Goethe's Theory of Colours, Part 3 - Colours in Nature

Third part of a presentation of approach to colour. It discusses colour phenomena in the atmosphere and turbid media. What he called “Physical colours“, that do not depend on the specific material properties of the objects involved. I also mention the “Chemical colours“, in particular the so called “Steigerung“ (the picture, I use to illustrate that, is borrowed from the exhibition “Experiment Farbe“ at Goetheanum, Dornach, in summer 2010) Part 4 follows at