Archived posting to the Leica Users Group, 2003/07/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On 2003-07-16 saganicc@MSKCC.ORG (Saganich, Christopher/Medical Physics) thoughtfully wrote: >As a physicist I would to add that until the middle of the 1800's, the generally >accepted theory of light was the particle picture. In this viewpoint, advocated >by Newton, light was considered to be a stream of tiny particles. However, in >the late 1800's, the particle picture was replaced by the wave theory of light. >This was because certain phenomena associated with light, namely refraction, >diffraction and interference, could only be explained using the wave picture. >In the early 20th century, experiments revealed that there were some phenomena >associated with light that could only be explained by a particle picture. Thus, >light as it is now understood, has attributes of both particles and waves. > >Chris Saganich Ah but remember your quantum electrodynamics: all the wave behavior of light is entirely explainable through quantum theory, while some behavior of light, indeed some of which photographers love the best (I'm thinking of partial reflection) are not explainable at all by wave theory - only a journey into QED will explain them. Engineers (like I used to be) don't care as long one theory or the other solves the problem! Grin. There's a wonderful little book by, of all people, Richard Feynman, called "QED" that does a very good job of explaining all of this. I remember he points out that our eyes need only be an order of magnitude more sensative and we'd not be debating it at all because we're that close to being able to image individual photons. An amazing thing when you think about it. I cannot, however, do the math. :) Adam - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html