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How To Destroy a Black Hole

KentuckyFC writes "The critical concept that makes a black hole black is the event horizon: a theoretical boundary in space through which light and other objects can pass in one direction but not the other. Since light cannot escape the event horizon, it must be black. The event horizon is a nuisance to astrophysicists because it hides the interesting new physics that must go on inside a black hole. What they would like is a way to get rid of the event horizon so that they can see what goes on behind it. It turns out that just such a thing may be possible, say physicists. According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass. However the calculations are so fiendish (PDF) that nobody knows whether the black hole would shed this extra angular momentum and charge before it could settle into a stable 'naked' state. However, the possibility that the event horizon could be destroyed raises the question of what astrophysicists would see behind this veil. According to some, black holes are regions of spacetime with infinite curvature called singularities. Many believe that 'naked' singularities cannot exist in nature. And yet there are enough question marks to suggest that this mystery is far from settled."

364 comments

  1. Whaazzaaaa? by Em+Emalb · · Score: 1, Funny

    What they would like is a way to get rid of the event horizon so that they can see what goes on behind it.

    Am I understanding this? We don't really know how black holes work, but we know the event horizon is the point where light and other matter stop "coming out the other side", and in order to see what's on the other side, they want to dstroy a black hole?

    two things...

    Thing 1: head asplode

    Thing 2: How is this a good thing to do? Aren't they basically stating that they don't understand how or why this is occurring, but they want to destroy something to figure out what goes on behind it? When are they planning to do this? December 21st, 2012?

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    1. Re:Whaazzaaaa? by Captain+Spam · · Score: 5, Insightful

      Thing 2: How is this a good thing to do? Aren't they basically stating that they don't understand how or why this is occurring, but they want to destroy something to figure out what goes on behind it? When are they planning to do this? December 21st, 2012?

      They're scientists and engineers. "Break something to see how it works" is how scientists and engineers of all walks of life think. They're just thinking bigger than most. I gotta salute them for that.

      --
      Demanding constant attention will only lead to attention.
    2. Re:Whaazzaaaa? by Kenoli · · Score: 1

      When are they planning to do this?

      Never. Theorizing that there may be a way to overcome an event horizon and actually overcoming it are quite different.
      How are they going to "feed it angular momentum and charge"? Magic?

    3. Re:Whaazzaaaa? by swanzilla · · Score: 1

      When are they planning to do this? December 21st, 2012?

      Seeing as we are roughly 1600 light years away from the nearest black hole, I'd say that is quite unlikely.

    4. Re:Whaazzaaaa? by BlackSnake112 · · Score: 1

      Well think of what the military types are thinking. If this device can destroy a black hole, Imagine what it can do if used on our enemies.

      I am thinking if this device can destroy a black hole, this planet we are on would also be destroyed if the device was used here.

      How about we get space travel to be a common as walking across the room. Then we get people (from Earth) living on different planets and living long term on space ships. Then we find an out of the way black hole to try this on. By the time we can do all of this, a few thousand years will have gone by. Hopefully humans are smarter by then.

    5. Re:Whaazzaaaa? by Surt · · Score: 1

      Fire mass at it at an angle, and for the mass, use plasma? Charge and angular momentum doesn't seem very hard to me. The hard part is reaching the nearest black hole to do it.

      --
      "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
    6. Re:Whaazzaaaa? by PieSquared · · Score: 1

      Thing 1: We don't know what lies behind the event horizon, since nothing (no light, no radio waves, no physical objects, no information) can come out. It's a one-way gate. Theory is all well and good, but the only way to find out for sure what is on the other side would be to remove or disrupt the event horizon. Scientists by their very nature aren't the kind of people who can fail to see what's inside a black hole, given the opportunity.

      Thing 2: "When are they planning to do this?" Well, for starters there aren't any black holes that it would be even possible to reach by 2012, and the kind of mass/energy manipulation we'd have to do to impart significant angular momentum on something a dozen times as massive as the sun... well, it's not in the near future. In short, they aren't planning to do this, just thinking about how they *could* do it if they had a convenient black hole and near-enough limitless energy.

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    7. Re:Whaazzaaaa? by BigBlueOx · · Score: 1

      Fret not, young one, this is just how things get done. You see, the whole damn universe was written in COBOL and we don't have the source code so any module we don't understand has to be disassembled. Hopefully, after disassembly we'll be able to make some sense out of what's going on. Once we understand everything in the universe, we can re-write it in Erlang.

    8. Re:Whaazzaaaa? by Xacid · · Score: 2, Funny

      Just don't cross the streams.

    9. Re:Whaazzaaaa? by Low+Ranked+Craig · · Score: 2, Interesting

      Well, theoretically, (unless the theory has changed) during the big bang matter could have been compressed past the Swartzschild radius due to pressure and black-holes formed that mass much less than is required for a black hole to form today from gravity alone. http://en.wikipedia.org/wiki/Primordial_black_hole Most of these will have evaporated by now (or maybe not depending on how you interpret the string theory), but if they can exist there should still be a great many of these in the universe. We know that a black hole can carry a charge, and the surface gravity can be calculated. It is possible that there may be some of these in the solar system, perhaps in many years we will discover a way to detect them, and increase their charge to the point where they could be manipulated electromagnetically.

      --
      I still cannot find the droids I am looking for...
    10. Re:Whaazzaaaa? by Anonymous Coward · · Score: 1, Insightful

      Engineers don't concern themselves with this BS. Theoretical Physicists and other loonies rave about this nonsense, while engineers focus on actually developing APPLICABLE technology to solve ACTUAL PROBLEMS in the real world, the one we live on. We deal with scientists in this fashion: "That's a great discovery, what can we do with it?" We also typically don't break things to see how they work. We see how they work by observing them working. We break things to understand how they fail, and how it can be prevented in the future. Does not apply to a black hole, IMO.

    11. Re:Whaazzaaaa? by 2names · · Score: 1

      Hopefully humans are smarter by then.

      Trust me, Snake, they aren't.

      --
      "I'm just here to regulate funkiness."
    12. Re:Whaazzaaaa? by AndersOSU · · Score: 1

      1600 light years away from the nearest black hole

      The nearest black hole that we know about.

      It's been theorized that the universe is crawling with rogue primordial black holes. Hell some people even think the Tunguska event was caused by a black hole.

      Obviously we're not going to be able to carry out this experiment in the next decade, but if we ever manage to sustained space exploration, finding and feeding a small black hole might be high on the list of experiments.

    13. Re:Whaazzaaaa? by FooAtWFU · · Score: 1

      More likely they will have a small black hole (a few tons, perhaps) in their space lab circa the year 2525, and will watch it with a microscope while they spin it up.

      --
      The World Wide Web is dying. Soon, we shall have only the Internet.
    14. Re:Whaazzaaaa? by ajrs · · Score: 2, Funny

      Well, theoretically, (unless the theory has changed) during the big bang matter could have been compressed past the Swartzschild radius due to pressure and black-holes formed that mass much less than is required for a black hole to form today from gravity alone. http://en.wikipedia.org/wiki/Primordial_black_hole Most of these will have evaporated by now (or maybe not depending on how you interpret the string theory), but if they can exist there should still be a great many of these in the universe. We know that a black hole can carry a charge, and the surface gravity can be calculated. It is possible that there may be some of these in the solar system, perhaps in many years we will discover a way to detect them, and increase their charge to the point where they could be manipulated electromagnetically.

      I love a sentence that can be misinterpreted to imply that I can retroactively change the workings of the universe based on my presumably mutable interpretation of a theory. I'm sure magic works just like this.

    15. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      What if we used some sort of quantum communication? I was reading some article a few weeks ago about some group in China testing quantum theories in which one set of particles changed, and immediately another set of particles (across the room) changed to mimic the original set of particles form. Would this be possible if somehow particles sent into the black hole could change form to somehow (communicate) those changes to another set of particles outside the event horizon?

    16. Re:Whaazzaaaa? by Talderas · · Score: 1

      You can't feed it! If you feed it, it will just follow you home.

      Damn strays.

      --
      "Lack of speed can be overcome. In the worst case by patience." --Znork
    17. Re:Whaazzaaaa? by Lunoria · · Score: 1

      They could test their theories on the black hole that the LHC will make!

    18. Re:Whaazzaaaa? by newcastlejon · · Score: 5, Funny

      Does not apply to a black hole, IMO.

      Not until stellar engineering encompasses more than theory.

      Oblig., but not XKCD for a change.

      --
      If God forks the Universe every time you roll a die, he'd better have a damned good memory.
    19. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      By the time we can do all of this, a few thousand years will have gone by. Hopefully humans are smarter by then.

      Good luck with that. Looking back a few thousand years we haven't really gotten any smarter. We are still trying to obliterate each other, we just have better toys to do it with. A few thousand years from now, if we haven't succeeded in killing ourselves off completely, we will most likely still be at it.

    20. Re:Whaazzaaaa? by saider · · Score: 1

      they want to destroy something to figure out what goes on behind it?

      AKA Reverse Engineering, Forensics, Vivisection, Autopsy, Accident Investigation, ...
      Pretty much everything we have learned has come from something's destruction.

      When are they planning to do this?

      Seeing as how the nearest black hole is light years away and we can barely leave Earth orbit, I'd say you and many generations are safe from a universe-ending naked black hole.

      --


      Remember, You are unique...just like everyone else.
    21. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      Subatomic black holes are thought to exist everywhere naturally within the fabric of spacetime. And soon we are going to use LHC in an attempt to create them on demand. If we are successful at creating them then its conceivable that with practice we will be able to take them apart.

    22. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      Also, if we can get to the black holes by some form of FTL transportation, theoretically, we could just go into the event horizon, and get back out using FTL. The event horizon is the point that light cannot get past due to gravity of the singularity being stronger than the speed of light. So if we have FTL travel, we should be able to travel faster than the singularity can prevent... up to a point.
      And this only works if we are actually travelling faster than light (which, given our current definition of physics, is impossible), not bending space-time etc.

    23. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      Unless they make on, and then break it.

    24. Re:Whaazzaaaa? by AndersOSU · · Score: 2, Funny

      We're talking about naked black holes here.

      The least you could do is buy it dinner.

    25. Re:Whaazzaaaa? by Guignol · · Score: 1

      In fact, our own universe could very well be a black hole !
      So we might have a super uper duper extra gallactic "everybody jumps at the same time" technique at disposal to actually get an understanding of the uiniverse inside an 'over/über/multi'-verse thing :)

    26. Re:Whaazzaaaa? by Smauler · · Score: 1

      This explains the Fermi Paradox relatively neatly - I just hope it's not true.

    27. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      1600 light years away from the nearest black hole

      The nearest black hole that we know about.

      No, I saw a huge one Aunt Jemimaing her way through the grocery store. I had to go to the next aisle to get around her.

    28. Re:Whaazzaaaa? by lgw · · Score: 1

      If Hawking is right about Hawking radiation (and I hear he may be way off base), then keeping any sort of charge on a small black hole would be problematic at best, as the process of Hawking radiation would dissipate charge quickly. Even if not, the charge of the black hole would make it quite difficult to hit it with a charged plasma. It would be an interesting experiment, to be sure.

      Spin is also strange. I don't think firing mass at an angle would work well - a black hole would have to be quite large before you could aim at part of it, and large spinning black holes twist space oddly. When you can orbit the black hole quite quickly with no angular momentum things get wierd. A hole can spin fast enough that even at the speed of light you'd be reducing the angular momentum, if I understand this frame-dragging stuff properly. Firing rapidly spinning massive objects in might help, but some natural black holes are thought to spin quite fast indeed, and it would be hard to give anything made of normal matter enough angular momentum to matter without tearing itself apart.
       

      --
      Socialism: a lie told by totalitarians and believed by fools.
    29. Re:Whaazzaaaa? by TerranFury · · Score: 1

      Am I the only one who gets "The connection was reset" 9 out of 10 times I try to go to abstrusegoose.com?

    30. Re:Whaazzaaaa? by lgw · · Score: 1

      Have you read some of the crazy shit some string theorists publish? You only think you're joking (and your "misinterpretation" is only about 50 milli-Tiplers of crazy). 100 years from now the publications in string theory-related journals will be a textbook example of how a scientific community can collapse into uselessness.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    31. Re:Whaazzaaaa? by ajrs · · Score: 1

      Have you read some of the crazy shit some string theorists publish? You only think you're joking (and your "misinterpretation" is only about 50 milli-Tiplers of crazy). 100 years from now the publications in string theory-related journals will be a textbook example of how a scientific community can collapse into uselessness.

      You can't reproduce my results because your interpretation of string theory shifts the universe into a non compatible state every time you try the experiment! Did you try more bat guano?

      When experimental results are reproducibly different based on the beliefs of the experimenter, we will have a definitive test for existence of god. Who will exist or not exist depending on what people want to find.

    32. Re:Whaazzaaaa? by wxjones · · Score: 1

      I don't see any reason to believe Hawking is wrong, at least in the case of stellar-mass black holes. In this regime, gravity is still relatively weak at the event horizon (compared to scales we don't understand), and quantum mechanics should work just fine. Since Hawking radiation just depends upon virtual particle-anti-particles being spontaneously created in vacuum (well established physics), and one partner of the pair (randomly chosen) crossing the event horizon toward the singularity, while the other goes in the opposite direction and stays out, this effect won't cancel the charge of the blackhole unless the charge becomes so large at the event horizon, that the electric field is strong enough to affect the trajectories of the virtual pair so that one charge is preferentially sucked into the event horizon.

      --
      My SIG is a P226
    33. Re:Whaazzaaaa? by davester666 · · Score: 1

      Hey! Don't bring two guys peeing into this discussion...

      --
      Sleep your way to a whiter smile...date a dentist!
    34. Re:Whaazzaaaa? by John+Hasler · · Score: 1

      > How are they going to "feed it angular momentum and charge"?

      Read the paper. You feed a black hole momentum and/or charge by dropping objects with momentum and/or charge into it.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    35. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      Well, the engineers and physicist did build the Large Hadron Collider together and there are many trained engineers who do pure and applied scientific research today. The engineering field is much more varied and larger than your given impression, just like the people. When you're dealing with the past post-docs and the equivalent degrees of other countries, you really don't care about "dealing" with scientists or any such attitudes. You're yourself one and with others, you're all solving the same puzzles of the Universe, in this case.

    36. Re:Whaazzaaaa? by Bungie · · Score: 1

      We could sit here for years inventing theories snd trying to figure it out.

      - or -

      We could just start blowing shit up and see what happens!

      If it's one thing mankind is goot at...it's destroying things!

      --
      The clash of honour calls, to stand when others fall.
    37. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      It's been theorized that the universe is crawling with rogue theatons as well, and even Tunguska was caused by Xenu.

    38. Re:Whaazzaaaa? by Anonymous Coward · · Score: 0

      Thing 2: How is this a good thing to do? Aren't they basically stating that they don't understand how or why this is occurring, but they want to destroy something to figure out what goes on behind it? When are they planning to do this? December 21st, 2012?

      It's worse than you think, the scienteists are smashing particles together to find out what makes them tick, and they are doing that RIGHT NOW! And have been doing for DECADES!

      Won't someone please think about the particles!

    39. Re:Whaazzaaaa? by sjames · · Score: 1

      It's really just armchair physics at this point. Given how far away the nearest black hole is and the amount of energy it would take to perform the operation, I wouldn't worry too much about it just yet.

  2. PDF a virus? by js3 · · Score: 1

    Why am I getting a DEP when trying to open that PDF link?

    --
    did you forget to take your meds?
    1. Re:PDF a virus? by Anonymous Coward · · Score: 0

      Maybe Acrobat is a piece of garbage that corrupts itself?

  3. Till then.... by cyberoidx · · Score: 1

    Someday, They'll find a way to actually go and feed a black hole all that charge and angular momentum. I'd like to be stored in a cryogenic storage till that day.

  4. Totally cool! by swordgeek · · Score: 1

    This is just damned neat. Destroy a black hole! Observe a singularity! Watch the cosmos bend into itself! Or...?

    The best science is the stuff that ends in a big question mark. e.e. cummings nailed it on the head: "always the beautiful answer who asks a more beautiful question."

    --

    "People who do stupid things with hazardous materials often die." -- Jim Davidson on alt.folklore.urban
  5. Re:look, i like making fun of star trek technobabb by jgagnon · · Score: 4, Funny

    On a less serious note, does Rule 34 apply to naked singularities?

    --
    Remember to maintain your supply of /facepalm oil to prevent chafing.
  6. Re:look, i like making fun of star trek technobabb by just_another_sean · · Score: 4, Insightful

    People thought communicators were way to far out too when TOS came out. Now we take
    them for granted.

    Now I don't think there are going to be any practical experiments around this theory
    anytime soon but "this shit" has to start somewhere. It's been said many times before
    on /. but I'll go ahead and repeat it; a lot of scientists are heavily inspired by
    science fiction and, especially when they are young, love to see if their favorite
    tech from their favorite shows are feasible.

    --
    Creationist Textbook Stickers Declared Unconstitutional by CowboyNeal
  7. Re:look, i like making fun of star trek technobabb by Sta7ic · · Score: 1

    It makes sense, but seems overly impractical due to the sheer energy or mass involved with a black hole. It'd be fun to see what would happen if the static forces were able to push photons hard enough to kick them out of the gravity well. I don't buy the bit about angular momentum so readily, I think the mass would then need to be flying off the sides of the black hole ~ impractical to get that much kinetic energy when you're adding more mass.

  8. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 2, Informative

    Christ, you always make the most asinine comments. It's almost impressive.

  9. Oh well by Vinegar+Joe · · Score: 1

    I thought this was another story about somebody wanting to nuke the Gulf of Mexico.

