Slashdot Mirror
Milky Way Black Hole Could Reignite
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.
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.
What does.. God.. need.. with a starship?
Slashdot Burying Stories About Slashdot Media Owned
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)
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
I for one welcome our "new" glactic core Overloards!
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)
Where's Beowulf Shaeffer when you need him?
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?
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.
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?
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
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.
If the terrorists get their hands on this, we're all doomed!
Quick, invade something, anything!
We emerge from our mother's womb an unformatted diskette; our culture formats us. - Douglas Coupland
The only thing we have to fear is if somehow the quasar spits out high energy tachyons.
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
Prediction: The real iPhone killer is going to be sex robots from Japan. Think about it.
... 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.
Real Daleks don't climb stairs - they level the building.
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!
There are two kinds of fool One says 'This is old therefore good' Another says 'This is new therefore better'- Dean Ing
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.
... is that true?
:-P
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
I must admit, my current understanding of what we think black holes are doing and where we'll find them is woefully lacking.
Cheers
Lost at C:>. Found at C.
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.
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.
Its 30K light yers away, so we wouldnt know for that long.
May 2008..... LHC Startup
Give or take ~1400 LYs.
HUGE difference.
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.
Don't active galactic nuclei fire out their "death rays" along the axis of rotation, ie perpedicular to the galactic disc, where we are.
that's easily the best HHGTTG reference I've seen in years. Congrats.
"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.
Guaranteed! This comment 100% Anthrax free!
I guess space as we know it would have to upgrade to class 3 pretty quick...
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!
There are only 10 kinds of people in this world... those who understand binary and those who don't
"Boom"
"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.
"As God is my witness, I thought turkeys could fly." A. Carlson
To be fair, it is still a way and not the (only) way that we know of now.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
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?
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
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.
Biologist are reporting that all of the dolphins have mysteriously vanished from the face of the earth.
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). That would re-ignite re-ignite the merged black holes, and we'd have to move to a better neighborhood.
Nothing for 6-digit uids?
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.
[b.belong('us') for b in bases if b.owner() == 'you']
OK, so if it does reignite, what the hell are we going to do about it? Lob a tac nuke or something? Waitaminit....
This sig no verb.
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.
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
Pfft... 30 LY? Is that all? I made the Kessel run in 13 parsecs, and all I got was this lousy t-shirt.
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.
Prov 9:8 Do not rebuke mockers or they will hate you; rebuke the wise and they will love you.
The ORI are coming and need the black hole to power the super gate.
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!
Guaranteed! This comment 100% Anthrax free!
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...
When I grow up, I want to have Christopher Walken hair.
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?
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.
*** Phil Plait, aka The Bad Astronomer http://www.badastronomy.com
Uh, yes. So what? No one was talking about neutrinos.
In 4.5 billion years or so, I suspect there have been few if any collisions between particles with high but opposite velocities. How often does one high energy cosmic ray particle knock into another going the opposite direction?
Yes, lots of collisions between high velocity particles with (roughly) stationary particles near the surface of the earth have happened, and nothing bad enough to destroy the Earth has happened. That is not proof about the results of collisions between particles with opposing high velocities.
Imagine shooting pool with balls that stick together. Imagine further that there's a possibility that the chemical process that makes them stick together is corrosive to the felt of the table. If the eight is sitting stationary right by the pocket and you shoot the cue ball into it, they stick together and go into the pocket together[*], and don't get a chance to eat into the table. You could shoot all day and the table would be safe, and you'd know nothing about whether the stickiness is corrosive or not.
But now I propose a new game. We'll stand at opposite ends of the table and shoot balls toward each other. Now when two hit, their momentum cancels out and this lump is left sitting on the table, maybe burning a hole in the felt.
([*]Yeah, there's the whole rolling versus sliding friction thing, conveniently ignored here. We're also assuming that the pockets take up the entire side of the table, so you never miss.)
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
"
If neutrinos can and do interact with particles...
Uh, yes. So what? No one was talking about neutrinos.
It's called an analogy. Much like your very lame pool ball analogy. Except mine makes sense.
If neutrinos, virtually massless particles with no charge, can interact with matter to an extent they are routinely detectable, then these super high energy particle generated in the upper atmosphere, it's likely in that in 4.5 billion years, at some point, that quantum black holes have been formed and that your so-called "evil particles" have also been formed, interacted with matter and NOTHING happened. Hasn't happened to Earth, nor Jupiter, Saturn, Uranus and Neptune.
Hasn't happened to the Sun, either. Nor, as far as can be determined, any other star we can observe.
If it hasn't happened via natural phenomina, it ain't a gonna happen in the LHC somewhere under France/Switzerland.
Guaranteed! This comment 100% Anthrax free!
No, it's called a non sequitur. Neutrinos, from man-made reactions or from natural ones, have not been seen to exist traveling at any velocity besides a whisker away from c. All neutrinos are equal.
The question here is not just whether weird dangerous particles could form, but with what velocity relative to the earth. If they can exist at all (and I'm not saying that they can) a non-evaporating micro black hole or a stranglet or a monopole at rest with respect to the earth is a different beast than one moving with a relativistic velocity, in terms of the probability that it could interact with the planet in a way hazardous to our health. The LHC would create the former, cosmic ray interactions the later (again, if they were created at all).
Five planets out of the entire damn cosmos is certainly an impressive sample size...
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
You know what they say about arguing on the Internet and the Special Olympics?
YOU WIN!
Guaranteed! This comment 100% Anthrax free!
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?
Unfortunately, the beams are so energetic that, this close to them, the percentage that scatters off the dense stars clusters and clouds near the core is still an issue.
I'd think of it as the difference between becoming a steam explosion and burning organics in a steel mill from having a crucible of molten iron dumped on you and being burned into a crispy critter by the infrared and splashed droplets from having one dumped on the guy next to you.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
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.
Of course the very center of a galaxy is a pretty busy area. So there's the possibility that a star, much farther out, has looped around another one and is on its way into the hole. Much like a comet being perturbed out of the Oort cloud or an asteroid getting perturbed into a hook around jupiter and dropping into the inner system. I imagine dumping a sun and its planets into the hole occasionally could cause a problem.
Orbital mechanics seems to be fractal, so I'd expect the core of a galaxy to have the same sort of issues with infalling stars, clouds, and clusters as the inner system of Sol has with comets. (And there IS that galactic cloud that's incoming...) If this is a general phenomenon, causing galaxies (or at least ours) to have a sterilizing flash every few million years, it could help to explain the Fermi paradox: We'd just be the first new lifeform since the last spring cleaning to develop to a radio-using tech level within radio range of our area.
There are a lot of galaxies like ours out there. Perhaps they can provide enough of a statistical sample to let us know how often such events can be expected.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
And the similar hypothesis about the layer of enriched iridium in rocks formed at the boundary between Cretaceous and those of the Tertiary periods and the associated extinction event ... 65.5 million years ago.
Could that suggest an alternative to the "impact from an asteroid or comet" hypothesis? Could this actually be the observance of a 100 million year "or so" natural galactic cycle?
If that is indeed the case, we should expect our local galactic black hole to go "milky white" in 15 to 35 million years or so.
Galactic Warming ... Keep your sunglasses handy!
BTW, if you couldn't already tell ... IANAAP and IANAG