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Space Science

Black Hole Sans Donut Puzzles Astronomers 119

Posted by timothy from the no-eclair-either dept.
Anonymous Squonk writes: "This time, a telescope made news by not finding something. According to this Honolulu Star-Bulletin article, a black hole was found that did not contain the expected 'donut' of warm matter swirling around it. This discovery (or lack of discovery) may lead scientists to rethink what they know about the core of active galaxies."
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Black Hole Sans Donut Puzzles Astronomers More

Black Hole Sans Donut Puzzles Astronomers

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  • viva la homer (Score:3, Funny)

    by banditski ( 163064 ) on Wednesday October 31, 2001 @04:54AM (#2501729)
    (as homer is sucked into said blackhole)

    mmmm.... intergalactic donut...

    d'oooooooohhhhhhh!!

  • Not necessarily (Score:4, Informative)

    by Apotsy ( 84148 ) on Wednesday October 31, 2001 @04:58AM (#2501737)
    A black hole without the "doughnut" of hot matter is not in conflict with current theory, if it is massive enough. Read Kip Thorne's "Black Holes and Time Warps [amazon.com]" and notice the description near the beginning of a hypothetical massive black hole called "Gargantua". It is so massive that its event horizon is far enough away from the center so that the tidal forces are not enough to produce the large, flattened disk of hot spiraling matter.

    The article doesn't say, but perhaps the reason they are puzzled is because this black hole is thought to be far less massive than Thorne's hypothetical "Gargantua". Nonetheless, the lack of a so-called "doughnut" is not necessarily in conflict with current theory.

    • If its a very big black hole, its a really big Donut and they just need to zoom out a bit.

      Just a theory

    • Re:Not necessarily (Score:2, Interesting)

      by MousePotato ( 124958 )
      good points and thanks for the tip on the book.

      My theory, albeit an unedumacted one, is that this may be a wormhole rather than a classic singularity/core type. The terms may be wrong but I think you get my idea of it being a conduit to another point in warped/folded space versus a "crush everything it can suck in to some insanely massive yet small space" type of black hole. All we need to do is look to see if there is an 'other end' to it.

      This may be one of the coolest discoveries yet :)

    • Re:Not necessarily (Score:3, Insightful)

      by mmontour ( 2208 )
      A black hole without the "doughnut" of hot matter is not in conflict with current theory, if it is massive enough.

      But according to the article, this black hole *does* have the hot accretion disk (as well as a huge jet blasting out of it). The missing "doughnut" is cooler matter (emitting in infrared, not X-rays) that they expected to find around the disk.

      I think (but I'm too lazy to check) that there's a picture in the Kip Thorne book you mentioned showing a few possible theories for what the gas around a black hole could look like, with a variety of electric and magnetic field patterns. So this "no doughnut" observation will probably help to refine those calculations, but I don't see it overturning any fundamental black-hole concepts.

    • This is about torus, not the disk (Score:5, Insightful)

      by Caid Raspa ( 304283 ) on Wednesday October 31, 2001 @06:03AM (#2501823)
      \begin{rant}
      If you see 'theory + astronomy + black hole' this does not automatically mean theory==relativity.
      RTFA
      \end{rant}

      It is so massive that its event horizon is far enough away from the center so that the tidal forces are not enough to produce the large, flattened disk of hot spiraling matter

      The 'flattened disk' you refer to is the accretion disk that is easily seen in M87. For example, the X-ray spectrum would be completely different if there was no disk.

      The 'doughnut' or torus is a cloud of cool matter, that is feeding the disk. It is about just as 'flat' as a real doughnut. Generally the torus of an average active galaxy is far enough from the black hole to make all relativistic effects insignificant. Relativity is very important at the inner edge of the accretion disk, where the disk meets the event horizon. However, this is literally light-years from the torus.

      Now, the astronomers can not see the torus. This means that the matter fed to the black hole is almost finished, and should not be able to power such a bright accretion disk. I believe this is the 'problem'.

