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...

[spuke4000]

Dude, Unicron doesn't exist, that's just in cartoons. It was Galactis.

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

[child_of_mercy]

I think you mean Galactus

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

[the_mad_poster]

Nobody who knows anything about science makes a blanket statement like that with a straight face. In fact, if they did, and people always believed things were so clearly cut and dry, we'd all be sitting around in caves marveling at the power of the Gods to make the sun rise.

Too bad the "interest" you convey is totally divorced from "understanding" of even the basic tenets upon which science is built.

Maybe before you go about berating other posters about their potentially lacking science skills, you ought to take the time to make sure you're not making a TOTAL ass of yourself, at least.

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?

Re:Cheers

[rokzy]

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

"current physics still says faster-than-light TRAVEL is impossible."

"At NO STAGE did I say that FTL Travel is impossible."

---

"you are a comple fuckwit by nature."

"Grow up, you little twerp."

Re:Cheers

[rokzy]

> "OUR CURRENT UNDERSTANDING OF physics says that faster than light travel is impossible"
is the complete quote.

that's still wrong though noobie.

>Why are you posting with "No Karma Bonus" checked?

because the whole point of karma bonus is to get good posts seen. I don't think this argument is composed of good posts.

Re:Cheers

[scatalogical]

Your assertion #2 is wrong "information cannot travel faster than the speed of light".
If you create a particle and anti-particle such that they are quantumly entangled and separate them to an arbitrary distance you will see that if you induce a change of spin on 1 it is reflected in the other with 0 time delay.

Re:Cheers

[TrueBuckeye]

You have an interesting take on it, but I tend to disagree. It isn't understanding which gets people (at least me) interested, it is mystery. Old, understood theories and technology are not nearly as interesting to me as the new, wild ones. Why? Imagination. That's where the fun is.

Re:Cheers

[dclydew]

Once upon a time, wise men studied the stars. They knew that the power of the stars were directly related to the fate of people and places. They called it Astrology and those who differed, were ridiculed.

Once upon a time, wise men understood that the earth moves around the sun and the earth was flat and the center of the universe. For God had told them so in their holy book. They called it religion and killed or ridiculed any who differed.

Once upon a time, wise men knew that Newton's Laws of Physics and later Principia Mathematica were fact. When some wise men disagreed, they were ridiculed.

We can interpret some (but not all) of what our senses relay about the world and universe around us. There is evidence to support that our brain 'filters' quite a bit of the signals we receive, so we actually make observations and guesses with only a portion of what our senses can relay to us.

Anytime I hear a physics say that they 'know' the facts, I have to wonder how long they've actually bee doing physics.

For me, I will say that I know one thing:

I will never fully understand the universe, nor the possibilities that exist therein.

Hail Eris, All Hail Discordia

Re:Cheers

[dclydew]

But of course, you do realize that General Relativity could be wrong, right?

I mean certianly you don't believe that we won't change our theories over the next hundred years, do you?

The words of the foolish and the words of the wise, are not far apart in Discordian eyes.

Re:Cheers

[Darby]

Thanks for the response.

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

Is it true that because one solution of the equations leads to the idea of black holes and there aren't any (for the sake of the argument) that the theory is wrong?

The Lorentz equations are solvable for all velocities except exactly c. So faster than light and slower than light velocities are both fine from a mathematical perspective. It just leads to imaginary masses whatever that means.
As far as I know, nobody really believes in tachyons anymore, but nobody has thrown out special relativity.

Admittedly, I'm not familiar with the math of general relativity but how is this different?

Re:Cheers

[rokzy]

it's not just a case of general relativity allowing black holes, but actually making them happen.

the idea of black holes has been around for ages. people thought what would happen if loads of mass collapsed to a single point. but they thought it would never actually happen because this would require a perfectly symmetric mass distribution. if it wasn't perfectly symmetric i.e. slightly distorted, then as it collapsed these distortions would get bigger and the matter wouldn't collapse to a single point.

but general relativity changes this. it predicts that any body with a quadrupole moment will emit gravitational waves. spherically symmetric bodies don't have quadrupole moments, but distorted ones do. so if the collapsing matter is distorted, it will emit gravitational waves, and this will make the collapsing matter more symmetric. in this way gravitational waves act like a correction make black holes "generic" i.e. ANY large enough body collapsing WILL form a black hole whether it's perfectly symmetric or not.

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."

Re:Better headline.

[tbone1]

ChandraWebAdmin writes:

Chandra webserver yawns at slashdot's meager attempts.

Hey, it's Baghdad Bob! Will you roast our stomachs in hell?

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?

[fembots]

How about Brown Dwarf, White Dwarf and Yellow Dwarf?

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?

[originalTMAN]

and red dwarf?

Re:Why they always gotta be racist?

[mkaltner]

Well, I'd suggest that posting as an annonymous coward isn't helping you in regards to respect.... :)

Re:Why they always gotta be racist?

[Snad]

and red dwarf?

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

Re:Why they always gotta be racist?

[bigfatwill]

So what is it?

Re:Why they always gotta be racist?

[Quixadhal]

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

Such radiation can be the cause for repeated stimulated emmissions of particle streams.

The fact that the universe is expanding...

[SharpFang]

...at such rate that there will be no Great Crunch, doesn't mean WE (oour solar system) won't get swallowed by a black hole.

Re:The fact that the universe is expanding...

[Tango42]

It's not a certainty () like it would be if there were a big crunch, but it's still a possibility.

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

[thomasdelbert]

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

Last time I checked, black holes are not directly observable, so their existance can never be proven, but no scientist has yet been able to disprove it either. Such are many things in science. Can you see a quark? a proton? Can you travel back in time to watch evolution occur (let the flames begin!)? Lack of a counter-example is not a proof, but sometimes you have to accept it as one in order to progress.

Re:/dev/null

[pclminion]

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

So, what you're saying is, when somebody finds proof of phenomenon XYZ, that doesn't mean anything, because nobody has ever found proof of phenomenon XYZ?

