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Milky Way Black Hole Could Reignite

kdawson posted more than 6 years ago | from the tinfoil-umbrellas-might-help dept.

Space 117

sciencehabit sends us to Sciencemag.org for an account of a survey of nearby galaxies that points to the possibility that once-quiescent galactic nuclei could wake up and become active again. If the Milky Way's dormant black hole should become active, it could be bad news for life on Earth (and elsewhere in the neighborhood). The paper (PDF) is up on the arXiv.

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Protect yourself (5, Funny)

Beavertank (1178717) | more than 6 years ago | (#23025120)

Remember kids, just like government mind control rays the gamma ray bursts generated by our galaxy's black hole center can be blocked by a tin foil hat.

You may want a tin foil codpiece, too.

Re:Protect yourself (1)

calebt3 (1098475) | more than 6 years ago | (#23025392)

+2, Informative?
*groan*

Re:Protect yourself (1)

SueAnnSueAnn (998877) | more than 6 years ago | (#23025490)

That is a conspiracy.
Use 30,000,000,000 sun block and you will be fine.

oblig. (2, Funny)

Rob T Firefly (844560) | more than 6 years ago | (#23025122)

What does.. God.. need.. with a starship?

Re:oblig. (1)

redtetrahedron (738841) | more than 6 years ago | (#23027430)

Worst. Trek. Movie. Ever.

Re:oblig. (5, Funny)

infonography (566403) | more than 6 years ago | (#23028196)

Worst. Trek. Movie. Ever.
Don't be so hasty, there are plans for many more....

Re:oblig. (1)

LithiumX (717017) | more than 6 years ago | (#23030578)

No... most regrettably, Insurrection has long-since beaten Final Frontier in the Worst Trek Movie Ever competition.

The difference between the two, on my end, is that I've watched FF at least once since buying it. I have started Insurrection twice, but never got more than 30 minutes into it. It was that bad.

Please note that the only reason I own either one is that I had two gaping holes in my Trek collection that had to be filled, regardless of how dirty I felt when I bought them.

Final Frontier proved that Shatner can't direct as well as Nimoy. Insurrection proved that, while Shatner deserved a beating for his mistake, someone else deserved a firing squad.

oblig. retort (1)

Mr. Jaggers (167308) | more than 6 years ago | (#23031766)

So, you're saying that when your obsession causes you to fill your two gaping holes, it makes you feel dirty?

Further, that you've only ever made it through 30m of the video? Twice?

Sure you aren't talking about another industry?

Just saying... ;-)

Re:oblig. retort (0)

Anonymous Coward | more than 6 years ago | (#23032144)

Sure you aren't talking about another industry?
Minutes, not seconds.

Re:oblig. (1)

infonography (566403) | more than 6 years ago | (#23028072)

What does.. God.. need.. with a starship?
I don't know about God, but I know the Puppeteers are bugging out even as we speak.

http://en.wikipedia.org/wiki/Pierson's_Puppeteer [wikipedia.org]

but they don't bother with spaceships either they use planets....

Re:oblig. (0)

pieisgood (841871) | more than 6 years ago | (#23029264)

Ring world is an awful book. "the sky was sky blue" yeah fuck you Niven... fuck you.

Re:oblig. (1)

MichaelSmith (789609) | more than 6 years ago | (#23030370)

We need a starseed lure. Fast!

Eye muss bee knew hear (4, Informative)

sm62704 (957197) | more than 6 years ago | (#23025136)

Darn, and I never EVER rtfa, but the summary made it necessary. So for my fellow slashdotters who hate to RTFA, what they mean by "reignite" is to turn into a quasar. The way the black hole could turn into a quasar is for the galaxy to collide with another galaxy.

I don't think we have anything to worry about. Nothing to see here (and if it happened, nobody to see it)

Re:Eye muss bee knew hear (0)

Anonymous Coward | more than 6 years ago | (#23025208)

On behalf of everyone who does not rtfa, I thank you.

Re:Eye muss bee knew hear (5, Informative)

Dan East (318230) | more than 6 years ago | (#23025216)

"The way the black hole could turn into a quasar is for the galaxy to collide with another galaxy."

That's not what the article says:
It's not understood what is causing the black holes to become newly active, because in most cases there is no evidence of collisions or mergers.

Re:Eye muss bee knew hear (0, Offtopic)

sm62704 (957197) | more than 6 years ago | (#23027258)

Give me a break, I'm seeing double because there's a nitrogen bubble in my left eye. Not only am I seeing double but that eye is REALLY out of focus. And since it's a bubble it moves around, which makes that part of the double vision move around too.

If I got pulled over there's no way I'd pass a field sobriety test, even though I've not been drinking.

