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Space Science

Resolving Beachballs in the Crab Nebula 123

Posted by timothy
from the only-the-really-active-beachballs dept.
Stranger4U writes "Researchers at New Mexico Tech and the NRAO have used the Aricebo radio telescope in Puerto Rico and some specilized equipment to more closely examine the pulses from the Crab Nebula pulsar. Some of the signals lasted less than two nanoseconds, meaning the originated from a volume no bigger than beach ball. Stories are here(1) and here(2)."
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Resolving Beachballs in the Crab Nebula

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  • by Anonymous Coward
    I was playing with my beach ball, and all of a sudden it was gone. I should've known that crab on the beach was the one that took it. Now where the hell is his nebula?
  • Sputnik? (Score:3, Funny)

    by Jafafa Hots (580169) on Saturday March 15, 2003 @06:25PM (#5521023) Homepage Journal
    little sputniks?
  • Actually.... (Score:4, Informative)

    by Pharmboy (216950) on Saturday March 15, 2003 @06:29PM (#5521038) Journal
    The article clearly states:

    Although it is premature to discount all other possibilities, Kern told UPI, "for now it looks as though the mechanism we propose is probably correct."

    "The interpretation here looks appealing," he told UPI, "although further predictions and tests will have to be made for it to carry the day."


    It article seems a bit more reserved than the editor posting it. An interesting read tho.
    • It article seems a bit more reserved than the editor posting it. An interesting read tho.

      So, you you're saying that it isn't beachballs in space?
      • Re:Actually.... (Score:2, Insightful)

        by Pharmboy (216950)
        So, you you're saying that it isn't beachballs in space?

        Actually THEY are saying that is SEEMS TO BE beachballs in space. But they need more evidence. And need to test it more. But it looks like beachballs in space. But they can't rule out other stuff yet.

        That is very different than "it IS beachballs in space". Its a matter of degrees of confidence.
      • Obviously they aren't beachballs, they are SpaceBalls [go.com]!
  • by rexguo (555504) on Saturday March 15, 2003 @06:29PM (#5521039) Homepage
    here's a pic of the Crab nebula: http://antwrp.gsfc.nasa.gov/apod/ap991122.html
  • by FFtrDale (521701) on Saturday March 15, 2003 @06:30PM (#5521045)
    In Story (1), Romani says,
    "but if the 'coolness' of seeing ultra-bright beachball-sized plasma clouds thousands of light years away captures some young person's imagination and encourages them in technical pursuits, that's a good day's work."
    How many of us spent years studying difficult topics in technical fields and learned how to do things because of the "coolness" of some things that we saw as children? I'm guessing that there are a lot of us for whom that was a big motivation for sticking with it when things got hard.

    • by Pharmboy (216950)
      How many of us spent years studying difficult topics in technical fields and learned how to do things because of the "coolness" of some things that we saw as children? I'm guessing that there are a lot of us for whom that was a big motivation for sticking with it when things got hard.

      with all due respect, pulsars (and more) are pretty damn cool as they are. I am not sure how them being the size of a beachball raises their 'cool' level. I agree that 'cool' helps, and get people to go forward at times, bu
      • No argument from me. I'm glad that the story put pulsars back in the news this week. UPI gets a lot of readers.

      • Perhaps it's the implication that there's still cool stuff to discover, rather than the idea that all the stuff worth discovering has is already available found. I was born after the moon landing. Although I know that it was more important than the Columbia's first space flight, it was seeing the space shuttle land for the first time that made me really feel that space flight was cool. Well, that and Star Wars.
    • by BWJones (18351) on Saturday March 15, 2003 @07:48PM (#5521303) Homepage Journal
      How many of us spent years studying difficult topics in technical fields and learned how to do things because of the "coolness" of some things that we saw as children? I'm guessing that there are a lot of us for whom that was a big motivation for sticking with it when things got hard.

      Shoot, I found "cool" things as an adult when I decided that human vision was pretty damn facsinating. Integrating computer technology into the study of retinal vision is also compelling allowing us to discover what is going wrong in retinas of disorders that cause blindness. The "coolest" outcome would be finding a prevention for blinding diseases or even figuring out how to "cure" blindness or enhance existing vision.