    --
    "The average reporter we talk to is 27 years old......They literally know nothing." - Ben Rhodes
  10. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 1, Interesting

    Rule 34 only applys if they exist... so if you can find port of a naked sigularity there's a good posability that they exist

  11. I know what's inside. by postbigbang · · Score: 5, Funny

    All of my lost left sox.

    Two bolts from my motorcycle.

    The lost chord.

    George Bush's dignity.

    Several B-19s last seen headed towards Bermuda.

    An iPhone 4G prototype.

    Darl McBride's balls.

    And I'm sure there's more.

    --
    ---- Teach Peace. It's Cheaper Than War.
    1. Re:I know what's inside. by Anonymous Coward · · Score: 1, Funny

      Boobies!

      Many believe that 'naked' singularities cannot exist in nature.
      That's because conservatives smother them with FUD, hyperbole and litigation before they can be revealed.

    2. Re:I know what's inside. by Attack+DAWWG · · Score: 1

      Huh? Are you suggesting that Darl McBride actually once had balls?

      Or that George Bush actually once had dignity?

    3. Re:I know what's inside. by coolmoose25 · · Score: 1

      You forgot the 18 minute gap on the Watergate tapes. Oh yeah, and the 4323 ball point pens I misplaced.

      --
      Brawndo: It's what plants crave!
    4. Re:I know what's inside. by postbigbang · · Score: 1

      He had to have..... insanity isn't a defense in civil litigation.

      --
      ---- Teach Peace. It's Cheaper Than War.
    5. Re:I know what's inside. by TheRealMindChild · · Score: 2, Funny

      - My glasses

      I can't see them ANYWHERE I look, so that is the only place left they could be

      --

      "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
    6. Re:I know what's inside. by dragonsomnolent · · Score: 1, Troll

      As a Moody Blues fan, your list struck a chord with me (I don't care if the pun is horrible, I've got karma to burn)

      --
      I got nuthin
    7. Re:I know what's inside. by __aasqbs9791 · · Score: 1

      I would have thought that telling the world things that he knew to be outright lies would have taken some massive balls. And he played it to the hilt, all the way through, even as it all came down around his head. Oh, right, that's not big balls, that's just insanity. My mistake.

    8. Re:I know what's inside. by OctaviusIII · · Score: 1

      Bush had his moments. Not many, but they were there.

      --
      What's this? Another weblog? On transit?
    9. Re:I know what's inside. by confused+one · · Score: 1

      Based on what he's done... the lies he's been willing to speak in public and in front of a judge... He has big brass one.

    10. Re:I know what's inside. by swb · · Score: 1

      Jimmy Hoffa
      Judge Crater

    11. Re:I know what's inside. by lgw · · Score: 3, Funny

      They're on your head.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    12. Re:I know what's inside. by Hurricane78 · · Score: 1

      George Bush's dignity.

      That was already mentioned:

      regions of spacetime with infinite curvature called singularities. Many believe that 'naked' singularities cannot exist in nature.

      --
      Any sufficiently advanced intelligence is indistinguishable from stupidity.
  12. Just wait a little while... by SloWave · · Score: 0

    and the event horizon should just disappear due to Hawking_radiation and Black_hole_evaporation leaving a naked singularity.

    1. Re:Just wait a little while... by A.+B3ttik · · Score: 1

      I don't think that results in a Naked Singularity... it results in its annihilation.

    2. Re:Just wait a little while... by Captain+Hook · · Score: 1

      Hawking Radiation would cause the blackhole to get smaller and smaller, and with it the diameter of the event horizon, you wouldn't get a naked blackhole.

      --
      These comments are my personal opinions and do not necessarily reflect the opinions of the other voices in my head.
    3. Re:Just wait a little while... by professionalfurryele · · Score: 4, Informative

      Although no one knows what happens at the end point of black hole evaporation it is unlikely it would leave a naked singularity since the mass of the singularity is what is being 'evaporated'. Besides, even if there was a naked singularity around just before the thing evaporates it would be kicking out so much energy you wouldn't be able to get anywhere near it. A 1kg black hole evaporating would release the equivalent energy to a large thermonuclear weapon in a fraction of a second.

    4. Re:Just wait a little while... by Ktistec+Machine · · Score: 1

      Black holes that evaporate due to Hawking radiation don't leave behind a naked singularity. They're just gone.

    5. Re:Just wait a little while... by astar · · Score: 1

      Did I miss a joke? Almost syntactically, if the conjectured black hole evaporates, there is not much interesting left. I bothered to look at the links too. Duh?

    6. Re:Just wait a little while... by jd · · Score: 5, Interesting

      That allows information from inside the event horizon to leak outside (which is all the astrophysicists really need) and allows the evaporation of black holes, but the event horizon would remain intact. However, we have never seen Hawking Radiation (yet) and it depends some on certain assumptions being valid. One of these assumptions is that the singularity is something "physical".

      A lot of cosmologists don't like infinities, so don't like singularities, but let us consider what "infinite gravity" would actually mean. It would mean you have a vertical gravitational well, with the universe being the "walls" of this well. As far as the universe is concerned. the actual hole that makes up the interesting part of the well is on the outside, just as the air in a physical well is outside the brick lining that comprise the walls. Since what we call "physical" are the objects inside the universe, it makes no logical or rational sense to talk of something that is on the outside as being "physical". You can detect it using the usual rules of topology and geometry (you can't apply any topological transformation to a torus to produce a sphere), but if you picture yourself as a Flatlander on the surface of said torus, you could NEVER observe the region on the outside that distinguishes the torus from a sphere. You could infer it existed, you could even prove that it has certain properties, but that's it.

      Cosmologists and topologists don't get along, which is why space/time existed as fact in geometry long, long before any physicist accepted it was real. Einstein is said to have loathed and despised the concept, and only grudgingly accepted it had to be true after being dragged, kicking and screaming, by his theories into reaching no other answer. (You might gather from this I have a low opinion of certain branches of physics.)

      But precisely because the rules of topology FORBID a torus to become a sphere, it would be impossible for a genuinely infinite-gravity singularity to evaporate completely. Instead of their evaporation speeding up as they shrank, it would have to slow down -- if they evaporated at all. Entirely the opposite of what physics expects. There's no reason for them TO evaporate, however. It is only required in cosmology to meet the requirements of the 2nd Law of Thermodynamics, but thermodynamics only applies to what exists. A hole is a region where the walls do NOT exist.

      There is a third possibility. Under the standard model for space/time, time is orthogonal to space. If space is bent at 90' to all other spacial dimensions, then it is no longer space. It is time. This means that not only is there a singularity at the heart of every black hole, it would be the SAME singularity. There would have only ever been one singularity, right at T=0, and the throats of all black holes would be directly and permanently hard-linked to this. There would still be no evaporation at this end of time (it has already happened).

      A fourth (and fifth) possibility is that black holes never actually form at all. There's an entire alternative model in cosmology which prohibits them outright, giving you that fourth option. Then, Professor Hawking's work on imaginary time and the curvature of time around singularities would eliminate the need for a singularity outright. If you factor time curving as well as space, then space/time never vanishes to a point. Space/time would become parabolic, giving it a minimal state, but there is no moment in which any variable hits zero or any infinite states are achieved.

      There's probably others I've either not heard of, or have heard of and forgotten. But at least five different ways DO exist and are recognized in modern physics as possible in which no black hole singularity of the kind imagined would arise. That means there is simply no theoretical ground (right now) to assume that this new theory has any meaning or would make any sense.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    7. Re:Just wait a little while... by steelfood · · Score: 2, Informative

      Maybe by the time anything reaches the singularity, the universe would've ended and time would cease to exist. That is, you can never reach a singularity, you (or what's left of you) can only ever continue to spiral around it until literally the end of time.

      --
      "If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
    8. Re:Just wait a little while... by f3rret · · Score: 1

      Show your work.

      --
      Admit nothing. Deny Everything. Make Counter-accusations.
    9. Re:Just wait a little while... by Xaedalus · · Score: 1

      I'm going to go outside and stare up at the sky for a while now... and maybe eat a doughnut.

      --
      Here's to hot beer, cold women, and Glaswegian kisses for all.
    10. Re:Just wait a little while... by lgw · · Score: 1

      Singularities in your model are always places where your model stops working - you have to be pretty silly to think what you're modeling has a singularity.

      A black hole, per general relativity, is just a place where (from the perspective of an outside observer) the space and time axes are titled significantly, so that the time "direction" looks like a spatial direction. Of course, that's how all of gravity works, just not ususally to such an extent.

      While Hawking's imaginary time is a good and clever way to make a model that doesn't have a sigularity, I rather suspect that the model we have based on the observable universe is just flat out wrong past the event horizon - but's it's boring to say "you can't do science there" and entertaining to read Hawking, so I'm not complaining!

      --
      Socialism: a lie told by totalitarians and believed by fools.
    11. Re:Just wait a little while... by lgw · · Score: 1

      Black hole evaporation converts the mass of the black hole into energy. 1 kg per the Google calculator is 8e+16 joules, or about a 20 megaton explosion.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    12. Re:Just wait a little while... by wxjones · · Score: 1

      The existence of an event horizon does NOT require the existence of a singularity. It only requires a certain amount of mass within a given volume (defined by the equation for the Schwartzchild radius http://en.wikipedia.org/wiki/Schwarzschild_radius. For the size of black holes we usually think about (up to the size of the black holes assumed to be at the center of most galaxies), the gravitational forces are so large that nothing we know of will stop complete collapse into a singularity. For extremely large black holes, however, the gravitational forces would be so small that ordinary matter exists inside the event horizon. In addition, there may be repulsive forces at very short distances that we don't yet know of that prevent singularities in smaller (e.g. stellar mass) black holes.

      --
      My SIG is a P226
    13. Re:Just wait a little while... by f3rret · · Score: 1

      This is true, it however, does not offer any evidence that a black hole will instantly evaporate if the event horizon is removed.

      --
      Admit nothing. Deny Everything. Make Counter-accusations.
    14. Re:Just wait a little while... by professionalfurryele · · Score: 1

      At no point did I claim that a black hole will instantly evaporate if the event horizon is removed. What I claimed is that if through some fluke of physics there was a naked singularity exposed during the end of the lifetime of a black hole like the OP suggests (perhaps a result of quantum gravity although I doubt it) then we would have a very hard time seeing it through the multimegaton TNT equivalent outpouring of radiation.

    15. Re:Just wait a little while... by jd · · Score: 1

      D'oh! This is further proof Homer Simpson is the greatest mind of our time.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    16. Re:Just wait a little while... by jd · · Score: 1

      It's pretty much accepted these days that time and space are indistinguishable other than that the 2nd Law of Thermodynamics creates a time arrow that no spacial dimension possesses. The notion that time is different from space was rejected in the late 1800s by mathematicians, early 20th century by physicists. In relativistic physics, the equations for modeling relative time, relative space and relative mass are merely Pythagoras' equations where the hypotenuse is fixed at C for all objects. (For reasons that escape me, I won an award from Warwick University for the proof of this. It's so bleedin' obvious.)

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    17. Re:Just wait a little while... by jd · · Score: 1

      Yawn. As I said, there are competing theories. Your absolutism, though, tires me. Have you tried founding a major religion? I hear it's quite profitable. It's certainly going to be more entertaining for the rest of us to watch than your posts. Your claim that singularities aren't required by an event horizon ignores not only all of the alternative theories put forward in physics (pretending a theory does not exist is NOT a way to win friends and influence people, your "proof" is utter drivel. You start by assuming that the radius of the singularity is equal to the radius of the event horizon, then "prove" singularities aren't present by showing this can't be true. Blah blah puke. Get over your ego.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    18. Re:Just wait a little while... by wxjones · · Score: 1

      You are arguing with nature, not me. A large enough mass in a small enough space will have an event horizon, but will never form a singularity because nuclear repulsion is enough to prevent complete collapse. No alternative theories required. Now whether such a large black hole actually exists is another question, but the laws of physics don't prevent it. BTW, you seem to not know, but a singularity has a zero radius by definition. You completely missed my argument.

      --
      My SIG is a P226
    19. Re:Just wait a little while... by Bryan+K.+Feir · · Score: 1

      But precisely because the rules of topology FORBID a torus to become a sphere, it would be impossible for a genuinely infinite-gravity singularity to evaporate completely.

      Of course, the same rules would make it impossible for a genuinely infinite-gravity singularity to form where there wasn't one previously. Which leads into your later points of black holes never forming at all...

    20. Re:Just wait a little while... by jd · · Score: 1

      Kerr ring singularities are interested in your theory and wish to subscribe to your newsletter. (Translation: I'd forgotten more about singularities by the 1987 Tercentenary lectures at Cambridge than you've ever learned.)

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    21. Re:Just wait a little while... by wxjones · · Score: 1

      OK, I'll try to say this slowly. The radius of the event horizon is linearly proportional to the mass. The radius of a spherical mass at constant density is proportional to the cube root of the mass. This means the average density required to create an event horizon is inversely proportional to the square root of the mass, Therefore, as the mass gets bigger, the average density to create an event horizon goes down. At a mass of 270 million solar masses, the density required to form an event horizon is the same as ordinary water. It is possible for enough ordinary matter to form an event horizon. As I originally said, no singularity is required. Of course, most black holes we imagine are much smaller, and require huge densities. A solar mass black hole requires an average density almost 400 times nuclear density. At these densities, we know of no force that can prevent complete collapse so we assume a singularity forms. Certainly there are alternate theories that apply in this case. I'm know stepping off your lawn, old man.

      --
      My SIG is a P226
    22. Re:Just wait a little while... by jd · · Score: 1

      And I will say this slower, as your brains make several weeks to percolate through each fact:
      OK, I'll try to say this slowly. The radius of the event horizon is linearly proportional to the mass.

      No. The radius of the event horizon fomr abssolut mean position to absolutute is directly proprtional to the total informatiomn present. If you want to offer a rebutall do so, but repeating yourself only makes you look the more moronic. Try to understand the basics of Hamiltonian Tensors and Minkowski spacetime. Try, however, may well be as far as your limited brains can go.

      The radius of a spherical mass at constant density is proportional to the cube root of the mass.

      Only useful for those cases where there is (a) a single, point-sized singularity.

      You have IGNORED the fact that:

      a) You don't need a sungularity
      b) The fact that singularities need not be points but may be any shape that cannot be reduced further (a torus is an example).
      c) The singularity, if it even exists and is the shape you imagine it to exist, need not behave as you think. Nothing else in the physical world ever has. Anything the size of a particle exists in all space and at all times, can simultaneously change position and velocity.
      d) One of the alternative theories listed had no black holes in them AT ALL!
      e) Another had one singularity, but not the one you are predisposed to believe at all costs.

      > This means (blah blah blah)

      "The world is full of obvious things which nobody by any chance ever observes."* You can say nothing about what "it" means until you have an accepted idea of what "it" is!

      "No, no: I never guess. It is a shocking habit, -- destructive to the logical faculty."

      Enough said, if you are incapable of reading the posts of others of reading even the most basic of replies you are not worthy of my attention.

      > I'm know stepping off your lawn, old man.

      Too late. I mowed your post into fertilizer. I'm sure there are some deadly parasitic species that could benefit from your gall-loaded remarks, but nothing beneficial, s gerroff my lawn and take your damn poster-made-fertilizer with you!

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  13. IANAA by plastbox · · Score: 1

    Isn't the event horizon the point at which the gravitational pull of a black hole becomes so powerful that not even light can escape? How on earth will feeding the black hole more mass make the event horizon go away? I thought more mass meant more gravity..

    1. Re:IANAA by Anonymous Coward · · Score: 0

      The issue with a black hole is the density of the mass, not the mass itself. Feeding it more, but less dense mass to reduce overall density might allow for the disappearance of the event horizon. (Disclaimer: This is a severely dumbed-down way of explaining the math in the PDF.)

    2. Re:IANAA by Jeng · · Score: 1

      Yes, but its gravity on our side of the event horizon which should pull the event horizon towards the mass perhaps opening a window in the event horizon.

      I could be very wrong.

      --
      Don't know something? Look it up. Still don't know? Then ask.
    3. Re:IANAA by Remus+Shepherd · · Score: 4, Informative

      (Disclaimer: I Am A Physicist, but this is not my area of expertise, and only the experts understand those equations.)

      It's not feeding it mass that does the trick; it's feeding it charge and angular momentum. The only reason you feed it more mass is because you need mass to carry the charge and momentum into the hole.

      What you get if you feed it charge and angular momentum is a spinning monopole. I think they are postulating that a spinning monopole causes rotational frame dragging, and if you do it right you can get the charged frame dragging effects to cancel out the gravitational effects -- namely, the event horizon.

      After you do all that, what will be left? Like the article says, nobody knows. That's why it's exciting.

      --
      Genocide Man -- Life is funny. Death is funnier. Mass murder can be hilarious.
    4. Re:IANAA by Anonymous Coward · · Score: 0

      Isn't the event horizon the point at which the gravitational pull of a black hole becomes so powerful that not even light can escape? How on earth will feeding the black hole more mass make the event horizon go away? I thought more mass meant more gravity..

      Because everybody knows that when you want to get rid of a hole, you just fill it with stuff.

    5. Re:IANAA by Anonymous Coward · · Score: 0

      As another person undereducated in astrophysics, I thought that some variation of Heisenberg would play in here as well - by altering it, you destroy that which you're trying to observe?

    6. Re:IANAA by wagnerrp · · Score: 1

      The density in a black hole is infinite. It exists at a single point, the singularity. Gravity has overcome the nuclear forces keeping the soup of sub-atomic particles apart, and it has become.... something else, no one really knows what. The idea here is that even within the black hole, basic conservation of momentum still holds true. Throw a bit of mass in tangent to the black hole, and it will retain that angular momentum even after being sucked in, at which point the lump of mass at the singularity has angular momentum. Your spinning singularity actually turns into a spinning ring or disk, and if it spins fast enough, the ring breaches the event horizon.