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

[Alexis Brooke]

I think it's fairly certain (and has been for a long time) that black holes exist. We can mathematically calculate the escape velocity for neutron stars based upon their mass and volume. Any neutron star with a mass large enough or volume small enough that the escape velocity exceeds the speed of light must, according to all current knowledge of physics, become a black hole.

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

[bakes]

cat star > /dev/null

More like:
rm star

Re:/dev/null

[Darby]

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.

And presumably, if there were a fair to large percentage of astrophysicists who didn't believe it or there were competing theories to explain the evidence, you (and me for that matter) would be less likely to accept it so readily.

Re:/dev/null

[Sivaram_Velauthapill]

Most science isn't empirical evidence alone. There is also mathematics involved. So you CAN prove SOME things. The things you can prove are called laws. These laws are usually just mathematical properties (eg. conservation of mass). In any case, what you said is correct: THEORIES cannot be proven.

I like hte idea of a black hole too... because it allows time travel--maybe :) Here's hoping that time travel is possible :)

Sivaram Velauthapillai

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 (-:.

Re:Great results from the great X-ray telescopes

[mbrother]

I never used HRI, only PSPC where the FWHM was worse than 30 arcseconds. Did HRI get used much? I confess I usually work on the fainter stuff. I should have remembered HRI, although to be fair I was also using Chandra ACIS resolution for comparison rather than the HRC. Thanks for all the numbers!

Re:Great results from the great X-ray telescopes

[Celandine]

Did HRI get used much? You bet... at least after the PSPCs were turned off when they ran out of gas! There was a long period when the HRI was the only thing you could use, and in spite of its low sensitivity and complete lack of any spectral capability it did do some good stuff.

There really isn't much difference between the Chandra ACIS and the HRC in terms of resolution -- the ACIS pixels only slightly undersample the PSF. Which is why nobody much uses the HRC (-:

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?

[cdf123]

IANAA/P (I am not an astronomer/physicist), but I beleave the theory is that time is relative, and as you get closer to a black hole, time slows down. So depending on where your taking your calculations from, the results would be different.

Re:How fast does a Blackhole consume?

[rjelks]

My astronomy class is now a blur, so my real knowledge comes from StarTrek and that SG-1 episode where they encounter a black hole.

Re:How fast does a Blackhole consume?

[jeff munkyfaces]

when you say time slows down, presumably it "stays the same" if you are the one being consumed, right? you wouldn't be able to tell? so who would it be visibly slowing down for? aah my brain!

Re:How fast does a Blackhole consume?

[Tango42]

What's the point of using an acronym if you are going to write it out in full anyway? It would have been much easier just to write IANA astronomer/physicist...

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.

Re:How fast does a Blackhole consume?

[techno-vampire]

From what I remember, if you were on the unlucky planet, the rest of the universe would seem to speed up and blue shift. From the outside, the planet would move slower and slower as it got close and be red shifted. Both points of view are equally correct. Weird, but that's one of the reasons it's called "Relativity:" everything is relative to your frame of reference, and no frame has priority over another.

Re:How fast does a Blackhole consume?

[madpierre]

In theory X-rays etc are produced by matter in an accretion disk around a black hole. If a black hole did not posess such an accretion disk then gravitational effects would be the only sure fire way of detecting it (lensing, peturbation of planetary orbits). If by planetary sized you mean the event horizon having a radius on the order of the Earths. This would represent a truly massive (stellar) black hole, if you mean the thing has planetary mass, then you're looking (or not) at an object the size of a pea.

Re:How fast does a Blackhole consume?

[techno-vampire]

The rate at which Hawking Radiation is emitted is inversely proportional to the Black Hole's size. There'd be very little coming from one big enough to be dangerous.

Re:How fast does a Blackhole consume?

[fbform]

The current plan is to throw Neptune in the black hole as an appeasement...A perfectly good chance to make a Uranus joke

Aaaaargh! My eyes! My eyes! Did you have to say "black hole" and "Uranus" in the same sentence? Man, if you want to say "goatse", please say so openly, not in some twisted way that sneaks past my mental defences.

A Twist

[hambonewilkins]

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

Re:A Twist

[Lord_Slepnir]

You forgot to add "In soviet russia" before that.

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.

Re:In other news...

[ChandraWebAdmin]

We fixed a few minor configuration problems on our webserver, and things picked up speed, handling over a million hits between 8 and 9 pm eastern.

Thank you for your patience.

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.

So What?

[tacokill]

Big deal. I could do this in my garage. A pair of pliers, some PVC pipe, and roll of duck tape.

This isn't news.

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..

[SmilingBoy]

Any evidence of gravity waves from this?

Where should the "gravity waves" come from? It's "just" a star being torn apart 700m light years away. Not much different gravitation-wise than if the star had just moved passed the black hole a bit less closely and staying intact. (IANAP)

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..

[thomasdelbert]

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

Einstein's theory of General Relativity suggests that gravity isn't so much a force as a curvature in space-time, thus needs no carrier.

Re:Is there..

[Rallion]

Hence the controversy, and hence the need for evidence.

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.

Re:Is there..

[ktulu1115]

If "gravity waves" do travel at C, this is a good way to see them.

I certainly hope they'd travel at at least C, if they were moving any slower (VB perhaps or maybe .NET) we'd never get to see them!

Re:Is there..

[Darby]

Hope this clarifies.

Actually, it does. Thanks.

Re:Is there..

[shadowbearer]

IIRC isn't there some direct observational evidence that gravity also acts at the speed of light? Wouldn't that imply a "carrier" of some sort?
The math is beyond me, but it makes sense to me that if gravity does have a limiting velocity than it would have a propogation front, which implies some sort of wave...

I read quite an interesting paper on this a few years ago, but can't for the life of me remember where it was. Somewhere in all these bookmarks probably :)

'scuse me, I'm more a geology student of life than anything nowadays - tho I went to college for astrophyics. A long time ago. Sigh.

