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How dense would neutron matter be?

  1. Apr 20, 2009 #1
    if you took plain neutrons, and put them in a bottle would a bottle full of neutrons weigh less than a bottle of bear protons with no electrons arround?
  2. jcsd
  3. Apr 20, 2009 #2


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    You'd have to squeeze them to change the density any. In a neutron star (that's a collapsed star that started out more massive than the sun, and ended up the same size as some asteroids--10ish km in diameter) neutrons at the core of the star avoid collapse via the Pauli exclusion principle. In other words, it's about as dense as matter can get without turning into whatever black holes are made of.

    Average densities are tabulated in the link below:
  4. Apr 20, 2009 #3

    Vanadium 50

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    I don't think your question matches the title. Putting particles in a bottle is a different situation than the density of a substance. Certainly the inward force provided by glass walls is much smaller than the inward force of gravity from a neutron star.
  5. Apr 20, 2009 #4


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    Why would the neutrons stay in the bottle?
  6. Apr 20, 2009 #5
    Thermal neutrons, which are not sensitive to the Coulomb forces in atoms or to the Pauli exclusion principle (except inside nuclei), will diffuse through the bottle walls until they are captured by nuclei that usually go through (n,gamma) reactions. Sometimes they go through (n,alpha) reactions like neutron capture on boron-10. Protons, which are repelled by other other protons or by nuclei, will stop in the bottle walls and capture electrons from the other nuclei. Hydrogen atoms, being small, can diffuse into the bottle walls (or back into the gas as hydrogen) and cause hydrogen embrittlement, especially in steels. This is a concern in the development of the hydrogen economy. To get a sense of the density of a proton gas, it is now possible to buy capacitors that hold a Coulomb of (electron) charge. But a mole (gram molecular weight) of protons contains 96,000 Coulombs of charge.
  7. Apr 20, 2009 #6
    so the neutrons wouldnt even be able to stay in the bottle because theyde just go through the walls? also, do you mean through like a path straight through the walls of the bottle?
  8. Apr 20, 2009 #7
    if you seal it they shouldnt escape right
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