Re: Just what is a particle?

["Glenn A. Carlson" <gcarlson@MAIL.WIN.ORG>]

Waves diffract, constructively and destructively interfere, disperse,
etc.; particles do not.  Particles collide with other particles (i.e.,
they exchange energy and momentum with other particles over short
distances and times), have definite momentum and position, etc.; waves
do not.

"Wave" and "particle" are idealizations.  Pointing out that "particle
beams interfere" does not refute the usual meaning of these terms,
but, rather, it illustrates the meaning of "wave-particle duality,"
i.e., electrons and photons, for example, are neither wave nor
particle, but, depending on the circumstances, behave **as if** they
were one or the other.

For particles, think of billiard balls; for waves, think of water
waves.  To the extent that this distinction becomes cloudy (or even
contradictory) in a particular real situation, we glimpse the mystery
of nature.

Glenn A. Carlson, P.E.
St. Peters, MO
gcarlson@mail.win.org

> Subject: Just what is a particle?
> Date: Thu, 17 Feb 2000 17:29:57 -0600
> From: Cliff Parker <cparker@CHARTER.NET>
>
> Hugh Haskell wrote in an earlier post --  Photons are particles (not like
> electrons or protons, but particles nevertheless)
>
> I would like some discussion on this point as I try to clarify my thinking.
> What characteristics are necessarily present in order to call something a
> particle?  I have listed a few characteristics particles often seem to have and
> thoughts about how each may apply to photons.  Comments, clarifications,
> disagreements, and instructions are hereby solicited.

 [snip]

> Cliff Parker