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Possible Hole in Black Holes

jd writes "Researchers have found what they believe may be a MECO (Magnetic, Eternally Collapsing Object) inside of a quasar. MECOs are rivals to black hole theory and involve plasmas that never reach the state of being a singularity. The most obvious differences between them are that MECOs have a magnetic field and do not have an event horizon. The problem lies in that the Universe cannot have both MECOs and black holes — it can only have one or the other. If this object truly is a MECO, then black holes do not exist. Anywhere. (Furthermore, this would require Professor Hawking to return a year's subscription to Private Eye and give Professor Thorne a year's subscription to Penthouse.) On the other hand, if this thing isn't a MECO, it's behaving very very oddly for a black hole."

93 of 495 comments (clear)

  1. Errr by Anonymous Coward · · Score: 5, Funny

    *Too complicated to coment*

    1. Re:Errr by bhima · · Score: 5, Funny

      like that's going to slow anyone down!

      --
      Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
    2. Re:Errr by TopShelf · · Score: 2, Funny

      Carl Everett? Is that you? Wow, a major league baseball player posting on /. - now I've seen everything...

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      Stop by my site where I write about ERP systems & more
    3. Re:Errr by unihoops · · Score: 2, Funny

      If black holes do not exist, how do you explain Madonna?

      --
      Can someone PLEASE get me the beerbong!!! I've got to speak to the seven out of ten!
  2. Why... by Pacifist+Brawler · · Score: 5, Insightful

    Why can't the MECOs and the black holes just set aside their differences and peacefully coexist?

    Seriously, if this thing really is an MECO then what are all of the things that we've thought were black holes?

    --
    IANA*
    1. Re:Why... by NecroPuppy · · Score: 5, Informative

      Seriously, if this thing really is an MECO then what are all of the things that we've thought were black holes?

      Probably MECOs.

      Because it's 3 AM, and I don't have the energy to reproduce all the math, there's two main theories about super-massive objects (simplifying a lot).

      One: Black holes. You've got an event horizon. Anything passes that point is gone forever. And they don't have magnetic fields. (remember, simplified massively)

      Two: MECOs. No event horizon, instead the matter pulled in is spun for a while then ejected at near lightspeed. They do have magnetic fields.

      Everything we know about black hole candidates falls into one of two sets of mutally exclusive equations (in large part to the magnetic field thing).

      That this object appears to have a magnetic field supports one set of Einsteinian equations; the one that supports MECOs.

      --
      I like you, Stuart. You're not like everyone else, here, at Slashdot.
    2. Re:Why... by de+Siem · · Score: 5, Funny
      One: Black holes. You've got an event horizon. Anything passes that point is gone forever. And they don't have magnetic fields. (remember, simplified massively) Two: MECOs. No event horizon, instead the matter pulled in is spun for a while then ejected at near lightspeed. They do have magnetic fields.

      So if I understand correctly,

      Black holes suck and swallow

      Meco's suck, gargle and then spit it out

      Dirty buggers the lot of them!

      --
      Beating up people in little rooms, if you do it for a good reason you do it for a bad one.
    3. Re:Why... by buswolley · · Score: 3, Informative

      God.

      --

      A Good Troll is better than a Bad Human.

    4. Re:Why... by aug24 · · Score: 4, Funny

      And given that the 'super massive black hole' at the centre of the galaxy is actually thought to be a multiple system, then this nes suggests that the entities at the centre of our galaxy do snowballs. Ewww.

      I think that's as far as we can take this. I hope so.

      J.

      --
      You're only jealous cos the little penguins are talking to me.
    5. Re:Why... by jafiwam · · Score: 3, Interesting

      Actually that's pretty compelling when coupled by a few other things;

      Though I have only known about MECOs for a few minutes, there's some things about black holes that never made sense to me.

      Why the near-light speed ejecta from a spherical event horizon object. Where does all that lateral energy come from? A super strong magnetic field makes more sense as a method for ejecting material than matter at oblique angles to the ecliptic accelerated so much it collides (and 99% of the energy evens out due to the circular input field and the last 1% spitting the stuff out) with classical physics.

      Instead, you get a south pole, and a north pole, and anything with any charge on each of those ends screaming in one direction or other.

      It seems to me though that plasma would give off tons of light, and there ARE some cases where a BH was "speculated" to be present where it's pretty clear there isn't a light producing object there.

    6. Re:Why... by lanswitch · · Score: 4, Informative

      Not snowballs, but meatballs (http://www.venganza.org/)

    7. Re:Why... by Bromskloss · · Score: 4, Funny
      MECOs. No event horizon, instead the matter pulled in is spun for a while then ejected at near lightspeed.
      Weeeeeee, I'm next!
      --
      Swedish plasma phys. PhD student; MSc EE; knows maths, programming, electronics; finance interest; seeks opportunities
    8. Re:Why... by Total_Wimp · · Score: 4, Insightful

      All good and fine. But if we have decades of good work with black holes and we've appeared to find quite a few of them, then why would we be throwing them away with just one possible MECO sighting?

      I mean, if all of a sudden my very smart next door neighbor told me the sky was purple, I'd have to give his account much more scruteny than normal, simply because I already have so much evidence that it's blue. I certaintly wouldn't elevate it much past "interesting" until I got a lot more information, and I'd certainly not discard blue until there was a great body of evidence.

      TW

    9. Re:Why... by cheater512 · · Score: 2, Funny

      Hmm...I'm trying to think of a question which gives 42 but I'm not having much luck.

    10. Re:Why... by eyewhin · · Score: 5, Interesting

      That black holes do not, in some way, posess a magnetic field seems to be a debatable subject.

      One of the articles, http://www.newscientistspace.com/article/dn9050/, concerns the effiency of black holes and has a representative picture of jets moving away from the black hole. The captions reads:

      Jets of high-speed particles may be powered by magnetic fields and either the rotation of matter swirling around a black hole, the spin of the black hole itself, or both (Image: NASA/CXC/M Weiss).
      No where does it state that a black hole is mutually exclusive of a magnetic field.

      Quasars are certainly misunderstood objects. They appear to be very far away. No one can really conclude what these distances are. Strictly basing an assumption on redshifts is not, for me, conclusive.

      When a star forms, there is a point before "ignition" where there appears to be nothing. We can see these globules in many photographs of nebulae. According to theory, anywhere that you see what looks to be a perfect cirlce of black is a candidate for star formation.

      Now, quasars are theorized to be precursors to galaxies. Why is it not possible that we are observing the same effect on a huge scale? The matter in the center of the quasar is simply reaching the critical point and in the end we have a galaxy with a core that is burning brightly and outer arms that would be the equivalent to the planets orbiting our sun?