    7. Re:IANAA by DarthVain · · Score: 1

      That sounds like the book slaughterhouse five when the alien was talking about testing a new prototype engine, and a red button was pressed to start it, and that is when the universe ended. It always ends that way, and the button is always pushed.

      Maybe that is just part of the uinversal cycle, life develops and becomes technologically advanced enough that it is capable of canceling out the huge gravitational effects of a black hole, making the event horizon vanish! BOOM!

      It also makes a gateway into hell as per the movie Event Horizon. :)

    8. Re:IANAA by clone53421 · · Score: 0

      Gravity has overcome the nuclear forces keeping the soup of sub-atomic particles apart

      The problem with that statement is that it is patently absurd. Gravity is several orders of magnitude lesser in strength than the nuclear forces keeping the sub-atomic particles apart, and they both scale up proportionally as the mass and density increase.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    9. Re:IANAA by Anonymous Coward · · Score: 0

      And where exactly will they get all this charge and angular momentum... another black hole?

    10. Re:IANAA by bruce_the_loon · · Score: 1

      This is so wrong I don't know where to start. If there was a -1 Wrong, I would have modded you down.

      Gravity starts out much weaker than than the electromagnetic, strong and weak nuclear forces, but gains over them as the amount of matter increases. That gain is why massive gas balls become stars when the gravity reaches fusion pressures, why electrons are punched into protons to form neutron stars at higher mass densities and eventually crushes protons out of existence at black hole densities.

      --
      Trying to become famous by taking photos. Visit my homepage please.
    11. Re:IANAA by clone53421 · · Score: 0

      Gravity starts out much weaker than than the electromagnetic, strong and weak nuclear forces, but gains over them as the amount of matter increases.

      As the density of matter increases, the other nuclear forces increase too.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  14. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    yeah, I didn't look at the maths either.

  15. Get us out of here, Scotty. by Anonymous Coward · · Score: 0

    Get us out of here, Scotty...

  16. Re:look, i like making fun of star trek technobabb by Red+Flayer · · Score: 2, Informative

    On a less serious note, does Rule 34 apply to naked singularities?

    Yes, of course. Rule34 applies to everything (and if not, Rule35 comes into play).

    In this case -- you've seen goatse, right?

    --
    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
  17. Will it fly? by Anonymous Coward · · Score: 0

    "According to the mathematics of general relativity" --- this is where i think it'll be a problem.
    According to the same math, gold should be sparkly white, and yet it isn't.

    Not everything that math spits out happens, for one reason or the other.

    Experiment away, I'm glad someone is. Let's just not get carried away: paper != experimentation

  18. CERN will definitely want to get in on this one... by Just_Say_Duhhh · · Score: 1

    So they can actually SEE how the earth was destroyed by the LHC. I mean, if you go to all that trouble to destroy our planet, don't you want everyone to SEE your handiwork?

    --
    I need trepanation like I need a hole in the head.
  19. You'd get blasted with raw energy by Anonymous Coward · · Score: 0

    Peel back an Event Horizon? Get blasted with Radiation/Exotic particles,etc... Um just think what happens to the axis area... They are evaporating just not in a observable curvature that we can understand or detect.

    Hey Hawkins back me up on this...

    1. Re:You'd get blasted with raw energy by jeffmeden · · Score: 5, Funny

      Peel back an Event Horizon? Get blasted with Radiation/Exotic particles,etc... Um just think what happens to the axis area... They are evaporating just not in a observable curvature that we can understand or detect.

      Hey Hawkins back me up on this...

      <robotic voice> that's what she said. ha. ha. ha.

    2. Re:You'd get blasted with raw energy by sznupi · · Score: 1

      Cool, a way to power warp drive.

      --
      One that hath name thou can not otter
  20. Create a Naked Singularity and ... by rcpitt · · Score: 1
    Steve Jobs won't allow you to discuss it or show it on your iPhone/Pad

    And the Australian Government will track every time you mention it in e-mail or surf the web to the site

    --
    Been there, done that, paid for the T-shirt
    and didn't get it
  21. But scifi writers already knew this! by magsol · · Score: 1

    See? The writers of StarGate SG-1 already knew this when they wrote the 200th episode, which had the line: "The singularity is about to explode!"

    ...I really need a life, don't I?

    --
    "I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
    1. Re:But scifi writers already knew this! by Unordained · · Score: 2, Interesting

      And yet, a small / primordial-enough black hole, after evaporating down to (and just below) its critical mass, could be seen as exploding back into flat-space, no? So the phrase could make sense?

    2. Re:But scifi writers already knew this! by sznupi · · Score: 1

      "Everything about that sentence is wrong"; equating singularity with only big ass black holes, a bit convoluted meaning of "about to", and "puff!" being suddenly an explosion which could harm you while you were far enoug not to be ripped apart by tidal forces (assuming it was a notable black hole after all)

      --
      One that hath name thou can not otter
    3. Re:But scifi writers already knew this! by sznupi · · Score: 1

      In that episode they also said "Everything about that sentence is wrong", or something close to it...

      --
      One that hath name thou can not otter
    4. Re:But scifi writers already knew this! by Unordained · · Score: 1

      Certainly wasn't saying it was valid in-context ...

  22. Gee, a little racist there? by DriedClexler · · Score: 4, Funny

    Since light cannot escape the event horizon, it must be black.

    Right, because anyone imprisoned anywhere must be black, because only blacks break the law and get locked up.

    --
    Information theory is life. The rest is just the KL divergence.
    1. Re:Gee, a little racist there? by magsol · · Score: 0, Troll

      You do realize that, within the realm of astrophysics, the term "light" typically refers to any sort of electromagnetic radiation? People in a pitch-black prison are still quite visible in terms of all the other wavelengths of "light" they emit and reflect.

      Unless this post was a troll, in which case: stfu, gtfo, and diaf.

      --
      "I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
    2. Re:Gee, a little racist there? by Anonymous Coward · · Score: 0

      woosh

    3. Re:Gee, a little racist there? by L3370 · · Score: 2, Funny

      People in a pitch-black prison are still quite visible in terms of all the other wavelengths of "light" they emit and reflect.

      Vin Diesel would like to disprove you.

    4. Re:Gee, a little racist there? by Anonymous Coward · · Score: 0

      It was a joke, retard. A funny one too.

    5. Re:Gee, a little racist there? by Anonymous Coward · · Score: 0

      That's mighty light of you. ;)

    6. Re:Gee, a little racist there? by Low+Ranked+Craig · · Score: 1

      So, if we change the name to !white will that make you happy?

      --
      I still cannot find the droids I am looking for...
    7. Re:Gee, a little racist there? by Anonymous Coward · · Score: 0

      They prefer to be called African American holes.

    8. Re:Gee, a little racist there? by Warbothong · · Score: 1

      Since light cannot escape the event horizon, it must be black.

      Right, because anyone imprisoned anywhere must be black, because only blacks break the law and get locked up.

      How dare you claim Astrophysicists to be racist on such misinformed prison analogy speculation! I'll have you know it's actually due to a sprinting analogy.

    9. Re:Gee, a little racist there? by Attila+Dimedici · · Score: 2, Informative

      There are people who think you are joking, and that is my best guess. The problem with your joke (if it is a joke) is that there are actually people who think there is something racist about using the word "black" in the term "black hole". I believe that there was a story on here about that one to two years ago (no, I'm not going to go search for it). Even if it wasn't on here, there was such a story in that time frame.

      --
      The truth is that all men having power ought to be mistrusted. James Madison
    10. Re:Gee, a little racist there? by DarthVain · · Score: 1

      Actually... it only looks black because the whites can't escape...

    11. Re:Gee, a little racist there? by StikyPad · · Score: 1

      The problem with your joke (if it is a joke) is that there are actually people who think there is something racist about using the word "black" in the term "black hole".

      There are also people who believe in unicorns. In other words, it's only a problem if you believe it's important to cater to idiots and quibbling malcontents.

    12. Re:Gee, a little racist there? by Attila+Dimedici · · Score: 1

      The problem with your joke (if it is a joke) is that there are actually people who think there is something racist about using the word "black" in the term "black hole".

      There are also people who believe in unicorns. In other words, it's only a problem if you believe it's important to cater to idiots and quibbling malcontents and government officials .

      The story I am thinking of involved a city councilman. And of course there was the city official who was forced to resign for using that well-known racist word "niggardly".

      --
      The truth is that all men having power ought to be mistrusted. James Madison
    13. Re:Gee, a little racist there? by Attila+Dimedici · · Score: 1

      I'm sorry to reply twice, but I posted my reply and then went to another aggregation site and came across this story. http://www.foxnews.com/us/2010/06/11/naacp-urges-hallmark-pull-racist-card-shelves/

      --
      The truth is that all men having power ought to be mistrusted. James Madison
    14. Re:Gee, a little racist there? by StikyPad · · Score: 1

      Yeah, but that was this year, and for a different reason (poor audio fidelity). While the validity of the NAACP complaint was questionable, the reaction by Hallmark was not, as ignoring the complaint risked alienating a large customer base. The story you referenced from two years ago, involving a pettifogging commissioner in Dallas, can be found here:

      http://en.wikipedia.org/wiki/Black_hole_naming_controversies

      The word "niggardly" is a separate issue, involving a term that is largely archaic, where confusion could easily arise. You don't have to be an idiot to misinterpret it; merely possess an average vocabulary. I'm not saying it's right, just that it's not directly comparable to the term "black hole," which is at least 17x more common, according to Google, and presumably more widely understood in a general sense (though obviously many of the particulars remain unexplained).

    15. Re:Gee, a little racist there? by StrategicIrony · · Score: 1

      I would contend that the use of the adjective "niggardly" would fall in a very different scope than the noun "black hole".

      LOL

    16. Re:Gee, a little racist there? by Anonymous Coward · · Score: 0

      >The problem with your joke (if it is a joke) is that there are actually people who think there is something racist about using the word "black" in the term "black hole".
      *sigh* Of course he's joking. He's making fun of those people...

      Why's it a problem with his joke? I don't understand.

  23. Something I was wondering by Lord+Lode · · Score: 4, Insightful

    I once read a bit about black holes, and one of the things I read was: a black hole doesn't necessarily have to be very dense. It can also be sparse (and the larger, the sparser it can be). For example, if you'd take a lot of stars and planets, and put them together (but not too close together), then at one point if you make this large enough, it'll also be a black hole: there appears an event horizon around all this matter. But inside of it are still stars with gaps between them, maybe some planets orbiting around them, ... So now I wonder, if the above is true: can someone live inside that? Would there be any noticeable difference between being inside of that, and the other side (the outside) of this event horizon?

    1. Re:Something I was wondering by magsol · · Score: 1

      I think Slashdot had an article a few months ago, regarding a new theory that hypothesized our known universe actually existing within a giant black hole. Or was it inside a wormhole? It might have been the latter, given that black holes are, by definition, exceedingly dense. I've never heard of "sparse" black holes before, since they have to be dense in order to form in the first place.

      --
      "I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
    2. Re:Something I was wondering by Jugalator · · Score: 1

      If you go inside the event horizon (i.e. where we can't see what's going on), regardless how big the black hole is, it is still inevitable that what goes in, must continue going in until it approaches the singularity, or whatever is there where our laws of physics break down. I use to look at the event horizon as something that is per definition the border where things mustn't go in, and where it must. So I don't think that environment is stable enough for life to thrive in; it'd inevitably enter the singularity.

      I've also read what you have however -- that more massive black holes suck you in less "forcefully", if you were to approach it.

      --
      Beware: In C++, your friends can see your privates!
    3. Re:Something I was wondering by quercus.aeternam · · Score: 3, Interesting

      It seems to me that in order for an established orbit to exist on the event horizon, the orbiting matter would have to be going at the speed of light. I would further presume that any matter orbiting within the event horizon would have to be /exceeding/ the speed of light.

      To my knowledge, matter cannot travel at or beyond the speed of light.

    4. Re:Something I was wondering by Luyseyal · · Score: 1

      The event horizon can be thought of as a photon gas where the photons "orbit" at the speed of light. My philosophical position is that <hand-waving>all the matter is converted into energy at the event horizon due to the extreme physics going on</hand-waving>, so the black hole itself is just a photon gas and everything in it travels at c.

      -l

      --
      Help cure AIDS, cancer, and more. Donate your unused computer time to worldcommunitygrid.org. Join Team Slashdot!
    5. Re:Something I was wondering by Anonymous Coward · · Score: 0

      Density = mass/volume.

      for a black hole, volume = 0.

      So, no matter what the mass, density is by definition infinite. What am I missing? Perhaps you meant to say "...a black hole doesn't necessaryily have to be very massive."

      That, I think, is allowable.

    6. Re:Something I was wondering by Ukab+the+Great · · Score: 1

      If you were inside a black hole you'd probably see crazy stuff happening like the universe expanding at an ever faster rate and all your calculations about the total mass of the universe that are derived from observing velocities over periods of time would be way off.

    7. Re:Something I was wondering by spaceman375 · · Score: 1

      To an observer within your aggregation, the formation of an event horizon would make it seem as if the entire rest of the universe were suddenly infinitely far away in space and time. You can't get there from here anymore.

      --
      On the one hand you take life too seriously, and on the other, you do not take playful existence seriously enough. Seth
    8. Re:Something I was wondering by Rene+S.+Hollan · · Score: 1

      Yes.

      Recall, that for a non-rotating, non-charged, black hole, r=2GM/c^2.

      So, M=rc^2/2G, and, for a sphere, V=4pi*r^3/3, so density is given by:

      D=M/V = rc^2/2G * 3/(4pi*r^3) = 3c^2/(8pi*Gr^2).

      Thus, the density of the black hole falls off as the square of its radius.

      A black hole of density 1000 kg/m^3 (that of water), would therefore have a radius given by:

      3c^2 = 8pi*Gr^2 kg/m^3 , and r = sqrt(3c^2 m^3/kg /8pi*G), or r = sqrt(3 * (300*10^3)^2 km^2/s^2 * 10^6 m^2/km^2 m^3 / kg / (8*3.14*6.67*10^-11 m^3/(kg*s^2)
      )).

      Simplifying:

      r = sqrt(2.43*10^18 m^2/s^2 / (1.68*10^-9 m^3/(kg*s^2)) m^3/kg) = sqrt(2.43*10^18 / 1.68*10^-9 m^2) = sqrt(1.45*10^27 m^2) = sqrt(1.45*10^21 km^2) = 3.81*10^10 km = 254 AU.

      Assuming I did the math right, that's much bigger than our solar system.

      Of course, if you did have that much water in one place, it would collapse gravitationally and wouldn't have a uniform density throughout.

      --
      In Liberty, Rene
    9. Re:Something I was wondering by tylersoze · · Score: 1

      No because once you pass the event horizon there's no way to stop from hitting the singularity in a finite amount of time. In fact, doing *anything* other than free falling will make you hit the singularity sooner, including firing rocket thrusters in the opposite direction!

    10. Re:Something I was wondering by tomzyk · · Score: 1

      if you'd take a lot of stars and planets, and put them together (but not too close together), then at one point if you make this large enough, it'll also be a black hole: there appears an event horizon around all this matter. But inside of it are still stars with gaps between them, maybe some planets orbiting around them

      Are you suggesting gravity doesn't exist inside an event horizon? O.o

      All of the matter making up these stars and planets would gravitate towards each other and become one massive object.

      And if they are far enough apart that gravity can't pull them all together, you get.... what? a "solar system"? Clearly there's no event horizon around us, because then we wouldn't be able to observer other solar systems. So lets go bigger... galaxies? No, we can see other galaxies too, so no event horizons around them either.

      Basically, if your body of matter isn't dense enough, then you're not going to get an event horizon because light should be able to easily move away from your body of matter. I'm sure some physics major could supply you with the appropriate equations (i'm just a lowly comp sci geek... and should be working and not trying to explain this right now! lol) but simply put: gravity gets weaker as you move further away from the center of your body of mass. If you have light moving about freely inside your event horizon... then, um... you're using the wrong definition of "event horizon".

      --
      Karma: NaN
    11. Re:Something I was wondering by Rene+S.+Hollan · · Score: 1

      Do not confuse the volume inside the event horizon with the volume inside the singularity.

      I think it's clear that talk of the density of a black hole refers to the density inside the event horizon and not at the singularity which would be infinite.

      --
      In Liberty, Rene
    12. Re:Something I was wondering by Rene+S.+Hollan · · Score: 1

      Yes, but the density within an event horizon of radius r falls off as the square of r.

      So, for very large r, the average density can actually be very small, and, as you consider the size of the known universe, as if it were a sphere, one finds that interstellar space appears to have sufficient density for the universe to have an event horizon.

      --
      In Liberty, Rene
    13. Re:Something I was wondering by Anonymous Coward · · Score: 0

      It's quite possible that we are living inside a black hole: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970408c.html

    14. Re:Something I was wondering by Anonymous Coward · · Score: 0

      It is theoretically possible for matter to travel faster than the speed of light. The only reason why it doesn't happen is because we know of nothing right now that does travel faster than the speed of light.

      I'll explain it like this. Say all we had as a propellant was sound waves. Could you make something travel faster than sound with sound waves? No it isn't possible.

      We use chemical reactions that expand faster than the speed of sound to propel mass faster than the speed of sound. If we understood enough to find a reaction that occurred and expanded faster than the speed of light we could use that to travel faster than the speed of light. As of now, there is none.

      Even if there was a reaction that expanded faster than the speed of light, that energy would be lost as a propellant force as it turned into mass.

      So, we are stuck at traveling less than the speed of light. But it doesn't mean that it isn't possible.

