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Neutron Star matter?

  1. Jan 5, 2005 #1
    There are no neutron stars within 1000s of light years that we know of but there could be chunks of one much closer. The speculation of a planet X in our solar system has been written about many times and some think the new found planetoid Sedna may be that object.However, a much smaller object like a chunk of neutron star material orbiting our sun may be overlooked and would cause the same effects that doomsdayers talk about. So, new objects are being found weekly and such small objects like neutron star material could be overlooked.How big of a chunk of this material would equal the mass of the Earth?
     
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  3. Jan 5, 2005 #2

    Chronos

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    The nearest known neutron star, AFAIK, is RX J185635-3754 located 200 light years away in the constellation Corona Australis. It was found by the Hubble telescope about 5 years ago. Unlike most neutron stars, it is viewable in the visible light spectrum. You cannot acquire a chunk of a neutron star, or a white dwarf for that matter. It is, and can only remain in a condensed matter state under intense gravitational pressure. If you attempted to mine a chunk and ferry it away, it would basically explode.
     
  4. Jan 5, 2005 #3
    How small of a volume would it have to be before it exploded?
     
  5. Jan 5, 2005 #4

    ohwilleke

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    In other word, once you take it would of a neutron star, it would cease to be neutron star matter with those characteristics, because it ceased to be in the conditions of a neutron star.

    One could imagine creating those conditions in a lab on a small scale, but it would be an immense effort.
     
  6. Jan 5, 2005 #5
    So what would you have to do to compress 10 million tons of matter to the volume of one sugar cube? Also, how small would this volume of matter be before it exploded? It sounds like there has to be a point in which it would explode?
     
  7. Jan 5, 2005 #6

    Nereid

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    In the case of neutron star matter, about the size of the nucleus of uranium ... and even that would probably disintigrate ("explode") within microseconds (or less). As a wild guess, I'd say the only chunks that would have any kind of stability (say, ~>1 second), would comprise ~60 neutrons, or ~4.
    Drop it onto a neutron star :surprised
     
  8. Jan 5, 2005 #7
    So lets say a sphere of this material 1 meter in circumference exists. How long would it last before it explodes if it will at all??
     
  9. Jan 5, 2005 #8

    Labguy

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    It would depend on where you store your sphere. IF the pressure were great enough, it could remain in the initial state. If it were suddenly exposed to the vacuum of space, I think that the time to explosion would have to measured in atoseconds or less (Planck time?)

    But, to have a pressure "great enough", it would have to reside in a larger mass of the same material or even greater density. Therefore, it would be indistinguishable from the surrounding material so you couldn't actually see or "measure" your sphere anymore. A paradox.
     
  10. Jan 5, 2005 #9
    Some people think it would not even explode at all because it is a new undiscovered element!!
     
  11. Jan 5, 2005 #10
    I went to arxiv to investigate if there's some nearer neutron star, and found this paper in which is suggested that RX J185635-3754 is not a neutron star, but a new class of object called P-star
    http://arxiv.org/abs/astro-ph/0401339
     
  12. Jan 5, 2005 #11

    Chronos

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    You would need new physics to explain that. To condense matter to the state that exists in a neutron star, you must overcome the neutron degeneracy pressure [for white dwarfs, it is the electron degeneracy pressure]. The minimum amount of matter required to generate a gravitational field sufficiently powerful to reach the neutron degeneracy pressure is about 1.4 solar masses. The minimum mass required to produce a white dwarf is about .67 solar masses. Anything less than .67 solar mass does not have enough gravity to self collapse into a condensed matter state. In other words, the smallest stable chunk of neutron star matter that can exist is 1.4 solar masses. It may be theoretically possible to compress a smaller quantity of matter to these states using external force, but, it would not be stable. Even if you crushed a small amout of matter down to a black hole, it would rapidly radiate mass away and explode. Degenerate matter also radiates intensely and would go poof as well.
     
    Last edited: Jan 5, 2005
  13. Jan 8, 2005 #12

    Mk

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    Maybe an incorrect assumption? Neutronium, and hyperionium aren't elements because they end in "nium."
     
  14. Jan 8, 2005 #13

    Chronos

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    Proton, neutron, electron numbers would be helpful. Can't invent new 'elements' without an atomic structure. Otherwise, you need new physics.
     
  15. Jan 8, 2005 #14
    I'd like to point out diamonds.

    Once was coal, under heat and pressure it turns into diamonds.

    REMOVE the pressure and it doesn't turn back into coal.

    It may be the same with this, it may not.

    It's about the same as bringing a container of gas up from the bottom of the deepest sea. Once on the surface the container would just explode because the container is still highly pressurized inside, but now outside, is normal sea level pressure.

    So on the one hand, removing part of the neutron star may yield neutron chunks where the dencity remains the same.

    Or once away from the pressure of it's gravity field, might turn into a huge neutron soup puddle.
     
  16. Jan 8, 2005 #15
    Depends how big the repulsive forces are. In the big neutron star, the gravitational force overcomes all the repulsive forces.

    But what repulsive forces do we have? Very close range strong force is repulsive. And all these neutrons have Pauli Exclusion Repulsion, I would have thought? Any more forces involved?
    So I would assume, below a certain mass that this material could not hold itself together. That is why neutron stars only form under high mass, extreme conditions.
     
  17. Jan 8, 2005 #16
  18. Jan 8, 2005 #17

    Nereid

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    It's certainly an interesting idea Gara.

    The difficulty with it is, as Chronos pointed out indirectly, it would very likely require new physics. Why? because to be consistent with today's physics, a chunk of neutron star would indeed 'explode' (IOW, it isn't stable in low pressure environments). To give a counter analogy to your diamond ... there are many crystalline forms of ice which exist in high pressure environments at 10C, 20C, ... but none are stable at the pressure on the surface of the Earth (this is fortunate ... I believe Kurt Vonnegut wrote a depressing scifi novel based on the your diamond idea, applied to ice ... called Ice-Nine?). Or, at low temperatures and pressures, the only stable form of ice is amorphous, so when recently Jewitt and Luu discovered crystalline ice on Sedna, it implies that at least parts of Sedna's surface is relatively new.
     
  19. Jan 8, 2005 #18
    *grabs a hard hat and pickaxe*

    *goes to mine a sun for diamond*

    Don't worry. I'll go when it's night time.

    Great find there!

    And yes, you're right. Some are unstable, Nereid. I guess we'll have to wait to find out.
     
  20. Jan 9, 2005 #19
    Perhaps,this is a new element never found before and perhaps it exists on Earth?
     
  21. Jan 10, 2005 #20

    Nereid

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    How would you go about searching for it errorist?
     
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