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Relationship between dark energy and the strong force

  1. May 30, 2012 #1
    Hello, I am a general physicist, pursuing it for fun. I work in solar, and the other day while driving up to Sacramento I had a interesting train of thought. From the data we have
    collected, one interpretation could be that on average, the universe is expanding in every direction at an accelerating rate. Here the assumption needed for this thought experiment:
    Dark Energy pulls the planets, molecules, atoms and nuclei apart, that is, we assume Dark Energy will pull things apart down to the scale of protons and neutrons.
    If Dark Energy prevails at this scale, than we have some strange circumstances. The Dark Energy will begin pulling the Hadrons apart. As some of us may know, when quarks are seperated, the energy in the gluonic field can pass a threshold and manifest another quark anti quark pair (quark babies).
    Then if we hold conservation of energy true, that is, we think of the universe as a closed system, than this Dark Energy must be conserved. That would make the strong force a mechanism for conversion mechanism for turning Dark Energy into mass/gravity via these quark fountains would create. What do you think about this?
  2. jcsd
  3. May 30, 2012 #2
    and in my mind, there would be an equalibrium point where the amount of mass and gravity oscillated into dark energy and back again. Converting from mass to dark energy and back again (though we may not yet understand how this mass turns to dark energy, perhaps it can be extrapolated through theory)
  4. May 30, 2012 #3
    A nice scenario, I think. But highly speculative. Except if we imagine that a di-quark behaves like a small piece of (elastic) string under the influence of two factors: the expansion (Nobelprize 2011) and the gravitation (between the two quarks; extrapolation of Newton). Unfortunately, I cannot propose peer reviewed articles concerning this discussion. Do you have some? If no: (be prepared to that option) the discussion will certainly be locked (this remark is not an ironic critic in direction of the moderators :cool:).
  5. May 30, 2012 #4
    Wow if there are no relevent articles, perhaps this idea is as original as I first thought, time to write the first scientific article. Thanks for the heads up!
  6. Jun 4, 2012 #5
    No, not quite orginal. Look up QCD ghost dark energy at ArXiv, e.g. here. In flat space expansion the quarks in a vacuum aparaently doesn't change the energy. But in curved space, the effect of Hubble expansion on a condensate of quarks in the vacuum, is according to the above paper, enough to generate a dark energy like acceleration of expansion, which switching on for low temperature and late red shift. z=0.75 in the above paper.
  7. Jun 21, 2012 #6
    Perhaps I don't have understand the paper correctly but I see a possible contradiction in the followed logic. If what I did learnt a few weeks ago in a planetarium is true, the accelerating expansion is a relatively recent chapter in the universal history; and this acceleration is increasing... this would indicate a greater curvature. On the other hand our actual universe is apparently flat. So the machanism explained above should no more act... What did I miss?
  8. Jun 24, 2012 #7
    A lot depends on what dark energy is. If DE turns out to be the cosmological constant with an equation of state of w=-1. Then what will happens is that the universe will stabilize so that anythng smaller than a galaxy will remain stable. w=-1 corresponds to "constant pressure". If you have constant pressue then things that aren't bound by gravity or some other force will get blown apart, but something that is currently resisting getting blown apart will continue to do so forever.

    Now if w<-1, things get interesting. At that point we have a situation in which the pressure due to dark energy increases to infinitity which means that everything is going to go to smittereens eventually.


    There is probably a FAQ for this but at cosmological scales, energy is *not* conserved. Part of the problem is that it's not clear how to define "the total energy of the universe" and if you define it in the obvious ways, you get numbers that clearly aren't constant.
  9. Jun 24, 2012 #8
    Yeah, but something to remember is that since we have no idea what dark energy is, you have theorists go totally crazy coming up with ideas for what dark energy could be, because we don't quite have the data to put a leash on those crazy theorists. That data is coming down the pipe.

    The crucial question is "what is w, and how does it change over time?" W the number that tells you how dark energy changes with the density of the universe, and once we have those numbers, then it should be easier to "put the theorists on a leash."

    Also, the hard part about published a paper for what dark energy could be is that there are so many ideas, that it's hard to come up with something that no one has thought of before.
  10. Jun 24, 2012 #9
    There is some fine print in the observational papers.....

    It turns out that if dark energy *isn't* constant and curvature is non-zero that you can come up with results that appear to mimic a flat universe. Basically, the effects of a changing dark energy and a non-zero curvature cancel out to give you observations in which the universe looks flat, but isn't.
    Last edited: Jun 24, 2012
  11. Jun 24, 2012 #10
    Here is one paper that describes the problem


    This is something that the observation groups are aware of so when they present their results, they usually put their results into a model in which the equation of state of dark matter changes.
  12. Jun 24, 2012 #11
    Reading some more papers I'm getting confused myself...

    Some of the papers seem to require a flat universe whereas others don't.

    http://lanl.arxiv.org/abs/1201.2494 tries to fit their results into a flat universe whereas

    http://arxiv.org/abs/0906.2162 seems to require that we live in a non-flat universe for this to work

    In any event, the current measurements don't totally exclude a non-flat universe, although the measurements are getting increasingly good so if the universe is flat it's going to be more and more obvious that it is over the next few years. On the other hand, it would be cool if the arrow doesn't land dead center at w=-1, omega_k=0.0
    Last edited: Jun 24, 2012
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