Chandra Sees Black Hole Rip Star Apart

beeplet writes "Nasa just sent out this press release titled about an exciting Chandra observation. It states: "Thanks to two orbiting X-ray observatories, astronomers have the first strong evidence of a supermassive black hole ripping apart a star and consuming a portion of it. The event, captured by NASA's Chandra and ESA's XMM-Newton X-ray Observatories, had long been predicted by theory, but never confirmed." There is more information on the Chandra home page, including the x-ray and optical observations that were involved in the discovery." Note that the star-ripping pictured on the front page is labeled an illustration, rather than an recorded image.

Comments

that wasn't a black hole...

[cloudship_tacitus]

it was just unicron eating one of the autobot mooons.

Re:that wasn't a black hole...

[Metallic Matty]

it was just unicron eating one of the autobot mooons.

The first time I read that I thought it said "unicorn" and I was very puzzled.

Re:that wasn't a black hole...

[FuzzyBad-Mofo]

That's no moon..

Cheers

[after]

This is super.

A lot of astronomers, scientists, and general hobyists were in great doubt that black holes even exist. Now a lot more people will be more interasted in the field (or area) of this study.
I, on the other hand, was confident. It just makes great sence to me.

Re:Cheers

[Mick Ohrberg]

I find it interesting that we went from thinking black holes were rare, to thinking black holes are pretty common, but super massive black holes are rare, to black holes are pretty common and we think there are super massive black holes at the center of every galaxy.

I don't know about you, but I find the phrase "the black hole is feeding" somewhat unsettling.

Re:Cheers

[EverDense]

Black & white, is it?

Our "understanding" of physics also says that faster than light travel is impossible.

We no this is false, otherwise Star Wars is a complete fabrication. :-P

Did you notice the story here a little while ago, about the fact that all that "dark matter" that has been the basis of many a theory, may not even exist?

(not that I think black holes don't exist)

Re:Cheers

[rokzy]

you are simply wrong.

1. "our" understanding is that any massive particle travelling at less than the speed of light (in a vacuum) cannot be accelerated up to the speed of light. [it is possible (but AFAIK all attempts to detect have given a null result) that faster-than-light particles (tachyons) exist, but they would be created with speeds > light in the first place.]

2. in certain x-ray experiments you can have x-rays for which both the phase and group speeds are greater than the speed of light. however, they are highly dispersive and so cannot be used for communications. hence the more accurate version of your statement is "information cannot travel faster than the speed of light".

3. in the quantum-mechanical view, light travels from A to B with all speeds and along all paths, however the different paths interfere destructively such that the most probable path by far is in a straight line at speed c. the effect of these different paths is seen in interference experiments, most famously Young's double-slit experiment.

no I didn't see that particular story, I guess I was too busy actually *doing* physics.

dark matter isn't actually the basis of many theories (or at least not any good ones), it itself is a theory to account for observations.

Re:Cheers

[Darby]

in fact, if they DIDN'T exist we'd be totally screwed.

Why is this?

Re:Cheers

[rokzy]

because they are predicted by general relativity, so if they don't exist there must be something very wrong with general relativity.

also, many explanations of observations rely on them, such as active galactic nuclei (AGN). these are very bright galaxies, emitting ridiculous amounts of energy. black holes explain them perfectly, so if we don't have black holes we have a very big problem of what's causing all this radiation.

black holes are actually the most efficient "engines" known, far more efficient that nuclear fusion that powers the Sun and maybe one day our power stations.

Re:Cheers

[rokzy]

attitude like yours are what piss off scientists.

you take keep saying "current physics still says faster-than-light TRAVEL is impossible".

I'm trying to tell you you are wrong. it does not say that, you are vastly oversimplifying it. I've just given you an explanation why, but you keep saying it!

the only way you could be right is if you're using "travel" in the sense of "go on holiday". that IS NOT a scientific defintion, and thus "physics" wouldn't say that.

I'm a physicist, you're not, so where the fuck do you get off telling me or anyone else what physics says!?

is your other hobby trying to explain what the law really says to judges?

Better headline.

[Anonymous Coward]

Black hole rips star a new one!

Re:Better headline.

[bigfatslob]

Or better yet,

Slashdot rips Chandra webserver a new one!

Re:Better headline.

[ChandraWebAdmin]

Chandra webserver yawns at slashdot's meager attempts. The bulk of our traffic is coming from yahoo news. And while I admit that there were a couple of configuration issues that were brought to my attention earlier, they've been resolved, and things are humming along nicely. Traffic peaked between 8 and 9 (eastern) with over a million hits in that hour.

If you want the details, we had compiled apache for up to 2048 clients, but had left maxclients set to a meager 512, which caused some problems up until about 7pm eastern, when I bumped maxclients to 1536, and watched as actual connections peaked up around 900. We also had an errant script that was "gracefully" restarting the web server every 15 minutes, which boosted the load up to around 20 (the server actually didn't seem to mind). Fixed that quick.