      For a good example of what this would look like, anyone can take a look at a picture of M104-the Sombrero Galaxy. Of course, there are many other spiral galaxies that one can observe, as well. The point is, the universe is very fractal in nature. We can compare the classical view of an atom to that of the solar system. Why can we not simply extend this to a view of a galaxy?

      The event horizon is something that any object with mass has, as well. Of course, not on the same scale as a black hole, yet, come to close to the sun and you are doomed. A comet slammed in to Jupiter and disappeared. It will never be seen again. Our moon is stuck to the earth. Without adding energy to the system, the moon will always be a part of the system. The event orizon of a black hole is important because light cannot ever leave the system once inside this critical boundary. That does not mean that other systems possess no event horizon.

      Also, there is a lot of evidence for black holes in binary stellar systems. I don't see how these MECO's offer an alternative eplanation for events that we observe vitually in our backyard. The quasars are too far away to readily observe and coem to any conclusion (if the distances are correct).

      The reason that it is so "easy" to accept the concept of a black hole is simply the fact that as the diameter of a body decreases while retaining mass, there is no choice but to have the system collapse to a singularity--given enough mass. If there is not enough "critical" mass, we end up with neutron stars, dwarves, etc.... What happens inside the black hole is anyone's guess.

      David
    11. Re:Why... by Mayhem178 · · Score: 2, Interesting

      There's actually a theory on this that renders this question irrelevant.

      Space, as we know it, is a place in which matter and energy exist. Particles can be attributed a "position" within space relative to some other object in space, giving rise to the concept of "distance," which gives rise to all kinds of theories, relativity among them. In this model, we assume the existence of space and, ergo, the "position" of any given particle within space is an extrinsic property of that particle (i.e. assigned to it by an outside parameter, in this case, it's relative placement in space).

      Flip that around for a moment and consider the opposite. Let's say for a moment that we don't assume the existence of space, but rather space as we know it is an illusion created by our perceptions. Since there is now no extrinsic parameter by which to assign a "position" to any given particle, the "position" of a particle must then be an intrinsic property (i.e. inherent to) of the particle which defines how we perceive it (or, more specifically, where we perceive it) in this illusion of space.

      Now the question of the bounds of the universe is irrelevant, because space is an illusion generated by our perceptions of the intrinsic "positions" of particles.

      Anyways, here's a page describing the theory in greater detail.

      --

      "You will pay for your lack of vision..." - Emperor Palpatine to Ray Charles

    12. Re:Why... by Fallen+Seraph · · Score: 2, Informative

      The event horizon is something that any object with mass has, as well. Of course, not on the same scale as a black hole, yet, come to close to the sun and you are doomed. A comet slammed in to Jupiter and disappeared. It will never be seen again. Our moon is stuck to the earth. Without adding energy to the system, the moon will always be a part of the system. The event orizon of a black hole is important because light cannot ever leave the system once inside this critical boundary. That does not mean that other systems possess no event horizon. Errr, that's not true. By definition, the event horizon is the theoretical threshold of a black hole's gravity well from which point nothing can ever escape under any circumstances under its own power (we're ignoring the ocassional black hole emmission jets which form for now). The Sun has no event horizon, and neither can anything else because light can always escape it. Saying "if you get to close to the sun, you're doomed" means nothing because we're arbitrarily picking the amount of energy human technology can generate to escape the forces of gravity. In the span of a few decades, which, by the standards of the Universe, is almost an instant, that may no longer be true. The reason it's special is because one of only true constants we know of is the speed of light. It never changes; except when undergoing refraction through materials. And in addition, any object with mass can never match its speed, therefore, when light can no longer escape a black hole's gravity well, nothing else can either.

    13. Re:Why... by samkass · · Score: 2, Insightful

      Mathematics doesn't really exist, though. There is no such thing as "proof" in science, just hypotheses, theories, observations, conclusions, and consensuses (what's the plural of consensus, anyway?). This observation may well have muddied the consensus that had previously grown around the black hole theory, but I'm sure it hasn't convinced most yet.

      --
      E pluribus unum
    14. Re:Why... by LS · · Score: 5, Funny


      Furthermore "mecos" is Mexican slang for cum. I just wanted everyone to know that, so you can never again think about black holes and MECOs again without thinking about cum.

      --
      There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
    15. Re:Why... by hunterx11 · · Score: 2, Insightful

      You should rephrase the first one as, "EVERYONE knows that people in the past thought the Earth was flat," since it really wasn't a very widely-held belief at all.

      --
      English is easier said than done.
    16. Re:Why... by Abreu · · Score: 2, Funny

      I am sorry, but that answer has been copyrighted and patented by Benjy Mouse and Frankie Mouse. You now must pay 1,000,000,000.00 Altarian Dollars, our accountants shall contact you to offer a convenient installment payment plan.

      --
      No sig for the moment.
    17. Re:Why... by Gattman01 · · Score: 3, Insightful
      My understanding, after reading the article this morning and never hearing of MECO's before, is that only one should exist.

      When the matter gets compressed to the point where one of these should form, one of two things should happen:
      1. The matter should keep getting compressed and very dense such that it has so much gravity it form a singularity ( black hole )
      2. As the matter gets compressed to a point where physics begin to be have weirdly, particles pop in and out of existence, energy is created and destroyed, a large magnetic field forms


      The idea is that these are mutually exclusive.
      The compressed matter will either form a MECO or Black hole. Only one thing should happen.

      I don't study these sort of things, but that is my layman's understanding.
    18. Re:Why... by agibbs · · Score: 5, Informative

      "consensus" is a fourth declension noun (in Latin) so it's plural, properly, is "consensus." No change. Who knows what it is in English though.

    19. Re:Why... by Mayhem178 · · Score: 2, Interesting

      Why in the world is this modded flamebait? All it says is "God" for God's sake. That's a valid theory, albeit an unpopular one among the Slashdot crowd. Just because you don't agree with it doesn't make it flamebait.

      --

      "You will pay for your lack of vision..." - Emperor Palpatine to Ray Charles

    20. Re:Why... by radtea · · Score: 4, Insightful

      All good and fine. But if we have decades of good work with black holes and we've appeared to find quite a few of them, then why would we be throwing them away with just one possible MECO sighting?

      Because the two are mutually exclusive.

      Black Holes are (or have, depending on how pedantic you want to be) singularities--that is their defining characteristic. No one has ever "seen" a singularity. What we see is indirect evidence for objects that are compact and too massive to be neutron stars. The theoretical upper limits on neutron star masses is quite strong, so we do not believe they are neutron stars.

      When a fairly massive star collapses, it stops when the density gets high enough that repulsive core of the strong force dominates gravity. When a really massive object collapses, the strong force is not strong enough, and the collapse goes on unimpeded, which creates a defect in our coordinate system known as an event horizon.

