Orbiting neutron?

Discussion in 'Physics' started by ross, Mar 14, 2012.

  1. ross

    Thread Starter Member

    Jul 30, 2010
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  2. Papabravo

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    The neutron in a nucleus does not stand still. The whole nucleus is rotating and any particle within the nucleus has an orbit around the center of rotation. The path may complicated but apparently it is measurable and predictable.
     
  3. logearav

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    Aug 19, 2011
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    Papabravo,
    All along i have studied nucleus is stationary and only electron revolves or orbits around the nucleus. Your view is news to me
     
  4. Papabravo

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    What can I say except graduate level courses go a bit deeper than freshman physics.
     
  5. Blofeld

    Active Member

    Feb 21, 2010
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    Perhaps there are several different ways to describe this effect, and in the interview Flambaum explained it as an orbiting neutron because he thought this would be the easiest way to understand it. This is the abstract of the paper, it talks about transitions between stretched states:

    "The 7.6(5) eV nuclear magnetic-dipole transition in a single 229Th3+ ion may provide the foundation for an optical clock of superb accuracy. A virtual clock transition composed of stretched states within the 5F5/2 electronic ground level of both nuclear ground and isomeric manifolds is proposed. It is shown to offer unprecedented systematic shift suppression, allowing for clock performance with a total fractional inaccuracy approaching 1 x 10^-19."

    http://arxiv.org/abs/1110.2490
     
  6. ross

    Thread Starter Member

    Jul 30, 2010
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    Would quarks have anything to do with this affect?
     
  7. Wendy

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    A Neutron is part of the internal structure of the atom. It's a part of the nuclease that makes the atom stable, if you have the wrong number of neutrons in a nuclease the atom will be an unstable element, and sooner or later fly apart (atomic fission). This is where radioactivity comes from.

    The two components of the nuclease are Neutrons and Protons, and the exact numbers are important. All the main components of atoms, Neutrons, Protons, and Electrons, are made up of three different types of Quarks. They are their smallest particles.

    http://en.wikipedia.org/wiki/Quarks

    Big bugs have small bugs,
    who tease and bite them.
    Small bugs have smaller bugs,
    And so, infinitum.

    Author Unknown to me.
     
  8. ross

    Thread Starter Member

    Jul 30, 2010
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    What I mean is, what causes the rotation in the first place? gravity would be too weak at that scale. Wouldn't it?
     
  9. Blofeld

    Active Member

    Feb 21, 2010
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    Sure, gravity is much too weak, it only becomes interesting if you sum it up over a very large number of particles. I think the nuclear force is the relevant force but I don't know the details. :(

    However, I don't think that this force cause the rotation. In the classical picture, you can have strong forces without any movement or vibrations if the system is already in a stable state of minimum energy. Look at a celestial body like the moon, hold together by strong gravitational forces, but it doesn't vibrate (unless you kick it).

    I'm pretty sure you have to look at quantum effects (Heisenberg's Uncertainty Principle) as the reason for the vibrations. If you can locate a particle very precisely ("the particle is in the nucleus") then you have a very big uncertainty in the momentum of the particle, that is, it has to move or vibrate. The nuclear forces make sure that the nucleus doesn't fly apart, but they don't cause the vibration. At least this is what I think about this stuff, hopefully Papabravo or Bill Marsden will provide a more correct explanation.
     
  10. russ_hensel

    Well-Known Member

    Jan 11, 2009
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    Gravity would not be the cause of rotation even if it were stronger. Rotation comes about for a couple of reasons: 1 ) conservation of angular momentum. 2 ) perhaps more important quantum effects.

    Without the quantum effects a hydrogen atom would collapse as the electron would loose all its angular momentum and "fall into the nucleus". ( in this case the force is electrical )

    For the earth the sun fails ( in human scale times ) to pull the earth in because of the conservation of orbital angular momentum. Here the force is gravity.

    Also beware of the so called fallacy of the single cause. If you suddenly turned off the force of gravity the angular momentum of the earth would stay the same, but the orbit would radically change.
     
  11. Markd77

    Senior Member

    Sep 7, 2009
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    Just nitpicking and not really relevant, but electrons are elementary particles and not made of quarks.
     
  12. Wendy

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    Mar 24, 2008
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  13. Papabravo

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    Feb 24, 2006
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    As has already been mentioned the uncertainty principle makes it hard to specify both position and momentum simultaneously. What a particular neutron will do as a part of a nucleus is called an orbit. What it looks like is probably not a circle or an ellipse. What we do know with high probability is that it moves in a periodic and regular way that can be measured presumably without upsetting and disturbing the system under observation.

    I'm sure I don't have a handle on the particulars of what the neutron is actually doing, but whatever it is doing is not surprising to me.
     
  14. mahnoorbloch

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    Apr 22, 2012
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  15. ross

    Thread Starter Member

    Jul 30, 2010
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    That link explains those things clearly, Its much better than other attempts that Ive come across.
     
  16. russ_hensel

    Well-Known Member

    Jan 11, 2009
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    And the wave function is odd as well so we get the exclusion principal!
     
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