Anyone else question why astronomers are so sure about things that happened 5+ billion years ago ? I guess otherwise there’d be a probably or a maybe in every sentence ? But then how do you tell when they really are sure ?
What evidence do you have for the sloppiness and how does the current model fail to explain the deviation in observations?
If we make the assumption that our model applies everywhere and at every time (colloquially, that the laws of physics don't change), we can ask our models what happened in the past. Under our assumption, that's probably quite close to what actually happened. This assumption is called the "principle of induction", the "uniformitarian principle", the "cosmological principle", the "Copernican principle", and many other things besides.