The pain in my neck and back from keeping my head down 50 minutes out of every hour is distracting as well, affecting my reading comprehension too.

But mcgrew haters can rejoice, it keeps me from posting at slashdot much.

Re:Eye muss bee knew hear (0, Offtopic)

HuguesT (84078) | more than 6 years ago | (#23029112)

Out of curiosity, how did you develop that bubble ?

It's not just definite, it's *in*definite. (1)

HTH NE1 (675604) | more than 6 years ago | (#23027836)

To be fair, it is still a way and not the (only) way that we know of now.

Re:Eye muss bee knew hear (1)

ShadowMarth (870657) | more than 6 years ago | (#23028506)

Only way for black holes to become "more active" is for more mass to fall into it. Don't know what they're talking about...

Re:Eye muss bee knew hear (1)

kesuki (321456) | more than 6 years ago | (#23031812)

"It's not understood what is causing the black holes to become newly active, because in most cases there is no evidence of collisions or mergers."

Clearly it's the dark matter that nobody has figured out where it is or where it's going that's colliding with all these black holes making them quasars.

In theory a super large gravity well that's tightly compressed shouldn't change into a quasar with no reason. After-all with no impact, that would require matter escaping the singularity...

But FWIW i doubt it would affect life on earth, after all the luminosity of a quasar at it's brightest would appear as a second sun to objects within 33 light years away. we're about 26,000 light years away, so the radiation levels by the time they reach us would be 1/787th the intensity of our sun. in other words just a little more background radiation. and that's at the brightest know quasar. if a large galaxy were about to collide with ours i think it would be visible, and a known event, if dark matter were on a collision course, it would have to be a large galaxy sized formation of dark matter to affect earth residents. I think that dark matter on that scale would be detectable long before it collides, as it should block out stars and galaxies..

Re:Eye muss bee knew hear (1)

kesuki (321456) | more than 6 years ago | (#23031858)

Should have wiki'd

"Current measurements suggest the Andromeda Galaxy is approaching us at 100 to 140 kilometers per second. The Milky Way may collide with it in 3 to 4 billion years, depending on the importance of unknown lateral components to the galaxies' relative motion. If they collide, it is thought that the Sun and the other stars in the Milky Way will probably not collide with the stars of the Andromeda Galaxy, but that the two galaxies will merge to form a single elliptical galaxy over the course of about a billion years.[36]"

Re:Eye muss bee knew hear (2, Insightful)

John Hasler (414242) | more than 6 years ago | (#23025246)

> ...what they mean by "reignite" is to turn into a quasar. The way the black hole could
> turn into a quasar is for the galaxy to collide with another galaxy.

You didn't RTFA very well. The point is that they have found galaxies whose black holes have reignited without there being any evidence of a collision.

Re:Eye muss bee knew hear (0)

Anonymous Coward | more than 6 years ago | (#23025332)

Well, it -is- a black hole... why would there be evidence?

Re:Eye muss bee knew hear (5, Interesting)

DirkGently (32794) | more than 6 years ago | (#23025624)

Because black holes can only "eat" so fast.

As matter accelerates and gets closer and closer to the event horizon, particles begin bouncing into each other, like outside that one Who concert. Except in this case, instead of being crushed to death (as those concert-goers), centripetal force slings matter towards the poles of the hole with enough energy to achieve escape velocity. This creates a massive beam of ultra-high energy particles that would be very bad for your health. Well, two beams (one "up" and one "down"), but you get the idea.

Soo close (1)

Jarjarthejedi (996957) | more than 6 years ago | (#23025836)

Never in my life did I think I'd see a concert analogy for black holes that was so close to correct. I applaud you king of absurd but mostly truthful analogies!

Re:Eye muss bee knew hear (0)

Kratisto (1080113) | more than 6 years ago | (#23026428)

Sorry, did you say "centripetal force"? Get out.

Re:Eye muss bee knew hear (4, Funny)

IndustrialComplex (975015) | more than 6 years ago | (#23026462)

Massive relativistic death lasers? Concertgoers bouncing against each other to near the speed of light?

It isn't a galactic collision. It's just the reunion tour for Disaster Area.

Speaking as user Slartibartfast... (1)

Slartibartfast (3395) | more than 6 years ago | (#23026570)

that's easily the best HHGTTG reference I've seen in years. Congrats.

Re:Speaking as user Slartibartfast... (1)

Keramos (1263560) | more than 6 years ago | (#23031530)

It gives me the willies.

Re:Eye muss bee knew hear (1)

ag3ntugly (636404) | more than 6 years ago | (#23028070)

I already have tickets for the alpha centauri show!!!