The server, by the way is a SunFire 280R (dual 750 MHz) with 4G memory, attached by 100Mbit ethernet (from us to Harvard is gigabit, and from Harvard to the world is something really big). Once the errant script was stopped, load was steady around 1.9 (and I now also realize that there was an incremental backup in progress since about 6pm).

To paraphrase Kirk:
"I'm laughing at your superior network."

Why they always gotta be racist?

[Anonymous Coward]

This is just another conspiracy by the white man. First it's black holes distroying this, then dark matter touching that. What's a brother gotta do to earn a little respect in the universe?

Re:Why they always gotta be racist?

[DigiShaman]

Don't worry. In another dimension, the other end of a black hole is called a white hole. Just imagine all of the white people being insulted as it's own universe is being flooded with "white trash". It's tough being white *sigh*

Re:Why they always gotta be racist?

[spanklin]

We have to be even more careful when we talk about "hot black body radiation".

Re:Why they always gotta be racist?

[Snad]

and red dwarf?

Smoke me a kipper, I'll be back for breakfast!

Police Investigated further..

[Metallic Matty]

Police investigation into the brutal act led to one eye witness, Chandra, who described the black hole's violent attack as "gruesome."

Clip at 11.

Re:Police Investigated further..

[iminplaya]

Does this let Gary Condit off the hook?

Don't bother

[dr_dank]

strong evidence of a supermassive black hole ripping apart a star and consuming a portion of it

The goatse jokes pretty much write themselves at this point.

Text-only version

[after]

The site is becoming a little slow already, so here is a text-only version. The http://chandra.harvard.edu site seems to be slashdoted already.

Uh, are you saying it's a fake?

[Anonymous Coward]

You must work for Fox.

/dev/null

[Anonymouse Cownerd]

cat star > /dev/null

i thought black holes were not proven to exist, or am i living in the past?

Re:/dev/null

[egomaniac]

i thought black holes were not proven to exist, or am i living in the past?

There is a tremendous amount of evidence favoring the existence of black holes. Whether or not you personally consider this evidence "proof" is up to you. Some people accepted the theory of evolution as soon as Darwin proposed it, while others still don't, despite the unbelievable preponderance of evidence and complete lack of scientific alternatives. In the end, all you have is the evidence, and what you make of it is up to you.

For what it's worth, virtually every astrophysicist considers the existence of black holes to be a simple fact at this point. As they know a hell of a lot more about the subject than I do, I tend to simply accept their beliefs on such matters. This in no way means that they can't be wrong, but they're much more likely to have things figured out than I am.

Re:/dev/null

[NumbThumb]

People, please get that streight: In empirical science (that's pretty much any science besides math and philosophy), *nothing* can be proven. You can observe *evidence*, and can *disprove* a theory by providing contradicting evidence. But one can not prove a theory, by definition. You can show it's consitent with other theories. But you can't prove it has anything to do with *reality* (whatever that is). Teach your selfs some basic epistomology/phenomenology.

Ok. Now to black holes: IANAPhysicist, but as far as i know even though black holes can not be observed *directly* you can very well observe their effects like gravitational distortion, the radiation emitted by matter being sucked in, and according to S. Hawkings also a type a quantum radiation which causes black holes to evaporate over time (i'm not claimin i understood that).

As to the question of wether black holes are real? -- WE JUST DON'T KNOW. But i like the idea...;)

end of rant.

Re:/dev/null

[spanklin]

i thought black holes were not proven to exist, or am i living in the past?

There are a number of experiments that show that an object exists at a particular location with an enormous mass and an incredibly small radius. No other object than a black hole fits the data, so we take this indirect evidence as proof of the existence of black holes. From my point of view, the best evidence is the orbit of stars around the black hole at the center of the Milky Way. Check out a movie here.

Re:/dev/null

[dclydew]

I once spoke to a christian, I asked him why he believed in God, the Bible and Hell... he told me:

"The Church knows a lot more about the subject than I do, I tend to simply accept their beliefs on such matters."

I once spoke to a suicide bomber, I asked him why he thought he would go to Heaven by killing... He told me:

"Our leaders knows a lot more about the subject than I do, I tend to simply accept their beliefs on such matters."

I once spoke to a Jehovah's Witness, living in a concentration camp in Nazi Germany. I asked him why he wouldn't say Heil Hitler and gain his freedom... He said:

"The Watchtower knows a lot more about the subject than I do, I tend to simply accept their beliefs on such matters."

I asked the Roman who was nailing Jeshua bin Joseph to a crucifix, I asked the apostles who were killed for following him, I asked the followers of Do, Jim Jones and David Koresh why they were willing to act in such strange ways... they all replied them same.

I looked out over the world and cried from the mountaintop: "Why? Why do you follow other men who are just as prone to mistakes as you? Why do you simply believe what someone tells you? Why do you think any of us really know the answers?

Then they came to my mountain, the Christian, the Jew, the Muslim, the Catholic and the Protestant, the Nazi, the Religous Right, the Scientest, the Physist and the Doctor. For I had attacked the one thing that they all believe in. Like an army they marched toward me, then crying havoc they let slip the War of Dogma.