      Either the accreted matter comes from some unknown source, and/or some mechanism makes the accretion disk brighter than expected. Thus theoretical problems are more probably related to galaxy evolution and/or accretion disks. These are both rather ill-understood issues when compared to general relativity.

  • Gemini's website (Score:4, Informative)

    by thesolo ( 131008 ) <slap@fighttheriaa.org> on Wednesday October 31, 2001 @04:59AM (#2501739) Homepage
    Is actually here: http://astra.hi.gemini.edu/gallery/science/m87/ [gemini.edu]

  • wheee (Score:3, Insightful)

    by smaughster ( 227985 ) on Wednesday October 31, 2001 @05:00AM (#2501742)
    >>This discovery (or lack of discovery) may lead scientists to rethink what they know about the core of active galaxies."

    ermz, isn't this the essential part of science? Every astrophysic I know is among the first to admit that the current theories are still based on several large assumptions, and can are turned over every once in a while. This makes it one of the most exciting parts of science since there still is lots of new things to find out and do. So next time, replace the word may with should or will. :)

    • Is it my imagination... (Score:4, Interesting)

      by tonyc.com ( 520592 ) on Wednesday October 31, 2001 @05:08AM (#2501758) Homepage
      Or has almost every astrophysics-related story I've seen lately included something like "this discovery will force scientists to rethink everything they know about [insert specialty here]?"

      Is this a requirement for continued research funding? Or is our understanding of astrophysics in general so incomplete that none of our theories form a coherent system that can stand the addition of even one more observation?

      • Re:Is it my imagination... (Score:5, Funny)

        by Jace of Fuse! ( 72042 ) on Wednesday October 31, 2001 @05:15AM (#2501770) Homepage
        It's not your imagination... it's just further proof that everything everybody knows is wrong.

      • Re:Is it my imagination... (Score:4, Insightful)

        by Lowther ( 136426 ) on Wednesday October 31, 2001 @06:42AM (#2501865)
        It isn't your imagination. Astrophysicists don't know - they are making a best guess on the limited information they have available. Just a matter of a few hundred years ago, we were prepared to throw a man in jail because he declared his belief that the Earth circled the Sun, and not vice versa. At that time it was also a matter of debate as to whether the planet was a sphere (or oblate spheroid even), or whether it was flat. And we were living on it at the time !

        Given the fact that our technology will only allow us to venture a miniscule distance from our planet in universe terms, and achieving more will take centuries (if we survive that long), and at best we can observe but a miniscule fraction of it from our planet, and it is supposed to be growing, it follows that we know nothing of the universe, and this will not change in our lifetimes or our children's.

        And yes, massive amounts of funding are tied up in this exploration. We need to explore the universe. But if the astrophysicists said "Well chaps, we have looked into the skies for centuries, spent trillions on manned and unmanned missions, and, to tell the truth, we still know jack s**t", I suspect the funding would dry up. It is better for them to present each new discovery as something which enhances and expands our comprehension, and challenges our hypotheses, rather than admitting that in real terms, we still know nothing about the Universe and how it works.

        • The real issue here is that (see asteroid story above) we take a lot of conjecture, logic, and current semi-proven / popular theories, release them to the press when they aren't yet finished, and call them probable. Just because I base my outcome on six facts which I am 80% certain are right does not in any way make my result probable. What is .8^6 again? Finished calculating? Not so impressive.

        • It could still be considered [alaska.net] a matter of debate as to whether the Earth is round or flat.
      • Of course, teasers such as "New Data Collected by Astrophysicists Confirm Current Theory -- Story at 11" just doesn't cut it.

        There are experiments every day that confirm and/or expand our understanding of the universe. However, the only "newsworthy" items are the ones that are either really new and interesting; or conflict current theories to a large degree. For the other "discoveries", you have to read scientific journals, and not the Honolulu Star. :)
        • Of course, teasers such as "New Data Collected by Astrophysicists Confirm Current Theory -- Story at 11" just doesn't cut it.