Re:Eye muss bee knew hear (0)

Anonymous Coward | more than 6 years ago | (#23029442)

As it turns out, the centripetal force is not enough to create those "jets" you are talking about. In fact, the limiting term to watch for when matter escapes a black hole's grip is angular momentum, the matter has to gain enough angular momentum to over come the pull of gravity and be flung off. Turns out, this isn't possible with pure hydrodynamics as you would suggest because the matter would have had to enter the pull of the field with enough momentum to leave anyway. What ends up forming the jets is strong magnetic fields that are able to move the plasma in a way that guide the particles to the poles of the (something*) to create these anomolies we call jets, and as of yet the mechanism is unknown.

*I say something because there is a possibility that the jets are oriented with relation to the spin of the black hole, the spin of the accretion disk, or some combination thereof.

Re:Eye muss bee knew hear (1)

justthinkit (954982) | more than 6 years ago | (#23030788)

Henceforth, no moderator shall mod up a post ending with the digits "3029442".

How else to explain it?

Re:Eye muss bee knew hear (1)

roc97007 (608802) | more than 6 years ago | (#23031158)

So, since these huge frickin' ... er... death beams ... exit via the poles, wouldn't most of the planets in our galaxy be relatively safe from irradiation? It seems that the galactic black hole would rotate on the same plane as the rest of the galaxy. So to us it'd be like those giant search lights they point to the sky at Wal-Mart openings.

I wonder if you could accomplish the same thing with micro black holes. That'd be a hell of a weapon, although it'd give new meaning to "Back blast area clear!"

Reading comprehension requires practice (1)

Mostly a lurker (634878) | more than 6 years ago | (#23025320)

Unfortunately, your lack of practice in reading articles is apparent in your attempted explanation. I am no expert on the subject matter, but even I know enough to recognize that you misunderstood what they are saying.

Actually, the main message I get from the article is how complex the universe is, and how little is known, even by the most knowledgeable, about how these mechanisms work.

Re:Reading comprehension requires practice (1)

sm62704 (957197) | more than 6 years ago | (#23027292)

See here [slashdot.org] .

Re:Eye muss bee knew hear (3, Funny)

A nonymous Coward (7548) | more than 6 years ago | (#23025982)

Nothing to see here (and if it happened, nobody to see it)
Move along, move along.

Feed Me (3, Informative)

iamlucky13 (795185) | more than 6 years ago | (#23028090)

For a black hole to be active, it needs stuff falling into it...gas, dust, stars if you're unlucky. The stuff heats up to an extraordinary temperature due to friction as it falls in. To be hazardous at our distance of 25,000 light-years from the galactic center, it has to be quite a bit of matter falling in for a harmful intensity of radiation.

Our galaxy's black hole, Sagittarius-A, is not considered active, although it does have some weak emissions, primarily at harmless infrared and radio wavelengths consistent with a very small accretion disc. The nearest star to the black hole is estimated to be about 70 times as far away from it as it would need to be for the gravitational forces to remove significant amounts of material from the star. It also has an orbital period of 15 years, so it would take a long time and a significant perturbance to fall significantly close. It doesn't seem likely at all that it would become active in the foreseeable future.

Re:Eye muss bee knew hear (2, Informative)

DynaSoar (714234) | more than 6 years ago | (#23029190)

Darn, and I never EVER rtfa, but the summary made it necessary. So for my fellow slashdotters who hate to RTFA, what they mean by "reignite" is to turn into a quasar. The way the black hole could turn into a quasar is for the galaxy to collide with another galaxy.

I don't think we have anything to worry about. Nothing to see here (and if it happened, nobody to see it)
Obviously there is something to see here. Us. Our sun was a member of a galaxy that was absorbed by the Milky Way. The evidence is in the fact that we do not orbit the center of this galaxy in the plane of its arms, but rather perform a wave-like motion alternatively above and below the center plane, passing through the plane in between peaks. A galactic collision could produce the effect noted in TFA, while simultaneously increasing interstellar gas and dust cloud densities, protecting the outer stars from the radiation produced (as well as forcing new star production). So much for "It's not understood what is causing the black holes to become newly active, because in most cases there is no evidence of collisions or mergers." We are the evidence, and our existence is evidence the result need not be as dangerous as stated.

While we are well out from the center, we'd be in periods of more danger from the radiation than those stars native to this galaxy, due to our cyclic motion going outside the galactic plane. More danger, yes, but whether the danger is significant and whether other side effects might dampen the effects, are factors not addressed.

In any case, reignition of an active galactic core is due to an increase in infalling matter, and that's obviously not necessarily due to galactic collision. We can't see the details of the matter near the core, so we can't tell whether there's clumps that can fall in en mass, or whether it's relatively smooth and unlikely to cause bursts of activity.

