Why milk appears white in color?!
Why milk appears white in color?
Milk of any origin is white in color .... what is the reason?
Answers:
Because milk reflects the wavelengths of light equally. Red things reflect "red" wavelengths, blue reflects blue. White reflects all the colors - combine to make "white."
calcium
Milk is an emulsion of tiny fatty droplets in water. Emulsion meaning; the droplets do not solve into the water but remain suspended in it due to their small size. The "mist" or "fog" of droplets creates the effect of opaqueness and whiteness just as in mist or fog as we know it from bad weather-conditions. Indeed the whiteness has to do with the way light is reflected and absorbed by that fog, giving it the white appearence.
Why is milk white? was a question asked in my Summer, 2003 newsletter from the dairy that delivers my milk, Royal Crest Dairy in Denver. The answer given was: "Milk contains casein, a milk protein rich in calcium that is white." Well, whether it is the casein or the calcium that should be white, this answer is incorrect.
The casein is soluble either in the water or the fat of the milk emulsion, and would be colorless and transparent in either case. Calcium, of course, is not white either. Even calcium carbonate is clear and colorless in a good crystal.
The whiteness is due to the scattering of light by the colloidal particles of the milk emulsion. Just the fact that we get white shows that there is no absorption, so whatever is there is transparent. This is true of most whites. The excellent white pigment titanium dioxide is actually made of clear crystals, dispersed as colloidal particles. Nearly all whites are the result of scattering from colloidal-sized particles. Colors, like green, may be produced in transmission by absorption of other colors; no such process can produce white, which in fact is a subjective color, existing completely in the visual sense. White is a very special color.
calcium