On 07/05/2004, at 10:35 PM, Brian Chandler wrote:
On Fri, 07 May 2004 21:44:45 +1000
Andrew Fildes <afildes@xxxxxxxxxxxxxx> wrote:
On 07/05/2004, at 5:26 AM, Brian Chandler wrote:
I have bad news for you. I surmise that your optics textbook was
written
by Plato, and unfortunately some of his ideas have been found to be
wrong.
What?! Name three!
AndrewF
http://www.pbase.com/afildes
Hmm. Well, I found Plato's "Postulates" for Optics on p. 195 of Richard
Gregory's excellent tome "Mind in Science". Here are the first three:
1. The rays emitted by the eye travel in a straight line.
2. The figure enclosed by visual rays is a cone which has its apex at
the eye and its base at the edge of the object looked at.
3. Objects on which the visual rays fall, are seen.
Nuff sed?
Brian Chandler
Nah! Need a precise translation of 'visual rays' - were actual rays meant or was it used in another sense related to cognitive perception and projection rather than physical projection. Given Plato's disdain of the actual existence of a material world in a real sense, it seems thoroughly inconsistent with his epistemology. How can one 'enclose' the figure of a mutable shadow?
Somewhere, deep within, you already know that he was right.
So there!
AndrewF
<x-tad-smaller>http://www.pbase.com/afildes</x-tad-smaller>