Re:Eye muss bee knew hear (1)

Sibko (1036168) | more than 6 years ago | (#23032242)

Obviously there is something to see here. Us. Our sun was a member of a galaxy that was absorbed by the Milky Way. The evidence is in the fact that we do not orbit the center of this galaxy in the plane of its arms, but rather perform a wave-like motion alternatively above and below the center plane, passing through the plane in between peaks. A galactic collision could produce the effect noted in TFA, while simultaneously increasing interstellar gas and dust cloud densities, protecting the outer stars from the radiation produced (as well as forcing new star production)
Yeah, this was in a slashdot story awhile back I think. It was pretty quickly debunked by Bad Astronomy: [badastronomy.com]

[Opening paragraph in above link.] Note: I generally don't do a thorough debunking of pseudoscientific nonsense on the blog, and instead relegate that to the main site. But I decided to do this on the blog, knowing that more people would read it than if I put it on the main site and linked to it from the blog. So here it is. Bon appetit.

Re:Eye muss bee knew hear (1)

sjames (1099) | more than 6 years ago | (#23030024)

So that's what Elvon [paganlibrary.com] was talking about!

Oblig overlord post (0, Offtopic)

clonan (64380) | more than 6 years ago | (#23025164)

I for one welcome our "new" glactic core Overloards!

And we care because? (-1, Troll)

HexaByte (817350) | more than 6 years ago | (#23025278)

So, IF something 5K light years away happens within the next 10K years, we'll be effected how? My rotted, petrified bones may be irradiated? My great x 500 grandchildren, who by then will have conquered intergalactic space travel, might have to move elsewhere?

Ho-hum. Must be a slow science news day.

Re:And we care because? (0, Offtopic)

Surt (22457) | more than 6 years ago | (#23025370)

What if it happened 4999 years ago?
I mean, sure, we may still not care if Bush manages to trigger another world war by nuking Iran, but what are the odds of that happening?

Re:And we care because? (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#23026200)

Thank you for reminding me why you Americans get such a bad rap...

Not only do you have a prez that everyone hates, but you guys feel the need to remind us about it EVERY FREAKING TIME. I bet I could go through every slashdot article in the past year and find a link to you guys reminding us how much you (apparently) suck.

As someone who doesn't feel the US is the centre of the universe, please stfu, we don't care how your president relates to black holes.

I swear your a bunch of emo kids...

Re:And we care because? (0, Offtopic)

R2.0 (532027) | more than 6 years ago | (#23027710)

"I swear your a bunch of emo kids..."

No, the emo kids on Slashdot feel a need to make those posts, and then mod them up. It's a troll that has a big enough group behind it to support it.

That being said, read the FAQ - this is a US centric site. Deal with it.

Re:And we care because? (1)

LingNoi (1066278) | more than 6 years ago | (#23029438)

That being said, read the FAQ - this is a US centric site. Deal with it.
I think you're missing the point. The article is about black holes.

Re:And we care because? (0)

Anonymous Coward | more than 6 years ago | (#23025394)

You're missing the frame of reference.

It could have already happened. Until the light/radiation gets here it "hasn't happened yet" to us.

Re:And we care because? (0)

Anonymous Coward | more than 6 years ago | (#23025524)

The only thing we have to fear is if somehow the quasar spits out high energy tachyons. [wikipedia.org]

Re:And we care because? (1)

boristdog (133725) | more than 6 years ago | (#23025570)

Actually it's more like 30K LY away.

And it may have already happened, so go ahead and have that extra dessert.

-science nerd, dessert lover

Wrong. We are ~26,000 LYs from the galactic core. (1)

Picass0 (147474) | more than 6 years ago | (#23026278)

Give or take ~1400 LYs.

Re:And we care because? (1)

j_166 (1178463) | more than 6 years ago | (#23029476)

Pfft... 30 LY? Is that all? I made the Kessel run in 13 parsecs, and all I got was this lousy t-shirt.

I am building a ringworld (3, Funny)

RichMan (8097) | more than 6 years ago | (#23025280)

So massive core explosions delivering a huge radiation wave are expected.

Step 1:
    - invent scrith
Step 2:
    - build Ringworld
Step 3:
    - profit (sell real estate)

Re:I am building a ringworld (2, Interesting)

PakProtector (115173) | more than 6 years ago | (#23025772)

So massive core explosions delivering a huge radiation wave are expected. Step 1: - invent scrith Step 2: - build Ringworld Step 3: - profit (sell real estate)

Dear Sir and/or Madam:

Good Day. My name is Jack Brennan. You may call me Brennan-monster. I am writing on behalf of my Protector brethern. This letter constitutes a cease and desist notice. You have been publishing our trade secret, that is, our business plan. Please remove said plan from you website at once or face litigation.

