It's incredibly frustrating replying to you, because your arguments are fundamentally anti-science. Everything you're saying can basically be condensed down to

It's incredibly frustrating replying to you, because your arguments are fundamentally anti-science. Everything you're saying can basically be condensed down to "Well, we though we've known things before, and we think we know things now, but we can't EVER REALLY BE SURE, can we? It's all an assumption!" Trying to compare our current understanding of the universe to that of a cave man is quite silly. We've nailed down quite a bit of the why and how of the structure of the universe, the laws of physics, etc. It's not perfect, there's parts we don't understand, and there's parts we may never be able to understand, but the scope is so much broader and understanding so much deeper that trying to act like it's meaningful to compare our understanding vs. that of a cave man is so disingenuous. A cave man would have no idea why that would be the limit of his observations - no understanding of physical laws that would make it so. But we understand why there are limits to what we can see. We understand that there is a maximum speed for a massless particle in a void. We understand why we cannot examine objects under a certain size - because the energy requirements would literally create a black hole if put into the space needed to see. A cave man could not understand why there is not more out there for him to observe. We can. >Sure there is. We might just be in a location where stars are diverging You seem to be misunderstanding either the meaning of the word "inherent" or the phrase "rule out". An anisotropic universe can 100% be expanding. It can also not be expanding. But you were previously arguing that our (evidence backed) belief that the universe is isotropic being incorrect would immediately rule out expansion, when it simply isn't the case. It's also not particularly relevant, because all evidence points towards the universe being isotropic.