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Dark Matter as possible ground state for all matter

  1. Oct 17, 2012 #1
    Are there any theories based upon Dark Matter (DM) being a precursor or sublayer or ground state to Observable Matter (OM)? Pre-Big Bang? Galaxy distribution linked to DM tendril intersections is consistent with DM providing a pre-existing structure.

    Any theories based upon DM interactions being able to occur faster than the speed of light since DM only interacts with OM gravitationally?

    Are there experiments which indicate that gravitational effects are limited to the speed of light? If DM gravitational effects are not constrained by "c", wouldn't a lot of cosmology ideas be changed?

    Do such theories provide alternative solutions to questions answered by Big Bang, Inflation Theory, Quantum Theory? Maybe DM scale is below Plank size limit.
     
  2. jcsd
  3. Oct 17, 2012 #2

    Drakkith

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    Staff: Mentor

    Ground state? I don't see how. The ground state of a material still interacts through whatever forces it does when it's not in its ground state. The structure of dark matter is the result of gravitational collapse, not a pre-existing structure.

    Gravitation is limited to c as well.

    If your theory breaks a fundamental law of physics, let alone multiple ones, you need to have amazingly good evidence to justify it. Otherwise it doesn't matter if the theory provides answers, as those answers are probably wrong.
     
  4. Oct 18, 2012 #3
    There are a few GR experiments, but these is something hard to directly measure. There are lots of theoretical reasons to think that gravity moves at the speed of light.

    If DM gravitational effects weren't constrained by "c", there would be some changes, but surprisingly few ones. Most of the effects of dark matter end up being pressure effects, which means that if you set "c=infinity" there are relatively few changes. Everything is controlled by the speed of sound which is much lower than then speed of gravity.

    One common approximation that people make in cosmology is to set "speed of light=infinity". It turns out that this approximation doesn't change very much, since the speed of gravity doesn't cause many observational differences.

    This is the flip side to the first answer. If the speed of gravity makes a big difference, we can do an experiment. If it turns out that it's hard to do an experiment to measure the speed of gravity, that means that's it's not going to have much practical effect.

    The trouble we have are too many alternatives. The hard part is not assuming this new weird thing about DM, but showing it this is wrong.
     
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