Sincerely yours, Jack Brennan

Re:I am building a ringworld (1)

fifedrum (611338) | more than 6 years ago | (#23026668)

I always figured such a move to be more like, "I sense you are a threat and will now destroy your entire lineage. With my bare hands." rather than a C&D letter on paper

Re:I am building a ringworld (2, Funny)

PakProtector (115173) | more than 6 years ago | (#23031028)

I am civilised, after all. I'm a Belter, not a lawyer.

Jack Brennan.

Re:I am building a ringworld (2, Interesting)

Anonymous Coward | more than 6 years ago | (#23026728)

Umm... Jack Brennan (AKA BrennanMonster) was trying to protect humanity from the Pak, and the Pak already made the Ringworld, so prior art, and all that... :)

Re:I am building a ringworld (1)

PakProtector (115173) | more than 6 years ago | (#23031050)

We Protectors stick together.

Now go away, or someone with Genetic Luck will come along and ruin this conversation by making it so that any further dialog entered into it will only work out in their favour.

Jack Brennan

Re:I am building a ringworld (1)

PakProtector (115173) | more than 6 years ago | (#23031094)

Rich Mann.

Have you read Down in Flames?

At the core (0)

Anonymous Coward | more than 6 years ago | (#23025288)

Where's Beowulf Shaeffer [wikipedia.org] when you need him?

Okay, so this isn't relevant to my day-to-day life (3, Insightful)

mmell (832646) | more than 6 years ago | (#23025292)

but it is intriguing. I'm always impressed when scientists come forward and admit that they've found something they didn't expect. It validates the scientific method and the people who apply it to research - whether it be mathematics, anthropology, physics, cosmology, . . .

SO - not unlike the assertion (for example) that there's a large asteroid with Earth's name on it, this research seems to indicate that perhaps we should start studying this phenomenon now even if there's nothing we can do about it now. After all, much of our modern technology was understood to be impossible/impractical as little as a century ago; if we start looking now, perhaps we can devise a mechanism for the preservation of our species before we need it. Then again, when has humanity ever shown that much foresight?

Re:Okay, so this isn't relevant to my day-to-day l (1)

gmuslera (3436) | more than 6 years ago | (#23026038)

Understanding something better could have a big reward. Maybe not avoiding that all the life in 30k light years from galaxy center is wiped out, of course (that is the core of the RTFA?), but think that that will not happen (soon, at least), and that we learn more... maybe we can use that to implement future technologies or even stop a very dangerous experiment at LHC.

Re:Okay, so this isn't relevant to my day-to-day l (1)

Chris Tucker (302549) | more than 6 years ago | (#23026720)

"or even stop a very dangerous experiment at LHC."

You DO know that particles with much higher velocities and energy levels than the LHC could ever produce interact with other particles every second in the upper atmosphere of Earth, and that no planet devouring quantum black holes have appeard and devoured the Earth, nor have any "strangelets" converted the Earth to its component bits.

Oh, wait. Apparently no, you DON'T know.

Stop listening to Art Bell (or whoever is in the chair at his radio program these days) and read more Hawking and other physicists.

Re:Okay, so this isn't relevant to my day-to-day l (2, Interesting)

Mr. Slippery (47854) | more than 6 years ago | (#23027904)

You DO know that particles with much higher velocities and energy levels than the LHC could ever produce interact with other particles every second in the upper atmosphere of Earth

You DO know that such collisions involve one particle with high velocity impacting a particle at rest (relatively speaking) with respect to the earth, making the collision products scatter like billiard balls after a good break and thus taking them away from the planet in short order? As opposed to colliding two streams with opposite and equal momentums, creating whatever they create at rest (relatively speaking) with respect to the earth?

Am I expecting the earth to get eaten up by strangelets or mini black holes? No. But the "oh, hush, collisions like this happen all the time" apology has a big leak in it that I haven't yet heard addressed. If evil bits get created in natural collisions, they go scooting off into space at high velocities before they have a chance to do damage here; while if evil bits where to get created in the LHC, they'd have little momentum and would hang around.

So how many orders of magnitude smarter than the guys who told us that the Space Shuttle would was safe to one mission in 100,000, are the guys telling us this is perfectly safe?

Re:Okay, so this isn't relevant to my day-to-day l (2, Interesting)

NewbieProgrammerMan (558327) | more than 6 years ago | (#23029044)

...the collision products scatter like billiard balls after a good break and thus taking them away from the planet in short order?

It seems to me that a significant fraction of the collisions would produce particle showers pointed towards the ground. Even if 99% of the "evil bits" have momenta that don't allow them to settle into the earth, there's still a lot of evil bits (produced by incident particles with energies 10^4-10^6 times more energy than the LHC) over the last 4+ billion years that haven't destroyed the earth.

Of course maybe I'm missing some fundamental point here, and there's a reason to view this as a "giant hole" in the theory. If someone could be so kind as to point it out I'd appreciate it.