SB

Re:Is there..

[shadowbearer]

Not so much that we haven't observed gravity waves directly, as it is that we haven't been able to sort out the disturbances in the detectors from background "noise" well enough to determine that what we are actually observing is gravity waves and not something else.

IIRC, anyway...IANAAP, tho I had a start on it in college twenty years ago.

SB

Cosmic game eh??

[Creepy Crawler]

Blue 5 in corner pocket.

In a related story...

[NeoTheOne]

Pres. Bush announced today that the US will be the first to land on the black hole. "my fellow americans, it is imperitive that America stand on the forefront of space exploration" Mr. Dean immediately volunteered for the job saying "and we're gonna go to the moon, and mars, and europa and planet X, and then all the way to the black hole! YEEEEEAAAAAAAHHHHHH!!!"

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

[Creepy Crawler]

Check out www.johntitor.com

It has^H^H^Hhad the scoop till another time traveler erased it, and JOhn came back and said it, until some.

SEGMENTATION FAULT. PARADOX ERROR

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

[Darken_Everseek]

I'd guess a cascade of the initial creation. Black holes have massive gravity; if the local gravity produced by one of the created holes exceeded our ability to stop more matter from entering it, the hole would grow in mass roughly exponentially. IANAPhysicist, of course, but that's what comes to mind.

On a side note, what happens when a black hole has no further matter to pull in?

Re:Blackholes and Time Travel

[red floyd]

should last about as long as a snowflake in hell

So, that would be a really long time? According to Dante, the Ninth level of Hell is frozen.

Re:Blackholes and Time Travel

[MajorBurrito]

I wouldn't worry too much. Any black hole produced in the LHC will have too little mass to do anything destructive. They will 'evaporate' via Hawking radiation in a matter on nanoseconds.

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

[SmackCrackandPot]

Even more importantly, Hollywood made the movie The Void about the dangers of creating black holes on Earth. . As long as the accelerator is underground we should all be safe.

Out of curiousity, does anyone remember the name of the sci-fi ahort story about a kid in the future who owns a micro-shrunk miniature model of a star, overfeeds it, eventually causing it spins out into a superthin black hole and eventually digests the Earth?

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

[Anonymous Coward]

Actually, scientists didn't fully understand what would happen during a nuclear reaction the first time around. There were some fears that the reaction could run away and consume all matter on Earth in an atom splitting orgy. They decided to set one off anyway and find out.

Re:Blackholes and Time Travel

[sahonen]

That short story is exactly what I've been thinking about... I read it, but I don't remember what it's called, sorry.

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

[amRadioHed]

That's not free energy. It would take far more energy to make a 1 ton black hole then you'll ever get radiated back out of it. Consider that the physicists are hoping to make proton mass black holes and they need the worlds largest supercollider to get that far.

Re:Blackholes and Time Travel

[shadowbearer]

You can stop building that black hole shelter now

Besides which :) the only black hole "shelter" that would even be marginally effective would be a orbital one, preferably at a high orbit (to reduce radiation effects).

So.... start supporting the/any manned space programs, if you feel your tinfoil hat isn't enough :)

SB

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

[Sivaram_Velauthapill]

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.

I'm not an astrophysist but I have been reading some books on this recently (books for layperson that is). I don't think the black holes in question will eat through earth. The horizon of the black hole will be VERY VERY small. Anything far away from it (which is where most of the mass on earth will be) should be fine. As far as I know, black hole horizons do not increase in size (only exception is when multiple black holes coalesce into one). So, if my understanding is correct, the size of the black hole will not get any larger--even if mass is sucked in.

The only real danger I see is some government creating a weapon out of it. If someone can create a "bomb" from a black hole, it will make nuclear weapons look like a joke. That's really the main danger IMO. Having said that, black holes are very hard to manipulate (it will probably take humans 1,000 years to master them). So no one can really use them as weapons per se. If someone creates a black hole, it will just sit there. We don't have the capability (or even the theory necessary) to move them.

Sivaram Velauthapillai

Re:Blackholes and Time Travel

[Morosoph]

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.

Sorry to be boring, but practically, there's no real risk. These "Black Holes" are tiny, and their mass (and therefore gravitational pull) is proportional to the energy that went into creating them, according to the formular E=MC^2. We simply can't put enough energy in to give the hole any sizable pull, so it doesn't seed; rather, it collapses through Hawking Radiation.

Re:Blackholes and Time Travel

[AllUsernamesAreGone]

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

Except for the uncomfortable fact that the universe is not one big black hole, which it would be if black holes did not evaporate and instead continued to suck in ever more matter...

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.

Re:Blackholes and Time Travel

[PakProtector]

Quite the alarmist, aren't we? I seem to recall learning about something called 'Hawking Radiation.'

The black holes that would be formed by these experiments, if it is indeed possible to do such a thing, would be so incredibly tiny that they would not exist for any humanly appreciable period of time before they would be destroyed from their own high rate of evaporation.

Please research more throughly next time before you spout off some hyper paranoid regurgitated theory.

Thank you.

Note: I am not a Physicist, but I have many friends who are who have deflated my ego enough of Physics subjects for me to remember every little thing that's wrong that I've ever said, and to recognize the stupid things that others spout.

Re:Blackholes and Time Travel

[0ddity]

That sounds reassuring except for one thing you seem to have overlooked:

Hawking Radiation is an untested theory. It sure would be a shame if it turned out the Hawking Radiation didn't work.

To say there is no real risk based on the assumption of an untested theory seems kinda risky to me.

Re:Blackholes and Time Travel

[Morosoph]

Hawking Radiation is an untested theory. It sure would be a shame if it turned out the Hawking Radiation didn't work.

Hawking Radiation is an outcome of a very well-tested theory: the second law of thermodynamics. Besides, this isn't the most important point.

