed early in the history of the Universe. It is thought that if there are any really small black holes, they are left over from the Big Bang. Those black holes could indeed be in places where we could not detect them, and because they are not very massive, we could not see their effects on nearby matter.
It is the very small black holes that emit lots of Hawking radiation. The intensity of it increases with the gradient of the gravitational field. Large block holes have a less steep gradiant, smaller holes a steeper one. Very small black holes may have formed early in the history of the Universe, but by now would have evaporated due to emitting all that Hawking radiation.
Re:Black Holes aren't hard to see because the suck (Score:5, Interesting)
Wouldn't that mean black holes aren't necessarily rare, but only that black holes near gas clouds are rare? There could be millions of them in the interstellar void, but with no gas to form an accretion disk, they would be completely invisible. And lensing effects would be incredibly difficult to detect. In fact, I thought that we only really detected most black holes if they were part of a binary system (which gives plenty of matter for x-ray radiation).
And, of course, it is absolutely impossible to see something that emits no radiation (ignoring the possibility of Hawking radiation, which is too weak to see in most cases anyways), so technically black holes aren't hard to see: they are impossible to see. We can only infer it's presence through the effect it has on matter outside the black hole itself. The x-ray radiation is not technically from the black hole itself, but rather from the effect that it's gravitational field has on incoming matter.
I'm not an astrophysicist... but I'm working on changing that.
This is similar to one alternate theory to the whole dark matter garbage, to explain the amount of mass thought to exist in the universe (most of which we can't account for). Except instead of millions this theory suggests billions of tiny (about the size of a small town) black holes.
Re: (Score:2)
What I'd like to know is how much matter would there have to be in this dust cloud for X-ray emissions to be dangerous to life in the galaxy? I'm assuming that this one isn't since it's "only" 3 times the mass of the earth and would presumably not go in all at one time; there's bound to be a tipping point though at which the radiation will be energetic (and sustained) enough to sterilize the planets in a galactic plate.
Life would not be possible near a black hole (Score:5, Informative)
But I don't expect that many black holes would be big enough as to irradiate an entire galaxy to the point that life is impossible anywhere in that galaxy.
However, the very brightest celestial objects that we can see are the Quasars, or Quasi-Stellar objects. They are "Stellar" in that they appear to be pinpoint light sources, but their spectrum is heavily weighted to the bluer, higher energy end of the spectrum, and if I understand correctly do not appear to be radiating light as a result of just being hot. When an object emits thermal radiation, while that radiation is blueer (or 'X-ray-er') if it is particularly hot, the shape of the spectral intensity distribution takes an easily calculated form called the Planck Distribution.
There are lots of other ways to generate blue light other than thermally, but for many years, the incredible power of the Quasars was a mystery. The red shift of their spectrum that results from the expansion of the Universe between us and them is quite large, so clearly they are the farthest objects we can see, as well as the oldest, and must have formed not long after the beginning of the Universe.
It is thought now that the Quasars are very large black holes, such as those at the centers of some galaxies such as our own, but much much larger. I expect life would not be possible anywhere in their vicinity.
If a supernova goes off in any nearby galaxy, we can easily resolve it from its neighboring stars with average sized astronomical telescopes. Supernovas in more distant galaxies cannot be resolved, but they are at times as bright as the entire galaxy that they are contained within. If a supernova goes off within our own galaxy, at times we can easily see it at high noon on a bright, sunny day.
If any of our nearby celestial neighbors were to go off in a supernova, we would only get the bad news when all life on earth was wiped out almost instantly. We wouldn't just get 73h c4nc3r and die a few years later; the Earth's entire atmosphere would be blasted off into interstellar space.
The abundance of heavy elements not just on earth but throughout our solar systems makes us certain that the Sun is a second generation star, whose first generation star went off in a supernova, the intense pressure, heat and particle energy of which formed all those heavy elements that we find so useful for things like hard drive platters and Liquid Crystal Displays.
Re: (Score:1)
Thanks for all your informative posts on this topic. I enjoyed reading them, and appreciate the lean towards layman's terms. Felt I had to say so. :)
thank you. I really appreciate your kind words (Score:3)
i regard my writing as by far the most important thing I do, but never even attempt to get paid for it as I feel that informationnshould be as free as the wind.
but my colleagues over at Kuro5hin bluntly ignore my writing while giving me no end of crap for not being more productive as a coder, despite my having made clear for years that I am sick to death of writing software, and am struggling to find some waybto not have to write software at all anymore, so I can devote more time to my writing and music.
Re: Life would not be possible near a black hole (Score:2, Informative)
I don't think that's true. Read here:
http://stupendous.rit.edu/richmond/answers/snrisks.txt
Although supernovae are among the biggest explosions we know, space is very very big and the earth's athmosphere is very dense, compared to interstellar space. A supernova has to be quite close to produce a noticeable effect.
To quote the conclusion from the linked article above:
Conclusion: I suspect that a type II explosion must be within a few
parsecs of the Earth, certainly less than 10 pc (33 light years),
to pose a
Re: (Score:2)
The author of that paper claims he couldn't find research on gamma ray bursts. http://lmgtfy.com/?q=deadly+gamma+ray+burst [lmgtfy.com]
Re: (Score:2)
Gamma ray bursts could ruin our collective day by sterilizing the planet in minutes if one were to happen nearby. Thankfully, that appears to be unlikely.
http://researchnews.osu.edu/archive/gammaray.htm [osu.edu]
http://www.spacedaily.com/reports/Earth_Deemed_Safe_From_Gamma_Ray_Bursts.html [spacedaily.com]
Re: (Score:1)
Re:Black Holes aren't hard to see because the suck (Score:5, Interesting)
you are correct (Score:3, Informative)
What makes the approach to a black hole dangerous is not the intense gravity, but the very high gradient of that gravity. That is, if you were falling headfirst into a small black hole, your head would be accellerated inward faster than your feet, as if you were on a medieval stretching rack. If you were falling into a large black hole, while your head would still be accellerated more than your feet, the structure of your body would be strong enough to resist any injury.