(The above is a metaphor... but then maybe everything else is as well)

Now there's an antacid commercial

[kammat]

The heartburn after chowing down on one of these has to be brutal. Where do you find a Rolaids or Tums to quench that sucker?

Great results from the great X-ray telescopes

[mbrother]

I know Stefanie a little bit (overlapped at some meetings). This is her second coup in the last year -- she was also involved with using X-ray observations to identify a binary black hole in another active galaxy. There has been good evidence for such X-ray flaring in the past from ROSAT data alone (now you see it, now you don't), but this is the first time to catch one of these things in the act using XMM and Chandra which are much more capable than the previous generation of X-ray telescopes. XMM can collect more photons, and Chandra can provide image quality equal to that of optical telescopes (telescopes like ROSAT were 100 times worse). We still have no idea how important such stellar disruptions are in the grand scheme of thing, fuelling black holes, etc., but dang, they are cool. I want to put one in a science fiction novel someday.

Re:Great results from the great X-ray telescopes

[Anonymous Coward]

How is $.94 five times less than $.99, no matter what unit you use? It's not. It's five units less, not five times less. That's assuming you meant to use $.01 as a unit and not $1.00, in which case it would be $.05 units - not times - less.

Why don't you just go on the assumption that most of the rest of the known universe will make when reading this: that "100 times worse" is not a specific measurement, but simply implies a significant difference in quality.

Re:Great results from the great X-ray telescopes

[mbrother]

I'm talking primarily about the resolution (Chandra resolution is 0.5 arcseconds, ROSAT resolution like 50 arcseconds). XMM also has a huge improvement in collecting area which may be something like 100 times better sensitivity, at least for harder energies, but I'd have to look up the numbers for a quantitative comparison. I think it's fair to say in general that the new X-ray telescopes are a couple of orders of magnitude "better" (in terms of resolution and sensitivity) than the previous generation of X-ray telescopes like ROSAT. Not to denigrate ROSAT, which was great for its time and produced wonderful science.

Re:Great results from the great X-ray telescopes

[Celandine]

The ROSAT HRI was nothing like as bad as 50 arcsec -- more like 5, depending on what exactly you're measuring (FWHM? 50% enclosed energy? etc). The PSPC (the other main imaging instrument on ROSAT, for those of you who aren't keeping up) was a lot worse than that, of course. Chandra is about 4 times more sensitive in the ROSAT band, 0.1-2.4 keV, than the HRI was, in terms of count rates from a soft source, and a little bit more sensitive than the PSPC. XMM (if you measure the raw count rate from all cameras) is about 10 times more sensitive than the PSPC, so if you want to compare XMM to the ROSAT HRI your `two orders of magnitude' is only about half an order of magnitude out. For energies harder than 2.4 keV and less than ~ 8 keV both Chandra and XMM are infinitely more sensitive than ROSAT, so the comparison is hardly fair (-:.

How fast does a Blackhole consume?

[fembots]

Does anyone have an idea how fast a blackhole 'finishes' a planet?

I mean, we have a blackhole closing in the Solar System, do we, the puny human, have time to feel anything? And if we do, what kind of thing will be happening on Earth?

Re:How fast does a Blackhole consume?

[rjelks]

Here's an interesting site (google cache) about black holes. I'm not sure how long it would take, but to an outside observer, it would seem like forever, relatively speaking. :)

Re:How fast does a Blackhole consume?

[Dylan Zimmerman]

To answer those questions, you have to first understand what it is that a black hole is. It isn't some magical thing that eats whatever it touches. It doesn't have infinitely strong gravity.

It's just a normal piece of matter like any other. The only difference is that a black hole is dense enough that it can catch light.

Now, as you approach a black hole, time dialation increases and the apparent event horizon of the black hole decreases. Once you hit the Schwarzchild Radius, there is no escape because there's an infinite red shift on anything moving outwards. However, for you, time would still be passing.

Black holes cause gravitational distortions sort of like shear forces on a bolt. These shear forces can break matter apart quite effectively. If the black hole is small (like a thin metal plate pushing on the bolt), then it might tear a hole in the matter. If the black hole is big (like a REALLY THICK metal plate), it will still eventually tear you apart, but much more regularly. Really, that second case is analogous to pushing a bolt into a block of metal sideways. The force is fairly even all over the bolt.

Another problem with the time dialation is that a small enough black hole (with an event horizon say, the size of a pea) would cause things to age differently. Put it near a plate of steel and the steel closest to it would age significantly more slowly than the steel at the edge of the plate.

To answer your first question, if a black hole was coming to devour us, it would take quite a while as percieved by us, the devoured. The second question is quite different. We would certainly be able to notice a black hole coming to devour us. X-Rays would probably be the best indicator, since black holes are quite powerful X-Ray sources.

And last, the third question. I don't really know. With a planet-sized or smaller black hole, I would expect the Earth to tear itself apart as the rotational inertia of the side away from the black hole would cause great internal stresses on the Earth. With a large enough black hole, it probably wouldn't be too noticible at all for quite a while. Again, internal stresses would eventually break the Earth apart. However, that would have to be one FREAKISHLY huge black hole. We're talking larger than most stars, here. If the black hole is tiny, it would rip a hole through things, but the Earth might remain intact. It all depends on mass.

