You don't have any evidence that physical laws and principles have remained uniform.
Sure we do; there's significant evidence from astronomy that the physical laws we observe here in the present day operate in areas very distant from here; because they are so distant in space, our observations constitute a record of the past.
The idea that the uniformity of natural law is somehow "unproven" is ludicrously wrong. Moreover, it's the obvious conclusion from a model of an expanding universe.
It's both predicted by model and confirmed by observation. The assertion of the uniformity of natural law is proven.