Re: (Score:2)
Darn, once again I'm reminded of an Asimov story I can't remember the name of. It concerned a spacecraft manufacturer (with two heads and four legs) hiring a detective to find out why people are dying in the ships that are supposed to be indestructable. Turns out that they got too close to a black hole and the gravity gradient tore them apart.
Niven not Asimov (Score:3)
http://en.wikipedia.org/wiki/Known_Space#Invulnerable_Hulls [wikipedia.org]
The story you reference may be Neutron Star.
Re: (Score:2)
You're right, that's the story. It was indeed Niven, and it was a neutron star rather than a black hole. Been a couple of decades since I've read it. Iirc, I saw the story in a collection of stories by different authors, but I don't remember what book.
Re: (Score:2)
It was a perfectly normal supergiant until it took an arrow in the knee.
Re: (Score:2)
It is thought that at the center of our own galaxy and many other galaxies there are black holes that are the result of the particularly plentiful gas and dust there, but they are hard to see because they are surrounded by more of that gas and dust.
It is thought that the black hole in this story IS the black hole at the center of our galaxy.
http://en.wikipedia.org/wiki/Sagittarius_A* [wikipedia.org]
Are you sure you are an astronomer? Or did you not even read TFS?
"Cookie Monsters" (Score:5, Funny)
Really Slashdot? "Cookie Monsters"? "Interstellar treat"? Wow, I think I may have found a new low for a Slashdot summary.
Well, until tomorrow, anyways.
Re: (Score:3, Informative)
That's actually what the article says.
Re: (Score:2)
The summary is actually quite good, in that it captures the essence of the article it's summarizing. It's made mostly of key, near-direct quotes.
I also don't see the problem with using a silly analogy in a popular science context. Even if it annoys you, the video is well worth a silly analogy.
Re: (Score:2)
Re: (Score:2)
At least it's accurate. Unlike the sensationalist ones we've gotten. Contrast this one with something like "Gluttonous blackhole devouring our universe. It's currently devouring a gas cloud but will it satiate its appetite?"
Re: (Score:2, Informative)
Isn't it possible that the gravitational field of a black hole would also cause some "masses" to rotate around it like a sun or does it just suck everything in?
Yes-one of the confirmations of our own galaxy's central black hole was the observation of 3 (I think) stars, whizzing around an "invisible" object at break-neck speeds.
Re: (Score:3)
Re: (Score:2)
Black holes don't actually suck anything in. Things just more like... fall in. After spiralling down at ever increasing speed toward the event horizon. Once it passes this boundary, we're not sure what happens next. It could carry on spiralling down toward the singularity forever, never actually making contact with it but spiralling faster and faster until it hits the speed of light and converting to some exotic form of energy. There again it could just disintegrate into its component subatomic particles as
Re: (Score:2, Funny)
Black holes don't actually suck anything in. Things just more like... fall in.
Well, can't we put up a sign or something? How many innocent gas clouds have to suffer needlessly from this preventable hazard? I mean, what does it say about us as a civilisation if our scientists just sit around watching while this tragedy occurs?
WON'T SOMEBODY THINK OF THE HYDROGEN?!?
Re: (Score:2)
Electrons just want to be free, let them be free man!
When? (Score:4, Interesting)
So what does "about to" mean in astronomical terms? Tomorrow? Next year? In a few million years?
Re:When? (Score:5, Informative)
So what does "about to" mean in astronomical terms? Tomorrow? Next year? In a few million years?
Roughly two years: http://www.scientificamerican.com/article.cfm?id=black-hole-gas-blob [scientificamerican.com]
Re:When? (Score:4, Informative)
But also 25,900 ± 1,400 years ago.
Re:When? - correction (Score:1)
By the way, I don't know if anyone has seen Sesame Street lately b
They know it's about to be pulled in? (Score:5, Funny)
So did these hot-shot researchers even consider warning the gas cloud? No, they just plan to sit back and watch it happen, the bastards!
Re: (Score:1)
Thing one: We are observers only. Never get involved in the affairs of other peoples or planets. (Unless there's children crying.)
Re: (Score:2)
Re: (Score:3)
Correction: This already happened 27,000 years ago. We're just getting a look at it now.
Every article we see about an astronomical event, some would-be-insightful smartass pops up to make this exact same point.
We *know*.
Re: (Score:2)
Re: (Score:2)
+1 for Red Dwarf reference.
-1 for spelling the wrong word for "they're"
Glen Beck is falling (Score:1)
Into Nancy Grace?
Gas Clouds Are A 'Sometimes Food' (Score:4)
Even Cookie Monster knows that you can't snack on gas clouds all the time. You need to have a balanced diet, with a regular supply of Rocky Planets (with organic lifeform spices!!), Dark Matter, and of course Light. A healthy growing black hole needs to take in lots of light to stay strong.
Gas clouds - only sometimes.
Um... it's not a black hole. (Score:2)
It's a charcoal grey hole, you insensitive racist clod!
That's a switch (Score:2)
Re: (Score:2)
Brown hole, surely?
Re: (Score:2)
Indeed, truly historic. Would this be considered a traf?
Re: (Score:2)
What if? (Score:1)
One super massive black hole gets sucked in by another super massive black hole?
Re: (Score:1)
Then the holes merge and you end up with a super-dooper massive black hole.