Bubbles (water) are usually translucent, and transparent too.
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one where the dimensions investigated are much larger than the wavelength of the photons in question), the photons can be said to follow Snell's Law. Translucency (also called translucence or translucidity) allows light to pass through, but does not necessarily (again, on the macroscopic scale) follow Snell's law; the photons can be scattered at either of the two interfaces, or internally, where there is a change in index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with the overall appearance of one color, or any combination leading up to a brilliant spectrum of every color.
But foam is always white, though it is made up of transparent constituents (waterbubbles).
I am not asking why foam is always white. I am asking how a transparent material, like water in bubbles, in big amounts will produce white light.
Now this might seem obvious, because transparent materials are reflecting off all light that is shone on them.
But, white (natural) light is a combination of certain wavelengths.
White objects fully reflect and scatter all the visible wavelengths of light. While there is no single, unique specification of "white light", there is indeed a unique specification of "white object", or, more specifically, "white surface". A perfectly white surface diffusely reflects (scatters) all visible light that strikes it, without absorbing any, irrespective of the light's wavelength or spectral distribution. Since it does not absorb any of the incident light, white is the lightest possible color. If the reflection is not diffuse but rather specular, this describes a mirror rather than a white surface.
So basically, white objects, like foam, should reflect all visible wavelengths of light, though they are comprised of transparent objects, bubbles, that are refracting all visible wavelengths.
And, wet objects are usually darker, not brighter.
So this cannot explain it either.
- So how does adding bubbles together change from total refraction (transparent) to total reflection (white) of all visible wavelengths?