> I bet someone wrote something equivalent to InclinedPlane's comment about it at one time
Doubtful, because an equivalent statement would sport an equivalent truth value for an equivalent statement of support. Substitute "aether theory" for "dark matter" in InclinedPlane's comment, and his assertion of its wide confirmation would be trivially false. Many physicists at the time believed the aether theory to be true, but confirmation remained (rightly) elusive, despite very sophisticated attempts.[1]
I feel the need to point out that the periodic table was also built up from observed effects without knowing what the stuff actually was. It wasn't the first attempt at categorizing the elements. Mendeleev's table was special because, like dark matter and unlike aether theory, it had positive predictive value. It made predictions about the properties of unknown elements that turned out to be correct.
Doubtful, because an equivalent statement would sport an equivalent truth value for an equivalent statement of support. Substitute "aether theory" for "dark matter" in InclinedPlane's comment, and his assertion of its wide confirmation would be trivially false. Many physicists at the time believed the aether theory to be true, but confirmation remained (rightly) elusive, despite very sophisticated attempts.[1]
I feel the need to point out that the periodic table was also built up from observed effects without knowing what the stuff actually was. It wasn't the first attempt at categorizing the elements. Mendeleev's table was special because, like dark matter and unlike aether theory, it had positive predictive value. It made predictions about the properties of unknown elements that turned out to be correct.
[1]: http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experi...