If I'm wrong here, somebody please correct me.

Re:How fast does a Blackhole consume?

[SharkJumper]

I wouldn't worry about it. The current plan is to throw Neptune in the black hole as an appeasement offering long before it gets to us.

Crap. A perfectly good chance to make a Uranus joke, and I missed it.

A Twist

[hambonewilkins]

In a twist, this time it was the hole tearing a new one.

In other news...

[drgonzo59]

A radio telescope has captured a wave pattern of a loud burping noise comming from the direction of a supermassive black hole.

New Fox special...

[Trickster Coyote]

When Black Holes Attack!

Re:New Fox special...

[cbuskirk]

Awsome. Now if only I could compensate for the time dialation I could figure out when it would be on.

Re:New Fox special...

[Dr Caleb]

If it does come on, it will never, never end.

In Other News...

[lexbaby]

Thanks to Darl McBride, executives have the first strong evidence of IBM ripping apart SCO and consuming a portion of it. The event had long been predicted by theory, but never confirmed.

Re:Someone lives in the black hole.....

[Patrik_AKA_RedX]

Well, some day we'll find alien life, although I doubt it will be much like SF showed it to be.
Most likely it will be a robot to make 'first contact' with an alien instead of Captian Kirk.

IMHO I think space exploration is going to be a robot-only job for the forseable future. I doubt manned mission are going to be more than a show than a real important part of the exploration*. At least not until we've developed a better space access (space elevator perhaps).

* I mean the exploration of space, not the development of space technology. Manned space missions will be valuable for developing the tech needed for colonies and space stations.

Is there..

[Creepy Crawler]

Any evidence of gravity waves from this? If "gravity waves" do travel at C, this is a good way to see them.

Or do we have to be outside the solar system to observe them?

Re:Is there..

[beeplet]

We don't have to be outside the solar system to see gravitational waves, but even LIGO wouldn't be sensitive enough to see gravitational radiation from something like this. At best, LIGO might be able to see a neuton star spiralling into a super-massive black hole, because it would be able to fall further in before being torn apart by tidal forces.

Re:Is there..

[forand]

Incorrect, Einstein's theory has allows for "gravity waves," i.e. you can find a periodic propagating solution for the stress-energy tensor that "looks" like a wave traveling through, or in this case, by, distorting space-time.
Similar to classical E+M, which allows E+M waves, GR doesn't state that these are propagators of the force just solutions that exist.
Hope this clarifies.

Re:Is there..

[forand]

Currently we do not have any Gravity wave detectors that could observe this, as stated in another reply LIGO could not observe this, nor pretty much anything short of something really strong happening within a VERY close range. We have not observed any gravity waves directly, however we have seen that rotation periods of certian large bodies indicate that energy is escaping the system beyond that predicted by hawking radiation, which is consistent with gravity waves carring said energy away. Hope this helps.

Cosmic game eh??

[Creepy Crawler]

Blue 5 in corner pocket.

Maitre D

[Reverend Beaker]

After eating half a star does anyone suppose the Maitre D said "And finally, monsieur, a wafer-thin mint" to the black hole?

Blackholes and Time Travel

[GillBates0]

For those of you interested in the implications of Black holes on higher dimensions and time travel, CERN is on the verge of producing a large number of black holes at their Large Hadron Collider.

Physicists at may soon be manufacturing copious quantities of black holes. When the Large Hadron Collider (LHC) at CERN, the European particle physics laboratory near Geneva, is completed in 2005, it could produce a black hole every second.

These tiny, fleeting phenomena might just give researchers a long-sought glimpse of the hidden dimensions of space.

This development of Black Holes on the planet poses big questions about the dangers and risks involved in handling Black Holes. If one gets out of control, it could potentially "eat" through our planet in no time.

This story has been getting a lot of attention on other time-travel/astronomy related sites, supposedly because people think it was predicted by a time traveller (do a google search). Just some food for thought.

Re:Blackholes and Time Travel

[Loki_1929]

You say this as though anti-matter (also produced in labs) has any less planet-annihilating potential. Basically, we passed the threshold for potential self-annihilation as a species back in the 1940s. Every day we survive is little more than luck. Come to think of it, that we are here at all is a remarkable stroke of luck. Thus, our existence extinguished would be less of a loss to the universe than we would like to believe.

If we are to destroy ourselves, it would be nice if we could do it in such a way that our life-building components are thrown about the universe so that we might actually father an entire new population on some distant world. Couple billion years of my DNA floating around space and a whole lot of luck could even spawn a whole race of 'Me's!

I, for one, welcome our new planet-destroying scientist overlords!

Re:Blackholes and Time Travel

[evilWurst]

I know, I know, this is slashdot, and people can't really be bothered to read the articles... but when someone actually links to something, I expect *them* to have read their own article!

"this too should form black holes. These will be about a million times smaller than the nucleus of an atom and will survive for barely an instant.