    • by On Lawn (1073)
      Its a tough call. I was very interested in sports as a child, as well as the outdoors computers and cars. Nowadays sports has kind of dropped off the map. Astronomy, creative writing, physics and mechanical engineering have climbed. I've gone back and read Watership Down, and other books that were assigned to me in High School and now I love them.

      In school, they couldn't get me to touch a bunch of these subjects but for some reason now that I'm an adult I find them much more fascinating. I'm going back and
      • by sjames (1099)

        In school, they couldn't get me to touch a bunch of these subjects but for some reason now that I'm an adult I find them much more fascinating.

        That's just because modern 'education' has a way of taking anything fascinating and dissecting it into a small pile of dessicated lifeless chunks. While a few teachers here and there manage not to do this, it's all on their own, and they have to swim upstream in order to do it.

        It's mostly a question of getting enough of the excellent teachers early enough to av

    • Yeah, but when I watched the picture go from subatomic to universal while listening to Philip Morris' whispery voice describe the science at each power of 10 change in scale, I recall that it was me who said "this is cool", not him.

      And Nova used to rule. Now it's a cross between Popular Science, Rush Limbaugh, and biotech-company commercials.
    • One famous example of this, although not sure if its true, is Albert Einstein, who was apparently fascinated as a child by the 'invisible force' that moved the needle of a compass given to him by his grandfather.

  • by cybrpnk2 (579066) on Saturday March 15, 2003 @06:39PM (#5521083) Homepage
    We ran this story with lots of extra URLs earlier this morning here [scifitoday.com]. Get Sci-Fi Today headlines on your Slashdot page by clicking here [slashdot.org] .
  • I thought... (Score:3, Insightful)

    by Wes Janson (606363) on Saturday March 15, 2003 @06:39PM (#5521084) Journal
    That something so small and so massive would have gone ahead and collapsed into a black hole. Were there multiple beachballs per supernova?
    • Re:I thought... (Score:5, Informative)

      by drudd (43032) on Saturday March 15, 2003 @07:17PM (#5521196)
      Yes, but not in the way you're thinking...

      The beachballs aren't the neutron stars, which are somewhere around 20 km in radius. So they weren't a direct result of supernova collapse.

      The beachballs they are observing are the regions of plasma near the magnetic poles of the neutron star which are causing the large bursts of radio waves.

      Doug
    • by Ardias (544478) on Saturday March 15, 2003 @08:02PM (#5521353) Homepage
      These are not separate beachball sized objects within the Crab Nebula. The pulses come from a beachball sized area on the pulsar within the Crab Nebula.

      The magnetic field of the neutron star is so strong that it sends out radiation. The points of origin for the radiation are at the north and south magnetic poles of the neutron star. Since the neutron star rotates so fast, the radiation looks like a pulse to us. The surface locations that create those beams of radiation are small, only the size of a beach ball. And the radiation is so strong that it ionizes the atoms on the surface or just above the surface, making a little plasma cloud above the neutron star's magnetic poles.

      Light travels across 12 inches in one nanosecond. (Side note: When radio astronomy technicians install optic cables, they have to measure the cables in nanosecond-light-lengths.) Since the subpulses are measured in nanoseconds, that means the beaming region on the pulsar is about that wide. A neutron star is 12 to 20km wide, and astronomers once thought the beaming region was as much as 10% of the surface area. Now, they are surprised to discover it is much smaller.

      So, the question now is: what confines the neutron star's very powerful magnetic field to such a small region?
      • Light travels across 12 inches in one nanosecond.

        Excelent!

        I knew imperial measurements wern't arbertary at all!

        A imperial foot is whole light-nanosenced long, in addition to also being the length of my penis!

        Take that, all you Metric poofs!

        • Light travels across 12 inches in one nanosecond.
          Excelent!
          I knew imperial measurements wern't arbertary at all!