Re:Okay, so this isn't relevant to my day-to-day l (1)

Mr. Slippery (47854) | more than 6 years ago | (#23029342)

It seems to me that a significant fraction of the collisions would produce particle showers pointed towards the ground.

Sure. But the idea is that the particles so produced would be zipping along rapidly due to the momentum imparted by the collision, and would go right through the planet with a small chance of reacting with anything.

Re:Okay, so this isn't relevant to my day-to-day l (1)

Chris Tucker (302549) | more than 6 years ago | (#23030196)

If neutrinos can and do interact with particles, I.E. pure water in the diverse detectors worldwide, then it appearsthat in the 4.5 billion years or so that there has been an Earth made of solid matter, and the 3 billion or so years there's been an atmosphere of one kind and another, there has yet to have been an "evil particle" that has interacted with terrestrial matter or atmosphere.

Apparently, that "small chance" you posit is so small, as to be effectively zero.

Thanks for playing! Vanna has some lovely parting gifts for you!

Re:Okay, so this isn't relevant to my day-to-day l (0)

Anonymous Coward | more than 6 years ago | (#23031982)

I'm trying to figure out how they decided that a quasar formed 27,000 light years away could possibly create enough energy to wipe out life 30,000 light years away... After all the brightest recorded quasar was only outputting as much light as our sun within 33 light years away, only 33 not 33,000 light years away, so supposedly this rare event that creates an object 30,000 times brighter than any recorded object is supposed to doom life on earth how? first of all there hasn't been anything even close to that bright ever recorded, ever, not even a super nova.

so how is this going to wipe out life on earth? the radiation would be so diffused that it would be 1/787th the effect of radiation from our own sun. so that means the radiation would have to be at least, 5,000 times more lethal than any type of energy recorded from any solar event... WTF where the heck are people getting this 'kill all life in 30,000 light years' BS if they had said in 30 light years, i could buy it. but where does it say it would wipe out all life?

Re:Okay, so this isn't relevant to my day-to-day l (0)

Anonymous Coward | more than 6 years ago | (#23026238)

I'm always impressed when scientists come forward and admit that they've found something they didn't expect.
Why? Scientists are not nearly as dogmatic as the media and talk radio would have you believe. The fastest way to get big in science is to disprove accepted theory, hopefully with a replacement. While verifying accepted theory is critical to science, it's not rewarded, because "everyone already knew that".

I didn't say "disprove existing theory" . . . (1)

mmell (832646) | more than 6 years ago | (#23026294)

I said "admit that they've found something they didn't expect."

HUGE difference.

Oh noes! (1, Funny)

RabidMonkey (30447) | more than 6 years ago | (#23025460)

If the terrorists get their hands on this, we're all doomed!

Quick, invade something, anything!

Re:Oh noes! (0, Offtopic)

Radish03 (248960) | more than 6 years ago | (#23026144)

Quick, invade something, anything!

Don't be so quick to invade! I say, we develop manned space travel so that we may send some of our elected leaders to meet with the black hole in its homeland of the galactic nucleus to discuss the situation.

Re:Oh noes! (1)

j_166 (1178463) | more than 6 years ago | (#23029420)

"I say, we develop manned space travel so that we may send some of our elected leaders to meet with the black hole in its homeland of the galactic nucleus to discuss the situation."

So what you're saying is we fight them over there so we don't have to fight them over here. Brilliant! You build the spaceship, I'll build the giant magnetic yellow support-the-troops ribbon. (Well, I won't really *build* it so much as I'll outsource the building of it to China).

Re:Oh noes! (1)

Culture20 (968837) | more than 6 years ago | (#23027132)

If you invade the black hole, you'll only make it stronger.

20 to 40%? Reignite? (4, Insightful)

Gat0r30y (957941) | more than 6 years ago | (#23025690)

From TFA it seems like somewhere between 20-40% of galaxies surveyed have active nuclei, but how do they know they reignited?

It's not understood what is causing the black holes to become newly active, because in most cases there is no evidence of collisions or mergers.
How could it be verified that despite the lack of a recent collision with another galaxy, these particular phenomenon were at some point dormant like ours, then reignited? How are they supporting this claim that these galactic nuclei must have spontaneously rekindled vs. they have been winding down from a collision very far in the past?

There's just one problem: Astronomers have found quasarlike centers--called active galactic nuclei (AGN)--in some relatively nearby galaxies, which should be far too old to generate such energies.
So they should be too old for this sort of behavior, but how are they verifying the time since the last collision? Another possibility is that these galaxies had a collision more recently right?