Since the energy in and on the earth isn't sucking us in deperately hard, a small fraction of that energy concentrated to a point won't either. It will have the same pull to a single point as it would have done over the whole of a larger object with the same energy content.

The term "Black Hole" is used in the article for effect; a less misleading term would be "singularity". "Full-scaled" black holes pull as hard as they do essentially because they start off as massive stars that collapse. The original star would have pulled pretty hard on the surrounding space, and being concentrated makes it pull no harder overall. Stars disrupt each other as much as black holes disrupt stars, and Supermassive Black Holes are the extremely rare and "lucky" ones that simply accumulated enough mass to form that way.

Re:Blackholes and Time Travel

[drakaan]

[nitpick]A black hole is not a "0-dimensional point" a black hole is a densely packed mass of matter that has a definite size.[/nitpick]

You're thinking of a singularity, I believe, which is a theoretical construct.

Re:Blackholes and Time Travel

[Morosoph]

Interesting article.

That'd be the heuristic explanation I'd give that most closely corresponds to the usual computation. There are additional things to say about the fact that the guy far in the future and far away from the black hole can't see what's in the hole, so he has incomplete information about the state, so he sees a state with entropy, in fact a thermal state. (Here I'm assuming the black hole was NOT eternal, so the guy way back in the past didn't have the black hole to contend with. Apparently Hawking's original computation dealt with this case, but people subsequently watered down his explanation by assuming the black hole was there eternally, to simplify the math. This is what the guy at the talk said... I'd only seen the watered-down version!)

Like I said.

Re:Blackholes and Time Travel

[Morosoph]

You're sounding like a Christian, I'm afraid. "Just a theory" is a ridiculous thing to say about something as well-tested and with the predictive power of quantum mechanics. You might as well say gravity is just a theory, and hold onto everything in sight for fear of being flung into space!

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.

Re:We found a WMD!

[glitch23]

A standard of decency never hurt anyone, except for those who don't want a standard to exist for the very reason they don't have one and don't want the rest of society to have one either.

Re:We found a WMD!

[zhenlin]

Mass isn't really destroyed in this case anyway... I don't really see many signs of mass-energy conversion happening.

Re:We found a WMD!

[Darkfred]

A standard of decency never hurt anyone, except for those who don't want a standard to exist for the very reason they don't have one and don't want the rest of society to have one either.

Actually A standard of decency was responsible for the death of my entire family.

You insensitive bastard!

Re:We found a WMD!

[revscat]

A standard of decency never hurt anyone, except for those who don't want a standard to exist for the very reason they don't have one and don't want the rest of society to have one either.

That's a really dumb thing to say. Just because I don't want the government regulating something you think is immoral doesn't mean that I am opposed to morality in toto. I happen to think that morality is incredibly important, but that when the government gets involved that nine times out of ten they do more to HURT morality than help it.

Hell, I even put up Ben Franklin's Thirteen Virtues on my website, and I try and keep them in mind throughout the day. Ethics and morality are not things that the government can force upon a free people, doubly so for things that a large portion - perhaps majority - of the population do not consider unethical.

I am very much for having a good moral society. I do not think that bared boobs are immoral.

Re:We found a WMD!

[danila]

I think there is a distinction between the ethics and the morals. Showing a boob might be immoral in certain parts of the US and in some Arab countries, but it surely as 1=1 is not unethical. Porn and gay marriages might be immoral to some people, but there is nothing unethical about it.

On the other hand, prohibiting gay marriages and stopping medical use of pot is moral according to some people, but is really unethical.

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.

Don't be so happy!

[Anonymous Coward]

It's amazing, everyone is so excited at the proof that one day, the universe will collapse and we will all die. Or that we may be sucked into one of these things.. Yippie!!! It's like the Los Almos guys being excited about creating a nuclear bomb...

Re:Don't be so happy!

[Hoi Polloi]

You need to catch up on your cosmology, the universe appears to be flat and will continue to expand, not collapse.

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?

Re:Match with Theory?

[Sivaram_Velauthapill]

DISCLAIMER: I am not an astrophysist :(

As far as I know, those theories have been observed as far back as the 70's. So x-rays being emitted by infalling gases and other similar phenomenon have been proven.

Having said that, the doubt over black holes mainly comes from the fact that you can only observe indirect evidence. For example, the X-rays are being emitted not by the black hole but by things outside it. People who doubt the exitence of black holes say that this isn't sufficient proof.

Overall, my impression is that the scientific community pretty much accepts black holes these days. As Kip Thorne remarked in his book, scientists are 90% sure of the exitence of black holes (as of mid 90's). Where scientists disagree is what happens inside a black hole (also, people disagree about things like time travel, or other "crazy" theories).

Sivaram Velauthapillai

So THAT'S how stars rip...

[revolvement]

...I always pictured Hulk Hogan ripping the star apart.

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.

Re:Doesn't work that way

[Jagasian]

Isn't science supposed to involve physical evidence and experimentation? Otherwise you are just playing with math.

Re:Doesn't work that way

[agildehaus]

Supposedly that's why it's called 'theoretical physics'. There's absolutely no hard evidence to back it up, but nonetheless mathematics is a very powerful tool for describing our universe similarly for creating these theories.

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

That headline....

[openSoar]

... sounds like it could be from the Calcutta Bollywood gossip page.

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.

Re:Quantum theory produces weird effects

[shadowbearer]

Note to mods:

Parent should be informative. This is fairly well-hashed over theory.

SB

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.

Deja vu?

[zdzichu]

Black ? Ripping? Star? I saw it before.

Link to AP release

[Anonymous Coward]

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

includes "illustration"

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

[FreeUser]

I wish they were doing this on another planet, preferably one in a distant orbit, or better yet orbiting another star. To wit:

The radiation from evaporating black holes in LHC experiments should signal their brief existence, say Dimopoulos and Landsberg. This would also confirm Hawking's prediction, which has never yet been put to the test. [emphesis mine]

If Stephen Hawking is wrong (and the black holes do not evaporate) this could literally be the end of us all. This strikes me as at least as dangerous as the first thermonuclear explosion (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).