      The thing is, if there is something that could interfere with the collapse, then the collapse would not occur. Apparently MECO theory includs something that will do this. I have no idea if it is right or not, but if it is it provides a generic mechanism that will operate in all collapsed objects, so none of them will ever get to the singularity stage.

      Proofs that Black Holes exist have always been a matter of elimination--it isn't a duck or a neutron star, ergo it must be a Black Hole. If there is another viable alternative, the proof goes by the wayside until more information is discovered.

      --
      Blasphemy is a human right. Blasphemophobia kills.
    21. Re:Why... by i+kan+reed · · Score: 2, Informative

      IANAP(physicist) but my understanding of black holes is that the angular momentum is what causes ejections. A non-spinning black hole would have a perfect event horizon and nothing could ever leave even as elementry energy carrying particles. The "poles" are just like earth's rotational poles, they form the endpoints(when extended to the even horizon) of the axis of rotation. Why this affects gravitation (or the escaping particles) I don't know, but it probably has something to do with that satelite they sent up that measured the effect of the earth's rotation on it's gravity

    22. Re:Why... by znode · · Score: 2, Funny

      There's actually a theory that renders your theory irrelevant. Let's say for a moment that CUBIC NATURE IS OMNIFIC, INFINITE, INEFFABLE, AND ON DUTY. Singularity is the death math
      of religious/academic Godism.

      Seriously, have you read your crackpot? "Why Software Is Bad"? "Simple Proof that Nothing Can Move in Spacetime"? At least Time Cube is funny.

    23. Re:Why... by wildsurf · · Score: 4, Funny

      Weeeeeee, I'm next!

      So you're saying Internet Explorer is really a MECO?

      --
      Weeks of coding saves hours of planning.
    24. Re:Why... by kirkjobsluder · · Score: 2, Interesting

      However...

      Observations of the universe are more uncertain. Perhaps the researcher made a mistake (not saying they did) or engaged in fraud (not saying they did). The identification of this particular object as a MECO is one interpretation of telescopic evidence. Perhaps there are mechanisms compatible with black holes that explain the observed phenomena? Perhaps not. This is why theories don't live or die on single observations.

    25. Re:Why... by cagle_.25 · · Score: 2

      Actually, I'm not even sure it's an assertion ... where's the verb?

      --
      Human being (n.): A genetically human, genetically distinct, functioning organism.
    26. Re:Why... by drinkypoo · · Score: 4, Funny
      informative? really, mods? are you absolutely and really sure that was informative instead of funny?

      Funny mods do not raise karma. If you are modded funny, then modded troll, or offtopic, then you will lose karma. I am very happy to see that more and more moderators are modding funny comments with other, karma-giving mods, not only because I think people deserve karma for making the world a funnier place, but especially because it helps to solve the problem that you can lose karma because people disagree as to whether you are funny or not. If the balance is 0, then the balance of karma should also be 0, but this is not how slashdot operates.

      I urge everyone to use a karma-giving moderation instead of the funny moderation in all circumstances.

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      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    27. Re:Why... by rufty_tufty · · Score: 3, Insightful

      Hang on,
      The maths our current model is based upon says they're mutually exclusive.

      If we have observed an object that isn't a duck or a neutron star, or a meco, then it might still be a black hole and our current model may be incomplete.

      i.e. if we prove observationally that mecos and black holes do exist, then that means our models/assumptions are wrong. or that what were observing is neither a meco nor a black hole but something else again...

      --
      "The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
    28. Re:Why... by dmartin · · Score: 5, Informative

      The definition of a black hole does NOT require a singularity. What the strict defintion requires (as in Hawking and Ellis, or Wald's "General relativity) is that the black hole region in an asymptotically simple spacetime is the region that is causally disconnected from future null infinity.

      In English: once you go into one, you can never get back out if you believe that nothing can travel faster than light. If you CAN get out, the thing you started with was not a black hole!

      Notice that for the concept of black hole to make sense, you do not need general relativity. You do need to believe that there is an ultimate speed limit, and then the black hole of any theory is the region you cannot escape from.

      It is then a THEOREM of (classical) general relativity that such a region contains a singularity. If GR is corrected by some version of quantum gravity where there are no singularities, then this theory can still have black holes (regions of no escape).

      Now this is a stricter sense in which black holes are talked about currently. The article mentions Hawking and Thorne's disagreement: is information carried off by Hawking radiaiton? The answer is no: if the information goes in then it cannot come out by (the strict) definition of what a black hole is. Technically, the argument about the information loss problem is whether or not black holes (as originally defined) exist at all!

      However, this is an arguement purely at the level of sematics. There is very little observational difference between a real black hole [one that locks information up forever] and an information returning black hole [one that locks up and processes particles for a long period of time, but the end result of this process is re-emission as Hawking radiaiton]. Because the definition given above is one made for convience, most researchers in the field take a somewhat more pragmatic definition of a black hole.

      The theory of MECOs seems to still be built on General Relativity. It claims that radiation increases to stop complete collapse. This does not preclude the existence of black holes! It just means that they are unlikely to form as the end result of astrophysical processes. However, there are situations where you can make black holes at very low temperatures, or ones that you can do in flat space (although these tend to be somewhat artificial).

          The moral is
              * MECOs are built on GR. If MECOs exist, then black holes are still solutions to GR
              * The MECO advocates claim that this is a universal process for very hot and dense gas. We should not expect that black holes are a typical end of stellar product.
              * MECOs may exist, but the process may not be universal (i.e. it may require particular thresholds of energy/pressure). This would allow a mix of black holes and MECOs.
              * There may be no MECOs at all.

          Personally I am dubious that MECOs exist at all. Pressure *can* support a star against collapse, but only to a certain extent in GR. After a while, the pressure required also acts as a stronger source of gravity and ends in a runaway reaction causing collapse. See this paper of mine for more details: http://arxiv.org/abs/gr-qc/0306038

  3. Unless... by taff^2 · · Score: 4, Insightful

    ...both MECOs and Black Holes can exist, and it transpires that we actually know a LOT less than we thought we did

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    Karma: Bad. (As in Good?)
    1. Re:Unless... by RsG · · Score: 2, Insightful

      Probably not. From what I gathered, the two objects are both presumed, by different theories, to occur when matter is compressed past a certain point. Presumably, collapse of matter has to yield one result or the other, depending on what theory is correct. I don't see any way we could get both in the same universe.

      And as these are both theoretical objects, there's no reason to assume they both exist.