The physicist Stephen Hawking predicted in the 1970s that black holes would evaporate by radiating away their energy. For astrophysical black holes this is a very slow process, but extremely small black holes should last about as long as a snowflake in hell."

You can stop building that black hole shelter now :)

Re:Blackholes and Time Travel

[ImprovOmega]

Note: IANAP(hysicist)

From a thought experiment point of view, a teeny-tiny black hole would have an event horizon (the point of no return so to speak) with a vanishingly small radius, as subatomic particles come into contact with it, it eats those, then it eats more and more of them until it's eating atoms, then...and so on.
It is worth noting that black holes, being 0-dimensional points, have infinite density and would (absent an electromagnetic field of some kind) fall straight into the earth's core, and in our little thought experiment, eventually eat the earth from the inside out. However:

A bit of googling turns up the following link:

http://www.alcyone.com/max/writing/essays/black- ho le-evaporation.html

which shows that a black hole evaporates over an amount of time proportional to it's mass cubed. Let's assume they make a black hole that weighs 1kg, then

tau=c^2/(3*(3.563*10^32)) * (1kg)^3
tau=8.4198*10^(-17) seconds

which is not long enough to worry about by any means =)

Re:Blackholes and Time Travel

[Anonymous Coward]

Interesting. So a 1 ton black hole will evaporate in 10 nanoseconds, and in that time emit 9*10^19 Joule, equalling 21500 megatons of TNT.

I have a feeling that this research will not be lacking in funding.

Re:Blackholes and Time Travel

[Ralph Spoilsport]

...not to be a total grouch, but all of this is assuming that Hawking is correct. We have no proof this is so.

There is a non-zero probability that one of these blackholes could eat a particle, then another and another and the next thing you know: poof. In a few weeks the moon will orbit a black hole.

Now, let's see - we have no tests for evaporating black holes, and some geek in Switzerland thinks it's a good idea to do it here on earth. It is likely that Hawking is *probably* correct. But if he's not, we could be TOTALLY fucked. Personally, I'm putting my money on Hawking, but frankly I find this kind of work a bit unnerving. The only justice would be that the first to get ripped into quantal goo would be the dorks at CERN.

All the more reason for a moon base, IMHO.

The moonbased atomsmasher could be powered by He3 fusion - right on site. although, if the moon disappeared into a blackhole, we'd get fried by the radiation anyway. Hmmmm.

All the more reason for a Mars Base, IMHO...

This way, if Mars gets eaten by a homegrown Blackhole, we'll be less likely to be nuked by the results. Maybe. Aaaaah - nemmind. When the ring gets vapourised by an errant blackhole, the Swiss geeks will say "MEIN GOTT!" just as they are vapourised. Good 'nuff. This sentient life thing was such a crap shoot from the start, anyway.

RS

Re:Blackholes and Time Travel

[Hays]

Anti-matter goes away when it touches normal matter, there's not really any danger of run away chain reaction.

I guess there could have been fear of run away nuclear reactions destroying the world... Of course we know it won't happen now.

But fears that run away black holes could eat the planet seem a little more reasonable. Even if the physicists say they will exist for only short periods. It just makes me nervous.

It just reminds me of someone's conjecture that the reason we don't find any advanced extraterrestrial civilizations in the universe is because they all stumble upon the same technology or experiment that destroys their civilization. And we'll be finding it in the future.

Ah well... back to building my robot army. That couldn't cause any problems.

Re:Blackholes and Time Travel

[Quantum Jim]

There really isn't much to fear from getting sucked into an artificial black holes, from being turned into strange matter, or from other proposed Armageddon scenarios. This is explained in this article from Popular Science and this paper on speculative Disaster Scenarios at another particle collider. Basically, there is a large probability that - if these objects are really dangerous - then they would have been already been produced by natural particle collisions in outer space near enough to destroy the earth. Since we exist, these objects can't really be dangerous!

Re:Blackholes and Time Travel

[John Meacham]

dear golly. there is NO CHANCE of the black holes being produced being a danger to anything for a number of reasons.

1. many more, much much larger (but still very small) black holes are constantly being created in our atmosphere by cosmic rays. these have not swallowed the earth. the energy of the collisions we can create is still insignifigant compared to what occurs naturally.

2. black holes do not attract matter because they are black holes. they attract due to gravity, just like planets, stars and all other matter. we are creating black holes the size of subatomic particles. A black hole the size of a proton has exactly the same gravitational pull as a proton. A protons gravitational pull is not going to cause any effect on anything. remember gravity is the weakest force that exists. by a whole lot. gravity is not amplified because it is eminating from a singularity rather than a particle.

Re:Blackholes and Time Travel

[Enonu]

The Earth is 4.5 or so billion years old, and we're still here. So basically, the odds that anything like this will affect your life is ~0. There are more important things we have to worry about that we actually have control over.

Re:Blackholes and Time Travel

[shadowbearer]

The only justice would be that the first to get ripped into quantal goo would be the dorks at CERN.