          Except you forget that light travels exactly one meter in (newly invented, by me) one metric second. It sure is a good thing that seconds aren't arbitrary eh? ;-)

        • I hate to burst your bubble (being from the US, feet and inches still seem "normal" to me too), but it's actually the meter that is based on the speed of light. A light nanosecond is really only around 98% of a foot.
          • I hate to burst your bubble (being from the US, feet and inches still seem "normal" to me too), but it's actually the meter that is based on the speed of light. A light nanosecond is really only around 98% of a foot.

            Actually - the Meter is arbatrary now.

            The reason? The definition of a second has changed in the last 75 years.

            A second use to be a slice of an earth day - but unfortunatly earth days are not quite stable.

            So the definition of a seond was changed to a specifc number of atomic vibrations at p
      • Since the subpulses are measured in nanoseconds, that means the beaming region on the pulsar is about that wide.

        Even assuming this very simple geometry and mechanism, it only means that they are 60 cm deep in the direction you are looking at them. Perpendicular to the optical axis, they can be much larger.

  • by DJPenguin (17736) on Saturday March 15, 2003 @06:55PM (#5521133)
    Resolving Beachballs in the Crab Nebula - this has to be the most nonsensical headline I've EVER read!
  • Very interesting that the first link in Google's Sci/Tech headline for this story was to the slashdot post. They referenced other sources too but /. was the main headline link.
  • by nlh (80031) on Saturday March 15, 2003 @07:59PM (#5521346) Homepage
    Did anyone else notice the sheet number of alliterations the author of the first article used? I think someone wishes he weren't a science reporter....

    Astronomers have tracked the long-sought source of brilliant beams that bounce across galaxies from super-dense spinning star...

    ...helps illuminate one of the most exotic environments ever perceived...

    ...a pulsar spews sprays of radio waves...

    ...A supernova marks the farewell flicker...

    ...expelling a great belch that spits the stellar shell into space...


    etc...
    • Did anyone else notice the sheet number of alliterations the author of the first article used?......"expelling a great belch that spits the stellar shell into space..."

      The author probably has a PhD in astrophysics, but the suits pressured him to "spice it up". You know, the same kind of managers who won't declare your app "done" until you add pretty icons.
  • by Tuxinatorium (463682) on Saturday March 15, 2003 @08:00PM (#5521348) Homepage
    Some of the signals lasted less than two nanoseconds, meaning the originated from a volume no bigger than beach ball. That is very presumptuous. There are ways to get around that. It would be possible for larger object to produce pulses much shorter than the time it would take light to travel the distance of its diameter. When a shockwave starts well below the surface of a sphere, and propagates uniformly along a fairly crisp expanding sphere, it could cause the surface to flare up briefly wherever it hits, and the radius of the affected area would expand faster than the speed of light because of the geometry of it. Something like that, only happening in a neutron star, could explain those kinds of pulses without the requirement that they occur in such a small volume.
    • You have to understand they are assuming already that this object is a pulsar, which means the pulses are very likely powered by a rapidly spinning neutron star. The energy is emitted constantly but is tightly beamed, so the rotation of the object causes the pulsing. For an object to pulse that fast and to not be spinning faster than the speed of light, the size must be less than the beachball.
      • Exactly. They shouldn't just assume thaty it's a pulsar and the time between pulses is how long it takes to rotate. There are plenty of other possible explanations, such as rapid changes of the direction of the jet relative to the rotational axis caused by small scale magnetic effects.
        • I think you might have to look to Occam's Razor on this one. Getting a spinning neutron star isn't very "hard". A asymmetric collapse of a white dwarf does just fine. As well there are mounds of experimental evidence to support a spinning neutron stars. Other interpretations are much more "difficult" to produce, and require vast amounts of energy and extremely strict circumstances for them to occur.
    • by Ardias (544478) on Saturday March 15, 2003 @08:35PM (#5521466) Homepage
      A pulsar does not produce pulses. The "pulse" that we see comes from a steady uniform beam of radiation from a rotating neutron star.

