It's an interesting philosophical question whether a more complex theory and a small amount of invisible matter or a simpler theory and a large amount of invisi

It's an interesting philosophical question whether a more complex theory and a small amount of invisible matter or a simpler theory and a large amount of invisible matter is the simpler combination. In any case, I think that any modified theory of gravitation has to fight an uphill battle because it seems to be easy to come up with a configuration of dark matter that explains any observation. That's my biggest grievance with DM, btw.: It doesn't make any predictions that could be used to falsify it, at least not in a sense that I could intuitively understand it. Effectively, it appears to act as a completely free parameter, distributed however we need it at the moment.