Change the chapter
(a) As a soap bubble thins it becomes dark, because the path length difference becomes small compared with the wavelength of light and there is a phase shift at the top surface. If it becomes dark when the path length difference is less than one-fourth the wavelength, what is the thickest the bubble can be and appear dark at all visible wavelengths? Assume the same index of refraction as water. (b) Discuss the fragility of the film considering the thickness found.
Question by OpenStax is licensed under CC BY 4.0.
Final Answer
  1. $35.6 \textrm{ nm}$
  2. The soap bubble will pop with the slightest breeze.
Solution Video

OpenStax College Physics Solution, Chapter 27, Problem 77 (Problems & Exercises) (4:29)

Sign up to view this solution video!

View sample solution

Calculator Screenshots

OpenStax College Physics, Chapter 27, Problem 77 (PE) calculator screenshot 1