Does the Universe behave uniformly?

      Is there an edge to our universe? There must be a place where there isn’t any matter, any more. So, let us say that outside our universe, is simply where there is no longer matter (and for a certain distance). But you can't say that it is nothing, because it has the potential to contain matter (and apparently it has length as well); it is empty space, but it isn’t nothing. I think where I am going with this is the question; what causes matter to be governed by physical laws (call them patterns if you want, formulaic ways of behaving...), how is it possible that matter behaves under the same physical laws here, as it would on the edge of our universe? Where are these physical laws (patterned ways of behaving) situated? Inside the particles, inside the electrons, inside the tiny bits of intertwining quantums of existence that make up subatomic particles? I mean, why is it that the universe behaves the same way everywhere (or rather, how is it that the universe behaves uniformly?) ? And should we even make this assumption that the universe is behaving uniformly?