I'm no fan of Luddites who want to ban genetic research, GM foods sight unseen irrespective of the details, research into nano-technology, etc. but producing black holes on the surface of our planet without knowing for certain whether or not they will evaporate?

Fuck.

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.

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.

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

[Threni]

> 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.

I'd look and see if the gun was loaded.

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

[amRadioHed]

I'd look and see if the gun was loaded.

I would too. But, that's not what the scientists on the manhatten project did and same goes for the super-collider project.

For the record, I'm not opposed to this project. For various reasons I don't think there is a real possibility that a sub-sub-atomic black hole will destroy the earth. But if I thought there was a real possibility (like the 2% chance that the nuclear bomb guys thought) then it would be irresponsible to go on with the project. Knowing what they did at the time, they probably shouldn't have risked it.

Of course I'm not factoring the risk of not stopping Hitler into my decision, where for the Manhatten project guys that was probably the deciding factor.

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

[squiggleslash]

If Hawking is wrong then the black hole will fall to the center of the Earth, possibly hitting the occasional subatomic particle on the way. It may possibly eat a small hole around it at the Earth's core, but it wouldn't get very big. And there it would sit, for millions of years.

Remember, unless it gained a large amount of mass, it'd not have enough gravity to even attract an occasional electron from nearby atoms.

I think we'd have time to move to another planet. And if we don't, well, who cares. Life sucks anyway. It's not like humanity's worth keeping.

Supermassive Black Holes & Galaxies

[Jonah Hex]

I'm definately not an astronomer but I recall that the theory of there being a supermassive black hole at the center of each galaxy made a hell of alot of sense when last I saw it presented on Discovery or somesuch. Anyone out there know the status on that theory, and if this particular blackhole that's munching the star is a (struggles for terms then makes some up) galaxy-center-hole or a free-floating-hole?

Jonah Hex

Re:Supermassive Black Holes & Galaxies

[beeplet]

This particular one is a supermassive black hole in the centre of the galaxy.

From the press release: The black hole in the center of RXJ1242-11 is estimated to have a mass of about 100 million times Earth's sun.

In general, I think the theory that most galaxies contain supermassive black holes at the centre is widely accepted.

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:Supermassive Black Holes & Galaxies

[mbrother]

Yes, those are spectacular. I use them in my lectures for both non-majors and graduate students.

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.

Re:Do Black Holes exist?

[shadowbearer]

No, no no

It's

cat /dev/random > star :)

SB

Re:Do Black Holes exist?

[shadowbearer]

I thought that black holes were inevitable results of star collapse when they were over the chandra mass limit. Has that changed any?

Great explanation; and certainly easier than trying to explain the concept of a "naked singularity" :) and the difference between a naked one and one cloaked with a event horizon, assuming of course that naked singularities can exist in the first place.

Wasn't quantum transference of particles across event horizons thought up by Hawking (and also the explanation for the eventual "evaporation" of black holes? - I always thought that "sublimation" might be a better term...). I have little time to keep up with modern thought on that subject, and I'm wondering if it's still viable as a theory...

I remember reading about Hawking's theory back in college and thought it was absolutely brilliant ,especially given that a event horizon would essentially be an infinitely small region(?)

Fascinating stuff, nonetheless. Do you have any links to some decent reading about Hawking anti-particles? That sounds new to me - technical links with math are OK. Thanks.

OMG /me runs from the straight lines I just delivered to the slashdot hordes

SB

Re:Do Black Holes exist?

[Mistshadow2k4]

Ohhhhhhhh... thanks for the headache, dude. Which way is up, again?

Re:Do Black Holes exist?

[NonSequor]

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

This reminds me of Bertrand Russell's short story,
"The Metaphysician's Nightmare." The metaphysician recalls a dream he had when he had a fever. He found himself in hell where the damned were punished by extremely improbable events. The devil himself was simply a region of nothingness. Every time a particle was about to enter another paticle would happen to collide with it knocking it away.

I highly reccommend everyone to read this story.

Re:Do Black Holes exist?

[Dr. Manhattan]

...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.

It's true that it can't be described by standard models, but if the black hole is charged or rotating (or both) then the event horizon is distored to the point where the 'singularity' (the place where all current models break down) is reachable.

One potential consequence is time travel, to give an idea of how odd the math gets.

Re:Do Black Holes exist?

[hcg50a]

It should be pointed out that the singularity is not a physical object. It is where the mathematics breaks down (eg., divide by zero).

What happens physically is that different or modified physical laws take over before the singularity is reached, and the result is that there is no longer a singularity.

Example: In a simple Newtonian gravitational model of the Earth, assume the Earth is a point mass. The center of the force (ie., at the center of the earth) is, in fact, a singularity.

In reality, the Earth has some extent, and what you find happening when you start burrowing into the Earth to get to the "singularity" is that the gravitational force begins actually decreasing as you get closer and closer to the center (because any mass of the earth that is further from the center than you are exerts no net force on you).

The result is at the center there is no longer any singularity, because the model has changed.

Re:Do Black Holes exist?

[Dr. Manhattan]

What happens physically is that different or modified physical laws take over before the singularity is reached, and the result is that there is no longer a singularity.

We assume that's the case, yes. But no one has a real clue what new model would apply in such a region. It would have to involve elements of both General Relativity and Quantum Mechanics, but those two models make radically different predictions for such a situation.

At least one and probably both are wrong, but we don't yet have any idea what might supersede them.

Re:Do Black Holes exist?

[taphu]

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.

Actually, this is not entirely correct. Remember that time warp effect is just a relationship between two space-time frameworks. From the particle's perspective, it would not take infinite time and would be just like crossing any other arbitrary point in space. It's just in our perception, being in a different framework than the particle, that time for the particle seems to move infinatly slower as it approaches the horizon.

