
No. That's called science. You come up with theories based upon what you've seen in experiments, and then try to do experiments which will provide evidence for/against the theory. Things in Astrophysics are just a bit messed up because we've evidence for things that act in certain ways (for example dark matter and dark energy) but we've not got much evidence yet for what they are. By thinking what makes sense from what we do know you can hopefully come up with ways to test it.