    15. Re:Something I was wondering by bcrowell · · Score: 2, Informative

      I once read a bit about black holes, and one of the things I read was: a black hole doesn't necessarily have to be very dense. It can also be sparse (and the larger, the sparser it can be). For example, if you'd take a lot of stars and planets, and put them together (but not too close together), then at one point if you make this large enough, it'll also be a black hole: there appears an event horizon around all this matter. But inside of it are still stars with gaps between them, maybe some planets orbiting around them, ... So now I wonder, if the above is true: can someone live inside that? Would there be any noticeable difference between being inside of that, and the other side (the outside) of this event horizon?

      No, this is totally incorrect. The Penrose singularity theorem forbids this.

    16. Re:Something I was wondering by Anonymous Coward · · Score: 0

      OMG - you've invented the inescapable watering hole!

    17. Re:Something I was wondering by Anonymous Coward · · Score: 0

      Couldn't you have something like a Klemperer rosette, in which a number of massive bodies orbited a common center, with their total mass enough to cause an event horizon around the whole set even though any one object's mass was too small to do so?

    18. Re:Something I was wondering by Anonymous Coward · · Score: 0

      I'll explain it like this. Say all we had as a propellant was sound waves. Could you make something travel faster than sound with sound waves? No it isn't possible.

      Well, that's not true for a start.

    19. Re:Something I was wondering by Rene+S.+Hollan · · Score: 1

      Dunno if I got the math right, though. I did that calculation once before and got a figure closer to the orbit of Mars, and that's suspiciously close to 2.54 AU to make me think I may have forgot to drop a couple of zeros somewhere.

      It's a fun calculation to do, though.

      Of course, what would happen would be that the tremendous pressure within such a sphere of water would compress the core and the rest would follow.

      --
      In Liberty, Rene
    20. Re:Something I was wondering by Rakishi · · Score: 1

      No it's not theoretically possible, go read up on this little thing called the theory of relativity.

      Even to move at the speed of light requires infinite energy for any object with mass. The universe has finite energy. Nothing moves even at the speed of light unless it has no mass.

      Moving information faster than light on the other hand leads to time travel except in very restricted cases (wormhole network with a certain topology that may be self-enforcing) or if relativity is incorrect in certain ways.

    21. Re:Something I was wondering by iDuck · · Score: 1

      There are NOT photon orbits at the event horizon! Starting with the Schwarzschild metric it is reasonably straightforward to show the smallest constant radius orbit possible for photons (or any other massless particle travelling at the speed of light) is 1.5 times the radius of the event horizon.

    22. Re:Something I was wondering by Anonymous Coward · · Score: 0

      Alright, now, I'm only marginally aware of how relativity works, but here we go.

      So for a massive black hole, you can maintain a stable circular orbit at distance X at half the speed of light. Woo, normalish Newtonian physics.

      If you nudge yourself closer to the black hole then you have to go faster to maintain a stable circular orbit.

      But if you double your speed, you don't hit the speed of light. Time slows down instead. So you're going something like 3/4th the speed of light, but experiencing 1/2 the time elapse. So your speedometer still reads C, because it doesn't take into account the change in the rate of time.

      Even if you double your speed every hour, you'll only approach the speed of light, and never surpass it.

      I dunno where the event horizon comes into play, because I really don't know what I'm talking about. Maybe you approach that point as the time you experience drops to zero so it's impossible to go any faster as acceleration does nothing where zero time elapses. Shrug.

      Also, captcha: aperture

    23. Re:Something I was wondering by agrif · · Score: 1

      Someone could surely live inside that. An interesting question is whether the edge of our universe is itself an event horizon. This is a neat idea, for sure; it's also pleasingly symmetric.

    24. Re:Something I was wondering by CrimsonAvenger · · Score: 1

      It might have been the latter, given that black holes are, by definition, exceedingly dense. I've never heard of "sparse" black holes before, since they have to be dense in order to form in the first place.

      No, they have to be massive in order to form. Dense just allows it to form with a smaller mass.

      One Solar mass is 2x10^30 kg or so, which would have to be mashed down into a radius (yes, I know radius is meaningless for a Black Hole) of about 3km. Density about 2x10^18 kg/m^3.

      For, say, 1,000,000,000 Solar masses, radius (still meaningless) would be around 3 billion km, and density would be about 19 kg/m^3 (note that liquid hydrogen has a density of about 70 kg/m^3)....

      Note further that for intact star systems to be inside a Black Hole, we're probably talking about something in the size-range of the entire sidereal universe.

      --

      "I do not agree with what you say, but I will defend to the death your right to say it"
    25. Re:Something I was wondering by hasdikarlsam · · Score: 1

      Your philosophical position would be wrong. Nothing particularly unusual happens at the event horizon, from the POV of someone falling through it. Well, communicating with the outside world does become impossible, but mass doesn't suddenly turn into energy or anything.

      What happens later is a somewhat different story. The event horizon also marks the point at which gravitational twisting has switched one of the spatial dimensions (specifically, the one with an axis going through you and the singularity) and [i]time[/i]. You can't escape, because that would require going back in time.

      Unfortunately, this also means that absolutely any acceleration you do means you hit the singularity sooner. Remember time dilation? Right. Keep those thrusters off, and you'll live slightly longer.

    26. Re:Something I was wondering by Luyseyal · · Score: 1

      If you can explain to me how switching dimensions manages not to destroy you utterly and how all the gamma and other radiation running in geodesics around the shell of the event horizon doesn't blast you into your component energy, I'd like to hear it.

      -l

      --
      Help cure AIDS, cancer, and more. Donate your unused computer time to worldcommunitygrid.org. Join Team Slashdot!
    27. Re:Something I was wondering by hasdikarlsam · · Score: 1

      For the first, it's a gradual process that's frankly more metaphorical than physical. There's no sudden jolt of any kind, and the usual laws of geometry stay in effect. Mostly.

      For the second, um.. well, you wouldn't get blasted apart by radiation *circling* the black hole, as there essentially is none. Good enough? ..blue-shifted radiation heading into it, though...

    28. Re:Something I was wondering by Anonymous Coward · · Score: 0

      I once read a bit about black holes, and one of the things I read was: a black hole doesn't necessarily have to be very dense

      It does have to be very dense. It has to be small enough so that all of it fits inside the distance from its center of mass at which escape velocity = speed of light.

    29. Re:Something I was wondering by Luyseyal · · Score: 1

      Wiki article that hints at why I'm thinking that

      Some choice quotes:

      "The horizon is a boundary defined by lightlike geodesics; it is those light rays that are just barely unable to escape."

      "In particular, they would come to equilibrium with a thermal gas of photons. This means that black holes would not only absorb photons, but they would also have to emit them in the right amount to maintain detailed balance."

      Where do the photons come from? Is it captured light or light emitted from within the horizon? Given the spacetime conditions and how black holes accrete, it sounds like the kind of light that would be high energy rather than low energy.

      -l

      --
      Help cure AIDS, cancer, and more. Donate your unused computer time to worldcommunitygrid.org. Join Team Slashdot!
    30. Re:Something I was wondering by Anonymous Coward · · Score: 0

      The Schwarzschild radius of our galaxy is 0.18 light years, I'd say that's pretty dense.

    31. Re:Something I was wondering by Anonymous Coward · · Score: 0

      Have you tried this out yourself or are you just typing in something that you read?

      Nobody had proved that at all. In fact it is just a guestimate. There is a math formula, I know, I've seen it many times. But what that formula doesn't state is that the possibility that as the speed of the wave increases to the speed of light that the energy may be changed into mass and is shed from the equation instead of adding to your own mass.

      I do not believe at all that the mass traveling at or near the speed of light increases in mass at all. YMMV.

      The reason for it to take infinite energy would be the exact same reasoning applied to sound waves. It would take an infinite amount of sounds waves to get something to the speed of sound. And then no faster.

      But, if you had something that occurred faster than the speed of sound, you wouldn't have to worry with using sound waves.

      Go do some mental thinking on it. You will eventually understand it.

  24. Really? by Tarchan · · Score: 2, Insightful

    I thought that the event horizon of a black hole was caused by the immense gravity of the main body. Just an area of space around the black hole where light would be unable to maintain enough momentum to escape the gravitational pull of the singularity. I don't even want to try understanding the calculations that this theory was derived from. If you were able to remove the event horizon, would that not mean that you would be destroying the singularity itself?

    1. Re:Really? by Statecraftsman · · Score: 3, Interesting

      The singularity is a lie. By which I mean, it's not as if this mass is all really in one infinitesimal dot...it's just that you do any characterization of that mass when even light can't escape. So no, you wouldn't be destroying the singularity since we don't really know that's what it is, but, if they do happen to change the black hole by adding charge and angular momentum, and it allows radiation to escape it will cease to be a black hole.

      I would like to find a black hole that's just barely massive enough and then try this.

      Finally, I think they're just trying to do a thought experiment whereby they change the shape or topology of the event horizon. Imagine a toroidal event horizon for example.

    2. Re:Really? by cyber0ne · · Score: 5, Insightful

      I'm not an expert on this by any means, but here's my two cents...

      Try not to think of it in terms of light trying to escape in a straight line and just not being strong enough to do it. Instead, think of the straight line as not being straight. Gravity wells curve space-time (a Google Images search for "spacetime" will yield some familiar diagrams of spheres resting on a fabric), and the event horizon of a singulatiry is the point in that curvature where it's so "steep" that it curves back in upon itself. This is difficult to show in the aforementioned diagrams, because it's less about the picture and more about the math behind it.

      Basically, from behind the event horizon it's impossible to escape not because you don't have enough force to get away but because all paths lead back to the singularity.

      If somebody with more knowledge/expertise on the subject can correct/elaborate, please do.

      --
      http://publicvoidlife.blogspot.com
    3. Re:Really? by Remus+Shepherd · · Score: 1

      If you were able to remove the event horizon, would that not mean that you would be destroying the singularity itself?

      No. The only reason the event horizon exists is because gravity is pulling so hard that light can't escape. If you were to alter the system so that the pull of gravity is weaker, or is offset by some sort of relativistic frame dragging effect (which is I think what they're postulating here), then the event horizon could disappear while the singularity remains.

      Think of the classic space-time fabric picture, where a black hole is an infinite vortex punched down through the fabric. They're pushing the fabric up so that it isn't an infinite funnel anymore -- now it's just a dimple. The singularity is still there in the center.

      You might say that gravity is the only thing holding the singularity together, but we don't know that. If it has collapsed to a single point then it's no longer matter, and the rules no longer apply, and even if they did matter sharing the exact same point in space wouldn't fly apart anyhow. Maybe. Cracking open a black hole is the only way to be sure.

      --
      Genocide Man -- Life is funny. Death is funnier. Mass murder can be hilarious.
    4. Re:Really? by canajin56 · · Score: 1

      That's just a muddling of the term "Singularity". By the original definition, anything that has enough mass to have a Schwarzschild radius greater than it's physical radius is a singularity. Singularity comes from "singular term", which in Mathematics, means a term that is undefined. The term in this case is part of the Schwarzschild Solution to Einstein's field equations for gravitational fields. It has a 1 / (2M-r) term, and so if you get too close, the term is undefined and physics as we know it breaks. So, anything that has a "wall" at which point everything breaks is called a singularity. You are correct that it's not necessary to have an infinitely dense point-mass at the center of a singularity, (and in fact it might not even be possible to get such a point mass). But it's still a singularity. But, nothing says things can't escape. They just can't cross the event horizon. So, if you do something that messes with a blackhole's rotation, the horizon will move. Something on one side would then be on the other. It still couldn't cross it, but there you go! It's also possible there's no such thing as a singularity, because our equations are wrong, and aren't actually undefined at that point.

      --
      ASCII stupid question, get a stupid ANSI
    5. Re:Really? by Anonymous Coward · · Score: 0

      The singularity is a lie.

      The singularity isn't a lie...

      But the cake is.

    6. Re:Really? by internic · · Score: 1

      I'm not an expert either, but I have at least taken a course in GR once. What you said seems pretty fair. I don't remember these things well enough to give a more detailed intuitive explanation (if such a thing is possible).

      One thing that might be useful to note is that the Schwarzschild metric that describes the geometry of spacetime in a black hole has the feature that inside the event horizon the mathematical role of time (in that coordinate system) and the radial coordinate switch (the time part of the metric gets the same sign as the two other spacial directions, while the radial part gets the sign time used to have). Based on this, it's been said that inside the event horizon, "your alarm clock turns into a ruler, and your ruler turns into an alarm clock." Because the role of space and time switch inside the event horizon, an object within is constrained to move only toward the center of the black hole in just the same way that any object is constrained to move only forward in time outside the event horizon. I'm not sure how much that helps, but it is another way of looking at it.

      Another picture that is sometimes useful is the diagram showing the light cone, the set of possible future paths, at different positions near the black hole. What you see is that the light cone gets narrower and tips toward the singularity as you approach the black hole. When you get to the event horizon the light cone has tipped so far that all future paths go into the black hole.

      --
      "You call it a new way of thinking; I call it regression to ignorance!" -- Operation Ivy
    7. Re:Really? by bcrowell · · Score: 1

      I thought that the event horizon of a black hole was caused by the immense gravity of the main body. Just an area of space around the black hole where light would be unable to maintain enough momentum to escape the gravitational pull of the singularity. I don't even want to try understanding the calculations that this theory was derived from. If you were able to remove the event horizon, would that not mean that you would be destroying the singularity itself?

      Cyber0ne and internic have done a good job of explaining what happens with a standard Schwarzschild black hole, but I don't think that really addresses what Tarchan was asking about, which is what it would mean to have a naked singularity (one without an event horizon).

      The only naked singularity that we actually can verify the existence of is the big bang. It was a singularity, but a different type of singularity than a black hole singularity.

      So you can see already that singularities come in more than one flavor. Just because a Schwarzschild black hole solution has a singularity surrounded by an event horizon, that doesn't mean that all singularities do.

      The kind of naked singularity they're describing in this paper is one that has a whole bunch of angular momentum and/or charge. This changes the properties of the space around the singularity, due to effects like frame dragging. It's well established that effects like these can lead to a naked singularity. What's much more uncertain is whether naked singularities can arise from any realistic initial conditions in our universe; this is what the cosmic censorship hypothesis says can't happen. The calculations in the paper describe such a process, which would be a counterexample to cosmic censorship. But they use various approximations, and nobody knows whether those approximations are valid.

    8. Re:Really? by Anonymous Coward · · Score: 0

      This is exactly what I've always hated about oversimplifications of General Relativity. The curve in space-time is a great method for picturing how things should work, but it's back asswards with regards to how they do work. Gravity cannot possibly be simply a property distorting space-time such that merely entering into a gravity well distorts your path by virtue of the curve in space-time as this implies some sort of higher-than-4-dimensional gravity. Essentially this way of thinking about things merely shuffles the essence of gravity to higher dimensions and encapsulates the actual work inside this property. But gravity does create a change in energy, implying that two massive objects do work on each other, and by the principle of conservation of energy, that energy has to come from somewhere. If mass itself is a property then there's some funny extra-dimensional gravity exerting its pull "downwards" with regard to spacetime from which this energy comes (maybe that's where all the dark matter and dark energy is hiding, just slightly shifted along the fifth-dimensional axis), which in my opinion is a silly idea as it does not make predictions, you can make no tests of it, and it is more complicated than it needs to be. The alternative is that every massive object (that is, objects with mass that exert a gravitational force and are thereby subject to gravitational forces) is exerting this force and is cannibalizing itself to exert this force, which would cause a corresponding reduction of mass in each object. If you keep the dimensions of space-time limited to 4 (or as I prefer, 6, time isn't linear, only our perception of it), then the apparent "curvature" is instead a "compression" (objects tend to move as though the distance were shortened the closer they get to the massive object at a rate inversely proportional to the square of the distance between them), then as objects grow less massive, space-time is less "compressed" around them, which further creates the illusion that space-time is actually growing. Since all observations seem to hint that there is a roughly even distribution of galaxies from our perspective, this growth of space-time would also appear evenly distributed (that is to say constant) in whichever direction we look. As theories go, my "melting universe" is at least better than the "space-time curvature" simplification of General Relativity, as it models what we see, makes predictions, and is in some ways testable (not sure how you'd test an actual reduction in mass or lack thereof as it would seem to require the absence of gravity, but it is indirectly provable, same as General Relativity).

  25. A little perspective here? by Anonymous Coward · · Score: 0

    While I definitely love thought experiments, and the subsequent mathematics of cutting edge physics, this isn't a realistic goal of even remote exploration.

    Let's say we get the math right within a short time frame, and it's possible to peal away the Event Horizon. The closest Black Hole is 1600 Light-years away.

    Like I said, I love the possibilities of physics, and where it may take us, but we have more pressing things to take care of. If this math somehow translates to more immediately implementable engineering concepts, all the better. I just don't see getting too excited over this when we have yet to increase are net efficiency as a species. And isn't that kind of the concept with new cutting edge physics aside from getting an adequate model for the Universe? Increase our effective energy usage as a whole? And I'm not referring to Nuclear Reactors either

    1. Re:A little perspective here? by holmstar · · Score: 2, Interesting

      Not true. we might be able to create a microscopic black hole that is massive enough to exist long enough that we could attempt this and observe the result. But you are right that attempting it on a natural black hole is pretty much impossible.

    2. Re:A little perspective here? by theguywhosaid · · Score: 1

      There is a 50/50 chance that would destroy the world!

  26. I dont know about anyone else but.... by pitdingo · · Score: 5, Insightful

    I sure am dumb

    1. Re:I dont know about anyone else but.... by JaredOfEuropa · · Score: 4, Funny

      Understanding the limits of your own knowledge is the furst step on the path to +3 insightfulness.

      --
      If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
    2. Re:I dont know about anyone else but.... by Anonymous Coward · · Score: 0

      So ... what does understanding the limits of your own spelling ability get you then?

