On Wed, 28 Aug 2002 23:58:56 -0400, elixsil...@citlink.net wrote: >My research shows the Tyndall Effect or Phenemon refers to the conical shape >a flashlight beam will take as it passes through a highly colloidal sol. How >pray-tell does the thin line of a laser equate to this?
As I posted on 8/25 to an earlier inquiry (yours?): "The reason Tyndall spoke of a 'cone' and modern experimenters don't is due to the nature of the light source. Lasers emit a 'beam' of light where the edges are near to parallel (collimated) which is why you see a relatively small spot when the laser is directed towards a far wall. Flashlight emissions (due to the nature of the reflector) are uncollimated and spread very quickly as demonstrated by the much larger spot when the flashlight is directed in the same manner as the laser. If you want to see a 'Tydall cone' then use a larger container and a flashlight with a small reflector, such as the tiny MagLights..." To expand a bit: "The Tyndall effect may be explained as follows. If a beam of converging rays, say, from a projection lantern, is passed through a liquid containing minute particles in suspension, each of these particles scatters the light rays that fall on it, becoming, in a sense, a luminous point. Thus, the entire path of the rays through the liquid becomes visible..." Source: Colloids & The Tyndall Effect from General Chemistry by N. Glinka, Peace Publishers, Moscow, circa 1960s As should be apparent from the above, the Tyndall effect is the appearance of the reflections themselves , not the shape which manifests due to the characteristics of the light source. Your "research" needs to be expanded a tad. The internet is crammed with explanations of this effect. A simple search of google.com on 'Tyndall effect returned 111,000 references and took a mere .41 seconds! Regards, George Martin >Johnny Silverseed -- The silver-list is a moderated forum for discussion of colloidal silver. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: silver-list@eskimo.com Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>
