On Tue, Jan 8, 2013 at 1:06 PM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: >> given that weather patterns have been known to follow cycles at least >> that long. > > That is not a given. "Weather patterns" don't last for thirty years. > Perhaps you are talking about climate patterns?
Yes, that's what I meant. In any case, debate about global warming is quite tangential to the point about statistical validity; it looks quite significant to show a line going from the bottom of the graph to the top, but sounds a lot less noteworthy when you see it as a half-degree increase on about (I think?) 30 degrees, and even less when you measure temperatures in absolute scale (Kelvin) and it's half a degree in three hundred. Those are principles worth considering, regardless of the subject matter. If your railway tracks have widened by a full eight millimeters due to increased pounding from heavier vehicles travelling over it, that's significant and dangerous on HO-scale model trains, but utterly insignificant on 5'3" gauge. ChrisA -- http://mail.python.org/mailman/listinfo/python-list