    3. Re:I dont know about anyone else but.... by sorak · · Score: 1

      Understanding the limits of your own knowledge is the furst step on the path to +3 insightfulness.

      I thought +1 Karma bonus was the first step.

    4. Re:I dont know about anyone else but.... by Anonymous Coward · · Score: 0

      Really? What's the secund step?

    5. Re:I dont know about anyone else but.... by Anonymous Coward · · Score: 0

      That's the wurst thing I've read all day!

    6. Re:I dont know about anyone else but.... by hAckz0r · · Score: 1
      No disrespect to you intended, but perhaps you and the author of the paper should go out for a beer together. You may have more in common that you think. ;)

      One question for the author; Just how does one expect to add this angular momentum to a black hole? How do you give a black hole enough angular momentum to allow the matter inside of it to actually travel faster than the speed of light, to achieve the escape velocity? By definition that requires infinite energy, thus it adds infinite mass equivalence.

      It seems to me that the concept even defies the basic laws of physics/math no matter what the adjusted formula says. The formula is incomplete because it does not account for the added mass the 'solution' requires. Even if you add just 'charge' energy you have also added mass. Mass equates to more gravitational attraction, and a bigger event horizon, not a solution.

      Your beer should be cold by now.

    7. Re:I dont know about anyone else but.... by Hurricane78 · · Score: 1

      Apparently, typos are the first step to +5 Furry...err...Funny too.

      --
      Any sufficiently advanced intelligence is indistinguishable from stupidity.
  27. Naked Event Horizon by Rockoon · · Score: 3, Interesting

    We always hear about singularities necessitating event horizons, but the converse is most certainly not true. An event horizon may exist without a singularity inside of it.

    It depends on scale more than anything. Small black holes almost certainly require a singularity, but a black hole the mass of a galactic cluster actually has a very low average density. So while at the event horizon space-time is very much distorted, on the inside it may not be distorted enough to overcome common everyday forces (the trick of treating a collection of mass as a point source of force doesnt work from inside that collection of mass)

    --
    "His name was James Damore."
    1. Re:Naked Event Horizon by Unordained · · Score: 1

      Exactly -- why go into space for zero gravity, when we've got an area of zero gravity right here inside our own planet? We should drill down, not rocket up!

    2. Re:Naked Event Horizon by doesnothingwell · · Score: 3, Insightful

      but a black hole the mass of a galactic cluster actually has a very low average density. So while at the event horizon space-time is very much distorted, on the inside it may not be distorted enough to overcome common everyday forces (the trick of treating a collection of mass as a point source of force doesnt work from inside that collection of mass)

      Now my brain hurts, could we already be inside an enormous black hole?

      --
      They can have my command prompt when they pry it from my cold dead fingers.
    3. Re:Naked Event Horizon by Anonymous Coward · · Score: 0

      I always thought that a black hole meant a minimum density, otherwise it couldn't warp space-time enough to create a strong enough gravitational pull for light not to escape.

      Are you actually knowledgeable about this subject & I'm wrong or are you just doing armchair physics like me?

    4. Re:Naked Event Horizon by crow · · Score: 1

      I have heard that very idea suggested--that the known universe is the inside of an event horizon of what appears as a black hole to those outside. I expect some simple math based on the estimated mass and size of the universe would suggest that is not the case unless we have greatly confused some of the variables.

      But I suppose it would be possible to have a black hole inside the event horizon of another black hole.

    5. Re:Naked Event Horizon by TeknoHog · · Score: 1

      We always hear about singularities necessitating event horizons, but the converse is most certainly not true. An event horizon may exist without a singularity inside of it.

      There is also the effect of simple acceleration. If a spacecraft has sufficient acceleration away from you, you can send photons after it, and they will never reach it. Thus there is an event horizon.

      A related phenomenon on a quantum scale is the Unruh effect. When particle physicists claim to see apparent evidence of tiny black holes, i.e. Hawking radiation, it may actually be due to this effect.

      (The effect is somewhat aptly named, as "Unruhe" is German for something like "discomfort". Even if you don't know German, you might recognize this word from an X-Files episode ;)

      --
      Escher was the first MC and Giger invented the HR department.
    6. Re:Naked Event Horizon by Rockoon · · Score: 5, Interesting

      I expect some simple math based on the estimated mass and size of the universe would suggest that is not the case unless we have greatly confused some of the variables.

      Estimates of the mass of the observable universe range from 3.0E+50 kilo's to 1.6E+60 kilo's. Citations.

      Wikipedia has it as 8.0E+52 kilos.

      A black hole with the wikipedia mass has an event horizon radius of approximately 1.9E+26 meters. Compare with the radius of the observable universe, which is umm.. approximately 1.3E+26 meters. In other worse, if the wikipedia mass is correct, then we are inside a black hole assuming that the Schwarzschild equation for calculating event horizons is correct. I think the existance of dark energy has changed the game tho, such that we certainly cont be confident of the Schwarzschild radius calculation at such large scales.

      --
      "His name was James Damore."
    7. Re:Naked Event Horizon by Rockoon · · Score: 1

      Indeed.

      Perhaps half a dozen times in my life I have encountered a self declared "physics enthusiast" and have never gotten the right answer out of my trick question:

      "If the earth was hollow and you jumped inside, would gravity pull you towards the outer shell or would gravity pull you towards the center?"

      The trick is of course that neither answer is correct. Gravity would be neutral all the way through. You would be completely weightless inside a hollow earth.

      --
      "His name was James Damore."
    8. Re:Naked Event Horizon by Rockoon · · Score: 1

      I always thought that a black hole meant a minimum density, otherwise it couldn't warp space-time enough to create a strong enough gravitational pull for light not to escape.

      Given a fixed radius, yes there is a minimum density. Allow different radii and the game changes.

      Formula for calculating volume is:

      4/3 * pi * r^3

      Formula for calculating the radius of a black hole is:

      2 * M * G / c^2

      As you see, radius grows linear with mass but volume (and therefore density) does not.

      --
      "His name was James Damore."
    9. Re:Naked Event Horizon by Graff · · Score: 1

      You would be completely weightless inside a hollow earth.

      Only if you were at the exact center of mass. If you were a bit outside that then you would be attracted to the nearest concentration of matter. The center of mass of a hollow object is akin to being a ball at the top of a hill, if you are a little off to one side you will roll down it. It's not a stable point at all.

      Now, until you actually hit something, you will experience weightlessness. Once you come to rest you will have weight (and it may be spread all over the place if you had enough velocity).

    10. Re:Naked Event Horizon by Rockoon · · Score: 1

      Only if you were at the exact center of mass. If you were a bit outside that then you would be attracted to the nearest concentration of matter.

      Wrong!

      All the farther-away mass exactly cancels that nearest-concentration of matter when inside a hollow object, in terms of gravitations attractions. This is so because there is so much more of the further-away stuff.

      That center-of-mass assumption (point-source of force simplification) you are using doesnt work from inside the hollow sphere.

      --
      "His name was James Damore."
    11. Re:Naked Event Horizon by Graff · · Score: 1

      Ahh yeah, it's been a while since I've encountered this problem and I was remembering it incorrectly. Once I ran through the calculations again I see what you are getting at. The sum of the force vectors always cancel each other out no matter where you are in a hollow object so there is no attraction to the shell once you are inside of it.

      That center-of-mass assumption (point-source of force simplification) you are using doesnt work from inside the hollow sphere.

      I wasn't thinking of the point-source simplification, I was thinking of the inverse square law. I was assuming that the closest spot would have a slightly greater attraction but I wasn't taking into account the fact that more of the force vectors would be opposing each other on that side than on the other, counterbalancing the inverse square law. The neat thing is that the two effects do exactly balance each other out, a fact I just didn't remember from when I was a physics major years ago.

    12. Re:Naked Event Horizon by Unordained · · Score: 1

      I was going to reply that Larry Niven's rings are unstable (pointed out by MIT students) and that therefore shells should be as well, but ... came across this instead: http://www.alcyone.com/max/writing/essays/why-niven-rings-are-unstable.html (Dyson spheres aren't dynamically unstable, rings are.)

    13. Re:Naked Event Horizon by dodobh · · Score: 1

      Yes. However, we cannot prove that such is the case.

      --
      I can throw myself at the ground, and miss.
    14. Re:Naked Event Horizon by internic · · Score: 3, Informative

      The Schwarzschild solution to General Relativity applies to a stationary, spherically symmetric (uncharged) distribution of mass with asymptotically Minkowski boundary conditions for space-time. So, it basically assumes that you have a ball of stuff surrounded by empty space, and that's the type of situation where the equation for the Schwatzschild radius applies.

      If we accept the idea that we can approximate the universe by a uniform distribution of matter on a large enough scale (and this is, perhaps, debatable), the Schwarzschild solution doesn't apply. But you can solve GR for this situation and what you get is the Friedman-Robertson-Walker metric, which doesn't have any sort of event horizon, no matter how dense the matter within. Of course, it does have the interesting feature of expansion (or contraction) which lead to the beginning of modern cosmology.

      It is interesting, though, if the numbers for the mass and radius of the observable universe come out that way. Perhaps it has some import, but I can't say what it is offhand (but then I don't study GR). My first guess would be that it has to do with the universe being approximately flat, but I don't think that's actually true (because that should depend on the density, Hubble's constant, and the cosmological constant).

      --
      "You call it a new way of thinking; I call it regression to ignorance!" -- Operation Ivy
    15. Re:Naked Event Horizon by crow · · Score: 1

      So essentially, at the point of the Big Bang, our universe was a black hole, and everything that exists in it is still inside the event horizon of that black hole, though the math may suggest that the event horizon is no longer there due to changes inside it?

      The physics on this scale aren't intuitive.

    16. Re:Naked Event Horizon by internic · · Score: 1

      Not exactly. You may be picturing the big bang as all the matter in the universe compressed into a tight little ball which then exploded out into the empty space around it. That's the usual thing that one would picture, but that's not actually the big bang that GR predicts.

      Unlike for the Schrwarzschild metric of a black hole, there's a pretty intuitive way to picture the Friedman-Robertson-Walker (FRW) metric that describes the most basic GR cosmological model. Let's ignore the cosmological constant for a minute. The FRW metric says that at any instant in time the spatial dimensions of the Universe have the geometry of a hypersphere (a sphere with a 3-dimensional surface), a hyperplane, or a 3D hyperboloid, depending on the energy density in the Universe and its rate of expansion. The easiest way to picture things is to imagine for a moment that the energy density of the Universe is a bit greater than it is in reality so that the universe has the geometry of a hypersphere. If you ignore one of the spatial dimensions, you're left with only two dimensions of space, and the spatial extent of universe at any instant is the surface of an ordinary sphere (but just the surface, not the interior). As the universe expands it's the radius of the sphere that increases, so it's just like blowing up a balloon. From the perspective of an ant living on the surface of the balloon (like us, living inside the space) the surface seems to be expanding at every point, there is no center to the expansion (that lies on the surface). If you now run time backwards, this balloon gets smaller and smaller until eventually it's infinitesimally small and reduces to a single point. That instant is the big bang, and all matter is compressed infinitely tightly together, but notice also that all of space has been reduced to a point. It's still not like the Schwarzschild situation, because now there exists no "outside" of the mass. There's only one point in space.

      In reality, the energy density of the Universe seems to be a bit lower, and the spatial geometry of the Universe at any instant is approximately flat. The expansion is a bit harder to visualize in this case, although one decent analogy people use is to imagine dough for a raisin bread that is rising. As the dough rises (i.e. space expands), any two raisins (bits of matter) move away from one another. Every point in the dough appears to be the center of expansion. Of course, the dough for our Universe is infinite in extent in the FRW model; it has no edges. In any case, the same thing I said before is true. As you go back toward the big bang any two raisin get closer and closer together, and by the time you reach the instant of the big bang any two raisins, no matter how distant, will be on top of one another. At the instant of the big bang, the Universe has only a single location in space, and there is no point in space that exists outside the big bang.

      Of course, it's a little questionable to talk about the instant of the big bang, because at that instant the curvature and mass density reach infinity and the equations of GR become undefined. Strictly speaking, we can only talk sensibly about the instants just before the big bang. In addition, we're rather certain that at about 10^(-43) seconds away from the big bang the equations of GR break down, because the effects of quantum mechanics (which they do not include) should become vitally important. In reality we don't know what actually happened before that time, though there are all sorts of conjectures.

      I have heard of models that suggest that a baby universe might form within a black hole, and I admit I don't quite know how that's supposed to work, although roughly speaking I think the idea is that the black hole has a wormhole in the center that leads to a baby universe. I've never seen the math to describe this, though, so I can't say much more about it. I'm not sure what relevance the Schwarzschild radius formula might have to this situation. I only wanted to point out that in the accepted model of cosmology there never an event horizon.

      --
      "You call it a new way of thinking; I call it regression to ignorance!" -- Operation Ivy
    17. Re:Naked Event Horizon by Qango · · Score: 1

      Would "size" be a moot point, since in some theories, one of the space-like dimensions becomes time-like and time becomes space-like within the black hole?

  28. Re:look, i like making fun of star trek technobabb by owlnation · · Score: 2, Insightful

    "People thought communicators were way to far out too when TOS came out. Now we take them for granted."

    er... transporters maybe, but most people in 1966 were pretty familiar with radio... and funnily enough, even the idea of sending pictures over the air, since that's how they watched the show.

  29. Re:look, i like making fun of star trek technobabb by wisdom_brewing · · Score: 1

    Isn't that brown hole?

  30. Re:look, i like making fun of star trek technobabb by Surt · · Score: 1

    Exactly. Same thing with light sabers, and now you can buy one online for $200, and go start carving people up (albeit a bit slowly with this generation ... the next generation should pretty much have nailed the tecnology though, just as cell phones are not quite communicators capable of reaching our orbital ships).

    --
    "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
  31. maybe it already happened? by sznupi · · Score: 1

    "Charge and angular momentum" aren't that hard to come by near supermassive black holes, after all - massive accretion disk certainly can add angular momentum; and with large part of it being ionized one way or another, we might have appropriate charge in some cases...

    What if naked singularity would turn out to be behind quasars; generally some unusually active cores of galaxies or relativistic jets?

    --
    One that hath name thou can not otter
  32. The horizon is not fixed by NicknamesAreStupid · · Score: 1, Informative

    Photons cannot escape because they are red-shifted due to time dilation. This means that the horizon will vary depending on the level of energy trying to escape it. For example, an X-ray might escape where an infra-red photon wouldn't. All or part of a huge energy blast may or may not escape, depending on its frequency, level and position. Whether it would affect the hole itself seems problematic.

    1. Re:The horizon is not fixed by alyosha1 · · Score: 2, Informative

      Uh, no. An X-ray photon and an infra-red photon have the same velocity, c. They have different frequencies. Neither will escape a black hole, which is pretty much defined as a body having an escape velocity greater than c.

    2. Re:The horizon is not fixed by Ktistec+Machine · · Score: 2, Informative

      The event horizon isn't wavelength-dependent. It's the place where the escape velocity equals the speed of light.

    3. Re:The horizon is not fixed by $RANDOMLUSER · · Score: 4, Informative

      The event horizon is ... the place where the escape velocity equals the speed of light.

      Ding ding ding - we have a winner. This is the point that so many cosmology shows on Discovery Channel or Science Channel (or whatever) completely fail to mention; they keep describing black holes as "so massive, even light can't escape" without explaining why (Michio Kaku, Alex Fillipenko, (sp) I'm looking at you). See Wikipedia for the details, but the important point is that escape velocity is dependent on an object's mass divided by its radius. So if mass goes high enough, or radius low enough, you get an escape velocity greater than the speed of light: AKA an event horizon.

      Say it again, and remember it later:
      The event horizon is ... the place where the escape velocity equals the speed of light.

      --
      No folly is more costly than the folly of intolerant idealism. - Winston Churchill
    4. Re:The horizon is not fixed by TangoMargarine · · Score: 1

      Saying "light can't escape" leaves the (remote, maybe) possibility that it is possible to get an object going faster than light, but it would still not escape the black hole.

      Non-scientific, I know, but it's a funny scene to imagine:

      "We're being pulled in! There's no escape!"
      "You're forgetting about the FTL drive." *flips switch*

      --
      Unity? Screw that: XFCE. Slashdot Beta? Screw that: SoylentNews. Australis? Screw that: Pale Moon. UX developers DIAF
    5. Re:The horizon is not fixed by Anonymous Coward · · Score: 0

      So if mass goes high enough, or radius low enough, you get an escape velocity greater than the speed of light: AKA an event horizon.

      While we're talking about basic physics which popular cosmology shows could mention, but somehow usually don't: this means that anything, if you compress it until its radius is low enough, can become a black hole. For the Earth, you'd need to compress it into a ball about a centimetre across. For the Sun, you'd need to compress it to a size of a few kilometres.

  33. Great! by spammeister · · Score: 1

    Let's get started and throw Alaska into the black hole that is New Jersey!

    --
    I tried to think of a good sig, and this wasn't it.
  34. Re:look, i like making fun of star trek technobabb by CyborgWarrior · · Score: 5, Funny

    There are a number of factors to overcome when making singularity porn:

    1. once you put it in, it's a real bitch to take it back out
    2. nobody has ever successfully pulled out in time
    3. they start at sucking and never manage to make it to the sex part
    4. Ebony has a trademark on the term "black hole"
    5. it's kind of a tease to watch because as much as they constantly approach the "event horizon", they never quite reach it

    --
    If you can't say something nice, make sure you have something heavy to throw.
  35. Re:look, i like making fun of star trek technobabb by jeffmeden · · Score: 1

    If by next generation you mean the next generation of the human species... There is this annoying problem with lasers that they tend to not really stop until they hit something. Make them as powerful as you want, until we crack how to make light "expire" any time you fire up your human slicer/dicer it will also slice/dice whatever else is around you too. Perhaps one case where a glass house is a good idea. And then, we need it form a beam that behaves as a force field and/or solid object (to allow for dramatic duels.)

