Ok - I have qualified this question with the word stupid so please go gently with me. Imagine you are talking to a rather stupid child when answering please. My question is about dark matter. Every time I do a search for "proof of dark matter", I get the same answer, which is that using the known laws of gravity the rotation of the galaxies can't be explained unless we 'invent' the concept of dark matter. So why is it automatically assumed that the existing laws of gravity are correct? I heard that Verlinde's theory of gravity just passed its first test. I can't remember exactly what had been tested, but it sounded a bit like a Schwarzchild kind of situation, with a non rotating mass. The point is that Verlinde's theory is able to acurately (so I've been told) the behaviour of the matter without resorting to dark matter.