No, if a quantum black hole created by the collider did (insert miracle here) manage to survive long enough to start eating atoms, it would, fairly rapidly, drop (well, orbit) to the center of the earth (where it would find higher densities and a lot more to eat). Remember that it's not going to interact with matter much at all at first, so essentially the only force acting on it then would be gravity (the earth's).

It would grow extremely slowly, at first, so it's likely that nobody would notice anything for quite a while - especially given how hard it would be to keep track of the thing in the first place. However, the last few days/weeks of the earth's existence would be quite, um, interesting :) as the accretion accelerated....

SB

Re:Blackholes and Time Travel

[dwighteb]

There is a non-zero probability that one of these blackholes could eat a particle, then another and another and the next thing you know: poof. In a few weeks the moon will orbit a black hole.

Ok - first of all, the gravitational effect from these black holes would be small - since, well, they're being made by particles from earth, their gravitational effect on the surrounding environment would be about the same as however much matter was compressed down to form the particular black hole. Also, note that the radius is is much smaller than than the nucleus of an atom.

Now, since the gravitational effect of these mini holes is neglible, compared to the earth's, they won't go sucking all the matter around them like a vacuum cleaner. If they aren't totally unstable, as predicted by Hawking, and they linger, their effects will be small. Think about it - they will either fall inward towards the earth's core, and occasionaly eat some particles, or they will fly out in to space, eating an occasional particle.

Remember - matter here on earth is made up of mostly empty space - if we took a carbon nucleus, and expanded it to the size of a football field, then placed it in the center of the earth, the electrons would be orbiting at the earth's surface. There is a _lot_ of empty space for these mini black holes to travel through - never mind the relative distances between molecules.

All the more reason for a Mars Base, IMHO...

Having said all this, I do agree with you on the Mars base. I personally doubt these mini black holes will have a catasrophic effect, but of course I can't prove it.

We found a WMD!

[moosesocks]

This is great news for both NASA and the Bush administration, as they have now located their first Weapon of Mass Destruction.

Oh... false alarm.... wrong type of mass...

Re:We found a WMD!

[revscat]

Didn't you get the memo? WMD is so last year. The new hotness is reaching out to social conservatives. You know, opposing gay marriages, increasing funding for anti-porn initiatives, screaming about Janet Jackson's left boob, etc., etc.

Re:We found a WMD!

[Barlo_Mung_42]

"increasing funding for anti-porn initiatives"

What!?!
Ok. I'm going to vote this year for real.

But...

[Loki_1929]

We don't need these old, damn-near useless satellites.

This is not surprising.

[pclminion]

They've been examining RX J1242-11 for over a decade. Check out this paper which describes X-ray observations made in 1999, and mentions investigations of this "non-active" galaxy going back to 1990 at least.

The phenomenon is termed "large-amplitude X-ray variability." It appears that they've finally advanced their models and observation techniques to the point where they are willing to state publicly that this is indeed caused by a black hole. But it's been suspected for years and years.

Re:This is not surprising.

[beeplet]

The last paragraph of the press release explains why this is a more convincing observation:

Other dramatic flares have been seen from galaxies, but this is the first studied with the high-spatial resolution of Chandra and the high-spectral resolution of XMM-Newton. Both instruments made a critical advance. Chandra showed the RXJ1242-11 event occurred in the center of a galaxy, where the black hole lurks. The XMM-Newton spectrum revealed the fingerprints expected for the surroundings of a black hole, ruling out other possible astronomical explanations.

Thus, it is not the X-ray variability itself that is news, but the fact that they have enough evidence to back up a specific mechanism.

Re:Can someone explain...

[pclminion]

The X-rays are not emitted from the center. They are emitted from outside the event horizon by hot gas (millions of degrees) orbiting at huge velocities. Centrifugal force spins the gas out into an "accretion disk" and superheats it as it slowly spirals into the black hole.

Match with Theory?

[4of12]

I seem to recall that there are theories about how a black hole devours a star, that accelerating ions spiraling inward do emit X-rays.

Also, something about polar jets of material getting expelled.

Any evidence of those theories applying, for those of you that know?

Doesn't work that way

[GunFodder]

The gravitational patterns around a black hole are like that of a star until you get very close to it. Just imagine what would happen if a star passed within the planetary space of the Sun. All the planetary orbits would be perturbed. Earth would probably freeze or burn.

If by some astronomical chance the Earth collided with this black hole the planet would be torn apart first by the differential effect of gravity from the black hole. As an object gets closer to a massive gravity sink it orbits more and more quickly, so the close part of the Earth would be torn from the far part. This process would continue until nothing but gas and sand was left.

Then this material would rub against itself while orbiting the black hole at high speed, giving off all kinds of EM energy. Eventually the orbits of this debris would decay and would slip inside the event horizon. The contents of that sphere cannot be explained by physics.

So to answer your question, I think what would probably happen is that first most people would die of starvation as all plants die from the extreme heat/cold. Then most of the remaining survivors would die of asphyxiation as the atmosphere gets ripped off the planet. Then if anyone was left they would be ripped into a fog of dead cells.

