Editing Soap bubble (section)

{{short description|Thin film of soapy water enclosing air}}

[[File:Reflection in a soap bubble edit.jpg|thumb|A soap bubble]] 
[[File:Girl blowing bubbles.jpg|thumb|Girl blowing bubbles]]
[[File:Soapbubbles1b.jpg|thumb|Many bubbles make [[foam]]]]
A '''soap bubble''' (commonly referred to as simply a '''bubble''') is an extremely thin [[soap film|film]] of [[soap]] or [[detergent]] and water enclosing air that forms a hollow [[sphere]] with an [[iridescent]] surface. Soap bubbles usually last for only a few seconds before bursting, either on their own or on contact with another object. They are often used for children's enjoyment, but they are also used in artistic [[performance]]s. Assembling many bubbles results in [[foam]].

When light shines onto a bubble it appears to change colour. Unlike those seen in a [[rainbow]], which arise from differential refraction, the colours seen in a soap bubble arise from light [[wave interference]], reflecting off the front and back surfaces of the thin soap film. Depending on the thickness of the film, different colours interfere constructively and destructively.