          Seven thousand images were takent today, and they chose the one wierd one to put on the front page.

      • Yeah, and the universe is far older than previously thought, scientists announced today. Another classic they wheel out every 6 months or so.
      • Is it my imagination... Or has almost every astrophysics-related story I've seen lately included something like "this discovery will force scientists to rethink everything they know about [insert specialty here]?"

        It's not your imagination:
        "There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened." - Douglas Adams
        Seriously(?), it probably simple bias - stories like "Scientists find what they set out to discover" just aren't newsworthy, unless the subject matter is newsworthy/wacky/humourous e.g. "Why shower curtains billow inwards." [umass.edu]

        Gravity sucks; black holes really suck.

      • Actually, no it hasn't. In fact I believe the one just two stories down the front page about dark matter measurement...

        Secondly - Of course every story you see is about some measurement that upsets our current theories about something. If they simply took yet another measurement that confirmed that yes, we pretty much understand this, it wouldn't be news, would it? Hence, we only hear about the ones that change things, cause it's more interesting to those outside the field.
      • Come on, this is the /. community. Would you rather them collect all this new information and keep it to themselves?

  • I have been bitchslapped, and must use another ip! (Score:1, Interesting)

    by Anonymous Coward
    It's not really surprising that some black holes don't match the canonical form. They draw the matter in the torus from the surrounding galaxy, so any galaxies with unusual properties would affect the black hole. The article doesn't give many details about the M87 galaxy or how much research has been conducted on it, and since noone bothered to look for a black hole torus in it before, there may be other related phenomena yet to be discovered.
    • Here's [seds.org] some info on M87. The main thing about it is that it's freakin huge, greater in diameter than the Milky Way or Andromeda and to top that it's an eliptical galaxy so it's volume is immense compared to spirals of equal diameter. It's fairly bright with an 8.6 magnitude (extremely bright absolute magnitude of -22!) and is well studied due to it's massive number of globular clusters and the prominant jet [seds.org] eminating from it at apparently superluminal speed (thought to be illusionary due to the jet pointing virtualy strait at us). The galaxy is also associated with the strong radio source Virgo A. Needless to say M87 has been a popular object of study among astronomers.

  • No wait... (Score:1, Funny)

    by Anonymous Coward
    I think they're confusing real life with TV again - this happened in StarGate on TV last night.

    All you need to do is cause an energy surge to make the wormhole jump from one gate to another, simple. job done. no more black hole.

  • SANS Donut? (Score:2, Funny)

    by Demerara ( 256642 )
    What has a black hole got to do with System Administration and Network Security?

    Am I missing something here?

    And, surely, it's "doughnut"?

  • It seems that the more we learn about our Universe, the less we can be certain about it. I remember when they first detected the background radiation from the 'big bang'. That was a big upset because it wasn't behaving how astronomers thought it should.

    Then there was the whole 'dark matter' brouhaha. It seems to me that Astronomers need to formulate some new models of space and time, to account for all these anomolies, Perhaps professor Stephen Hawking holds the key to this...

    • Re:Astronomers are always being surprised (Score:4, Interesting)

      by DullTrev ( 533249 ) on Wednesday October 31, 2001 @06:53AM (#2501880) Homepage

      Well, of course astronomers are always being surprised. This field, which essentially relates to observational cosmology, is incredibly young. Observational cosmology only really started with Hubble (the man, not the machine...). When you think of how long other sections of physics have been going, this is a minute amount of time.

      Astronomy itself is ancient, but this has essentially been only data-collection, rather than trying to understand the processes. It has been more like botany than biology - a taxonomic exercise rather than a science. Now we have the instruments so that theories we formulate can be tested observationally, so we are bound to have a lot of theories lost along the way.

      Remember, only a hundred or so years ago, we thought the sun was acually combusting - burning some fuel in a chemical reaction with oxygen! Don't be surprised if theories change - perhaps we are missing some fundamental information. In fact, most cosmologists would say we definitely are - they know that the present system of physics we have breaks down in 'extreme' situations. And a black hole most definitely counts as extreme.

