About the most useless game to play in discussions about global warming is to worry much about the distinctions between “proven facts”, “theories”, “hypotheses” and so on and so forth. These are ideas best left to philosophers and schoolmen. My image comes from the ever-helpful RS which is my excuse for having noticed a WUWT post. RS has picked out one obvious problem – which, oddly enough, the WUWT commentators notice too. A further one comes up when our hero attempts to probe these concepts further:
In the scientific community, for both a law and a theory, a single conflicting experiment or observation invalidates them. Einstein once said:
“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”
So, let’s examine our topics in that light. Newton’s descriptive law of gravity, based on mass and distance, are there any exceptions? Not to my knowledge, except possibly on galactic sized scales, black holes and probably on very, very small sub-atomic scales. In everyday life, Newton’s law works fine. How about Einstein’s theory of gravity (Relativity), any exceptions? None that I know of at any scale.
That rather forgets the “anomalous” precession of the perihelion of Mercury, as well as some more esoteric effects. But it also blows a hole in the idea that a single conflicting experiment invalidates a theory. That just isn’t how science works. I find I wrote about science before but didn’t cover this point, perhaps because it was too obvious. So, the unexplained precession of Mercury didn’t suddenly cause everyone to lose all faith in Newtonian gravitation. For any number of reasons. It still worked, obvs, in all the places it had worked before. And, well, maybe the observation was wrong? Who knows, whenever this kind of thing happens people will make lots of suggestions as to how to rescue it: perhaps there was a dust belt between Mercury and the sun?
One (well, not just one, but I’ll pick this one out) of the other examples is dubious, too: is 6 + 6 = 12 really a fact, or is it a definition? What, after all, is 12?
[Update: since I’m browsing Einstein’s Philosophy of Science:
Theoretical holism and the underdetermination of theory choice by empirical evidence are the central theses in Duhem’s philosophy of science. His argument, in brief, is that at least in sciences like physics, where experiment is dense with sophisticated instrumentation whose employment itself requires theoretical interpretation, hypotheses are not tested in isolation but only as part of whole bodies of theory. It follows that when there is a conflict between theory and evidence, the fit can be restored in a multiplicity of different ways. No statement is immune to revision because of a presumed status as a definition or thanks to some other a priori warrant, and most any statement can be retained on pain of suitable adjustments elsewhere in the total body of theory. Hence, theory choice is underdetermined by evidence.