      --
      Erotic is when you use a feather. Exotic is when you use the whole chicken.
    2. Re:Unless... by cakefool · · Score: 2, Insightful

      you crash a car into a building, there is only one possible outcome right? - you plough through without taking damage.

      alternatively, mayby there are different cars, and different buildings.

      You can have multiple outcomes of such a large event, depending on different starting conditions (weight of car and building material for the above analogy)

      As we don't have a grand unified theory yet, we'll keep adjusting our disparate theories as we see new things.

      I love science me, except the bits that hurt...

    3. Re:Unless... by xouumalperxe · · Score: 2, Informative

      FTFA: Black holes is collapsed matter, MECOs stand on the idea that matter CAN'T fully collapse like that and stays in a permanent state of collapsing (but is never actually done collapsing).

    4. Re:Unless... by Daniel+Dvorkin · · Score: 4, Insightful

      They still can not prove that our solar system is not in a bottle on an alien's desk sitting in a diaroama surrrounded by a construction paper universe waiting to go to school to be judged for a science fair project.

      Blah blah blah. By that standard, no scientist in any field can "prove" anything -- you can't prove that it is not the case that the Universe was created five minutes ago by a deity that's having fun with his creations making them think that it's anywhere between six thousand and several billion years old; you can't prove that it is not the case that our eyes are completely deceiving us and the air is actually filled with floating jellyfish that want to eat our brains; you can't prove that it is not the case that "bacteria" and "viruses" are actually a clever Freemason conspiracy to hide from the rest of the world the truth that disease is caused by an imbalance of bodily humors ... etc. So keep enjoying your fantasies. Meanwhile, those of us who rely on data collected by observations made to the best of our abilities, and rigorous theories representing the state of current knowledge, will go on doing our best to understand the world around us.

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  4. Slashdot experts by mtenhagen · · Score: 4, Insightful

    From the article:
    "But Chris Reynolds of the University of Maryland, in Baltimore, US, says the evidence for a MECO inside this quasar is not convincing."

    Apparently the experts are not conviced about this "interesting" observation but at slashdot the expert will come to a final conclusion. How many slashdot posters actualy are qualified to talk about these subjects?

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    1. Re:Slashdot experts by linvir · · Score: 5, Funny
      Having a strong opinion on something doesn't mean I have to actually know anything about it ;)
      The universe isn't a big truck, it's a series of tubes!
    2. Re:Slashdot experts by vikingpower · · Score: 4, Insightful

      As Zen master Eihei Dôgen Daiôshô ( 1200 - 1253 AD ) already put it:

      "Mere lack of doubt does not imply understanding"

      ( "Uji", paragraph #2, in: Shôbogenzô )

      --
      Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
    3. Re: Slashdot experts by Black+Parrot · · Score: 5, Interesting

      > From the article: "But Chris Reynolds of the University of Maryland, in Baltimore, US, says the evidence for a MECO inside this quasar is not convincing."

      > Apparently the experts are not conviced about this "interesting" observation but at slashdot the expert will come to a final conclusion. How many slashdot posters actualy are qualified to talk about these subjects?

      The named researchers aren't neutral observers in some grand BH vs. MECO debate; they're the proponents of the MECO idea. See for example the bibliography at the bottom of this article. (And while you're at it, notice the author's persecution complex, his attempt to dismiss scientific dating methods at the very end, and, of course, the curious URL.)

      Doens't mean they're wrong, but it's useful to keep in mind that they're partisans in a debate, offering an interpretation of some observations that they think supports their side of the debate. They haven't convinced Reynolds, and the persecution complex displayed in the linked article suggests that they haven't had much luck convincing other people about MECOs in the past.

      --
      Sheesh, evil *and* a jerk. -- Jade
    4. Re:Slashdot experts by dhalgren · · Score: 3, Insightful

      No. You're welcome to talk about whatever you want to, not necessarily qualified to.

      Unless, of course, what you talk about counts as hate speech. Then you may speak of it, but only if you accept that you could be prosecuted legally--you do not, in Canada, have the right to say whatever you want, whenever you want.

      Speaking only about Canadian rights here, the rest of you understand. :)

    5. Re:Slashdot experts by mgblst · · Score: 4, Funny

      The universe isn't a big truck, it's a series of tubes!
       
      Ah, another string theorist!

    6. Re:Slashdot experts by Daniel+Dvorkin · · Score: 4, Insightful

      the Germans are so sorry for having been Nazis, and so eager to show the world how tolerant they have become, that now if anyone in their country professes Nazi-like beliefs, they are sent right to the gas chambers.

      Please give the name, and date of execution, of the last person executed by gas chamber (or any other means) in the Federal Republic of Germany for having "Nazi-like beliefs."

      Today, questioning thoughts about human evolution or global warming are practically considered hate speech.

      No, the "questioning thoughts" are not hateful; they are, however, universally incoherent and contradictory with the data. What's hateful is that they are then picked up by political partisans and used in an attempt to control policy.

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  5. Okay, dumb question then. by mcc · · Score: 4, Interesting

    I know that there are cases where black holes have been indirectly observed by their effects on neighboring objects and light. Could these same data that were used to indirectly observe the black hole be adequately explained by the presence of whatever this other hypothetical object is?

    1. Re:Okay, dumb question then. by Pacifist+Brawler · · Score: 2, Informative

      I think (if I remember this correctly, which I doubt) that the bending of light that we attribute to black holes could just be anything else of massive, well, mass in a rather small space. We know gravity warps light, and we see light being warped by something we can't see, that doesn't actually tell us the dimensions of it. I do know that all spherical masses (which would include most things in space) act as a point mass, so unless the light had to get really close it would be possible.

      --
      IANA*
    2. Re:Okay, dumb question then. by xouumalperxe · · Score: 3, Informative

      No, spherical masses do NOT act as point masses. They can be modelled by them without too much loss of detail if the difference between the radius of the sphere and the distance to the other body is big enough, but ultimately the two are mathematically different (if infinitesimally so). When the very thing you're trying to determine is that difference, you're suggesting we toss out the baby with the bath water.

    3. Re:Okay, dumb question then. by Mark+Maughan · · Score: 3, Informative

      No, you are wrong. In both Newtonian and Einstein Gravity, you can use the point mass solution for a spherically symmetric mass as long as you don't extend your coordinates to beneath the surface. Outside the surface they are identical.

  6. Penthouse by gamer4Life · · Score: 5, Informative

    I was reading it fine until I hit the word "Penthouse", then I forgot everything else and had to look it up:

    http://science.slashdot.org/article.pl?sid=04/07/1 4/2330221

    http://en.wikipedia.org/wiki/Stephen_Hawking#Losin g_an_old_bet

    1. Re:Penthouse by Fred_A · · Score: 5, Funny

      I'm sorry but I checked your URLs and they are all wrong. Here is the correct one : http://www.penthouse.com/

      --

      May contain traces of nut.
      Made from the freshest electrons.
  7. Ha! by mac.convert · · Score: 4, Funny

    Finally! Now that movie Contact doesn't have any scientific merit! (Like it did before...)