Re:20 to 40%? Reignite? (3, Informative)

HTH NE1 (675604) | more than 6 years ago | (#23028026)

How could it be verified that despite the lack of a recent collision with another galaxy, these particular phenomenon were at some point dormant like ours, then reignited?
By the velocity vectors of surrounding matter affected by the blast? A collision would give the local matter directionality whereas a spontaneous reignition would send matter out in all directions uniformly.

Haven't you watched CSI: Stellar Cartography Unit?

Re:20 to 40%? Reignite? (1)

antic (29198) | more than 6 years ago | (#23030568)

Newbie question - things like galaxies colliding and black holes igniting and ungulfing galaxies - what sort of time scale would be involved with these events? If very high, I'm assuming that very high speeds are involved and that a drawn out event would simply stem from the sheer size of the objects in question?

The galactic core could be exploding? (4, Funny)

meringuoid (568297) | more than 6 years ago | (#23025752)

... Well, shit. I'd nearly saved up enough to buy a General Products hull, and now it seems they've shut up shop and left town.

Still not getting it ... (1)

gstoddart (321705) | more than 6 years ago | (#23025922)

OK, so I've R'd TFA, and I've read what people have posted so far. But, I'm still too thick to get it.

So, a quasar is an energetic black hole? Or it's kinda like a black hole, but different, and with more spinning and less dark?

What is the black hole "doing" when it's not spraying high energy particles every where? What happens to turn a black hole into a quasar short of two colliding galaxies? We're now sure that there is a black hole in the center of all-if-not-most galaxies seems to be implied by this ... is that true?

I must admit, my current understanding of what we think black holes are doing and where we'll find them is woefully lacking. :-P

Cheers

Re:Still not getting it ... (0)

Anonymous Coward | more than 6 years ago | (#23028170)

Yes, a quasar is an active black hole...or at least it seems to be. Theory and observations both support this, but it's not, to the best of my knowledge, considered confirmed.

For a black hole to emit strongly as a quasar, it has to have an accretion disc of matter falling into it. Actually, it's not the black hole that's emitting, it's the accretion disc, which near the event horizon heats up to millions or so degrees due to friction in the rapidly swirling matter.

When a black hole is not emitting, it just sits there acting invisible and heavy. They're actually quite boring.

Galactic collisions (not a collision in the normal sense of the word, since galaxies are mostly empty space), stir up lots and lots of dust and gas, which can lead to a dramatic increase in the rate that material falls into a black hole.

If you'd like to learn more, the wikipedia articles on black holes, quasars, and galactic mergers are all good starting places.

Re:Still not getting it ... (2, Informative)

Stevecrox (962208) | more than 6 years ago | (#23028668)

http://en.wikipedia.org/wiki/Quasar [wikipedia.org]

Quasars are an effect created by the supermassive black holes at the centre of each galaxy, these black holes consume tremendous amounts of mater (something like 10 sun masses a year) the more solar masses they consume the brighter they are. Obviously there is only so much material than can be pulled in by the supermassive black hole, eventually all the material is either ejected as high intensity engery (the quaser pulses we can observe) or consumed by the black hole.

The article mentions that astronomers have discovered galaxies with quasars which are old enough that the matter orbiting the black hole should have been used up. The current scientific hypothisis for old galaxies with quasars, is that the collision of two galaxies can generate new material which is pulled in by the supermassive black hole (thus supplying the matter to generate a quasar.) These older galaxies don't show any signs of recent collision and so the question of how the black holes in the centre are getting enough matter to generate a quasar needs to be asked. Since scientists don't know why there are quasars on these older galaxies they seem to be assuming that something else is causing new matter to be sucked into a galaxies supermassive black hole. The articles twist is this could potentially happen in our own galaxy, potentially killing us all.

Re:Still not getting it ... (1)

random coward (527722) | more than 6 years ago | (#23029880)

But this posits, without evidence, that the black holes in these galaxies in fact had run out of matter to pull in, before coming into contact with more, thus the re-ignite. It may just be that they never stopped being quasars and that some galaxies take longer for the matter to be pulled into the black hole than others. It may be that they never stopped being quasers and the theory on how long until the matter orbitting "should have been used up" is wrong.

The scary part (1)

portwojc (201398) | more than 6 years ago | (#23026068)

The scary part is this thing could already be active and we just don't know it yet!

The night sky would be pretty though.

maybe it already has (2, Insightful)

peter303 (12292) | more than 6 years ago | (#23026080)

Its 30K light yers away, so we wouldnt know for that long.

Re:maybe it already has (2, Insightful)

Culture20 (968837) | more than 6 years ago | (#23027278)

Unless it happened (30k years - 1 second) ago.

