Not sure if this subject belongs in Astrophysics, or Cosmology, or even Quantum Mechanics, or somewhere else! It is my (weak) understanding that the motions of the greater universe as a whole seems to require more mass than what is observed in order to fit with the known laws of gravity, which apparently are pretty well understood and tested. So the idea that there must be something that pervades all of space, has mass, can carry energy, and at the same time does not interact through any force except gravity with other matter was invented to help resolve the issue. Having the specified properties, the stuff obviously isn't made of the same stuff the visible universe is, so it is assumed that it must be composed of as-yet unobserved particles of a new variety, the WIMPS. And try as they might, the bar keeps getting raised higher and higher for the energy range of where these new particles may be seen by particle accelerators. OK, so here's my problem, I guess: That doesn't sound very scientific to me. An observation doesn't fit with a well established theory... a new type of "matter" is hypothesized to bring everything back into line... the properties of this matter become abstract and un-testable very quickly... new and yet more exotic theories and properties and particle types are invented to explain why we have yet to be able to begin to test the first wave of the new theory... more abstraction. It seems that it is far simpler to say that either the observation that caused the confusion in the first place is flawed, or the theory that is used to describe the problem is flawed, or the theory has properties that are not apparent on the scales that we have "proved" them, or all of the above. So, can our observation be off, and if so, why? Could it be that the fundamental theories of gravitation that we know and love can have effects that may not be apparent at the scale of our little (solar system-sized) experimental window? P.S.: I know this is very scientific of me, but what I'm driving at is that the theory of dark matter just doesn't "feel" right. My mechanical intuition, down in my gut, says something is bad. I know that means nothing in reality, but other strange theories, a little closer to home, such as QM, "feel" like they are at least aimed in the right direction. Dark matter has a certain grit to it... Anybody get what I mean by that?