    --
    "Every time a bell rings, a Dell laptop bursts into flame."
    1. Re:Ha! by harlows_monkeys · · Score: 3, Interesting
      By Carl Sagan no less

      With the interstellar travel system worked out by Kip Thorne. There's a funny story behind that. One of Thorne's pet peeves is science fiction stories that just hand-wave things like faster than light travel. One day, he and Sagan, who were friends, were talking, and Sagan tells Thorne he is writing a science fiction book, and sheepishly admits he is using faster than light travel and hand waved it. When Thorne finishes being outraged, Sagan asks him if he can fix it. Thorne tells him no, it's not possible--and then a bit later thinks of a way to do it, and works out the math. That's what appeared in the book.

      Between the time he worked it out, and the time it appeared in the book, Thorne found another use for it. He put it on the final exam for the class he teaches on gravitation. Just the physics of the worm holes, not anything about how they could maybe be used for travel. He wanted to see if any of the students would see that, or if they would just solve the equations without thinking about or realizing what they mean. He was disappointed that the later is what happened.

      I got this from a very interesting book Thorne was writing for the general public. He kept his drafts in 644 files in a 755 directory on a Unix system in the physics department, so all of us who worked there at the time eagerly read them. Some of that material ended up in his "Black Holes and Time Warps: Einstein's Outrageous Legacy" book, but I don't recall if this Sagan story did.

  8. Vague data + wild supposition = NEWS FLASH! by bloodredsun · · Score: 5, Insightful

    Cosmology isn't my field but the data here is incredibly vague. I'm not sure this deserves more than a raised eyebrow and an "Okay...now come up with something a little less tenuous". Interpretation of data is an art in itself and can be wildly skewed by the observer's own opinions - show mw that this hasn't happened here.

  9. let's side with caution for now by N3wsByt3 · · Score: 4, Insightful

    Ok, when we have, like, numerous observations of black holes (which, granted, have only been 'seen' indirectly, but which follow the predictions quite good and at least in one instance, have observed it directly enough to rule out anything else then a black hole) and just one observation of a MECO - especially when scientist themselves say it's not totally convincing - then logic dictates that it's more likely the black-hole theory is correct.

    Until further obervations is being done and it is being confirmed it's truelly a MECO (or other MECOs are observed), then we really can't get say anything beyond wild speculation (which is what slashdot is very good at ;-).

    Most probably, it will turn out to be not a true MECO, but rather an odd variant of a black hole.

    If it DOES turn out to be a MECO, then, as theory predicts, there can't be any black holes - so then all our past obsrvations must have been wrong or misinterpreted. And if it turns out we have MECO's AND blak holes...well, then something very, very, very wrong must be going on with our current understanding of the universe and all the theories thusfar.

    Which, actually, would be a fantastic thing to science, contrary to what some might believe.

    --
    --- "To pee or not to pee, that is the question." ---
    1. Re:let's side with caution for now by iabervon · · Score: 2, Informative

      A MECO is an odd variant of a black hole. The matter under debate is not whether these things exist, since we have plenty of evidence for them, but what happens to physics in these extreme conditions. The standard black hole theory, in addition to being the first to propose that there can be so much mass in a region that light can't escape, proposes details on what is going on inside this region. MECO theory proposes different details. Of course, they agree for most observed effects (the event horizon, bending light, Hawking radiation, and so forth); the main difference seems to be whether they can have a magnetic field: a standard black hole would have all of the mass at a single point, and therefore doesn't have room for charged particles to spin, so there's no magnetic field; a MECO would have the mass spread over an extremely small area, which is sufficient to have spinning charges and therefore generate a magnetic field. Of course, it's a bit tricky to determine if an object like a black hole has a magnetic field, because that field, if it exists, is practically in the noise compared to the gravitational field.

  10. Singularities by Anonymous Coward · · Score: 5, Interesting

    So if these MECO are for real, then gravitational collapse canot result in a singularity, which is nice, right? Then how about the big bang? Does that need to have been a singularity, or can we continue with this programme of avoiding the nasty things?

  11. The third option by Gerzel · · Score: 5, Insightful

    Lets not forget that there is another alternative to one or the other theory being right, and that this alternative is far more likely, almost certain in fact.

    The option is that neither of these theories are correct or rather neither is entirely correct. Both may still be partially true, and probably both are to a certain extent.

    Newton was right on with his theories, yet they were proven to be incorrect, and they are still the first thing a physics student learns today. I find the idea of "if phenomina A exists then phenomina B, that we have also have some evidence for, cannot exist" because when you get right down to it we don't understand our universe we perceive it.

  12. Question... by Balinares · · Score: 5, Interesting

    Okay... If this was detected in a quasar, and, as I understand it, quasars are insanely far away, with the implication that what we see of them happened insanely long ago... Is it possible that, as I think I once read here on Slashdot, some cosmological constants may really be variables that shift very slowly as the universe ages, and that MECOs were thus possible then, but no longer are?

    Just askin', and my apologies if this is a stoopid question.

    --

    -- B.
    This sig does in fact not have the property it claims not to have.
    1. Re:Question... by kjorn · · Score: 3, Funny

      ARRRG!

      The universe is so anoying, why won't it let us just go out an take a look?

      Bloody speed of light crap.

      monk.e.boy

    2. Re:Question... by insanarchist · · Score: 2, Interesting

      I think I get what you're saying, but iirc we've "Seen" black holes at least as far away (or as long ago) as this MECO, so the theory that they could exist and now can't, while possibly valid by itself, doesn't stick as an explanation for black holes and MECO's seemingly "co-existing" in some impossible way.

      P.S. Slashdot stories this complicated shouldn't be posted until later in the day, I need coffee!

    3. Re:Question... by agurkan · · Score: 5, Informative

      Is it possible that, as I think I once read here on Slashdot, some cosmological constants may really be variables that shift very slowly as the universe ages, and that MECOs were thus possible then, but no longer are
      I am an astrophysicist but not a general relativity (GR) or cosmology person; take the following with a grain of salt. As far as I understand all solutions of GR equations involving singularities require some assumptions, since they need to take quantum effects into account and we do not have a theory of quantum gravity. So, we should be living in a very interesting universe if a few parameters about quantum gravity had such values and changed in such a way that MECOs were possible in the past and black holes are possible now. It is certainly possible, but if this happened I would suspect that there is a deeper reason for this.

