Tyndall Effect (particles interacting with light)

Colloid: A dispersion of particles of 1 substance (dispersed phase) throughout another substance or solution (the continuous phase). Differs from a "true solution" in which the particles are larger.

Tyndall Effect: The scattering of light by colloidal-size particles (NOT particles in a "true solution"--those are too small). Beam of light ("path of the light") is visible/detectable.

COLLOIDAL PARTICLES ARE BIG ENOUGH TO SCATTER THE LIGHT.

http://www.youtube.com/watch?v=k5HMVIb4J7A&feature=related

BLUE SKY / RED SUNSET
http://www.youtube.com/watch?v=Eo1WoKfJfkA&feature=related

- blue light scatters MORE EASILY than red light
- red/orange light scatters the LEAST
- gradual addition of colloidal particles makes it gradually more difficult for the light to pass through "the container"--"as it gets saturated...more and more light gets scattered at the beginning...will see the differentiation of colors of red, orange, and blue (sunset)"
- observing light traveling the LONGEST/FURTHEST throughout the atmosphere (orange/red) as opposed to traveling DIRECTLY/SHORTEST throughout the atmosphere (blue)

http://www.youtube.com/watch?v=sEB-6uxtxyE&feature=related