Theories have verifiable aspects and theoretical aspects yet to be empirically proven! Ie dark matter!
Observations whereby we see the effect of something ie gravity, dark matter acting on Baryonic matter, is a matter of interpretation of the data. Those proposing dark energy theory interpret the data to fit their theory a plasma theorist will do the same, one gets more attention simply on the philosophical criteria and implication if the theory in reality. Does that make sense, if dark matter was verifiable like you claim then it would not be the great mystery phycists are claiming it is! There is a reliance on indirect evidence, which fuels dark matter doubts.
Read this :
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the Wilkinson Microwave Anisotropy Probe, has in the decade since its launch delivered a robust indirect detection of dark matter's footprint on the ancient echo of light known as the cosmic microwave background. And dark matter's effects are also inferred in gravitational interactions around clusters of galaxies as well as around individual galaxies themselves.
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But the dark stuff itself has yet to be detected, either directly, in particle physics laboratories as a new subatomic particle, via neutrino telescopes also operating in the subatomic realm, or with concrete evidence of such hidden matter using telescopes operating in the electromagnetic spectrum.
If it's matter whether visible or not is detectable and observable via neutrino telescopes, LHC and other technology!!!
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Stars at the very edges of spiral galaxies, for instance, rotate much faster than can be explained by Newtonian gravity alone; the picture makes sense only if astrophysicists either modify gravity itself or invoke additional gravitational acceleration due to an unknown source of mass such as dark matter.
See dark matter is an extension theory to model to account for affects that Newtonian physics don't, either gravity needs modification or we add a theoretical accelerator!
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Theory predicts that spiral galaxies, including our own Milky Way, are enveloped by massive dark matter halos that provide the galaxy's missing mass. But the Milky Way's own dark matter halo has also yet to be detected, even indirectly. Its putative existence is primarily inferred from the anomalous rotations of satellite galaxies such as the Magellanic Clouds, which orbit the Milky Way too quickly to be explained by ordinary gravity alone.
Finally I think this point sums up my point.
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"There is a lot of misplaced certainty in the dark matter model—a feeling that it's not 'if' we directly detect dark matter, but 'when,'" Mihos says.
Or, as McGaugh puts it, "Once you convince yourself that the universe is full of an invisible substance that only interacts with ordinary matter through gravity, then it is virtually impossible to disabuse yourself of that notion. There is always a way to wiggle out of any observation."