      Ever see a lighthouse in action at night? That light is a steady beam from a very strong lamp mounted on a rotating platform. The platform spins at a steady rate. If you are nearby, such as on the ground looking up at the lighthouse, you can see the rotating beam. If you are on a ship, far away at sea, you don't see a rotating beam. Instead the observer on the ship sees a pulse.

      The neutron star inside the Crab Nebula spins at a very steady rate of 33 rotations per seconds. It has 2 hot spots, one at the magnetic north pole, and another at the magnetic south pole. These hot spots produce a steady beam of light, which we see as 33 pulses per second.

      Now, there are shockwaves produced by by seismic shifts within the neutron star. The neutron star has a crust that breaks into pieces and shifts around occasionally. (Think of earthquakes here, but the crust is very thin, and very dense, so the energy released is much greater than what powers an earthquake around here.) These shifts cause "hiccups" in the radiation beam. We can actually measure these hiccups because the "pulse" goes out of phase for a moment.

      But, to finally answer your question, those shockwaves do not cause the "pulses", but merely adjust their timing for a brief moment. Also, a shockwave would be only an occasional event, rather than something that happens 33 times every second like clockwork.

      The subpulses within the pulses are also very well timed, to within 2 nanoseconds. Since light travels about 61 cm in 2 nanoseconds, the hot spots that cause the subpulses are at most 61 cm wide.

      We still have a few unknowns here, such as what confines the hot spot to such a small region. But, what causes the pulse itself is known.
    • by Anonymous Coward
      It wouldn't create a two nanosecond pulse. You would see a ring who would star at the center of the star and would move outward. If you have a star with a radius of .03 seconds(like a neutron star) you would get a pulse of .03 seconds out of it
    • this seems to be the most enlightened thread in here, so I guess this is the best place to ask this:


      Is there any chance that losses 'left' us with nohting but the very brief pulses to look at ?


      If you compare that to any other wave analogy, you could say that a wave has 'tops', and the smaller the slice of the tops the shorter the 'pulse' would seem, but it doesn't say anything about the size of the wave underneath it (but the PERIOD does!).

      • Waves have characteristic "shapes" in both frequency and time domains depending on what created them. A pulse of waves would itself be a wave, and if the output from a pulsar is not a simple sinusoidal wave, it's probably some other form from which a distinct start and end can be determined. There are some forms that come to mind that do not lend themselves to a meaningful determination of start and finish, like exponentials, but those would have infinite energy output anyway, so they're not too likely.
      • its a few nanosecs between pulses, so that is the period. Your comment ignores that.
    • I have to agree that other sources of the pulses should be ruled out, it just seems likely to my lay mind that something that dense, and spinning that rapidly would very likely be very homogenous. This would decrese the probability that the emissions come from that small of a area of the total surface.

      The other thing that seems hockey is these are pulses in the range of 0.5 -1 GHz, what kind of carrier freq are they looking at? I don't think anybody should get to excited untill ther's indendent confirmatio
  • by g4dget (579145) on Saturday March 15, 2003 @10:03PM (#5521736)
    First of all, it is only "nearly imperceptible subpulses" that are 2ns short, so we are not talking about the entire energy output of the pulsar.

    But just as importantly, all that this seems to tell you is that the region from which these subpulses come is less than 2ft thick along the line from here to there, it tells you much less about its area. So, perhaps this is just the signal you see when looking straight at the neutron star and something happens on a surface pacth. The patch could have a much larger diameter than 2ft.

  • you mean to tell me the could see a beach ball at intersolar distances????

    that is fucking insane! Now not only if we descover alien life, we can see what they are eating for breakfast as well
  • In Frank Herbert's "Whipping Star", Beachballs were "houses" for multidimensional superbeings whose three-dimensional projections on our universe were our stars.
  • space balls!!!

    Ow!! What was that for?!!

  • Maybe this is an alien transmission a la the movie Contact. The 30th-of-a-second pulses are only a carrier signal, and the sub-pulses, once analyzed more closely, will reveal a message containing detailed blueprints for a massive transportation/communication device!

"From there to here, from here to there, funny things are everywhere." -- Dr. Seuss

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