Palumboism wrote:That's how science works. When you see something that doesn't make sense, you come up with a hypothesis for the reason why. In this case calculations for many galaxies show they should fly apart based on the amount of matter they have. The math indicates dark matter should be there.
So, putting it more generally, we observe patterns in our observations. We use mathematics as the language to describe those patterns; like English but more precise and quantitative. That then helps us to extrapolate from those patterns and make predictions of future observations. In some cases, the predictions lead to the hypothesis that the best way to describe those future observations would be to propose the existence of some thing. In this case, that something is "dark matter", but in principle it could be anything.
The issue that some people seem to have with this process is that last part. There appears to be a view that jumping from patterns in observations to proposing the ontological existence of "things" whose proposed existence fits the patterns in the observations is going too far. It seems almost like a form of dualism - i.e. a fundamental separation into two parts - between ontology and utility; between what
is and what is useful for predicting the results of experiments. In some ways ( but certainly not all ways) it reminds me of the disdain for experimentation that is often traced back to the likes of Pythagoras, and which led, for a thousand years or more (at least in Western Science/Natural Philosophy), to the view that if you want to understand the way that the world
is, the one thing you don't do is look at it!