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Astronomers See Another Star Torn Apart By a Black Hole
The Bad Astronomer writes "A star in a galaxy 2.7 billion light years away wandered too close to a supermassive black hole and suffered the ultimate fate: it was literally torn apart by the black hole's gravity. The event was seen as a flash of ultraviolet light flaring 350 times brighter than the galaxy itself, slowly fading over time. Astronomers were able to determine that some of the star's material was eaten by the black hole, and some flung off into space. Although rare, this is the second time such a thing has been seen; the other was just last year."
I prefer "hole-of-color".
You are welcome on my lawn.
In this article the scale of the gravity comes into focus:
http://news.sciencemag.org/sciencenow/2012/05/giant-black-hole-shreds-and-swal.html?ref=hp
"Before its fiery demise, when the star was about as far from its nemesis as Pluto is from the sun, the black hole stripped off its hydrogen envelope."
At 3.5 billion miles the black hole is able to out-gravity a star of its own hydrogen atmosphere. Am I reading that right?
How is this different from a quasar?
http://en.wikipedia.org/wiki/Quasar
We'll never get to witness that, either Sol will become a red giant first, consuming anything that still lives on the earth, or, the gravity of the black hole with eat the earth before Sol succumbs. Either way, we'll already be dead.
Unless, of course, you have reservations at Milliway's
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We know that black holes can suck in matter - the gamma ray radiation emitted when matters are flatten to a disc before it's being sucked in are indication of black hole devouring matter.
But how about dark matter, or anti-matter?
Will black hole's gravity pull pulls in dark matter and/or anti-matter?
What effect would that have?
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Dark matter responds to gravity, and antimatter should as well. So they'd get pulled in and never seen again.
The odds of such an event are... [sunglasses]....Astronomical.
May the Maths Be with you!
Does anyone ever wonder if antimatter is our representation of what exists as matter on the other side of any given (or perhaps all) black hole(s) inside another dimension/universe/whatever you wanna call it? Universe pairs? Hawking theorized that black holes have white hole pairs - maybe his math just indicated that there is no Lord Nibbler poo at the completion of a black hole (or the start of our universe) but rather another instance of er...space ie- how does a singularity occur w/ infinite mass (or so we would calculate) with the law of conservation of mass - lots of cosmologists must be trying to prove it goes somewhere so why not another dimension/universe/etc - and to consider attractive forces like that perhaps draw a theoretical parallel with polarity so that since our typical everyday matter is attracted to a black hole, perhaps that dimension/etc's typical everyday matter is as well (their own BH, WH to us) and perhaps the other side of any black hole is what would be our theoretical white hole counterpart to a black hole, our antimatter counterpart to our matter, etc etc?
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This scenario was observed twice in two years. Not exactly rare when you realize how little of the sky we watch.
ie- how does a singularity occur w/ infinite mass (or so we would calculate) with the law of conservation of mass
"How the Universe Works: Black Holes", The Discovery channel, Netflix (and others I'm sure) is an excellent reference for your answers.
The entire series is very informative.
Dark matter responds to gravity, and antimatter should as well. So they'd get pulled in and never seen again.
Which really isn't saying much, since they were never seen before, either.
I am not a physicist
:p
The mass doesn't just go "somewhere". Blackholes slowly dissipate over time as they give off energy in the form of gravity. Eventually a blackhole will just disapear. poof
Mass and energy are interchangeable. You have to stop thinking of a blackhole as matter and think of it as a big ball of energy.
Blackholes don't have infinite mass, they have infinite density.
That being said, what Trax3001BBS posted is really good. Netflix "Universe". There is A LOT. Keep using your imagination
I think the Q continuum is at war again.
"This food is problematic."
Uh, antimatter is seen all the time. Heck, the "P" in "PET scan" stands for "positron", the electron's antiparticle. As for dark matter, it's "seen" in gravitational effects, which is admittedly indirect and somewhat inconclusive. Still, humans are rather biased. The matter you're made out of is mostly quarks and electrons. Quarks are affected by all four fundamental forces: (G)ravity, (E)lectromagnetism, (W)eak, and (S)trong. Electrons are only affected by GEW. Neutrinos have just GW and are therefore hard to detect. Maybe there's matter that's just affected by G; it would only show up on cosmological scales like dark matter seems to.