      --
      ato
  13. Quasars don't exist anymore by aadvancedGIR · · Score: 2, Interesting

    The youngest observed quasar are billions of years old, so why can't an universal constant have changed since the beginning of the universe up to the point it would have changed the quasars and MECOs into galaxies and black holes?

    1. Re:Quasars don't exist anymore by whathappenedtomonday · · Score: 2, Interesting
      sounds unlikely though.

      Does it? There is some debate going on about how constant the Constants of the Universe really were in the past, so the GP might actually be on to something...

      --
      I hope I didn't brain my damage.
    2. Re:Quasars don't exist anymore by bytesex · · Score: 2, Interesting

      But if the constants of the universe aren't constant in place or in time, then those quasars may not even be as far away or as old as we think them to be (the light may have sped up to ludicrous speed underway, you know) - and then maybe those crazy religious people are right after all; the universe is just a lightshow put up for our entertainment and the universe is only fourthousand years old or whatever age it's going to be next tuesday !

      --
      Religion is what happens when nature strikes and groupthink goes wrong.
  14. You must be new here... by Anonymous Coward · · Score: 4, Funny

    Come on! This is slashdot! No-one needs to actually know anything about a subject to comment on it - we don't even read the fucking articles!

  15. Neo-con physics by SomPost · · Score: 5, Funny

    Maybe we should invade its surface, kill its plasma and convert it to black holeness.

    1. Re:Neo-con physics by jafac · · Score: 3, Funny

      That - of course, is not the true neo-con philosophy.

      The true neo-con philosophy is to:

      1. Invest in MECO futures.

      2. Invade it's surface with just enough troops to create chaos, but not enough to actually accomplish any other real objective.

      3. Come up with the "kill its plasma and convert it to black holeness" understory to keep the conservative yokel voting base exited, so you don't get kicked out of office halfway through. (because the neo-con philosophy is based on Straussian doctrine that "religion is the opiate of the masses - and we need to keep pumping it to control them - for their own good).

      4. Wait for the escalating violence and chaos cause MECO futures traders to speculate the price up 400%.

      5. Profit.
      (wait - was that for their own good or ours? Oh well, chalk it up to "enlightened self-interest")

      --

      These are my friends, See how they glisten. See this one shine, how he smiles in the light.
  16. Could someone with some knowledge explain... by Colonel+Angus · · Score: 2, Interesting

    If a MECO spits everything that it sucks in back out again at light speed... then, wouldn't it do the same thing with light itself? Making them visible and directly observable rather than having to indirectly detect them through their interactions with objects around them?

  17. Wrong thread? by 140Mandak262Jamuna · · Score: 2, Funny

    Eternally collapsing.... Never reaches the final state .... I think they are talking about Microsoft Vista. Please retag the thread as MS with that cool cyborg morph of BGates as the icon.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  18. the bet by Seto89 · · Score: 2, Informative

    Accorfing to Stephen Hawking's Universe series Hawking was the one who bet that Black Holes don't exist (as some kind of insurance, so if they don't exist and all his work is useless, then he at least would get a subscription to a nice magazine) and he then gave the other guy (forgot his name) 1 year subscription to Penthouse, so if this is true and black holes don't exist, he would get the Penthouses back + a 4 year subscription to Private Eye. Why can't they co-exist though? Can't there be a reasionable scientific explanation that would allow both of these to live???

    --
    There are two kinds of people - those who are radioactive and those who have already decayed..
  19. Occam's Razor by astrogirl2900 · · Score: 5, Informative

    Preface: I have a Ph.D. in Astrophysics and my ressearch has to do with computer models of black holes.

    This is yet another one of these things where an observational astronomer who just doesn't like black holes comes up with some incredibly complex theory to explain their oberservations so they don't need a black hole to explain them. There is an incredible resistance towards black holes in some parts of the astronomical community. Saying that "A black hole can't do this" when our models of accretion discs arount black holes are still at the state they are in i.e. fixed background metric, many models are only HD not MHD (no magnetic fields in the disc) is just not backed up by the facts.

    This reminds me of the whole "we don't need black holes to explain jets" discussion a couple of years back.

    Besides I do not se how the existence of Mecos would prevent the existence of black holes in general. We are still using the same Einstein Equations, right?

    I think the operand word in the article is "controversial". Occam's Razor is a good rule of thumb.

    1. Re:Occam's Razor by astrogirl2900 · · Score: 5, Informative

      Jets from AGN (Active Galactic Nuclei) are thought to be generated by a rotating black hole winding the magnetic field from the accretion disc up in a tight beam. The beam contains accelerating particles at incredibly high speeds.

    2. Re:Occam's Razor by Bern_2003 · · Score: 5, Insightful

      I wouldn't worry to much about this. As the article clearly states all observations were made with an optical telecope. They saw this mysterious "hole" in the center and made the assumption that there was nothing there. It could be full of hot gas but you wouldn't be able to detect it with a visible light telescope becasue the gas itself would not not emit any light. This is kind of like the monty python sketch where it was agreeded that a duck is made out of wood becasue it floats.

    3. Re:Occam's Razor by astrogirl2900 · · Score: 5, Interesting

      I agree with the fact that you should always keep your mind open. It is just that General Relativity has been tested and tested (we we keep on doing it) and the results always back it up. Will the next result also fit with the? It's likely but not 100% sure.

      If you told me you had a horse in your back yard, I'd look at it and if it looked like a horse I'd believe what you said. If you told me you had a unicorn in your back yard, I'd take a good hard look at it, make sure the horn is attached, take DNA samples and analyze them ... perform all kinds of tests before I believe you. General Relativity is like a unicorn that has stood up to all the tests we could possibly throw at it and then some. This article is basically saying it has a Pegasus and expects us to treat it like they were saying they have a horse. Okay, I'll stop the analogies :-)

      Another issue entirely is the fact that this whole MECO theory is based on the assumption that plasma might behave oddly/unexpectedly under extreme conditions. I have no problem with that idea. But to leap from that to saying that if plasma behaves in an unexpected way in extreme conditions it means that no black holes can exist... that's a stretch.

  20. Wilting, politically correct, lefty-libby physics by ScentCone · · Score: 5, Funny

    Maybe we should invade its surface, kill its plasma and convert it to black holeness.

    Maybe we should just ask it how it feels to think that it's a MECO, and no matter what it says, start up a government program designed to empower its sense of communinity with the black holes. Then, if Kofi Annan decides that the arrangement is suitably free of human suffering that no one in Europe will notice, we can assign a series of attractive Hollywood types to set the tone for more research by doing some short publicity pieces that will help all MECOs feel better about ejecting mass, even if it hurts other stellar objects (which isn't their fault, since the laws of physics are really just The Establishment and Hawking is just The Man, running Big Physics from his position of authority-backed, but morally weak institutional power).