This is more a measurment of how different our framework is from that at the location of the event horizon than it is a description of the actual behavior of the particle within it's own framework.

Re:Do Black Holes exist?

[whig]

Yes, but when it crosses the "point" of the event-horizon, the event-horizon will have disappeared, as the "black hole" would have evaporated in the meantime.

Re:Do Black Holes exist?

[taphu]

If this happens, how do black holes grow or ever consume anything?

Or, for that matter, how do they exist at all?

If all black holes evaporate when left to their own devices, and any particle takes an infinate amount of time to pass the event horizon (and/or the black hole always evaporates before the particle gets there), then Black Holes are impossible, because they could never actually consume anything and they would always evaporate.

There is something wrong with your argument, and I think it has to do with your understanding of how extreme relativity works.

Or, maybe your argument is correct and black holes don't exists. No black hole has ever walked up to me and asked the time of day. :)

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:More mirrors

[ChandraWebAdmin]

Please give the original site another try. Minor configuration problems have been resolved, and the server is moving along nicely.

Re:More mirrors

[ScorpioIlya]

In yoda's soviet russia, tears YOU a new one, the black hole does.

Re:More mirrors

[Temporal Outcast]

Would you like me to remove the mirrors off my servers? Do let me know. Thanks.

Black hole sun, this Coronas for you

[jeoin]

I am so glad it was pointed out that the image was an illustration. First I was concerned about the big arrow looking object, and immediately there after I began to lose sleep dreaming of the physics behind the black hole corona effect, which shifted into a lazy pondering of the perfect perspective the picture offered us. We should pray, it looks like God is hungry.

In other news...

[ChiralSoftware]

Scientists observe for the millionth time the Slashdot Effect ripping apart a perfectly good website. "If this were a black hole ripping apart a star, it would be astonishing, but unfortunately, this happens every day," one frustrated website operator said.

-----
Create a WAP server

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

[Anonymous Coward]

At least not until we've developed a better space access (space elevator perhaps).

It's already been done. You'll need a gold ticket for a ride in the glass elevator.

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).

This is a funny headline.

[Anonymous Coward]

Most of you guys may not realize why I am smiling to myself. "Chandra sees blackhole rip something-or-other apart" to me sounds like "The Moon sees blackhole rip something-or-other...".
Chandra = Moon. and please dont pronounce it as "shaandddraa", its "chan" (as in jakie chan)+"dra" (as in "drape")

shaaandra sounds ridiculous, retarted and painful to my Indian ears.

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.

How'd it feel ... in that galaxy?

[jfaughnan]

700 million years ago that event pumped out a lot of x-rays. I wondered what that "felt like" out in the periphery. The NASA press release actually answered my question:

"The odds stellar tidal disruption will happen in a typical galaxy are low, about one in 10,000 annually. If it happened at the center of the Milky Way Galaxy, 25,000 light-years from Earth, the resulting X-ray outburst would be about 50,000 times brighter than the brightest X-ray source in our galaxy, beside the sun, but it would not pose a threat to Earth."

Odd thought about resolution

[techno-vampire]

I'm talking primarily about the resolution (Chandra resolution is 0.5 arcseconds, ROSAT resolution like 50 arcseconds).

It just occured to me that X-Ray telescopes should be capable of very fine resolution. Consider: resolution is directly proportional to the arpature and inversely to the wavelength. Or, to put it a different way, directly proportional to the arpature measured in wavelengths. This is why radio telescopes have such poor resolution. Now, X-Rays are of a higher frequency and (naturally) lower wavelength than visible light. Wouldn't that mean that for a given instrument you'd get better resolution?

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.

My Dads View

[darth_silliarse]

When I was a lad black holes ripped bloody galaxies apart not like these pussy-faced star sucking buggers...

ex-star?

[caino]

"Giant Black Hole Rips Apart Unlucky Star In Cosmic Reality Show" Why does everything have to be like american idol?, although it would be better if losing contestants were ripped apart. Maybe american idol should start trying to be more like a black hole for stupid wouldbe teen popstars.

Interstellar Advertising

[n3tkUt]

While perusing the other images Chandra has sent back I came across what appears to be a "Quicktime" supernova. Forget about NASA releasing their software, Apple's seems to already have the ability to manipulate Magellanic Clouds!

Re:BINGO

[Creepy Crawler]

That would be called someting you earthlings call a .... joke.

Seriously, I was being sarcastic, or couldnt you tell after I said "SEGMENTATION FAULT: PARADOX ERROR".

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-

Nope, you're misreading

[Durindana]

He didn't say "the contents of the event horizon." He said "the contents of that sphere," as in, the three-dimensional "volume" bounded by the event horizon. In space-time, of course, a black hole's gravity sink is not a sphere but an (infinitely deep? asymptotically deep?) sloped well.

His point was that disposition of the mass and information that falls into a black hole is not explainable by the laws of physics operative outside the hole in normal space-time. Theoretically, as you note, all that matter may simply stop in the form of a sphere, but if that's true it will not be at the event horizon, the radius beyond which nothing can escape the hole's gravity, but within it, at that radius where the relativity equations cease to be useful. And that's really the real question; the shell idea is just that, one idea, and all sorts of questions are posed by the potential loss of information as matter enters a hole, and in what form it "exists" while it's "in" "there."

Hawking Radiation, on the other hand, really has nothing to do with what falls into (or does not fall into) a black hole, and where that stuff all ends up and in what form. The radiation Hawking predicted (it has yet to be observationally verified, if it ever will be) arises from the formation of particles from vacuum energy near the event horizon, as you describe. But what really goes on within the event horizon, whether information is preserved in there... these questions are the interesting ones, and they don't yet have answers.

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:LMFAO

[Cosmik]

P8Ds? They must be those new toys in the breakfast cerals boxes, right?

Re:LMFAO

[Cosmik]

And I just shot myself in the foot with that typo.