Date Set (1)

4g1vn (840279) | more than 6 years ago | (#23026104)

May 2008..... LHC Startup

No evidence for "re-ignition" (4, Informative)

random coward (527722) | more than 6 years ago | (#23026296)

Quick summary of TFA: Scientists observe that the black holes at the center of galaxies were Quasars on far away galaxies. The one at the center of the Milky Way and other nerby galaxies were observed to not be Quasars. So they theorised that the black holes initially are quasars after galaxy formation, and they run out of fuel. New observations show that nearby galaxies do in fact have quasars. A scientist conjectured that it re-ignited. Better conjecture may be that the fuel source of those blackhole-quasars is more variable than previously thought.

Re:No evidence for "re-ignition" (1)

ceoyoyo (59147) | more than 6 years ago | (#23029482)

That would be the most likely mechanism for reignition.

Black hole eats everything in easy reach, goes dormant. New source of fuel builds up in the neighborhood, black hole starts eating again, and the galaxy "reignites".

Axis of Rotation (2, Interesting)

FromellaSlob (813394) | more than 6 years ago | (#23026408)

Don't active galactic nuclei fire out their "death rays" along the axis of rotation, ie perpedicular to the galactic disc, where we are.

Re:Axis of Rotation (2, Interesting)

ivan256 (17499) | more than 6 years ago | (#23027418)

Take that a step further. Could that mean we wouldn't even notice? Would we be able to tell?

Space as we know it.. (1)

_14k4 (5085) | more than 6 years ago | (#23026730)

I guess space as we know it [wikipedia.org] would have to upgrade to class 3 pretty quick...

Here's a theory (2)

Alizarin Erythrosin (457981) | more than 6 years ago | (#23027514)

OK, here's my theory:

We detect the presence of black holes at galactic centers by observing the stars whirling around said galactic center at high rates of speed, right? All those stars whirling around have mass, therefore, gravity. Other stars moving around, maybe not as near to the galactic center, also have gravity. All this movement and such may attract, due to gravitational pull, a cloud of gas somewhere nearby. Slowly it gets pulled by the stars' gravity, until it gets into the gravitational pull of the black hole. Quasar'd!

A Message From the Milkway (1)

ndnspongebob (942859) | more than 6 years ago | (#23027616)

"Boom"

On an Unrelated Note... (1)

ExploHD (888637) | more than 6 years ago | (#23028290)

Biologist are reporting that all of the dolphins have mysteriously vanished from the face of the earth.

Just you wait... (1)

vrmlguy (120854) | more than 6 years ago | (#23028724)

Sure, it may seem academic now, but in just 3e9 years, our galaxy is going to merge with the Andromeda galaxy(http://en.wikipedia.org/wiki/Andromeda-Milky_Way_collision [wikipedia.org] ). That would re-ignite re-ignite the merged black holes, and we'd have to move to a better neighborhood.

Re:Just you wait... (1)

Geoffrey.landis (926948) | more than 6 years ago | (#23029286)

Sure, it may seem academic now, but in just 3e9 years, our galaxy is going to merge with the Andromeda galaxy(http://en.wikipedia.org/wiki/Andromeda-Milky_Way_collision [wikipedia.org] ).

Nope. That's entirely speculation. We do not know the transverse velocity of the Andromeda galaxy, only the velocity along the line of sight. No way to tell if it's going to hit or not.

What to do? (1)

dacarr (562277) | more than 6 years ago | (#23029104)

OK, so if it does reignite, what the hell are we going to do about it? Lob a tac nuke or something? Waitaminit....

stranger than fiction? (1)

Bob-taro (996889) | more than 6 years ago | (#23029494)

It seems like I read a sci-fi short story along these lines. Only I don't think it was a "black hole reignition". It was a "sun-like" object, only on a much larger scale. Scientists had verified it's existence and determined that, coincidentally, the first light from that object would soon reach earth (I don't know how they discovered it before the light from it reached us, but that's beside the point). Anyway, everyone's watching waiting to see this amazing new thing when it appears ... and it burns everyone up.

The ORI are coming and need the black hole to powe (1)

Joe The Dragon (967727) | more than 6 years ago | (#23030020)

The ORI are coming and need the black hole to power the super gate.

We're probably safe (1)

The Bad Astronomer (563217) | more than 6 years ago | (#23032810)

Our supermassive black hole is quiescent right now, more or less, because it's not feeding. But there are a number of events that can dump gas into it. Collisions are the best way, but we're not colliding with anything right now massive enough to do the deed. However, I have read that there is a large repository of gas not too far from the BH that could fall in sometime in the next 30 million years or so. Not too much to worry about now, but it could fire things up a bit. However, our BH isn't terribly massive as these things go (4 million times the Sun's mass) and there is some correlation between BH mass and activity strength when it occurs. Also, it's safe to assume that any jets of energy and matter would head up and out of the disk. There's a lot of gas and dust between us and it, so we're probably pretty safe.
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