    Crack those little catches, oh and increase the power by about ten thousand fold at least, and you might have something like a Light Saber.

  36. Re:look, i like making fun of star trek technobabb by Jaysyn · · Score: 1

    LUDDITE!, LUDDITE! Someone get me the rope & torches!! :D

    --
    There is a war going on for your mind.
  37. Solution by Anonymous Coward · · Score: 0

    On mythbusters, they normally run a scale test, before deploying. I suggest that someone create a small scale stable black hole, and test the theory. If it looks plausible, then let's pick a black hole (suggest: center of milky way) and see if this works. Report back when done please.

  38. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    I think communicators were TOS form of a cell phone not a radio or TV.

  39. In theory, yes. by maillemaker · · Score: 4, Informative

    One of the problems with approaching a black hole (aside from massive amounts of radiation around ones actively eating matter) is the fact that the force of gravity increases as you approach the mass responsible for the gravity.

    With small black holes, as you approach (feet first) the difference in gravitational pull at your feet would be many times larger than the gravitational pull at your head. You would be literally ripped apart, down to the molecular level. This is known as "Spaghettification".

    http://en.wikipedia.org/wiki/Spaghettification

    However, with a large enough black hole, you should be able to pass the event horizon before these tidal forces grow large enough to rip you apart. Of course, this does you no good, because once you are inside the event horizon you cannot exert a great enough force to prevent yourself from falling deeper until the forces ARE great enough to rip you apart.

    But for a large black hole, in theory, you could cross the event horizon without being ripped apart.

    --
    A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
    1. Re:In theory, yes. by Anonymous Coward · · Score: 0

      once you are inside the event horizon you cannot exert a great enough force to prevent yourself from falling deeper until the forces ARE great enough to rip you apart.

      So the answer to whether we can have long-term living conditions inside an event horizon seems to be 'no'.

    2. Re:In theory, yes. by The+Grim+Reefer2 · · Score: 1

      Of course, this does you no good, because once you are inside the event horizon you cannot exert a great enough force to prevent yourself from falling deeper until the forces ARE great enough to rip you apart.

      I'm pretty sure if you reroute the warp drive through the Heisenberg compensator and then create a tachyon stream through the main deflector it's possible. Failing that you can always eject the warp core, blow it up and ride the shock wave out.

    3. Re:In theory, yes. by Anonymous Coward · · Score: 1, Interesting

      But this blackhole would have no center, remember.
      Its center of gravity will be blank space.
      Think of a bunch of stars orbiting each other rather fast in a donut.

      All we need now is a highly efficient method of blocking / using the temperatures that close to several stars.
      Planet-sized metamaterial invisibility cloak anyone?

    4. Re:In theory, yes. by dreamchaser · · Score: 1

      It's tetrions, not tachyons! Man you could have gotten us KILLED!

    5. Re:In theory, yes. by Fractal+Dice · · Score: 1

      But for a large black hole, in theory, you could cross the event horizon without being ripped apart.

      I have a hard time believing there is any scenario where you can just cruise into a black hole. If you're standing waste-deep in a black hole, the blood in your toes, inside the event horizon, is never allowed to reach your heart which sits outside of it. So even if a frame of reference exists that doesn't rip you apart, it would have to be falling into the black hole fast enough to cross the event horizon in a heartbeat.

      (if you take this same thought experiment all the way down to the size and speed of the motions of individual atoms, it seems to me that what happens at the event horizon has to be very fast or very messy)

    6. Re:In theory, yes. by Anonymous Coward · · Score: 0

      I don't think you understand what an event horizon is. It is not some magical boundary, past which the black hole's force becomes a hundred times stronger. The gravitational field of a black hole works like any other, it increases at a gradual rate. Standing waist deep in an event horizon is not significantly different from standing, well, right above it, or right under it. Assuming you have a very, very large black hole there is no reason you would die right away.

    7. Re:In theory, yes. by The+Grim+Reefer2 · · Score: 1

      Sorry, my bad. I did say I was pretty sure, not that I was positive. Wait a minute, what in the hell does the frame surrounding Tetris have to do with anything?

    8. Re:In theory, yes. by Anonymous Coward · · Score: 0

      Suppose you find one of these black holes and observe it from a distance. You will observe a "black" event horizon at a certain radius from its centre, meaning that no light can escape it.

      Now, suppose you manage to pass through that event horizon unscathed, and look towards the centre of the "singularity". Since light still gets absorbed towards the centre, you will certainly not observe anything but complete blackness towards the direction of the centre.

      The "event horizon" that was at a certain fixed radius from the centre for an external observer will in effect be moved to below your eyes when you pass that fixed distance. To an external observer you will disappear past the event horizon. But you will never manage to see anything when you cross that "magical" distance, since the event horizon will to your eyes always appear beyond you.

      At some point you will get spaghettified and die none the wiser of what is inside an event horizon...

    9. Re:In theory, yes. by Anonymous Coward · · Score: 0

      In a sense, that is *exactly* what there is beyond an event horizon :
      yet another event horizon!

      rinse and repeat until you die...

    10. Re:In theory, yes. by Rakishi · · Score: 1

      Not quite, as I understand it to an external observer you will grow ever dimmer and slower. Approaching the event horizon but never crossing it. A trick of the light, literally.

      Basically, it takes light longer and longer to escape the black hole the closer it is to the event horizon (gravity, time contraction, etc, etc.). Beyond the event horizon it takes infinite time to leave (ie: it cannot) but just on the outside side of it it'd take almost that long. Thus it's impossible to see anyone cross the event horizon for an outside observer. The light would be very dim since it's intensity is stretched out over longer and longer periods of time (intensity emitted in one second but seen over fifty billion years).

      My head hurts.

    11. Re:In theory, yes. by sjames · · Score: 1

      Actually, time should stop at the event horizon.

    12. Re:In theory, yes. by Anonymous Coward · · Score: 0

      To an external observer it would appear to, sort of (but that's just a trick of the light). To someone falling in it wouldn't.

  40. Fiendish calculations? by InfinityWpi · · Score: 0

    Oh, come on... all you have to do is divide by zero! ... no, wait, that's how we got black holes in the first place... well, multiply by infinity, then.

  41. Would the event horizon retreat if you approached? by PeterM+from+Berkeley · · Score: 1

    Hello,

        Suppose you were falling into a black hole, and you didn't get turned into spaghetti (as might be possible if you're approaching the event horizon of a supermassive black hole). Would the event horizon seem to retreat before you? I mean, light can't escape a black hole's event horizon as we see it, but if you're falling in, wouldn't you be able to see further into the black hole as you fall?

    --PM

  42. Easy! by Evildonald · · Score: 1

    Just get BP to pump hydraulic fluid into it. That HAS to work!

  43. Bounce a gravition beam.. by tekrat · · Score: 1

    Off the main deflector dish;
    That's the way do things lad;
    just makin' shit up as we wish.

    The klingons and the romulans,
    they pose no threat to us!
    'Cause when we find, we're in a bind;
    we just make some shit up

    --
    If telephones are outlawed, then only outlaws will have telephones.
  44. Re:look, i like making fun of star trek technobabb by MouseR · · Score: 2, Informative

    Goatse is not a black hole but a brown dwarf.

  45. Strange by lennier1 · · Score: 1

    Didn't the last Star Trek movie already prove that you only need some bad writing to destroy one?

  46. turtles all the way down by Anonymous Coward · · Score: 0

    The event horizon is like where reality has hit a divide by zero error. Things just stop making sense. That's great these scientists think they've figured out a way to sneak a peak in there, but I doubt the human mind can make sense out of a "place" where the fundamental logic of math breaks down.

    I think this is more about making physical cosmology sexy. At the next cocktail party these guys are going to chat up every girl with talk of their exiting work probing black holes... I can see it now: "I'll show you my naked singularity if you let me in your black hole".

    1. Re:turtles all the way down by divisionbyzero · · Score: 1

      The event horizon is like where reality has hit a divide by zero error.

      Hey! Who are you calling an error?

  47. Re:look, i like making fun of star trek technobabb by AndersOSU · · Score: 1

    I don't think we're talking about black holes measured in solar masses. However, if it's possible for a naked black hole to exist, we might be able to feed and disrobe a small primordial black hole or micro black hole formed through high energy collisions.

  48. Re:Would the event horizon retreat if you approach by Anonymous Coward · · Score: 0

    Hello,

        Suppose you were falling into a black hole, and you didn't get turned into spaghetti (as might be possible if you're approaching the event horizon of a supermassive black hole). Would the event horizon seem to retreat before you? I mean, light can't escape a black hole's event horizon as we see it, but if you're falling in, wouldn't you be able to see further into the black hole as you fall?

    --PM

    without knowing anything about any of this, that wouldn't make sense unless you were going faster than the light that's also being sucked in.

  49. Re:look, i like making fun of star trek technobabb by Surt · · Score: 1

    I'd say that given they can burn flesh now, they are probably only 10x power from carving through it. Ending the beam seems like a job for a transparent length of carbon nanotube fibers ending in a dispersant point (or reflectors if you want to conserve power). Really, the engineering problems seem entirely solvable at this point (expensively), and the cost will be coming down fast.

    --
    "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
  50. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 1, Interesting

    Hold it... Rule 34 states that "if it exists, there's porn of it." It says nothing about "if there's porn of it, then it exists." I'm willing to give you the benefit of the doubt since you said "there's a good possibility that they exist," but you shouldn't assume that the converse of an if-then statement has the same truth value as the original.

    Exactly how you would make porn of something that doesn't exist is left as an exercise to the reader.

  51. Oh no... by Tenek · · Score: 5, Funny

    liberate tutamae ex inferis

    1. Re:Oh no... by Anonymous Coward · · Score: 0

      I see lots of people get that one word in the quote wrong, so I figured I'd contribute to our collective knowledge of Latin. It's tutemet.

  52. Wow! But can they stop an oil leak? by bigredradio · · Score: 1

    I understand that this is important science, but what a weird gap in scientific knowledge when we are considering how to collapse a black hole when we can't stop the damn oil leak. Maybe we should get some of these guys involved.

    1. Re:Wow! But can they stop an oil leak? by toastar · · Score: 1

      I understand that this is important science, but what a weird gap in scientific knowledge when we are considering how to collapse a black hole when we can't stop the damn oil leak. Maybe we should get some of these guys involved.

      Yes, Because theoretical Astrophysicists make great subsea engineers.

      That would be like hiring a guy to build your next leer jet because he's good at building solar cars.

    2. Re:Wow! But can they stop an oil leak? by L3370 · · Score: 1

      The world has many questions to be answered and problems to be solved. Are you suggesting we should funnel the talents and resources of these experts to something else (regardless of subjects they are experts in) because you believe its more important?

    3. Re:Wow! But can they stop an oil leak? by bigredradio · · Score: 1

      I am just commenting on the fact that it is unfortunate we do not have this level of technical understanding of something we can see and effects our environment so closely. That whoosh sound over your head was my point.

  53. Inside black hole is not necessarily exotic by u19925 · · Score: 1

    Most of the calculations about black hole are based on steady state. However, the time it takes to reach this state is of order of event horizon size divided by speed of light. Larger the black hole, larger the time. Thus if you have a black hole of the size of our visible physical universe, it can take billions of years to reach steady state. During this billions of years, life can go on normally! In fact the equation of universe with omega greater than one (which means that the whole universe would eventually contract and collapse to singularity) are almost same as a black hole with event horizon of the size of the universe.

    However, most black holes are much smaller in size and hence are much more exotic. From what I understand, it is impossible to see any events which happened inside the event horizon. Thus you may be able to supply enough charge and angular momentum to remove its event horizon and reveal the interior of the black hole, but that would only let you observe the events that happened after you pass the charge and angular momentum (there is nothing new here, it is known for a long time). Any event that happened inside event horizon is forever lost (from classical point of view). From QM perspective, those events carry signature in Hawking radiation but that has nothing to with changing event horizon by supplying charge and angular momentum.

  54. Re:Would the event horizon retreat if you approach by DamienRBlack · · Score: 1

    Due to time dilation, it takes a seemingly infinite amount of time to reach an event horizon because your speed will approach the speed of light. So it is impossible for an observer to reach an event horizon without an infinite amount of time.

  55. Many believe that naked singularities cannot exist by clone53421 · · Score: 1

    A significant number believe that singularities cannot exist in the first place, naked or otherwise.

    Anyway, if a singularity could exist, it would be a point of infinite curvature in space-time, i.e. a point of infinite mass. As such I don’t see any way for it to not create an event horizon.

    --
    Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  56. Interesting approach... by McNihil · · Score: 1

    however I will argue that to make it work it may end up being a matter of trying to collide two black holes into each other with great speed. Further that though I wouldn't be surprised if that speed ends up being c.

  57. Uh, you wouldn't destroy the black hole... by divisionbyzero · · Score: 1

    I'm guessing you'd cause the black hole to eject particles that hopefully would be structured enough to provide us with information about what's happening beyond the event horizon or they might be completely random and tell us nothing. The summary and the article itself seem very confused. They portray the event horizon like it's some kind of shell that surrounds the core of the black hole hiding it from view. The event horizon is more like an asymmetric field that you need to find the right frequency to pass back out of once reflected off the structure of the black hole. I seriously doubt the event horizon would be blown away revealing a naked singularity either. It would just become permeable to a certain stream of particles going out instead of being infinitely internally reflected.

    1. Re:Uh, you wouldn't destroy the black hole... by divisionbyzero · · Score: 1

      ... infinitely internally reflected.

      Sorry, I meant totally internally reflected.

  58. Why not just use anti-matter? by Maltheus · · Score: 1

    Jeez, it's like these dudes have never watched Star Trek.

    1. Re:Why not just use anti-matter? by somaTh · · Score: 1

      That was a solution I came up with as well. Make a black hole of anti-mater (white hole?) and cram the two together. Also, don't be nearby.

      --
      Nostalgia isn't what it used to be.
  59. Event horizon paradox.. by goffster · · Score: 1

    If you are inside an event horizon (you can't ever see anything outside of the event horizon),
    then if something enters your event horizon you are now able to see it, thus
    invalidating the premise of the event horizon.

    That means either:

    1) Event horizon's do not exist.
    2) You can't *really* enter an event horizon from the outside.

    1. Re:Event horizon paradox.. by spaceman375 · · Score: 1

      To an observer within the aggregation, the formation of an event horizon would make it seem as if the entire rest of the universe were suddenly infinitely far away in space and time. You can't get there from here anymore. As you said, you can't really get there from the outside; that's because what was inside is infinitely far away. Spacetime is stretching towards the center faster than light can go.

      --
      On the one hand you take life too seriously, and on the other, you do not take playful existence seriously enough. Seth
    2. Re:Event horizon paradox.. by Lithdren · · Score: 1

      If you're in a bedroom with no windows to the outside and the door is closed, its pitch black. You cant see anything outside or inside the room because there's no light! If you flip the switch, and turn on the nightlight suddenly you can see the room, thus invalidating the premis of the room being black.

      That means either:


      1) The room doesn't really exist
      2) You can't really turn on the nightlight by flipping the switch.
      3) You would be eaten by a Guru before you flip the switch.

    3. Re:Event horizon paradox.. by Noren · · Score: 1

      You have it backwards. There would be no inherent difficulty in seeing the outside from within an event horizon, as light can travel _into_ an event horizon just fine. It's the reverse (seeing the inside from the outside) that isn't possible.

  60. Re:Would the event horizon retreat if you approach by dcmoebius · · Score: 2, Interesting

    Hello,

    Suppose you were falling into a black hole, and you didn't get turned into spaghetti (as might be possible if you're approaching the event horizon of a supermassive black hole). Would the event horizon seem to retreat before you? I mean, light can't escape a black hole's event horizon as we see it, but if you're falling in, wouldn't you be able to see further into the black hole as you fall?

    --PM

    Well, since sight depends on light reflecting off of objects to work... No, as you approached the event horizon, you still wouldn't be able to see into the black hole, as no light would be escaping (hence no visual information conveyed).

    As to other point, no, the event horizon would not appear to be receding. You would seem to be approaching it normally (from your perspective), however due to time dilation, the rest of the universe would seem to be aging quite rapidly compared to you.

  61. Re:look, i like making fun of star trek technobabb by tsalmark · · Score: 1

    More of a Giant than a Dwarf from what my scarred psyche remembers.

  62. Two words by Anonymous Coward · · Score: 0

    Bruce Willis.

  63. Re:Would the event horizon retreat if you approach by Anonymous Coward · · Score: 0

    I am noob at physics, but my guess is no, because the light would need to reflect back from whatever is in the black hole into your eyes and the reflected light will probably get sucked in again before it reaches you.

  64. hell, drop 50 nukes at the edge by swschrad · · Score: 1

    you guys are all token-ring, let the ethernet-heads take this one over. tickle it and record what happens.

    --
    if this is supposed to be a new economy, how come they still want my old fashioned money?
  65. Re:look, i like making fun of star trek technobabb by jeffmeden · · Score: 1

    I have a pair of highly reflective scissors that say your idea won't hold up well in a duel... And for what it's worth handheld lasers (in the 500mw range) than can 'burn' flesh for the most part just blacken it, and have a relatively short duty cycle (10s/min for example) and lasers with enough power to reliably cut through things (such as those used in surgery, research, or manufacturing) are 100 or 2000 times as powerful (in the 50w to 1000w range) and also use an entirely different process (chemical) versus handheld lasers.

    We might get there, but I would put money on clean fusion power before lightsabers or a lightsaber-equivalent portable device.