Chandra Some info

[Charvak]

This telescope is named for the physicist Chandrashekar who got noble prize in physics. Dr Chandra of Space Odyssey:20?? was also based on this bloke(though he was a computer scientist). Truly an American icon.

Re:Can someone explain...

[pclminion]

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

I always wonder whether it's worth it to mention this. As a physics minor (I took enough to be dangerous), I had this drilled in early, but once it's understood, people go back to referring to "centrifugal force." It's a convenient way to refer to a well-known phenomenon.

I don't think the term is confusing if it's sufficiently explained. People also refer to "Coriolis force" which is similarly fictitious -- the result of being in an accelerating reference frame.

At any rate, I was referring to the phenomenon whereby a quickly rotating mass becomes oblate, much like a ball of pizza dough flattens into a disk as the pizza maker spins it in the air.

Some people have all the luck

[sharkey]

First Dr. Chandra gets to train HAL, then SAL. Then he gets to spacewalk above Jupiter. Now, he sees a black hole take on a star. I'm just a little jealous.

Re:Can someone explain...

[glitch23]

This why Hawking says black holes aren't really black, because they do emit energy.

I feel a disturbance in the Force...

[billstewart]

Like thousands of ... oh, wait, that movie reference is getting really old and stale by now.

Still, pretty scary stuff, if you live nearby.

Hubble ? eh ? Hey lookie over here: Chandra...

[neurocutie]

Chandra's great and all but my cynical self first thought upon seeing this NASA PR was: DIVERSION, get the public to forget about Hubble. Remind them that we still have Chandra (of course Chandra is an XRAY telescope, but what's a few angstroms between friends (or to the dumb public)?).

It will be a tremendous shame to lose Hubble. But one can guess that Bush bought NASA off with the: Forget about Hubble and the Space Station (and our commitment to the Russkies), you will get $$B$$ with the Moon/Mars plan/ploy. And I'll get re-election points and more space/military spending.

So, good for Chandra. But we won't forget Hubble...

Launch the "B" ark!

[HiggsBison]

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

Of course it isn't a unicorn. It's a giant space goat.

(Hey! Stop that! No goatse links!)

Can you still hear the lambs screaming, Chandra?

[Branch_Dravidian]

...astronomers have the first strong evidence of a supermassive black hole ripping apart a star and consuming a portion of it with some fava beans and a nice Chianti...

correction

[Sivaram_Velauthapill]

Small correction (before I get flamed)... black holes don't allow time travel. Rather wormholes do (wormholes are two black holes connected together)... also, it is not clear if time travel is allowed by the laws of science

Sivaram Velauthapillai

Yes there is a picture

[tj500]

Picture of the Black Hole

PICTURE OF THE BLACK HOLE HERE

[tj500]

Picture of the Black Hole

Indeed

[maroberts]

..whilst wrong about the source of X-rays (sorry), the post is still interesting and informative extra information about black holes for those too lazy to use google to look around, and should be modded up accordingly (not that I give a damn, I suspect that if I posted flamebait for the next two years my karma would still be Excellent)

The post is factual and should be rated above a 1. Probably doesn't merit a 5, but somewhere inbetween is fine.

laws of science

[NumbThumb]

you are mistaking. "Laws" are just parts of theories that allow predictions. Laws are consideres valid as long as the observations are consistent with the predictions. You can not prove that a law is correct (how would you do that?), you can only a) (mathematically) show ("prove") that a low is *consistent* with some other law/theory -- you can not prove that it is "correct" as a representation of "reality" under all circumstances. You can only say that so far, we have not observed anything that violates a proposed law. In fact, manny of the "laws" of physics have already been shown to be not "entirely" true, i.e. the depend on surten simplifications: Conservation of Mass (and of Energy) for instance is only "correct" (i.e. consisten with observation), als long as we do not take into account the possibility of converting mass to energy (and vice versa), following the well known formula of E=MC^2: Atomic fission actually *destroys* mass. Now, folowing Einstein, we could say that the product of mass and energy in the universe is constant. But we can't be sure that that is really true -- we can only say that it "looks like that".

Again: a scientific statement is by definition a statement that could (in theory) be disproven by contrary observation. Stating an "irrefutable fact" is, again by definition, unscientific (see for a start the works of Karl Popper). Thus there is no absolute known "truth" in any science. All we can "prove" is the consistency of different sets of rules, according to yet another set of rules (arithmetics, logic, etc). That's where math comes in: in showing consistency. But it doesn't tell us anything about "reality".

Face it: science is not about "knowing what's really going on". It's just about producing "good guesses" about expected effects. Math is an exception here: it does not even try to tell us anything about reality, it works entirely on trying to show consequences and consistencies according to specific sets of rules and axioms (which are called "theories" or "calculus" (in the broader sense)).

Re:laws of science

[Sivaram_Velauthapill]

Laws can be proven. The reason is because they are generally mathematical properties. Unless you claim mathematics is wrong (no one does that, except religious people), all laws are correct within the constraints of the law. Sometimes things get labelled a "law" when in fact it isn't. An example would be Moore's Law in computer science/engineering. This is not a law even though it is called one.

The conservation of energy/mass is correct. When mass seems to dissapear, it gets converted to energy. Therefore, the original law is still correct (if you go with the view that mass and energy are the same thing).

The only way you can say a law is wrong is if:

1. You claim that mathematics is wrong. That is, you don't believe in a logical framework like mathematics. Nearly all theists (i.e. religious people) follow this path.
2. Or if you apply the law outside the constraints in which it was formulated. For example, 1+1=2 may be flase if you use a different number system. BUT if you stick within the constraint (the constraint being a real number system), it is correct.

If you do not follow either path above, you CAN prove things. Just like how you can prove 1+1=2, you can prove the law of entropy (for example). You don't even need to make any observations.

Thus there is no absolute known "truth" in any science.

