Bubbles....

Wonderful World of Soap Bubbles....

Its always a fun challenge to photograph soap bubbles.  With a little, well maybe a lot, of patience, you can get some very interesting images. I hope you enjoy my last efforts.

A soap bubble is a very thin sheet of water sandwiched between two layers of soap molecules. The film of soapy water surrounds a bubble of air. Soap molecules have one end that repels water, and one that attracts it, and these molecules move to the inner and outer surfaces, thrusting their water-repelling ends out into the air, and their "heads" inwards. Without such molecules on the surface, the bubble would spontaneously break apart into tiny water droplets. Surface tension causes the bubble to be spherical, which is the shape that gives the minimum surface energy - the lowest ratio of surface area to volume.

How soap bubbles change colors.....

The colors of a bubble are dependent on the thickness of the film. A bubble becomes thinner and thinner as it dries out (due to evaporation), before finally popping. As the surface film of the bubble becomes increasingly thinner, a change in overall color can be seen. Thick walls cancel out longer wavelengths in the red range. As the bubble film gets thinner, yellow wavelengths are cancelled out. As it gets even thinner, green light is lost. Beyond this point, even shorter wavelengths in the blue wavelength range disappear.

The resulting colors are a combination of the colors that do not undergo destructive interference and their degrees of constructive interference. Blue-green colors do minate in thicker films and yellow hues in thinner films. Eventually, the film becomes too thin to create interference of visible wavelengths, as all wavelengths are cancelled out. At this point the bubble appears colorless. Against a black background the bubble surface could appear black.