I picked up Milton A. Rothman's "Discovering the Natural Laws" in a used bookstore in Door County, Wisconsin, recently. He has two points he wants to make. First, he wants to show the empirical evidence for the laws of physics in order to justify those laws which is the main reason I'm reading the book. Second, he wants to discredit his own consciousness. He doesn't put the part about consciousness in those terms, but that's how I read it.
Anyway, he writes this about how the laws of physics have not changed (and I admit, for practical purposes, it is a useful assumption we might as well make):
"Thus we know, by direct evidence, that the laws which operate here and now are the same laws that existed early in the history of the universe. They have not changed in all the time that has elapsed since very soon after the beginning." (page 209)
Because of that beginning, we can't say "we know" the laws have not changed, or rather, that the universe is actually following the laws we think it is.