    --
    Don't disappoint your bird dog. Go to the range.
  21. Vote for Meco by Fear+the+Clam · · Score: 3, Funny

    MECOs are rivals to black hole theory and involve plasmas that never reach the state of being a singularity.

    No singularity, but Meco did come out with that that singularly awesome Star Wars and Other Galactic Funk album back in '77. Take that, black holes!

  22. The bet is the other way around by morie · · Score: 2, Insightful

    Hawkins conceded the bet that black holes did NOT exist and gave the Penthouse subscription, so this could force him to reclaim that and claim his prize.

    Hawkins called the bet an insurance policy so he would not be empty handed if black holes did not exist after all...

    --
    Sig (appended to the end of comments I post, 54 chars)
  23. Paper explaining MECO's by Anonymous Coward · · Score: 3, Informative

    Here is a direct link to a (free) pdf paper describing the idea of a MECO in all the gory details:
    http://www.citebase.org/fulltext?format=applicatio n%2Fpdf&identifier=oai%3AarXiv.org%3Aastro-ph%2F06 02453

    As a physicist (though not a cosmologist) it looks not at all convincing.

    1. Re:Paper explaining MECO's by astrogirl2900 · · Score: 5, Informative

      Just skimmed it. This theory definitely does not exclude the existence of black holes. This is just another solution to the Einstein equations, involving matter.

      If the contraints they impose on the stress-energy tensor (i.e. the the assumptions they make about the behavior of matter) are always enforced in the universe, I think they'd have a problem with creating neutron stars.

  24. Schrödinger by camperdave · · Score: 5, Funny

    Schrödinger would have loved anything he could stick a cat into. He hated cats. You should have heard him go on about the microwave oven, and the wood chipper.

    --
    When our name is on the back of your car, we're behind you all the way!
  25. One problem... by JDevers · · Score: 2, Insightful

    I'll point out one problem with this that no one else has already, it is in New Scientist. That alone makes it probable pseudoscience. These guys have made a career out of taking one valid data point and building the rest of the line as they see fit. If this is believable, we will see mention in journals in the near future.

  26. Re:Dangerous by Nimey · · Score: 2, Insightful

    I believe the tidal effects would reduce a planet into a debris ring.

    --
    Hail Eris, full of mischief...

    E pluribus sanguinem
  27. speed of light by spikesahead · · Score: 2, Interesting

    I have thought for a long time that singularities were impossible due to conservation of angular momentum. Velocity is all relative, so if you have a spinning basketball and squish it down to half it's original circumference, the relative velocity of two opposing points on it's equator will double. Divide the circumference again and the relative velocity will double again. There is a lot of dividing that can be done between any rational number and zero (the theoretical diameter of a singularity), and if you have any spin in the original matter that relative velocity is going to hit the speed of light long before you hit zero.

    1. Re:speed of light by Mark+Maughan · · Score: 3, Informative
      First of all, no.

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

      I have thought for a long time that singularities were impossible due to conservation of angular momentum. Velocity is all relative, so if you have a spinning basketball and squish it down to half it's original circumference, the relative velocity of two opposing points on it's equator will double. Divide the circumference again and the relative velocity will double again. There is a lot of dividing that can be done between any rational number and zero (the theoretical diameter of a singularity), and if you have any spin in the original matter that relative velocity is going to hit the speed of light long before you hit zero.

      Your mistake is that you are using a Newtonian definition of angular momentum, L = m r × v.
      L = r × p, where p is the relativistic momentum. This p is not m v, but gamma m v and can become arbitrarily large.
  28. space by deuterium · · Score: 4, Interesting

    So given that there is no space, what explains the experiential artifact of space? Our known physical laws all operate in direct relationship to space. If everything follows the same rules and exists in a dimensionless void, what determines the apparent distortion in the way these particles interact? There is *something* different in the way the Earth interacts with the moon versus an asteroid in some other galaxy. Space has proven a useful concept in understanding the universe for some reason, and must be explained by some qualitatively similar property or force in a spaceless framework. For example, if I were to write a program that simulated the gravitational interactions of several bodies, the data would indeed exist in an irrelevant physical space, but I would need to store the values for each object's position and velocity. Does the universe have some type of data register for each particle? How do I conceptualize this?

  29. Re:Particles popping in and out of existence??? by Theaetetus · · Score: 4, Informative
    A. the law of thermodynamics is broken? since new particles enter the universe, the amount of energy in the system is not constant.
    Not broken... Thanks to work by Feynman, Heisenburg, and Hawking (among others), we know that empty space isn't really empty. The *vastly* simplified version is that the lowest energy state of empty space isn't at 0... it's slightly above. And if there's energy there, then there are particles, since they're really one and the same... So, if you were to look really closely at empty space, you'd find a sea of particle-antiparticle pairs popping spontaneously into existance (both have to form, to keep conservation laws intact), then colliding back into each other and causing mutual annihilation. Net gain is 0, and if you were to take an average over time or a decent sized area, you'd get 0 also, so there's no problem with thermodynamics.

    Now, the really funky part is Hawking Radiation... You take a black hole with its event horizon, and at the edge, you have a particle-antiparticle pair form... They fly apart, and one of them crosses the line, getting sucked into the black hole, while the other escapes - and now you've actually gained a particle "radiating" away from the black hole. Because of a whole bunch of complicated stuff, this means that the black hole itself eventually evaporates (bigger it is, the longer it takes, though).

    Oh, and this has been confirmed, since it's the driving force behind the Casimir Effect... Put two parallel plates close together, and the spontaneous particles between them can only form in wavelengths equal to multiples of the distance they're apart. But, outside the plates, any wavelength can form. So, you end up with more pressure outside the plates than between them, and they get pushed together. What makes it really stand out is, unlike gravity and magnetism with their inverse-square laws, the Casimir Effect has an inverse-fourth relationship. Halve the distance between the plates, and the force is 16 times stronger.

  30. Flawed summary by Hao+Wu · · Score: 2, Funny
    MECOs may exist inside of a Black Hole, since we cannot know what exists beyond the event horizon.

    --
    I suggest you read Slashdot
  31. The truth is somewhere in the middle by MarkusQ · · Score: 5, Insightful

    The problem that the grandparent pointed out is very real. While we need to assume that "the state of current knowledge" is sound and trustworthy to do any engineering it is fatal to make that assumption in science.

    I had a friend who made a minor discovery while in undergrad, simply because he didn't fudge his data in a lab assignment. He got graded down for it, and decided to redo the experiment. When he got the same results, he started asking around and found out that quite a few of his classmates had also gotten the results he had, but written it off to "experimental error" since it didn't match the predicted outcome. He took this back to the professor, and challenged him to actually do the assignment himself. They wound up publishing a joint paper on it, but to me the most interesting realization was that, for all the years that assignment had been given, nobody else had caught the error in the accepted theory.