  66. Terminology (Warning: Bad Pun Ahead) by psbrogna · · Score: 1

    So would a naked black hole be known to have a "Non-Event Horizon?" Sounds like a suitable term for new title launches from 3-D Realms ...

  67. Wrong by Anonymous Coward · · Score: 0

    Very interesting theory but inherently flawed....

    At the event horizon, the escape velocity from the black hole is equal to the speed of light so light is trapped in an orbit around the black hole at that radius. INSIDE this radius, the escape velocity is greater than the speed of light so anything that crosses the event horizon will be sucked into the singularity.

    If we were to manipulate the black hole in some way (giving it extreme spin or whatever) so that the escape velocity lessens, this would only decrease the radius of the event horizon (so the "black hole" will appear to shrink). If you were to keep this up, there is only so far you could go. You would never be able to get the event horizon down to this infinitesimal point at the center. The force of gravity is way too strong.

    I think the perceived "size" of the black hole would just shrink some.

    1. Re:Wrong by Anonymous Coward · · Score: 0

      I'm the same poster.... I forgot to mention something.

      One way you could "sneak a peek" at what's inside the event horizon. You could take a spacecraft, accelerate it to a speed beyond the speed of light along a path that cuts through the event horizon at a tangent to the center so that your path curves toward the singularity but you miss it and exit the event horizon on the other side. This assumes that Einstein is wrong about some things but we're already seeing that he is, and this also assumes that the particle shell at the event horizon wouldn't destroy your ship. Just think, ANY photons or other particles that are moving at the speed of light and enter orbit right at the event horizon are trapped forever. They keep building up at that radius. I'm wondering if anything that crosses it would be vaporized!

      Once inside, you should see that, in between the singularity and the event horizon is completely empty space (no obstructions of the singularity) ...Unless faster than light particles are orbiting in there!

  68. misleading title by bcrowell · · Score: 3, Informative

    The title of the paper is "Destroying black holes with test bodies," and the language about "destroying" black holes is echoed in both the arxiv blog summary and the /. summary. This may be somewhat misleading. They're actually talking about processes that would strip away the event horizon, leaving behind a naked singularity. The black hole wouldn't have been "destroyed," but just changed into a different form. The authors themselves put the word "destroying" in quotes in the paper.

    The paper doesn't settle this one way or the other. It says shows that if you use a certain set of approximations, the result is that the event horizon can go away. However, there is no particular reason to believe that the approximation is correct.

    The real issue here isn't whether a black hole can actually be transformed this way, it's the question of whether cosmic censorship holds. If cosmic censorship fails, then general relativity is fundamentally flawed as a classical field theory, because it fails to make predictions. John Earman's famous way of expressing this is that anything could come out of a naked singularity: lost socks, green slime, even horrible things like Nixon's "Checkers" speech or Japanese monster-movie creatures.

    1. Re:misleading title by geekoid · · Score: 1

      You do understand that he was just saying there is no way to actually formalize a singularity, right? That there really isn't any chance socks will come out of a singularity.

      The fact they may now have an idea of way to create a naked singularity that is also physically reasonable is awesome.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    2. Re:misleading title by bcrowell · · Score: 1

      You do understand that he was just saying there is no way to actually formalize a singularity, right? That there really isn't any chance socks will come out of a singularity.

      I don't think you're understanding his point correctly. Singularities can be formalized mathematically. That's not the issue. The issue is the inability to use the theory to make predictions, when there are naked singularities. What he's saying is that if we observed a naked singularity, it would not violate the field equations of GR if any unpredictable thing whatsoever came flying out. In fact, actual, literal socks do come flying out of naked singularities. I'm wearing a pair of cotton socks right now, and they came flying out of a naked singularity known as the big bang. The question posed by the cosmic censorship hypothesis is whether other naked singularities could arise in our universe from realistic initial conditions.

  69. Picking nits by joeyblades · · Score: 1

    ... event horizon: a theoretical boundary in space through which light and other objects can pass in one direction but not the other.

    Event horizons only refer to light (or rather events or information that could be conveyed by light). Event horizons have nothing to do with other objects (with mass).

    Other objects will have their own horizons, at greater distances from the black hole. These horizons are a function of the mass of the object. In scifi stories and thought experiments they like to talk about how some guy gets stretched thin like a noodle as he crosses the even horizon... Well, I have some bad news. You would get noodle-fied long before you crossed the event horizon.

    Of course, the good news is that since this happens before you reach the event horizon, the rest of us get to see it!

    1. Re:Picking nits by LordofEntropy · · Score: 1

      I believe it is also quite dependent on the mass of the black hole which affects the Schwarzchild radius. In the case of a super-massive black hole, spaghettification would occur well after passing the event horizon. With smaller black holes the spaghettification would occur before hitting the event horizon.

      --
      Entropy just isn't what it used to be.
    2. Re:Picking nits by joeyblades · · Score: 1

      Well, I'm no Stephen Hawking, but I believe that the mass of the black hole is irrelevant. The event horizon occurs at that point where gravity overcomes the escape velocity of a photon. For different black holes, there may be a difference in radius that is mass dependent, but once you reach the event horizon we have an even playing field for all black holes. In other words, the gravitational force at all event horizons is equal, by definition, because the speed of light is the same at all event horizons.

  70. wow by geekoid · · Score: 0, Flamebait

    the submitters understanding of Black Holes is only about 25 years behind.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  71. Like removing a whirlpool to see what's behind it. by 0m3gaMan · · Score: 1

    dumb.

  72. Probably not physically allowed by MetricT · · Score: 3, Informative

    I did Ph.D. research on this exact subject a decade ago, and at a quick glance I didn't see anything new in this paper. A spinning and/or charged black hole in theory can be spun or charged to the point where a naked singularity would appear. But, the harder you spin/charge the black hole, the harder it tries to neutralize itself by preferentially emitting particles of a given angular momentum or charge. So the equality probably is a physical limit. I thought someone had proven that years ago, but I've been out of the field for a while.

    This looks kind of like someone wrote a paper so they could go to a conference or something. There doesn't appear to be anything earth-shattering (or black hole-shattering) here.

  73. Summer Blockbuster by Anonymous Coward · · Score: 0

    Destroy a black hole? I smell summer blockbuster! Plus the sequel: "The Hole 2: It's back and it's black!"

  74. Angular Momentum? by Artifakt · · Score: 1

    Adding lots of angular momentum means the object has substantial velocity relative to the observer. If the observer is moving along with the black hole, then it doesn't have angular momentum, relative to whatever tools you are using to observe it, so that observer will still see an event horizon. If the observer isn't moving along then the black hole will move out of range for a lot of observations pretty swiftly. Note that a black hole can gain momentum relative to an observer just as well if the observer is the thing accelerated instead of the hole.
          Probably the only even slightly practical way to add angular momentum to a black hole would be to get a serious electric charge on it first, so it could be accelerated magnetically. That's still far fetched engineering, but isn't theoretically banned. So the device that could do the preliminary job of making adding momentum possible, most likely could simply do the whole job by pumping more electrons in. Ergo, any species wishing to conduct the experiment will only build the gigantic electron gun, not the space magnets.

    --
    Who is John Cabal?
    1. Re:Angular Momentum? by John+Hasler · · Score: 1

      > Adding lots of angular momentum means the object has substantial velocity
      > relative to the observer.

      No it doesn't. Angular momemtum has to do with spin, not linear motion.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  75. This doesn't really make sense by KriticKill · · Score: 2, Interesting

    Does this make sense to anybody else, or I am just getting it wrong? From what I understand the event horizon is just a boundary signaling a point of absolutely no return due to the intense gravity pulling anything and everything into it. Neutralize the event horizon and you neutralize the gravity, which is proposed to be the element of the blackhole. Without gravity, no blackhole, or at least its a blackhole in stasis. Is the article meaning to neutralize gravity in the area around the blackhole, while leaving said hole itself intact?

  76. Re:look, i like making fun of star trek technobabb by wagnerrp · · Score: 1

    They still had pack radios. It's not like it was a new impossible technology. It just took them about 30 years worth of miniaturization to get them down to the size as was in Star Trek.

  77. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    Perform a Google search on: John Titor

  78. Re:look, i like making fun of star trek technobabb by ReverendLoki · · Score: 3, Funny

    That's what Japan is for.

    --
    09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
  79. The Naked God by Anonymous Coward · · Score: 0

    Reminds me about the 3 book in the Nights Dawn Trilogy by Peter F Hamilton.

    http://en.wikipedia.org/wiki/The_Naked_God

    (read the second to last paragraph, but only if you don't mind spoilers!)

  80. Re:Would the event horizon retreat if you approach by cowscows · · Score: 1

    That's not really correct. You don't directly perceive the time dilation, in that time seems to be passing the same to you. Only compared to an outside observer do you experience time dilation effects. Assuming that tidal forces/radiation/etc. weren't an issue, you wouldn't really notice much of anything different as you actually crossed the event horizon.

    --

    One time I threw a brick at a duck.

  81. Re:look, i like making fun of star trek technobabb by zakeria · · Score: 1

    what I suggest is sending all those used tissue papers and playboy mags laying around young mens rooms! should be enough mass to plug that hole!

  82. Racism! by Korey+Kaczor · · Score: 2, Funny

    Since light cannot escape the event horizon, it must be black

    That's racist!

  83. ugh. i don't get it. by Anonymous Coward · · Score: 0

    reference please, for us lamers?
    i want in on the joke!
    waaaaaaahhhh D-:

    1. Re:ugh. i don't get it. by Anonymous Coward · · Score: 0

      It is from the movie Event Horizon. The rescue ship picks up a broken transmission which they partially translate as "help us". Later, they get the full transmission (GP post) which means "save yourselves from the fires of hell".

    2. Re:ugh. i don't get it. by Hidyman · · Score: 1
      --
      You can't take the sky from me ...
  84. Re:Many believe that naked singularities cannot ex by gmuslera · · Score: 1

    Where some see a problem, other see an opportunity. Seems that the market niche for black hole haute couture has just opened.

  85. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    4. Ebony has a trademark on the term "black hole"

    Always remember that, in Russian, 'black hole' does not refer to a collapsed star.

  86. uh oh by Anonymous Coward · · Score: 0

    in before ray kurzweil/lemonparty mashup

  87. Scale of things by gmuslera · · Score: 1

    Unless we are talking about microscopic black holes (lhc could be useful there) the typical scale of the maybe only useful for this black holes could imply throwing in things of the size of big suns or small galaxies. Probably by the time we could do that we already know what happens inside black holes (almighty usually implies allknowing too),

  88. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    Sorry I was talking on my satellite phone. What was that about not reaching orbit?

  89. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    Easy enough to solve. Just tether (magnetically) a charged miniature black hole to the handle and shine your laser at that. This could also be used to create the force-field effect that would only apply to other light-sabers. Giving you the end-state where you have a glowing rod of light that can pass through anything except another similar glowing rod of light.

  90. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    Come on now, everyone knows you use an ionized plasma contained in a magnetic field for a light saber, not a laser.

  91. Re:look, i like making fun of star trek technobabb by david_thornley · · Score: 1

    Not to mention the Dick Tracy comic strip, which featured futuristic gadgets like a two-way wrist radio. It was, as I remember, fairly popular before Star Trek.

    --
    "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
  92. You can't destroy a black hole by Hognoxious · · Score: 1

    You can't destroy a black hole. Don't bee silly.

    But you could block it with several parsecs of duct tape.

    --
    Confucius say, "Find worm in apple - bad. Find half a worm - worse."
  93. Re:look, i like making fun of star trek technobabb by frinkacheese · · Score: 1

    Looks like nobody took you seriously ;-)

  94. One question... by Thelasko · · Score: 1

    According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass.

    Who's gonna go spin the black hole and zap it with a few billion tazers?

    Anybody?

    Come on, it's for science!

    --
    One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
  95. Re:look, i like making fun of star trek technobabb by Anonymous Coward · · Score: 0

    Always remember that, in Russian, 'black hole' does not refer to a collapsed star.

    I thought in Russian, hole blacks you.

  96. Mod this by nuckfuts · · Score: 1

    +3 Insightful

  97. A white hole? by N0Man74 · · Score: 1

    What are you trying to imply with a "white hole"? It would sound like you are suggesting that an antimatter variation of a black hole would have strong anti-gravity... That it would be so strong that even light could not reach it. Would that make the antimatter version of an event horizon to be... a U-Turn?

    Though that is a funny though, I have serious doubts about such an idea.

    1. Re:A white hole? by somaTh · · Score: 1

      It was a weak play on the "anti" portion of anti-matter. Apologies for physics making it silly.

      --
      Nostalgia isn't what it used to be.
    2. Re:A white hole? by clone53421 · · Score: 1

      an antimatter variation of a black hole would have strong anti-gravity...

      http://en.wikipedia.org/wiki/Gravitational_interaction_of_antimatter

      Consensus: Antimatter has normal gravity.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    3. Re:A white hole? by N0Man74 · · Score: 1

      an antimatter variation of a black hole would have strong anti-gravity...

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

      Consensus: Antimatter has normal gravity.

      I can't tell. Are you intentionally taking that fragment of a sentence out of context in order to try to imply that I was stating that as a fact, or are you just interjecting science into the silliness?

      If the former, then shame. It's obvious that I was not intending to present that as a fact, but questioning if the earlier poster was intending to imply that.

      If the latter, then yeah, I'm aware of that, hence my doubting. somaTh and I were just engaging in a bit of absurd and silly thought experimenting.

      I'm a total physics and astronomy noob, but I always saw black holes not so much as *pulling* the light so hard it couldn't escape, but rather distorting space so much that shortest path for light to travel is right back toward the singularity.

      The idea of something distorting space in the exact opposite way is certainly an amusing idea, even if I think it's impossible.

    4. Re:A white hole? by clone53421 · · Score: 1

      To be honest, I thought you were stating (implying, at least) that as a fact.

      It's obvious that I was not intending to present that as a fact, but questioning if the earlier poster was intending to imply that.

      It wasn’t obvious... and apparently I was confused.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    5. Re:A white hole? by clone53421 · · Score: 1

      I'm a total physics and astronomy noob, but I always saw black holes not so much as *pulling* the light so hard it couldn't escape, but rather distorting space so much that shortest path for light to travel is right back toward the singularity.

      Light doesn’t take the shortest path. It just travels in straight lines (relativistically speaking – to an outside observer its path might not seem straight).

      Anyway, looking back I realise now that you latched onto his use of the term “white hole” and assumed things that I don’t think the poster intended to imply by it. He was just trying to come up with a word for the antimatter equivalent of a matter black hole, and apparently “white hole” was the answer that seemed obvious to him.

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    6. Re:A white hole? by N0Man74 · · Score: 1

      I wasn't really trying to assume anything. I was just posing the question about what a white hole was, and if it would have the properties that the name suggested. My part of the discussion was meant to be quite hypothetical and largely in jest.

      Perhaps "shortest path" was a bad way of phrasing it, but I think we meant the same thing. What I meant was in the sense that it continued going in the same direction in a straight line (the shortest distance between two points). Of course that "line" (or shortest distance between 2 points) is only straight from the perspective that the light travels, and could appear non-straight to an outside observer due to the curvature of space.

  98. We are all good Spaghetti-fearing folk here. by Bysshe · · Score: 1

    'tis the wrath of our lord, the fly spaghetti monster as he takes his vengeance on those who disturb his home.

    --
    Read what I mean, not what I wrote.
  99. Re:look, i like making fun of star trek technobabb by CubicleView · · Score: 1

    The biggest problem is efficiency. Even if you had a battery with enough energy and power for a workable lightsabre, at even 99.9% efficiency the handle would probably melt in less than a second of use.

  100. Finally... by PrototypeNM1 · · Score: 1

    Emergency protocol at the LHC: blast it with charge and angular momentum.

  101. IANATABIPTBOOS by TiggertheMad · · Score: 1

    I am not a theoretical astrophysicist, but I pretend to be one on Slashdot...

    One thing that bothers me about this paper is that it suggest that by increasing the angular momentum (and/or the charge) to a great degree relative to the mass will cause the singularity to be exposed.

    The problem I see is that as you add angular momentum or charge to a black hole, (even if you do it without directly dumping mass in), you are still adding mass. (E=mc^2, remember energy is mass). Without breaking out the old pencil and paper to check the numbers, I would suspect that by adding enough energy to the system to get it into an 'extreme' state with respect respect to the initial mass, you will have increased the mass to the point that you wont have enough charge or momentum to expose the singularity.

    --

    HA! I just wasted some of your bandwidth with a frivolous sig!
    1. Re:IANATABIPTBOOS by John+Hasler · · Score: 1

      Read the paper.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  102. Re:look, i like making fun of star trek technobabb by Surt · · Score: 1

    You were talking to an astronaut on the shuttle? Cool, the secret missions continue!

    --
    "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
  103. Re:look, i like making fun of star trek technobabb by Smauler · · Score: 1

    On a completely unrelated note, I listened to a BBC radio 4 report this morning all about the "Goatse hackers". I was sniggering all throughout the report, wondering how many of the unitiated googled goatse. I'm suprised this story hasn't hit /. yet, to be honest.

  104. Foolish Fools by ae1294 · · Score: 1

    What they would like is a way to get rid of the event horizon so that they can see what goes on behind it

    I'll save you the trouble and expense.. The answer is Cthulhu and creeping madness... That's what's behind the event horizon and that's what goes on there...

    You've been warned.

  105. Black Hole Destruction? by xorcyst · · Score: 1

    Save the Black Holes!

  106. Free-fall is assumed. by maillemaker · · Score: 2, Interesting

    It is assumed that you are falling into the black hole accelerating according to the force of the gravitational pull of the black hole. So you WILL pass through the event horizon in a heartbeat.

