As I understand it dark matter is predicted by one set of observations and confirmed by many others within calculated error bounds. It's not some kind of overfit model trying to explain a single observation. So to discount it you'd need to explain why it just so happens that many observations converge to the same results as that which you would expect from the predicted dark matter distribution. I don't think mere refraction can explain lots of different observations.
Dark energy on the other hand is a whole other story.
First thing to understand is the only evidence we have for the universe expanding is redshift.
Do I believe refraction is at all related to Dark mass/energy? Not all all. Refraction has nothing to do with that. Refraction has to do with redshift being miscalculated.
Compression waves are the culprit and the field that propagates those waves for dark garbage. baryonic acoustic waves give direct evidence as the perp.
I think you missed the actual point of my comment? Refraction was kind of irrelevant to it, I was trying to say something about the consistency of different observations and the strength of the evidence behind them. You could replace "refraction" with "squirrels" and it wouldn't really change what I was trying to explain.
Well you misunderstood that I was referring to refraction as being the reason for dark matter predictions. I was trying to imply that it can explain why the universe is expanding. Instead of the theory of dark matter.
I already gave you my reasoning for dark matter calculation, baryonic waves. Which you so happened to ignore?
That is incorrect. It's directly relevant. Redshift is measured and there is a willful disregard for the refraction that is inherent and a statistically overwhelming effect, given the distances and known matter in space. Redshift exists after a megaparsec in any direction, so it's not surprising that it's the farthest thing we see given we're seeing some amount of mass in the far distance from any given angle.
Don't see why refraction needs to explain lots of observations?
While dark matter may fit multiple different observations better, it may also be the multiple different observations are due to multiple phenomena. So really don't see any reason we need a magic bullet that fits all observations...
Frankly, I think refraction and reflection make a good candidate for explaining redshift of the universe, and should be easily testable...
Dark energy on the other hand is a whole other story.