Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] Galileo was wrong



Apropos Galileo there is an article in TPT Oct 2010 about "Is Magnification
Consistent?" in which the author brings up Feyerabend, who is claimed to be
science's worst enemy. Apparently Feyerabend said "The church at the time
of Galileo was much more faithful to reason than Galileo himself, and also
took into consideration the ethical and social consequences of Galileo's
doctrine. Its verdict against Galileo was rational and just, and revisionism
can be legitimized solely for motives of political opportunism."

Actually reading about Feyerabend I came to the conclusion that he had some
very good ideas. Looking at the article in the TPT the author is trying to
make the case that the magnification of a lens is consistent. But that is
not completely true when you consider the situation of something in the near
field where the magnification varies for different parts of a 3D object.

The author of the TPT article also makes the point that Galileo showed that
stars were round, and apparently that went into some of the arguments that
Galileo used. But of course this is entirely due to diffraction.

I think the TPT author completely missed Feyerabend's philosophical point.
At that time the telescope was considered to be a weak device, and the
consistency of magnification was not known, and there was no way to really
prove the Copernican hypothesis. The data could be fit equally as well by
the Copernican or Ptolemaic model. The Keplerian model was not considered
by Galileo. So under those circumstances the church could be considered to
have been the more rational. Feyerabend has arguments showing the Galileo's
ideas were not completely rationally consistent.

I found the TPT article to be a bit simplistic in its historical treatment
of Galileo and Feyerabend. And the author apparently is unaware that
scientific revolutions result in historical revisionism. Also he seems to
imply that Feyerabend did not understand lens magnification, but there is no
reference to a specific statement to show this. I suspect that Feyerabend
was talking about the historical view of telescopes, and not a more modern
view.

Another example just came to mind, that optical microscopes do not magnify
atoms is a perfectly good statement based on wave mechanics. I find the
author's insistence that there is a misconception that about magnification a
bit disingenuous. To check this out one needs to use some conceptual
questions about lenses. But he has made this claim on the basis of the
common statement that telescopes do not magnify stars. One could interpret
this shorthand as saying that "telescopes do not magnify starts enough to
see them". I would think that PER studies would be much more reliable about
finding whether there is a misconception.

How could the reviewer let some of these statements by? The author quotes
from the starry messenger some of Galileo's observations. Then next
paragraph claims they can't be true. But observations are data, and are
true as such, but must be interpreted. The author did not quote an
interpretation which can be possibly refuted. I would not have accepted the
article in its current form.

John M. Clement
Houston, TX