    Think of it this way:

    Even if you had a magical platform that you could stand on just /outside/ the event horizon, you'd still be dead. The amount of gravity pulling down on your would not just stop your blood from flowing upwards, it would crush you into a puddle of goo on the platform.

    The ONLY way you could survive the fall into the black hole would be under freefall. Any attempt to appreciably slow down your fall would result in you getting crushed. So any trip through the even horizon will be very, very fast. Probably an an appreciable fraction of the speed of light.

    --
    A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
    1. Re:Free-fall is assumed. by clone53421 · · Score: 0

      So any trip through the even horizon will be very, very fast. Probably an an appreciable fraction of the speed of light.

      The event horizon is precisely the point at which you will be traveling at the speed of light... because not even light can escape it.

      To use a similar analogy to gp’s blood analogy, suppose you held a flashlight in your toes as you passed through the event horizon. As soon as the flashlight passes through the event horizon, it’ll disappear: not even the light from it will be able to reach you. The only way for this to be possible is for the light source to be moving away from you at a speed equal to or greater than the speed of light. Oh, and your toes will also be moving away from you at that speed. Remember that bit about being ripped apart?

      Not to worry much about that, though, because the rest of you will be moving at very nearly the speed of light and it’ll all be over quickly...

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
    2. Re:Free-fall is assumed. by Rakishi · · Score: 3, Informative

      You're bringing horribly naive Newtonian physics into a realm they do not belong in. Stop before you make yourself sounds like even more of a fool.

      As you fall into a black hole the event horizon appears to move away from you from your point of view. An external observer on the other hand would never see you cross the horizon due to other effects, just see you falling ever more slowly into it as the light from you takes ever longer to reach them. You'd see some odd effects from crossing the event horizon but you'd continue to observe things.
      http://casa.colorado.edu/~ajsh/singularity.html
      http://jila.colorado.edu/~ajsh/insidebh/schw.html

      The event horizon is precisely the point at which you will be traveling at the speed of light...

      No it's not. Matter cannot go at the speed of light and never does. Nothing can go faster than light. That's the whole bloody point of relativity. Stop watching bad sci-fi movies. There are I believe odd effects for certain observers who might see you but practically speaking you'd just be moving at just something like 0.99c. But that's just due to the acceleration of the black hole and it will continue to increase even after you cross the event horizon.

      As soon as the flashlight passes through the event horizon, it'll disappear: not even the light from it will be able to reach you.

      Nope, you continue seeing the flashlight. Well in some way at least. The event horizon for you has receded. Another way to think of it is that while the light is no longer moving towards you, sort of hovers at the event horizon, you're now moving towards the light. Relative velocity is all that matters. You'll get some odd relativistic distortions I believe, makes me wonder if a human nervous system even survive them, but you'll continue to observe things that went before you through the even horizon.

    3. Re:Free-fall is assumed. by Fractal+Dice · · Score: 1

      hmmm, relativistic freefall does satify the crazy speed loophole of my critique ... I could salvage my argument if I could somehow start from rest close enough to the event horizon so that freefall hadn't yet reached relativistic speeds upon reaching the event horizon. But I guess there's no possible trajectory that would let me reach that state without enough deceleration to turn me into a puddle of goo?

      (disclaimer: I acknowledge that my layman's intuition about physics is probably not terribly applicable to relativistic freefalls into black holes)

    4. Re:Free-fall is assumed. by NitroWolf · · Score: 1

      Wow... do you guys arguing about crossing the "event horizon" of a black hole even understand the basics of it?

      With a large enough singularity at it's heart, you wouldn't even realize you had crossed over the Schwarzchild radius - there would be no specific difference from one moment to the next, besides the increase in gravitational pull increasing at the same rate it's been increasing as you approach the singularity from outside the radius (inverse square). The Schwarzchild radius is just a mathematical boundary, it's not a physical boundary.

      If you crossed the radius on an tangential orbit, you could conceivably orbit the singularity within the radius for millions or billions of years, living out your life aboard your vessel in your personal reference frame for as many years as you live, watching the universe speed past you at an apparent accelerated temporal rate until the ultimate heat death of the universe consumes you, your vessel and your local singularity as well. There's nothing special physically about the event horizon of a black hole, besides the fact that it cuts off two way communication with the outside universe. Beyond that, it has no effect on anything else. It just so happens that many of the Shwarzchild radius limits of singularities are so small that crossing them puts you into a proximity of the singularity that is lethal. That is purely coincidental though.

    5. Re:Free-fall is assumed. by Anonymous Coward · · Score: 0

      Hahahaha! You don't understand physics and you're trying to cover it up by attempting to ridicule someone who obviously knows more about it than you!

    6. Re:Free-fall is assumed. by Rakishi · · Score: 1

      Seriously, you failed so badly with that post I didn't even need to reply for it to be moded to oblivion, that's hilariously serious fail.

      Clearly you lack even a basic understanding of advanced physics so I'm not even going to bother, could probably have more luck with a lobster or a high school freshman who had a couple hours with wikipedia.

      As for your comment, the event horizon is not the singularity nor is it the outer boundary of the singularity. The event horizon is mostly just a mathematical construct.

    7. Re:Free-fall is assumed. by Anonymous Coward · · Score: 0

      Didn't they thrash the light barrier bull awhile back? Since light has mass(however infinitesimal) and light has a measurable variable speed? If there were such a thing as a light barrier, the speed of light would absolutely have to be a universal constant, as it can be slowed down and manipulated(no, I'm not just referring to the light, but the speed thereof), it is not a constant. The barrier may very well technically exist in that case, but it would be more akin to the sound barrier than something that is absolutely impossible to circumvent.

      Thats unless they proved the experiments that measured that stuff were hogwash.

    8. Re:Free-fall is assumed. by Rakishi · · Score: 1

      The fuck? Seriously, I honestly expected better from slashdot.

      Light has momentum NOT mass. There is a difference. Photons are massless particles and all that, the usual edge case quirks of physics aside since they don't matter here.

      The speed of light in a vacuum is a universal constant. It does not change. It cannot be crossed. It cannot be reached by anything with mass. It's c. It is invariant. It's the maximum speed of light. When someone says the speed of light they mean c unless they note otherwise.

      Now, light can go slower, nothing says otherwise. It goes slower in anything else including plain air. You can as a result go faster than light in a given medium, it's why nuclear reactors have that nifty blue glow. However you still can't go faster than c. That's all that matters.

    9. Re:Free-fall is assumed. by Ginger+Unicorn · · Score: 1

      Stop before you make yourself sounds like even more of a fool.

      Garshk Popeye, thanks for the heads up. Hugugugugug!

      --
      (1.21 gigawatts) / (88 miles per hour) = 30 757 874 newtons
    10. Re:Free-fall is assumed. by clone53421 · · Score: 1

      Light has momentum NOT mass. There is a difference. Photons are massless particles and all that, the usual edge case quirks of physics aside since they don't matter here.

      To be more accurate, photons do have relativistic mass (pure energy) even though their rest mass is zero.

      http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html

      --
      Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  107. it's easy to destroy a black hole by roman_mir · · Score: 0, Troll

    first, please, it's not politically correct, they don't like it to be named black anymore, it's an African American hole. Past this, it's fairly easy to destroy the black hole. Paint it in 7 different colors and then tell it that it's OK to come out, they are getting rid of the don't ask don't tell policy.

  108. Re:Would the event horizon retreat if you approach by instagib · · Score: 1

    So, if you cross the event horizon, time doesn't exist or is infinitely fast - which means you live forever. Then, as you hit the singularity, you are transported back to the begin of the (some?) universe. Fascinating.

  109. Re:look, i like making fun of star trek technobabb by TerranFury · · Score: 1

    1 - Is this literally true?

    2 - What does it mean?

  110. Re:look, i like making fun of star trek technobabb by ILuvRamen · · Score: 0

    Simmer down, sparky. This is for real, that article just sucks at explaining it. I remember hearing about this in a book I read about 10 years ago so it's not new news by the way. Let me explain. A singularity has mass but no radius. It can still rotate though. That means if you shoot a particle into it at an angle, it gives is angular momentum and spins a little. Feed it a super powerful laser nonstop for long enough in the same direction and theoretically, it can rotate faster than the speed of light. That's because there's no point on the edge of the radius to measure the speed of so no speed limit is imposed. I don't know why they think it will stop "causing" gravity in the immediate area around it at that point but that's what they think will happen.

    --
    Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
  111. maybe they have the wrong idea... by Nyder · · Score: 1

    I've always wondered about this.

    We got space, which is a vacuum, from what i understand.

    We got black holes, that apparently light and nothing else can escape from.

    We also have massive blackholes that are the center of galaxies that seem to be seeding the galaxies.

    Here's my theory (construction zone ahead, ie, work in progress)

    Our "big bang" started from a black hole being started in another universe. My thoughts are: A black hole starts, it's like pimple or something. A weakening in the structure of time & space that's able to hold stuff in it, but not spit it back out the way it came. When it gets full enough, it causes a "big bang" in a new universe.

    Being as space is a vacuum, that the pressure created from one universe to the other is enough to push the galaxies like they are going.

    Of course, there's a lot of work to go in this theory, and it's not based of math or physics, or anything, other then my own understanding or trying to understand.

    --
    Be seeing you...
  112. Fun playground by Lvdata · · Score: 1

    For a more entertaining look at a naked black hole see http://www.amazon.com/Compleat-McAndrew-Charles-Sheffield/dp/067157857X "The Compleat McAndrew" by Charles Sheffield Good read on how to use and abuse a black hole for fun and profit.

  113. Re:look, i like making fun of star trek technobabb by hAckz0r · · Score: 1

    No, but North Korea is better known for making things that don't really exist. I'm not sure that Japan has yet proven successful at making things out of nothing, as of yet. But if anyone can do it, I bet it's North Korea's Kim Jong Il.

  114. Re:Would the event horizon retreat if you approach by clone53421 · · Score: 1

    Not quite.

    Time stops... and you are moving infinitely fast... the two of which, together, mean you get ripped apart. On a sub-atomic level. Sorry about your luck.

    What happens to the particles that formerly composed you when they hit the singularity... well, that’s anyone’s guess. Personally, I’m inclined to believe that the universe is a continuous medium and singularities are impossible, but it’s all theoretical no matter what theory you believe.

    --
    Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  115. An interesting video. by maillemaker · · Score: 2, Informative
    --
    A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
  116. Did anyone think to try using a.... by 3seas · · Score: 1

    flashlight and an energizer bunny battery?

  117. OK, But We Can't Even Go to the Moon, Yet... by LifesABeach · · Score: 1

    If one can assume that there is a reason for an event horizon to be missing from a Black Hole, why don't we just look for one that has? And while I'm depositing my 2 cents in a bank account so that I can get a table at the End of the Universe, what would a Black Hole look like without an event horizon?

  118. Re:look, i like making fun of star trek technobabb by Alex+Belits · · Score: 1

    Always remember that, in Russian, 'black hole' does not refer to a collapsed star.

    It means exactly the same in Russian that it does in English (what formally is not a "collapsed star" but "an object capable of capturing light by its gravity").

    (In Soviet Russia humor fails you).

    --
    Contrary to the popular belief, there indeed is no God.
  119. Partial black hole? by Pro923 · · Score: 1

    I always wondered - if you had a body that was just under the mass of a black hole, and then put another star nearby such that it was a binary star, could the resulting gravitational effect be a partial black hole? From all angles except opposite the smaller star, it would appear to be a black hole.

  120. Star Trek was right? by Mad+Alchemist · · Score: 2, Funny

    "According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass. "

    You mean... all we have to do to escape the event horizon is... reverse the polarity?

  121. Brainfarts by olehenning · · Score: 1

    Some people have brainfarts... my brain just shat itself.

  122. Low Average Density by HydroPhonic · · Score: 1

    So is that why we can't see outside the "universe"? Because it's a giant "black hole" the event horizon of which we can't escape because all paths lead back to within?

  123. BLACK HOLES ABSOLUTELY DO NOT EXIST. by Anonymous Coward · · Score: 0

    Black holes absolutely do not exist because true Gravity (proven on EinsteinGravity.com) is an Electrical pushing force of Mass Expansion.

    Gravity is only upon the surface of a particle.

    Black holes are an erroneous creation resulting from Einstein's inversion of Mass and Light in his equation.

    Absolute Fact.

  124. Donut Holes by DynaSoar · · Score: 1

    I want credit for the name if the maths work out.

    Consider the Kerr solution, a rotating, non-charged body approaching the Schwarzchild limit. As it shrinks the spin increases. As this happens the matter near the edge of the now disk-like body gains mass via increased speed a la relativity. The amount gained may not be significant in normal space, but near the Schwarzchild limit it might prove enough to alter the development of the hole. (This mass gain may or may not serve to increase rotational speed more. If it does the following becomes more likely. We'll take the conservative view and ignore this possibility.)

    As the body as a whole nears the limit, any portion of the body with greater mass will cross the limit first. This is generally taken as the center. However, the additional mass of the material near the edge of the disk causes it to cross over first and development of the hole begins around this material rather than the center. The hole begins to develop as a toroid. The matter that crosses over first becomes a singularity in terms of its effects, but takes the shape of a ring. The resulting toroidal black hole finishes its parent body off as the outer portion having turned into a black hole pulls in the remaining matter nearer the center, feeding the toroid formation process. The result is a black 'donut' hole, with a path through the axis that does not cross the event horizon. The center is empty (ie. non-horizon involved) because of the balance of gravity in the region neat the 'center' where the gravity from the opposite side of the ring balance out. The size of the hole remains to be calculated. From macro to quantum sized as long it stays non- zero, the donut remains. Even zero may work out as a toroid with a zero diameter center is possible. Perhaps only a negative result (indicating a merger of the opposing event horizons) ruins this postulation.

    The singularity ring itself is presaged in description by Mbrane theory. It is simply a circular macro-string of the sort postulated as having been created with the Big Bang. One could approach this from the other direction and starting with that description increase the mass until an external event horizon forms.

    The above approaches the Kerr solution in tiny steps very near the time of formation and the logic as well as the physics and associated maths well known. It shouldn't be too difficult to test. If it is borne out, the paper referred to in the article, regarding 'destroying' a black hole, may have other solutions to consider. While an increase in angular momentum may 'destroy' a particular conformation, rather than shedding the event horizon, the singularity/hole may simply take up another form such a what is described here. If a rapidly spinning object can form a toroidal black hole, perhaps a rapidly spun black hole can also.

    --
    "I may be synthetic, but I'm not stupid." -- Bishop 341-B
  125. Re:look, i like making fun of star trek technobabb by Bungie · · Score: 1

    A lazer is simply not the correct type of technology for that type of weapon. A lazer will be great for guns which fire a direct beam at a target. To contain a laser into the shape and functionality of of a sword will be more work than it would be practical.

    A sword has a set blade length, while lazer beams have an infinite length and would need to be contained somehow. A sword has a strong solid blade which can parry blows, a lazer is not solid at all. A sword has a sharp blade edge for cutting cleanly through opponents without getting stuck. A lazer would have to have enough heat to vaporize whatever it contacts or else it won't cut through opponents at all. A sword doesn't need a power source, lazers do.

    The lightsaber itself only has a few advantages over a regular sword anyway: Carry space (lightsaber handle that blade expands from vs. whole sword & scabbard), blade maintainence (sword blades need to be kept sharp and free of oxidization), blade durability (sword blades can break, lightsabers shouldn't), blade strength/sharpness (sword blades cannot cut through all materials, lightsaber might be able to).

    So a lightsaber would need to be constructed using a more suitable technology. It also would have to provide a significant enough advantage over a sword in the first place.

    --
    The clash of honour calls, to stand when others fall.
  126. Re:BLACK HOLES ABSOLUTELY DO NOT EXIST. by marcosdumay · · Score: 1

    Oh, no. Gravity's caused by heat!

    But, ok, if it is caused by heat, it may be due to eletricity, you have a point... Or entropy, of all weard things, entropy is the worst ofender, so it MUST be entropy.

  127. it's a fabulous gedanken experiment by shnull · · Score: 1

    shit i feed on, but like most of those it will ofcourse not be happening anytime soon. Still, i prefer people doing this with the freedom of choice they got ever since lightbringer freed them from the prison of Eden ;-) maybe inthere they will find the stuff dreams are made of ?

    --
    beware he who denies you access to information for in his mind, he already deems himself to be your master (SMAC-ish)
  128. I Gotta Be The First??? by SoVi3t · · Score: 1

    Divide by zero???

    --
    Defender of Microsoft and Communism!!!
  129. The ability to destroy a black hole... by hallux.sinister · · Score: 1

    is insignificant compared to the power of the force...

  130. As for what astrophysicists might see... by hallux.sinister · · Score: 1

    I think they might, for a few femptoseconds see a formation of particles that could, from the right angle, be mistaken for the words, "We're sorry but the universe does not have imagery at that zoom level." Or, just possibly, "We apologize for the inconvenience."

  131. Re:look, i like making fun of star trek technobabb by RivenAleem · · Score: 1

    What do you think all the detectors are for in the LHC? Trying to catch them in the act.

  132. Re:BLACK HOLES ABSOLUTELY DO NOT EXIST. by Anonymous Coward · · Score: 0

    Oh, oh, I know this one! Next you're going to explain how time has four corners and how evil educators have educated us stupid, right? I can't wait!

  133. Re:look, i like making fun of star trek technobabb by clone53421 · · Score: 1

    The lightsaber itself only has a few advantages over a regular sword anyway

    Don’t be ridiculous...

    Pit an expert swordsman against a Jedi knight and if the swordsman’s blade is in any fewer than eight pieces when he hits the ground then the Jedi knight obviously wasn’t trying very hard.

    --
    Alexander Peter Kristopeit bought his basement from his mommy for one dollar.