Laws are the absolute truth. At least, that's how you would view things if you follow the scientific path. In other words, if you follow a rational path, with logic, a law is true. If you are irrational (eg. religious) or if you do not subscribe to logic (some people don't), then you can argue a law isn't true.

Stating an "irrefutable fact" is, again by definition, unscientific (see for a start the works of Karl Popper).

But all laws ARE irrefutable facts. The reason is because they are mathematically proven.

All we can "prove" is the consistency of different sets of rules, according to yet another set of rules (arithmetics, logic, etc). That's where math comes in: in showing consistency. But it doesn't tell us anything about "reality".

But science IS mathematics. You cannot have science without mathematics. Mathematics is what gives science its logical framework. Science is nothing more than modelling the world via mathematics. Therefore, if you prove something in mathematics, it is proven in science--that's what scientific laws are.

Face it: science is not about "knowing what's really going on". It's just about producing "good guesses" about expected effects. Math is an exception here: it does not even try to tell us anything about reality, it works entirely on trying to show consequences and consistencies according to specific sets of rules and axioms (which are called "theories" or "calculus" (in the broader sense)).

Yes, science is simply an attempt at guessing, or modelling, our world. But since it involves maths, there WILL be some things that CAN be proven. I'm not saying all of it is; but some of it is. I would say 99.99% of science is theories and hypotheses but there is a tiny percentage that are laws.

Sivaram Velauthapillai

Re:laws of science

[NumbThumb]

Ok now... first let me tell you that you happened to come across one of my pet peeves here. Please do not take it personally that i'm convinced you are missing a point here. I's actually a point that'S kind of hard to comprehend in a world where we are told about "hard science" all day. What i'm telling you is that the very basis of that "hard science" is to know what can't be known. That's what epistemology is all about -- try reading up on the subject: Keywords would be "Theory of Science" and "epistemology". A very important book in that regard is 'The Logic of Scientific Discovery' by Karl Popper (which i myself have only read in part). B. Russel is another famous name to be mentioned here, even if he was more concerned with (purely) mathematical proofs.

Now, let me answer some of your statements:

laws are correct within the constraints of the law

Depends on what you mean by "correct". A mathematical "proof" shows that some statement a follows neccessarily from a set of statements B. That's it. It does not tell us if the statements have anything to do with the "real" (i.e. observable) world.

The only way you can say a law is wrong is if: [...]

You are missing my point. I'm not saying math is "wrong". I would say it is consistent (and that is saying a lot). What i'm sayin is that we usually don't konw the "constraints" (i.e. the scope) of a "law" (i.e. a predictive model): 100 years ago most scientists would have said Newtons pysics is "correct": it is mathematically sound, and its predictions are very accurate compared with what we can observe. Then along came Einstein and told us that, when viewed on a larger scale, those predictions no longer hold. Far later, we even made observations that where indeed contrary to the laws of motion etc as proposed by Newton. Thus a "law" was overturned -- and this is possible for *any* law of physics (or any other empirical science that is build around modelling the observable world).

Laws are the absolute truth. At least, that's how you would view things if you follow the scientific path.

That's dead wrong. I would agree that there is such a thing as absolute mathematical truth -- but that's a truth stated inside a specific system about that system. Nothing is said about the observable ("real") world. In science dealing with modelling observable facts (like physics), you can't postulate an irrefutable statement: that is to say, any scientific statement must be able to be tested by experiment (irrefutable statements CAN NOT be tested by experiment -- that's a little tricky... think about it. Note that "irrefutable" means indead that there is no way (even in theory) to refute a statement -- it does not merely mean that the refuting outcome of the experiment will never occur). In short: irrefutable statements are scientifically meaningless (and rather hard to construct). Examples of irrefutable statements would be tautologies (like 1=1) and unknowables (like "there are things we will never know" itself).

But all laws ARE irrefutable facts. The reason is because they are mathematically proven.

No. The "laws" you are talking about are mathematically *deduced* from other statements (models), of which we can not know if they are "true" (i.e. if they yield correct predictions under ALL circumstances). None of the "laws" of physics can be mathematically derived from the rules of arithmetics (arithmetics and logic are just used to derive them from other statements, which assures their *consistency*, not their *truth*). Even the rules of arithmetics are build on axioms that we simply *belive* (see peano axioms).

But science IS mathematics

Again, no. Mathematics is a *tool* of science, and a very useful and powerful one. But most science is most definitely not mathematics.

You cannot have science without mathematics. Correct. Mathematics is what gives science its logical framework. Correct. Science is n

Sun is not within the reach...

[IllForgetMyNickSoonA]

Hehe... while reading user comments, I also heard it on the local news here in Austria: "The phenomena is taking place some [insert insane number of light years] away, meaning that our Sun is outside of the danger zone".

Gee, I'm feeling better now! :-)

+5

[sheapshearer]

Is "dwarf star" still PC?

Or should we call it "Volumetrically Challenged"?

Nerd Pride

[darkmeridian]

How dare he mock us?! Come on, Slashdotters. RTFA for once in your life!! Wipe out his webserver!!!

I feel bad for any life

[Vandil X]

Seeing how easily that star was ripped apart (albeit as an artist's animation) made me think of what it must have been like for any life living on a planet orbiting that star.

Especially any sentient, self-aware, intelligent life.

Makes you wonder if that will ever happen to our star.

Re:I feel bad for any life

[serutan]

Makes me wonder what beings might have perished on planets orbiting that star, and also if any other creatures were on hand to measure and observe the phenomenon, say from the safety of a spaceship or by remote probe. Was the event broadcast to an audience on thousands of planets? And most importantly, is some sort of intergalactic recording industry persecuting whole species of aliens for transmitting illegal copies of the event?

Elucidation

[Morosoph]

QM doesn't negate the invokation of the 2nd Law of Thermodynamics. QM gives a mechanism (tunnelling of particles) by which entropy can still increase. Given this mechanism, the 2nd Law simply implies that this mechanism will be used.