Quoting myself,
Who knows? Maybe there's a whole segment of matter humans are unfamiliar with which interacts very little with the matter we know about but interacts with itself in complicated ways. Maybe there are dark matter solar systems populated by dark matter people who are just as confused as we are about the weird gravitational anomalies caused by our otherwise invisible existence. Communicating through gravity would certainly be an interesting challenge! I don't really believe this, but my point is basically the same as Hamlet's: "There are more things in heaven and earth than are dreamt of in your philosophy"--that is, it's arrogant to expect humans to be in a position to observe all the parts of the universe. Perhaps some things are just hidden.
Another recent post of mine in this vein is a summary of particle classifications.
I'll grant you the antimatter issue, but I still like my tongue-in-cheek jab at the GGP for saying that dark matter wouldn't be "seen" after falling into a black hole. It is "dark" after all, meaning it cannot be seen in the human sense of the word, so the difference between it being in a black hole and not being in a black hole is visibly none.
Of course, the really interesting thing is that it's possible that the actual act of falling into a black hole is the only thing that would ever make dark matter visible. So it would never be seen before, or after, but possibly could be seen *during* its descent into the singularity.
I just finished Leonard Susskind's "The Black Hole War" - also very readable and informative.
No Inflation Taxation without Representation
I apologize if it's a dumb question, but isn't the whole point of a black hole that not even light escapes?
The gravity tore apart the star before it entered the black hole. Watching all the videos about black holes and space might lead one to think that orbits are easy to achieve, but after I ran some particle simulations using simple Newtonian physics in my game engine, I noticed that most particles will slingshot around a source of heavier gravity when they approach, and be flung too far away for gravity to recapture it. In a stellar nursery this sling shot effect places a limit on the star's size, the other main contributing factor being initial density of the nebula. This is true for black holes as well as planets or asteroids approaching a star. So, although some of the star will fall into the black hole, a lot more of it gets flung away from the black hole -- It's a classic case of Conservation of angular momentum...
They're seeing what happens when something gets close to a black hole, not goes into it. You can see things "going into a black hole" before they've reached the event horizon. Also: In my sim, elliptical orbits that didn't result in the object being flung away became tighter and rounder orbits over time.
That schools don't have kids play with simple sims like these in class is Ridiculous! My high-school age little brother hasn't played a traditional game in three weeks. Since I gave him the gravity sim (particle engine stress test) to play with -- all he does is simulate solar systems and formation of stars, or big stars eating little stars, etc. It's the first time I've ever seen him interested in space beyond the Halo Universe! He asked me about Quantum Physics yesterday!
Correction: Gravity affects everything, its the weakest fundamental force of all .
Glad I could help.
This sig is not paradoxical or ironic.
Well, we've created antimatter in the lab and it seems to behave very much like normal matter, it just has the opposite charge (for protons/electrons) and Baryon number (a QM property). So I suspect it would behave very much like normal matter, in fact I doubt we can actually tell whether a celestial object/event involves matter or antimatter, though it seems fairly likely that all the "native" matter in a particular galaxy will be the same type, otherwise it would have mutually annihilated whenever a gas cloud of one kind interacted with it's opposite, though a matter galaxy could conceivably capture a rogue star from a passing antimatter galaxy - as long as the rogue star never exploded or hit something directly it would likely be indistinguishable except for a *very* faint and diffuse halo where its antimatter-based solar wind contacted and annihilated the interstellar medium.
Dark matter though... that's an interesting question. As far as we can tell it only interacts gravitationally so it will never glow or collide with anything, since both are EM interactions. The Bullet Cluster would seem to indicate that it even passes right through other dark matter. Which raises an interesting question, while it could presumably be sucked into a black hole's event horizon it might continue to behave just as bizarrely, possibly even being able to escape again somehow. We just have no idea what the stuff is, it's even possible that it's not matter at all, but rather a phenomena symptomatic of a fundamental misunderstanding of the nature of reality, much as black-box radiation in the 1800s led to the development of quantum mechanics and radically altered our understanding of the universe. It was widely believed at the time that we basically understood everything about physics, with just a few loose ends still to tie up (BB radiation, the cause of spectral lines, and a couple others). Instead those loose ends led to the unraveling of virtually everything we thought we knew and opened the door to something far stranger.
