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Space Science

The Fate of the First Known Black Hole 67

sciencehabit writes "Cygnus X-1 bears its name because it was the first source of x-rays found in the constellation Cygnus. In 1971, astronomers discovered that the x-rays came from the direction of a bright blue star whirling around a mysterious dark object. They speculated that the x-rays were resulting from material being torn away from the bright star and falling onto the dark object, perhaps a black hole. This year, astronomers established that Cygnus X-1 does indeed harbor a black hole, a dead star whose great gravity lets nothing, not even light, escape. Now that result has inspired a forecast for the system's future: The black hole will swallow even more mass from an unfortunate star circling it, then likely dash away on its own when its companion explodes."
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The Fate of the First Known Black Hole

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  • by Anonymous Coward

    Run for your lives!

  • by idontgno ( 624372 ) on Monday August 08, 2011 @06:55PM (#37027926) Journal

    Never, ever, EVER bet against Rush. [] Ever.

    Steven Hawking, [] I'm looking at you.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      I think Steven Hawking's Speak and Spell should be auto tuned to Geddy Lee's High Falshetto.....

    • by Daetrin ( 576516 )
      Invisible to telescopic eye
      Infinity, the star that would not die

      All who dare to cross her course
      Are swallowed by a fearsome force
      • by Anonymous Coward

        for she has the face of a horse
        and the ass of an otter
        she eats and eats and eats and eats
        she's your fat mother.

    • So... if they were right about that... what does that mean for us in 101 years time?

  • by Anonymous Coward

    I for one welcome our new gravitational overlord.

  • by Anonymous Coward

    The mound is the hole's only natural enemy.

  • by decora ( 1710862 ) on Monday August 08, 2011 @07:02PM (#37027988) Journal

    then does light also attract black holes?

    that is, does light exert a gravitational force on other celestial entities?

    then, the next question, how fast is that force of gravity propagated?

    • Light gravitates, albeit very weakly. Everything gravitates.

      Changes in the gravitational field propagate at the speed of light, according to relativity theory. This has never been measured directly (although the LIGO observatory is being upgraded to hopefully do so). But the 1993 Nobel Prize in physics was awarded for astronomical work that demonstrated this indirectly.

  • Not me (Score:1, Informative)

    by Anonymous Coward

    No, I didn't. Honest... I ran out of gas. I... I had a flat tire. I didn't have enough money for cab fare. My tux didn't come back from the cleaners. An old friend came in from out of town. Someone stole my car. There was an earthquake. A terrible flood. Locusts! IT WASN'T MY FAULT, I SWEAR TO GOD!

  • We at the Society for Extreme Alarmism take this opportunity to warn you of the impending end of the world! In only 12,000 years (Earth years, that is) the matter being sucked away from the blue star will cause it to explode. The same universal force that causes dropped toast to land butter-side-down will determine that this explosion will hurl the black hole on a direct collision course with Earth at about half the speed of light. Elementary mathematics proves that in only 24,000 years, then, a force more

  • >> that result has inspired a forecast for the system's future: The black hole will swallow even more mass from an unfortunate star circling it

    So basically, they're modeling based on our economy?

  • Sagittarius A* (Score:5, Interesting)

    by bcrowell ( 177657 ) on Monday August 08, 2011 @08:59PM (#37028740) Homepage

    You actually don't have to be a complete kook to doubt that solar-mass bodies like Cygnus X-1 are black holes. There are all kinds of other hypothesized objects that they could be, including black stars, gravastars, fuzzballs, quark stars, boson stars, and electroweak stars. These are all long-shots, but they exist in certain reasonably well-motivated physical theories.

    For skeptics, I believe the evidence is stronger that Sagittarius A* is a black hole than that Cygnus X-1 is. Sag A* is the supermassive black hole at the center of our galaxy. Sag A* has been proved by indirect but very strong evidence [] to have an event horizon, which is essentially the defining characteristic of a black hole. (A singularity without an event horizon would be something different; the big bang singularity is an example of that.) It may become possible in the near future [] to do direct imaging of Sag A*'s event horizon, which would be direct proof that it's a black hole. There are fundamental reasons why we will never be able to do anything like that with any other black hole besides Sag A*, using foreseeable technology.

    • by Anonymous Coward
      Vag A* is the supermassive black hole at the center of our galaxy.
  • I thought nothing could escape a black hole, so how can it explode? An explosion requires escaping it. I'm asking this as a non-physicist :)

    • They didn't say the black hole would explode, they said that the companion would.

      Also, to answer the question you asked (even though it's not relevant here), a black hole won't "explode" but unless something's very wrong with our theories, it will dissipate. Black holes emit Hawking radiation, which you can view more or less as pair-production in the vicinity of an event horizon. Two quanta pop out of the vacuum; one falls into the hole, while the other escapes into the universe at large. The energy for tha

      • Black holes emit Hawking radiation,

        Well understood.

        Now, to the extent of my knowledge, the black-body equivalent temperature of Hawking radiation is related in an inverse manner to the radius (or surface area, I suspect the latter for accuracy) of the black hole's event horizon, and the radius (surface area) is proportionally related to the energy content of the black hole.

        So, when a black hole loses a quantum of energy via Hawking radiation, it's surface area/ radius decreases, and so the black-body temp

        • I don't think the wavelength can go below the plank length. Photons have a fixed maximum energy that corresponds to that length. To release more energy more photons would be emitted instead of more energetic ones. If you could get smaller wavelengths (higher energy), presumably your photon would fall below the threshold of the uncertainty principle, and then I have NFI what would happen.

          Also such a super energetic photon would not be a black hole - it exerts gravitational force yes, but a tiny one. Eve
        • Basically, we don't know.

          We don't know what happens when a black hole evaporates. That requires a theory of quantum gravity, which we don't have. Hawking radiation can be worked out in a semiclassical theory of gravity, so we know a black hole will shrink, but when you get down to "the last photon", we can't say what ultimately happens to the black hole.

          Similarly, we don't know what would happen to a photon if you gave it Planck energy. That too requires a quantum theory of gravity. Below the Planck ene

        • They're perfectly good questions - you just didn't get a reply because no-one knows the answers. Those would require a quantum theory of gravity, and we simply don't have one that's developed enough to answer such questions. For all we know, string theory is dead wrong and at a fundamental level all particles are little black holes that can't evaporate further. That seems unlikely, but until we have a working (and useful) theory of quantum gravity it can't be ruled out. (It's also basically useless as a sup

          • Oh goody, I like asking awkward questions, and I came up with this one out of whole cloth.

            Old joke, you've probably heard it before:
            Physicist is converted to "God" in some way shape or form. Physicist specialises in studying turbulence. Someone comments that physicist is likely to ask "God" to explain turbulence to him when he ascends to the Pearly Gates (Bills Cockney cousin?). "Oh, no," replies the newly-converted physicist, "I wouldn't want to embarrass the chap at a first meeting."

Genius is one percent inspiration and ninety-nine percent perspiration. -- Thomas Alva Edison