Name: Emily D.
Hi, I am trying to learn about why colors show up in
spilled gasoline. Is there a web site I can visit to learn more about
The short answer to your question is that the thickness of the film of
gasoline is about the same as the wavelength of visible light, which is
about 400 to 700 nanometers. When light passes through films about as thick
as their wavelength the rays of light reflect off both the front and back
surfaces of the film giving rise to constructive and destructive
interference of the light. You see the same color producing effects in
As to a website -- I don't know of one off hand, but if you look up "light
interference" on a site such as www.britannica.com or
www.about.com, or www.google.com you will be flooded with sites at any level
of sophistication you wish.
Click here to return to the Physics Archives
Update: June 2012