But the bright side is we would probably have plenty of time since we would almost certainly detect a black hole years before it contacted our system. We would see the perturbations caused by its gravity, and black holes cause all kinds of interesting EM radiation when they get close to matter.

Re:Doesn't work that way

[Anonymous Coward]

The contents of the event horizon can indeed be explained by physics. Read up on your Hawking. He talks about electrons and positrons spontaneously forming and being destroyed and how a certain percentage of them form with one of the pair inside and the other outside such that the black hole loses mass.

Also, a while ago, there was a physicicst who proposed that just inside the event horizon, where time dialation goes to infinity, a sort of shell of matter forms. This shell expands and contracts with the black hole and as you near the black hole, the event horizon seems to recede.

Anyway, given a long enough time, Hawking Radiation will cause a black hole to 'evaporate', as it were. It loses more and more mass until it simply doesn't have enough to hold everything else in anymore. Of course, this is on an astronomical time scale, and as such may take longer than the expected lifespan of the universe, but In theory, it will eventually happen.

Written in the stars

[StuWho]

"Astronomers believe a doomed star came too close to a giant black hole after being thrown off course by a close encounter with another star."

The same thing happened to Kurt Cobain

Quantum theory produces weird effects

[maroberts]

This is the reason why Stephen Hawking is so famous. The theory is his baby.

Black holes evaporate as a result of the fact that quantum theory allows particles to be created near the boundary of the black hole. Particles are created in pairs (particle + antiparticle) and they normally annihilate one another when created in this way. However on the edge of a black hole, one particle may fall in whilst the other is then free to escape.

IANAP (anyone with a physics/ astronomy degree is free to expand/ correct outright lies in the above)

Re:Quantum theory produces weird effects

[pclminion]

Hawking radiation is a real phenomenon, but that's not what is happening here. The amount of Hawking radiation actually decreases as a black hole gets bigger. A black hole of this scale -- 100 million times the Sun's mass -- is going to be emitting essentially no Hawking radiation.

As I said in another reply, the X-rays are emitted from superhot gas spiraling around the black hole. Your description of the Hawking radiation theory is (mostly) correct, however. Virtual particles are constantly created/annihilated all throughout space, not just near black holes.

In other news...

[berkut1337]

Supermassive /. traffic ripped apart a Chandra server and consumed a portion of it.

Oh, SNAP!

[read-only]

What that black hole did to that star was just plain wrong!

Did you see that? That star rolled-up on that black hole, but that black hole wasn't messing aroung. It straight-up punked that star!

Let this be a lesson to stars everywhere: you better think twice before rolling up on some black hole's turf. Word.

Link to AP release

[Anonymous Coward]

http://apnews.myway.com/article/20040218/D80PREA80 .html

includes "illustration"

Do Black Holes exist?

[whig]

i thought black holes were not proven to exist, or am i living in the past?

It depends on what one means by "exist," I suppose.

The phenomenological data supports the existence of black holes, very clearly and without controversy. But what "exists" within the event horizon (the radius at which the gravitational force equals the speed of light) of the object we call a black hole is unobservable, and cannot be described by standard models.

Consider that the time dilation at the event horizon is "infinite" according to relativity, thus an infalling particle would require infinite time to cross this boundary. On the other hand, the lifespan of the "black hole" is, according to Hawking, finite. Thus, the event horizon would evaporate before the particle crossed it.

Alternately, the particle might "quantum jump" across the event horizon, this was suggested to me by Dr. Michael Shara at the Space Telescope Science Institute (Johns Hopkins) about 15 years ago. If he's right, black holes may indeed exist.

Or, the particle might be negated by a Hawking anti-particle before it crosses the event horizon.

Finally, the particle might only cross the event horizon when it evaporates, which is to say, if and when the black hole becomes a white hole.

More mirrors

[Temporal Outcast]

All the sites seem to be slow, and the Chandra site seems to be down, so I have put up some mirrors.

Chandra article mirror here.

NASA article mirror here.

Picture of rxj1242 is here.

Re:Black Holes and the end of time...for humanity?

[Threni]

> in which scientist thought there was a small, but real, chance of igniting the
> atmosphere and literally roasting everyone and everything on the planet. IIRC it
> was something like 2% odds ... horrifically high for such a terrible risk).

Well, no..there wasn't that risk at all. There was *believed* to be such a risk.

It's like saying train travel is dangerous because people once believed that if you exceeded 15 mph or went through a tunnel then all the passengers would suffocate. It's simply not true.

Almost there...

