Why is red light seen at the bottom of a soap bubble?

[rojasharma]

which of the following colours would you expect to see near the bottom of a soap bubble, red or blue?...i think red is... because it has longer wavelength?

 

[Dick]

Maybe. I'd be more convinced if you explain what wavelength has to do with it.

 

[rojasharma]

if the thickness of the soap bubble is much smaller than the wavelength of light, the result is destructive interference (dark color). the thickness required to produce constructive interference for red is larger than that required for blue. ...

 

[rojasharma]

but we see all the rainbow colors in soap bubble because thickness of the bubble varies...the bottom of the bubble is thicker...therefore we see red at the bottom/??

 

[Dick]

if the thickness of the soap bubble is much smaller than the wavelength of light, the result is destructive interference (dark color). the thickness required to produce constructive interference for red is larger than that required for blue. ...

Not bad. Though if the thickness is much smaller than wavelength of light then you won't see much interference at all. But I'll take that explanation.