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Matter less Neutrons behave the same Less Inertia?

  1. Dec 29, 2011 #1
    If there was some way to strip matter of it's neutrons, would that give you matter of all the same properties except for inertia? Or would it diffuse throughout space? I kind of get the notion that neutrons act as anchors to keep objects in one place. Maybe that's what a black hole does and spews out such weird no inertia matter on the other side. (could that be the origin of "dark matter"?)

  2. jcsd
  3. Dec 29, 2011 #2
    You'd still have protons, electrons, neutrinos, pions, etc., so matter would still have different properties. The rest of your post makes no sense. What diffuses through space? What do you mean by anchors?
  4. Dec 29, 2011 #3
    Diffuses through space- Without inertia to give it momentum or directionality, it would just generate space. That would explain how radio waves travel through the "vacuum" of space. Electrons and protons are there but without neutrons, they don't interact with regular matter and seem invisible to us.

    Anchors- Neutrons give atoms relativity? and enable them to react and interact as electrons and protons are shared according to quantum physics. The subatomic particles indicate that there is complexity in the design of protons, neutrons, etc.

  5. Dec 29, 2011 #4
    This leads me to think that black holes may serve as a means of recycling matter into dark matter by stripping away its neutrons and generating more "space" as it were. This could also account for the theory of the expanding universe I suppose. You would have "neutronic matter" and "aneutronic matter" perhaps.

  6. Dec 29, 2011 #5


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    Where did you get the notion that only neutrons are responsible for inertia and momentum? This is patently false. For instance, the majority of hydrogen atoms consist of just a proton and electron with no neutron present, yet they still have momentum and inertia.
  7. Dec 29, 2011 #6
    Perhaps you might want to look at this site first. Protons and electrons interact all the time without neutrons - that's what hydrogen is (1 proton, 1 electron, no neutron). And miost of the universe is made of hydrogen.

    Inertia is a property of matter, not just neutrons. Protons and electrons have inertia whether or not there's a neutron around to "anchor" them (and neutrons' normal interaction with electrons is via ionization of atoms when some neutron flux interacts with matter. As for neutrons giving atoms relativity, this also makes no sense.
  8. Dec 29, 2011 #7
    I suppose that's my question then. The relationship between neutron and mass and momentum. Does hydrogen behave the same as matter with neutrons? I'm just exploring ideas. How does the presence of neutrons change things for an atom?
  9. Dec 29, 2011 #8
    It depends upon the atom in question. Neutron capture by an atom just changes the isotopic identity. The new isotope might be radioactive or stable, depending upon what the original isotope was. What neutron capture does do is increase the nuclear binding energy. As for removing a neutron, other than nuclear reactions of the (*,n) type, or fission, I'm unaware of any way to remove neutrons from an atom (I guess spallation might work, but I doubt it).

    Edited: Most hydrogen is 1 proton, 1 electron. Deuterium (which is also chemically identicle to hydrogen for the most part), is hydrogen with a neutron (tritium has 2 neutrons instead of 1)
  10. Dec 29, 2011 #9
    I should say that neutrons give the greatest portion of mass to an atom. Don't know the percentage breakdown though.

    BTW, If you threw a hydrogen atom and a lead atom, the lead atom would no doubt carry further so "patently false" needs more explanation. :)
  11. Dec 29, 2011 #10
    Protons are about 938 MeV and neutrons about 940 MeV, and since for A number > 20 an atoms needs more neutrons than protons, yes, neutrons do provide most of the mass - they just don't provide all of it.
  12. Dec 29, 2011 #11
    Sounds like protons and neutrons are pretty close mass-wise, or not? Well, anyway the neutron-free theory gets pretty well nixed by the hydrogen atom. So much for my theory.
  13. Dec 29, 2011 #12
    Just came across this on another forum. So it appears more a question of "up" and "down" quarks, electrons, positrons, neutrinos and so forth and how they are combined to establish relative mass. Pretty cool stuff!

    "This is a very complicated question with no simple "hand-waving" answer. In energy units (using E = mc^2), the masses are: Proton: 938.272 MeV, neutron: 939.566 MeV, mass difference = 1.293 MeV, electron: 0.511 Mev.

    It is tempting to say that a neutron consists of a proton plus an electron; the mass of the electron would make up 40% of the mass difference. This argument is totally invalid. It would be equally valid to say that a proton consists of a neutron plus a positron (a positron has exactly the same mass as an electron, but is positively charged). The validity of using this argument in both directions is strengthened by the fact that neutrons in neutron rich nuclei beta decay into an electron and a neutrino while protons in proton rich nuclei beta decay into a positron and a neutrino. For example a N13 (nitrogen 13) nucleus decays into C13 (carbon 13), a positron, and a neutrino with the release of 2.221 MeV.

    The charge of the proton adds some electromagnetic energy to the proton mass, but the magnitude of that effect is not only impossible to calculate, but works in the wrong direction.

    Quarks give the best chance to explain the proton-neutron mass difference by "hand-waving". A proton consists (mainly) of two up quarks and one down quark. A neutron consists (mainly) of one up quark and two down quarks. Current estimates are that the up quark has a mass in the range 2-8 Mev and the down quark 5-15 MeV. So replacing one up quark in the proton by a down quark would increase the mass by something between -3 MeV and +13 MeV. Clearly this is not a precise calculation, but it is (mostly) in the right direction and could overcome the electromagnetic contribution and produce the correct answer. There are other known contributions to these masses including interactions with the weak and strong interactions, but this is probably already more than you want to know about this subject!"
  14. Dec 29, 2011 #13
    Thanks, Daveb

    I'll try to get my head around the current understanding of all this at that wonderful site you suggested!

  15. Dec 29, 2011 #14


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    In both cases the two atoms would travel equally as far (an infinite distance) as long as there was no force acting upon them. It would simply take more energy to get the lead atom up to the same velocity.
  16. Dec 29, 2011 #15


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    Save for hydrogen, there is no stable atomic nucleus composed solely of protons.
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