[bigmaddog]

That's pretty much what's happening, except (for the picky bastards out there):

• There really is no such thing as "centrifugal force" - it's the apparent force that acts in the direction opposite of centripetal acceleration; it's a manifestation of Newton's first law of motion, that "Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it." When you're in a car and turn sharply, the car accelerates towards the inside of the turn (centripetal acceleration on account of the friction between the road and the tires, which "direct" the car) and you feel pushed to the outside of the turn because your body would much rather keep going in a straight line, if it wasn't attached to the car (this is the apparent centrifugal force, and one reason to wear seatbelts). Hence, if it's not a real, "centrifugal force" has nothing to do with anything astronomical or otherwise - it's just an aspect of the way we view the world.
• The accretion disk of a black hole (or anything that can have an accretion disk, really, like a protostar, white dwarf or a neutron star) is heated and radiates energy because particles in the disk lose energy as they fall inwards. First, conservation of energy means that, as particles get closer to the black hole, gravitational potential energy is converted into kinetic energy. That means that particles closest to the black hole are moving faster than the ones further from it, and they end up losing energy through friction with these slower, outer particles, and this is energy is radiated away. In this manner, matter falling into a black hole radiates away 10-40% of it's mass-energy (the E in E=mc^2) before vanishing from the observable universe beyond the event horizon, compared with 1% of mass-energy being released by fusion, and that's why we get high-energy radiation like x-rays emmited from accretion disks around black holes and neutron stars. That's also the process that (most likely? I don't even know what theories get confirmed or disproved in astronomy these days) generates the incredible energy released by quasars - they're accretion disks around super-massive black holes at the centres of young galaxies (young as in created early in the history of the universe, not as in recently formed).

Boob reality check

[Gorimek]

screaming about Janet Jackson's left boob

Those screaming about her left boob, which was the one left covered, were not social conservatives, but rather the strip club crowd.

Re:Supermassive Black Holes & Galaxies

[mbrother]

Hey Jonah Hex was a favorite comic of mine! On topic, yes, the theory that every massive galaxy hosts a massive black hole at its core is in fine shape. Observations, particularly from the Hubble Space Telescope, continue to offer strong support for this idea to the level that we can now make good estimates of the black hole mass just from looking at the galaxy. In this case we are indeed talking about a supermassive black hole at the center of a galaxy rather than a stellar-sized black hole. And I'm not sure I'd say "free-floating hole" in mixed company. Stars are so small anyway that stellar collisions essentially never happen in a galaxy, and the cross-section for a black hole is really the same as a star.

Re:Supermassive Black Holes & Galaxies

[Celandine]

It is. Anyone who hasn't seen the movies of stars orbiting around the (presumed) black hole (3 million solar masses in a tiny volume) at the centre of our own galaxy should go here or here right now.

Re:Odd thought about resolution

[mbrother]

Yes, you're right in general but the problem is that X-rays tend to go through things like mirrors if you build a conventional mirror. To focus them you need to use glancing angles and this means that you need to build enormous and super accurate mirrors to get the equivalent of any substantial diameter. The Chandra mirrors are probably the finest optics ever produced and consist of nested, gold-coated paraboloids (I think) that cost some $200 million just on their own.

Re:Can someone explain...

[ultramk]

Centrifugal force spins the gas out into an "accretion disk" and superheats it as it slowly spirals into the black hole.

Well, technically there's no such thing as centrifugal force, it's just an expression of angular momentum.

Yes, it's a nitpick.

m-

Not quite...

[Robert1]

Actually you're definition of a blackhole is a bit off.

Every object has a point at which gravity is so intense that light cannot escape it. This is called the schwarzschild radius. However, black holes are unique in that their radius lies OUTSIDE the object, whereas every non-black hole object's radius lies INSIDE the object.

The earth, even you or I have this radius too. For the earth however it is underground; were you to attempt to approach it (by digging down for instance) gravitational force would decrease as you decsended. As this force decreases the schwarzschild radius would decrease as a result. Thus you would never be able to reach the schwarzschild radius of the earth because it would always be receeding from you the closer you approached it.

My question is....

[SecretSauce]

What would happen if two black holes came into close proximity of each other? I don't have enough knowledge about black holes to hypothesize, maybe some of you guys with more background on the subject could shed some light?

Re:My question is....

[beeplet]

Two black holes that come too close together will simply merge, becoming a single black hole with the combined mass (or nearly, as some will escape in the form of gravitational radiation during the merger). Such mergers (between stellar-mass black hole binaries, for example) are one of the things LIGO should be able to see in the near future...

One theory of supermassive black holes at the centre of galaxies is that they formed by successive mergers of smaller black holes as smaller galaxies collided to form larger ones. There have been observations of binary black holes in some galaxies, and these will eventually merge... It won't look like anything spectacular to the naked eye, though, since the only energy being released is in the form of gravitational waves.

Re:My question is....

[PhuCknuT]

The merger won't be that simple, the black holes will most likely end up orbiting each other, and emitting very powerful gravitational waves in the process. The waves will leech orbital energy from the system, causing them to fall closer and closer together, increasing the wave frequency as they go until a final massive gravitational wave burst as one reaches the other's event horizon and it merges into a new rapidly rotating black hole. It should be a very easily recognizable signature from ligo, assuming ligo works as planned.

Re:Black Holes and the end of time...for humanity?

[amRadioHed]

It doesn't matter that we now know their was no risk of igniting the atmosphere. The fact is that at the time, we didn't know it.

It's as if someone gave you a gun and said that there's a good chance it's not loaded, but it could be. Do you take the gun, stick it to your head and go *click*? Hell no! Maybe he knows there aren't any bullets in the gun, but you don't. From the knowledge available to you the risk is far too great.