On Fri, 25 May 2001 09:53:57 -0600 John W Burgeson <burgytwo@juno.com>
writes:
> George noted that "All data, as is often said, is theory laden. &
> of
> course in turn, all theories have to be tested against data. &
> there
> isn't any cookbook formula that tells us how to keep those two
> requirements in balance."
>
> In agreeing with George on this point, I also note that it was
> Harold
> Jeffreys, the British astronomer, who showed (about 1920 I think)
> that
> any set of observational data could be explained by an infinite
> number of
> theories.
>
> The above is from memory; I cannot find a citation or even my own
> notes
> to verify it, so if I'm wrong, please set me straight. I do have one
> note
> that this claim appears in one of the essays in GAMBLING ON GOD by
> Jeff
> Jordan (1994) but there is no citation in that book, just the claim
> itself.
>
> I also have a note (too many of these) that it was Jeffreys, a
> fairly
> famous (with his wife) British scientist of the last century, who
> was
> instrumental in keeping the "continental drift" idea from gaining
> recognition for many years.
>
> Burgy (John Burgeson)
>
> www.burgy.50megs.com
>
Burgy,
I don't know about Jeffreys, though perhaps he made the point most
directly, (I'd like to have the reference)but the infinity of theories
has earlier roots. P[aul] Koenigs, "Sur les chaines secondaires," Comptes
rendues, 133:621-4 (21 octobre 1901) showed that any type of mechanical
motion may be generated an infinite number of ways. Henri Poincare
generalized this to the claim that any set of data meeting the least
action principle has an infinite number of mechanical models. Science and
Hypothesis and Mathematics and Science: Last Essays, pp. 167f and 4f,
respectively, in the Dover editions. I don't have the dates of the
original publications at hand, though 1905 comes to mind for the former.
HP died in 1912, and the latter was published posthumously. Sorry, but
those knowing French will have to supply the accents. My e-mail program
produces garbage when I try to insert them.
Dave
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