so, i love physics, and the more i look the more it seems our understanding of things are wrong. no planet #9, but now a mysterious planet-nine, dark energy, etc etc. so my question probably lies in theory, but getting close to applied physics. planet-nine, from what i have seen, the prediction model predicts a mass in orbit which is very very far away. cant this be a black hole or some other cluster of dark matter? as for black holes, they were very mysterious until the concept of dark matter/energy came to light. cant we explain a "black" hole in terms of a collection of dark matter/energy? and does anyone believe that we can some day have some tools to observe dark matter? or is it believed that we can only describe the theory via math? if you have a working theory that is 100% described by math yet we cannot make the observation, where does that put the problem?