validation from data is also insufficient

[cal]

hihi, all -

just to throw in another odd fact, remember that ptolemy's model of the solar
system was much more accurate than copernicus' for many years (i think it was
even a few hundred years), until the sun-centered model started to use
ellipses (after kepler and newton) and the data got lots better

validation from data alone is not sufficient (with enough parameters, any
model can mimic any behavior to some degree of accuracy) - there should also
be some kind of model plausibility argument, based on theory or something
(part of good modeling is making good choices of these somethings)

if this sounds too wishy-washy, just remember that physics is in the same boat
here - predictions from some physical models have been shown to match the
appropriately measured data for a very long time, and that combined with the
theoretical simplicity and completeness (which is not perfect, of course) of
the corresponding explanations leads us to think too often that the models are
correct, instead of merely well-validated

it was after many years of gradually improving measurements that the anomalies
in some of the consequences of newton's gravitational laws led a few people to
look for better descriptions of gravitation, which led to relativity (and a
host of practical philosophical problems about model correctness - newton's
model is wrong, but it is very, very good across a wide range of conditions)

more later,
cal


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