It's supposed to be, but far too many scientists, and most notably fans of science, forget that and instead see science's current explanations as certain truth.

On the Aristotle-Galileo comparison, I don't know to what in my various you refer. I'm curious because I perhaps gave a wrong impression in my wording. I of course know that Galileo demonstrated that falling bodies fall at the same rate. That was a very important watershed in natural philosophy, as it was called then.