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Are dark energy and dark matter the same?

  1. Jan 29, 2012 #1
    Someone said that they are by mass-energy equivalence. Also, is it possible to say that dark matter is a indeed a form of matter, and dark energy is a form of energy?
  2. jcsd
  3. Jan 29, 2012 #2
    No. Dark Energy and Dark Matter are two entirely different concepts that are related only by their similar names.

    Dark Matter is a proposed solution to a problem with a lot of observational support that galaxies have more mass than our models show.

    Dark Energy is term to describe several theories that strive to explain why the expansion of the universe is accelerating.

    It is however correct (probably, assuming the little we know about these things is true) to say that dark matter is a form of matter and dark energy is a form of energy, although I am more hesitant to say the latter. This does not mean they are the same via mass-energy equivalence.
  4. Jan 29, 2012 #3
    Ok, thanks, that's what I thought.
  5. Mar 13, 2012 #4
    In short, dark energy is repulsive (avoids matter and floats in contact with gravity) and dark matter only is affected by gravitational influence and exerts it
  6. Mar 14, 2012 #5


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    Uh ... what does that mean, if anything?
  7. Mar 14, 2012 #6


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    Staff Emeritus
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    This is not correct. First, energy is not a physical object that responds to forces. It is a quantity that things such as matter and light have. Second, dark energy is the theorized reason for the acceleration of the expansion of the universe.
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