There's also the possibility that black holes don't exist at all and the question is nonsensical. We have evidence of ultra-massive non-luminous objects, but little if any for the existence of the defining characteristic of black holes, an event horizon. We assume they are black holes because our theories say that anything that massive would collapse into a singularity, but think about it - we're postulating that a body can become so dense that it creates a region of space where the laws of physics themselves to break down! There are several competing theories that make such a situation impossible, one that I like is based on the fact that Einstein treated gravity as a special case - all other energy fields generate a gravitational field based on their energy density. Einstein felt that it would be "double dipping" to have gravitational fields do so and discarded the idea. However, if we rework the equations assuming that they do in fact do so then we find that as the gravitational field strength becomes extreme the "secondary" gravity generated by the extreme energy density of the "primary" field pulls back against the primary source, causing the field strength to plateau at a level less than that required to create an event horizon, regardless of the density of the central object. If that, or some other mechanism, puts an upper limit on gravitational field strength it seems likely that the ultramassive objects are simply some sort of exotic quark-degenerate matter that happens to be non-luminous. As far as I can remember photons are radiated when (1) charges accelerate through space (as with radio transmissions), (2) electrons descend to a lower orital, and (3) nuclear processes result in lower binding energies. I don't know much QM, but it seems likely that (4) quark bindings and transmutaions that result in "left-over" energy would be a final source, and the only one that might apply to a neutron star, which are apparently directly observable (I couldn't find much in the way of de
--- Most topics have many sides worth arguing, allow me to take one opposite you.
GP said "most powerful" which is not synonymous with strongest. For example, conspiracy theories aside, the US president is probably one of the single most powerful men on the planet, but it's a matter of force multiplication, in a test of strength I'd bet on most any bodybuilder that challenged him.
In the case of gravity it's more a matter of force division. The nuclear forces fall off very rapidly with distance, becoming effectively nonexistent at even molecular scales. Magnetism fairs better, but still falls off with the inverse cube, becoming negligible at any significant distance. That leaves the electrostatic force as the only real challenger at long range, and it's bi-polarity causes opposite charges to tend to clump together in equal quantities, neutralizing it's effects.
And thus gravity is left standing as the long-range champion, free to shape the universe as it sees fit with little interference from it's myopic stronger cousins.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
If you want to learn more about the phenomena this might be a good place to start. That's the distance at which a satellite will be torn apart into a ring by the gravitational shear of its primary. First gasses, then liquids (both fluids, but liquid's higher density and stronger inter-molecular attraction would let it get closer), and finally, even rigid bodies will get torn apart. I would guess a star could be roughly modeled as a liquid body with a gasseous atmosphere. The formulas don't really account for bodies with non-uniform density, but I'm betting the atmosphere would elongate far more readily than the denser than the much higher density core and cross the limit much in advance of the rest of the star.
An interesting feature is that the Roche Limit is independent of the mass of the satellite, it's only the mass of the primary and density of the satellite that matters. Conceivably you could have two identical stars tearing each other apart as they approach their Roche Limits, though they'd probably just end up merging into a single rapidly-spinning star instead of forming an awesome ring-shaped star. Still, with enough angular momentum you might at least get an extremely flattened ovoid, that'd be kinda cool.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
IANAP either, but as far as I know gravity isn't energy. Black holes evaporate due to Hawking radiation.
Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
No. Black holes like the one being talked about do not loose much energy to gravitational waves. In order to dissipate energy via gravitational waves the mass must accelerate. So a pair of masses orbiting each other will shed gravitational energy, a galactic black hole sitting in the center of the galaxy does not move much and so does not emit gravity waves.
Regarding Hawing radiation dissipation, the temperature of the Hawking radiation is greater as the mass of the BH is smaller. In order to loose net mass, this temperature has to be larger than the CMB, which is only true for I think smaller than stellar size BHs.