  • We humans have a tendency to think we are smart and know how the physical world works. That is until some scientists come across a phenomenon that counters current theories. The last time I checked, science defines/accepts theories as laws after a sufficiently long test period. Once the theory is put to test and proves to be better than other theories, it is accepted as a physical law. One important fact people tend to forget is everything we based on observable information. There are numerous phenomena we can't observe or are beyond our abilities, therefore all theories are subject to a large margin of error.

    Statements like "this will change how scientists think about x" really shows how self centered our species are. I find the scientists' reaction far more interesting than the fact there is no donut around the blackhole.

    Maybe it's shy :p or it let his neighbor borrow his donut.

  • Is that a new font type for X? where can i get it?
    any links?

  • Blah! (Score:2, Funny)

    by Caine ( 784 )
    When will they stop fooling around with this kind of lame stuff, and give me hyperspace or warpdrives. I'm getting restless!
  • About this blasted hole, I keep reading stuff like:
    "Hubble Space Telescope observations have shown that at its heart is a black hole, containing the mass of about three billion stars compressed into a region approximately the size of our Solar system." (http://www.spaceref.com/news/viewpr.html?pid=6427 )

    size of our solar system? we could use the mean distance of Pluto to the Sun: 5 913 520 000 km ~ 6e9 km
    size of a star? the Sun is supposed to be just below average, let's just use its size. radius : (695 000 km)/2 ~ 3.5e5

    volume of the Sun: 1.8e17 km3
    volume of the solar system: 9e38 km3

    you can fit 5e12 (5000 billion) of our Suns into one of our solar systems.

    The mass of three billion stars 'compressed' into the volume of our solar system would hardly reach black hole densities.

    What did they really mean?
    • volume of our solar system 2e29 km3, sorry.

      But the ratio is correct (I copied the wrong line).

      Here's my calculation (I left out factors that would cancel each other out):

      perl -e "\$system=(6e9)**3;\$sun=(35e4)**3;\$ratio=\$syste m/\$sun;print \"system=\$system, sun=\$sun, ratio=\$ratio\\n\";"

    • Re:The diameter and mass figures seem screwy (Score:1, Informative)

      by Anonymous Coward
      According to the Schwarzschild formula (Rs = 2GM/c^2), the radius of a black hole is about 3 kilometers per solar mass. So a 3 billion solar-mass black hole would have a radius of about 9 billion kilometers. That's about 50% larger than the radius of Pluto's orbit, hence the "approximately" in your quoted statement.

      What you're neglecting is the fact that a black hole is not necessarily more dense than a star. In fact, a sufficiently large black hole is less dense! For instance, a black hole of ~100 million solar masses only has an average density near that of water. It's not just how dense it is, it's how much of it you've got. Take a bucket of water, and it won't form a black hole. Take 100 million solar masses worth of buckets of water all next to each other, and they will

      (I got the last example from this nice page discussing black hole myths [aspsky.org] at the bottom.)

  • this one has an SEP field ;)
  • Maybe they were right with the initial theory and someone simply forgot to take the lense cap off - doh!
  • A black hole without a donut...? I'm not impressed. The other day I saw something much stranger: a donut without a hole.

  • Quality submissions (Score:3, Funny)

    by BigBong ( 309376 ) on Wednesday October 31, 2001 @11:47AM (#2502610)
    I read Slashdot religiously every day and the Science section is the main reason. In general the Science posts to /. are great. This post was not. The article linked in this post is terrible. One sentence paragraphs comprise the entire article! Let's try to raise the bar back to where it was here people.

    And in my experience...

    $journal_name =~ m/(.*) star.*/i;
    $tabloid = $1;


    Please don't give me bad karma just because I prefer quality.
  • If my black hole and a donut are near each other, the donut soon is gone.
  • The biggest clue they had was not only the lack of the donut, but the lack of police cars in the vicinity.

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