A Philosophy of Science professor of mine was Father William A. Wallace, O.P. He wrote a book, two volumes, entitled Causality and Scientific Explanation. Within this book, as an aside, he said a few things about the role of falsification in doing science. He mentioned Popper and Feyerabend and a few others. But he also gave quotes from Aristotle and Peter Maricourt and Robert Grosseteste which clearly referred to the need to use falsification. It is interesting that these three and other ancient scholars who commented about falsification, were doing so in the context of meteorological issues.
On one of the pages, Wallace wrote that it was understood that in order to confirm a new explanation of some phenomena, it was necessary to first/also prove previous explanations false. The underlying assumption here was that there must be only one correct explanation for a given phenomenon. In a universe governed by causality, there must be one cause for a specific phenomenon.
I ask you and I to focus our attention on this specific statement; i.e. "The underlying assumption was that there is one causal explanation for a given phenomenon."
We have heard the statements about the possibility of their being multiple universes and that different universes might have different physical laws.
In light of this possibility of universes with different laws, let's now focus our attention on our universe which has a set of physical laws specific to itself.
My first question: "Is there some obvious scientific reason why the physical laws within a given universe cannot change over time?"
Assuming the physical laws operating within a given universe can change over time. my second question is, "Would it not then be possible for a given phenomenon to have multiply and equally correct causal explanations?"
And finally, my third question is, "Would a reality of physical laws changing in a given universe over time, call into question and challenge the validity of falsification as a tool of scientific explanation?"
Dave, i believe you are the person who has read up on Popper and what he has to say about the role of falsification in doing science. I would appreciate your response as well.