    By all means, if you have to bet on the outcome of any particular situation, go with the current state of knowledge. But if you're asked if our current knowledge is correct in its entirety, bet heavily that it is not. And if observation doesn't match the theory, don't lock yourself into the assumption that the data must be wrong because the theory couldn't possible be.

    --MarkusQ

    1. Re:The truth is somewhere in the middle by Starker_Kull · · Score: 2, Insightful
      The problem that the grandparent pointed out is very real. While we need to assume that "the state of current knowledge" is sound and trustworthy to do any engineering it is fatal to make that assumption in science.

      I had a friend who made a minor discovery while in undergrad, simply because he didn't fudge his data in a lab assignment. He got graded down for it, and decided to redo the experiment. When he got the same results, he started asking around and found out that quite a few of his classmates had also gotten the results he had, but written it off to "experimental error" since it didn't match the predicted outcome. He took this back to the professor, and challenged him to actually do the assignment himself. They wound up publishing a joint paper on it, but to me the most interesting realization was that, for all the years that assignment had been given, nobody else had caught the error in the accepted theory.

      By all means, if you have to bet on the outcome of any particular situation, go with the current state of knowledge. But if you're asked if our current knowledge is correct in its entirety, bet heavily that it is not. And if observation doesn't match the theory, don't lock yourself into the assumption that the data must be wrong because the theory couldn't possible be.

      I think that your usage of the phrase, 'correct in its entirety', though, guarantees the outcome of the argument you are looking for. Of course it's impossible to be 'correct in its entirety' - experimental error, limitations in resolution, and even quantum randomness means that you can not make a perfectly true statement. But just because that is the case does NOT mean knowledge is not advancing and approaching the Truth.

      For example (and I freely admit I lift this example from Issac Asimov), the flat earth theory. We poo-poo it, laugh at it, wonder about the silly primitive people who beilived it.... but it is not a bad theory. Put it this way. The flat earth theory posits that the earth has a curvature of 0 inches per mile lateral. The reality is that the earth curves 8 inches per mile lateral. An error of 8 inches per mile in your theory is not too bad, really, and until a large number of humans were regularly travelling far enough where those 8 inches per mile began to add up and make the maps and timekeeping go funny, it would have gone unnoticed.

      Okay, now you figured out the earth is a sphere. Great! Except here comes Newton, with his F=ma and F=Gm1m2/r^2 stuff... and he predicts that the earth is NOT sperical... it's really an oblate spheroid, due to it's rotation, and so the curvature is not 8 inches per mile ALWAYS (as it would be on a true sphere), but varies from 7.998 to 8.002 inches per mile depending whether you are going around the equator or the poles when measuring.... Does this make the spherical earth theory silly, outmoded, wrong? Of course not. It merely points out that it can be REFINED.

      So, I guess that's what I'm trying to get at. The state of current knowledge has soundness and trustworthiness in science, as well as enigneering. After all, it has to fit with all the current observations or it would not be considered an adequate, sound, trustworthy theory of nature! You can always say, "well, you haven't done every possible experiment" - this is trivially true - and what allows science to be USEFUL is that it makes predictions of what will happen BEYOND just regurgiating the results of experiments - but of course, since these predicitions have not, a priori, been tested, we really don't know what will happen until we try, as your friend discovered! The price of making science useful is eternal uncertainty as to what happens when you "stretch" it a bit. I suspect I am agreeing with you more than disagreeing, but I felt the point was important to make.

  32. An amateur question involving singularities . . . by mmell · · Score: 2, Insightful
    I was once taught that the more powerful a gravity field, the slower time progresses within that field - a consequence of Einstein's General Theory of Relativity. If that is true, then during the collapse of a star towards becoming a singularity, we would expect the passage of time to be slowed more and more severely as the mass collapses and produces a denser and denser gravity well. Wouldn't this result in a real-universe equivalent of Zeno's paradox - i.e., wouldn't the collapsing mass always be moving closer to becoming a black hole but never arriving at that point due to the increasing time dilation?

    I've been wondering about that for some number of years now - but the fact that cosmologists have generally accepted the existence of singularities as all but proven fact and have even had many observations which supported this belief has always prevented me from thinking too hard about it (after all, why pit my amateur understanding of cosmology and relativity against that of experts?).

    If this assertion proves to be tenable, what effect will it have on collateral theories in cosmology (for example, estimates on the total mass of the Universe, which in turn affects our understanding of whether or not space is curved and if so, positively or negatively)? Much of our current understanding of the cosmos is based directly on the correctness of the Theory of Relativity, but this finding (if confirmed) would appear to falsify at least some of relativity's conclusions. Does this tenative finding square with string theory? How much of Einstein's Theory of General Relativity will need to be updated to accomodate these findings?

    Then again, the New Scientist isn't exactly the most unimpeachable scientific news source. Perhaps I won't trash Al's most famous (and best supported) theory just yet.

  33. What are you talking about? by sean.peters · · Score: 2, Interesting
    I have thought for a long time that singularities were impossible due to conservation of angular momentum. Velocity is all relative, so if you have a spinning basketball and squish it down to half it's original circumference, the relative velocity of two opposing points on it's equator will double.

    And its angular momentum will be unchanged. So what's the problem?

    The math is difficult to reproduce on a slashdot posting, but I'll leave it to anyone interested as homework. Suffice it to say that for L = angular momentum, I = moment of inertia, and w = angular velocity, L = I * w. Also, for a uniform sphere, I = 2/5 m r^2, where m = mass of the sphere, and r = radius of the sphere. It's easy to show that if r (before) = 2 * r(after), then w(before) = .25 w(after) (where "before" and "after" mean before and after squashing the basketball). And since the velocity v of a point on the equator of the spinning sphere is v = 2 * pi *r *w, it's also easy to show that every time you halve the diameter of the sphere, the linear velocity of a point on the surface doubles. This means that when angular momentum is unchanged, the limit of the linear velocity of any point on the sphere is finite as the radius goes to zero.

    In case it wasn't obvious, IWAPMIC (I was a physics major in college).

    Sean

  34. Where d'ya get that from? by Wolfger · · Score: 2, Insightful
    the Universe cannot have both MECOs and black holes - it can only have one or the other.
    Nothing in the attached article indicates this is true. It is merely one person's opinion that all supposed black holes are instead MECOs. I have no problem envisioning that two equally-unproven and equally-poorly-understood phenomenon could co-exist in the same universe. This is the scientific equivalent of daytime talk shows... mostly hype, little substance.