From: D. F. Siemens, Jr. (dfsiemensjr@juno.com)
Date: Sun Oct 19 2003 - 19:48:26 EDT
On Sun, 19 Oct 2003 19:26:21 -0400 George Murphy <gmurphy@raex.com>
writes:
> Don Winterstein wrote:
>
> Keith Miller wrote:
> "Any accepted scientific theory is simply the best existing
> unfalsified explanation for the observations already made. This is
> as
> true for physics as it is for evolutionary biology."
>
> Keith, I liked your post and mostly agree with it, but for my
> edification I'd like to hear your (or anyone else's)responses to
> two
> sets of questions:
>
> (1) Given what we know about Mercury's orbit today, wouldn't
> the
> inability of Newton's theory of gravity to account for the motion
> constitute falsification? That is, Newton would predict one thing,
> and we'd observe another. Yet, if we didn't have an alternative
> such
> as general relativity or something similar, wouldn't physicists
> still
> accept Newton even though he'd been so falsified?
> .............................
>
> The anomalous precession of Mercury's orbit was known by at
> least the mid 19th
> century yet physicists & astronomers did not consider Newton's
> theory to be falsified.
> You could, e.g., postulate sufficient mass between the sun &
> Mercury, in the form of a
> planet (Vulcan), or dust, or meteorites, to cause this precession.
> Leverrier, who had
> predicted Neptune & solved a similar problem for the orbit of
> Uranus, devoted a good
> deal of effort to the search for Vulcan. If you wanted to be a bit
> more radical you
> could keep Newton's laws of motion & his idea of a universal
> gravitational but change
> the dependence of the latter on distance from 1/r^2 to 1/r^(2 + s)
> with s a small
> number.
>
> All of these ideas illustrate Lakatos' approach that I
> sketched earlier -
> maintaining the hard core of a theory by modifying the protective
> belt of auxiliary
> hypotheses. But in doing this Newtonian theory wasn't predicting
> any "novel facts".
> Einstein's theory did that by explaining the anomalous precession of
> 43''/century in a
> natural way. & this counts as a "novel fact" for Einstein's theory
> even though the
> observational result had been known for quite awhile because it
> wasn't used in the
> construction of his theory.
>
> In Keith's statement, "best" would need to be understood as
> "most progressive"
> (in the sense of being better able to predict novel facts) or
> perhaps in some cases
> "least regressive" (in the sense of having to do the least
> adjustment of the protective
> belt). In the case of Mercury's orbit both Newton's & Einstein's
> theory were
> "unfalsified" - though of course the failure to detect Vulcan or
> other necessary masses
> counted more & more against Newton as time went on.
>
> & for all that Boltzmann said that elegance should be left
> to tailors, it does
> play a role in evaluating theories. The proposal to replace 1/r^2
> by 1/r^(2 + s) is
> just ugly & would be acceptable only under duress.
>
> Shalom,
> George
>
George,
You left out my favorite solution--all the mass of the sun concentrated
in a central cylinder. As to inelegance, I've read that there's a new
theory that gravity does not fall off according to the square of the
distance at great distances. There did not seem to be a threat involved.
Dave
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