Colour Theory. Goethe.
Goethe's Color Wheel
Colours are seductive. Good painters love colour and are wary of it at the same time, because of the difficulty in doing it justice. The glorious richness and subtlety of colour in nature and made things can dazzle and overwhelm you for hours at a time. Some expressionists in art so love colour that they attribute emotion to it, as in Franz Marc's yellow cow of sublime happiness (yellow expressing joy), which I used at the top of a recent entry.
Science is just as seduced by colour, or it used to be, when it still looked at the world with wonder rather than through the agonistic field of grants and rival theories. Newton is attributed with laying the foundations of the science of colour, the same Newton of gravitational eureka, with apples falling on his head. Most famously he decided that ordinary 'white' light is comprises a spectrum (rainbow) of colours - red, orange, yellow, green, blue and violet. Just as famously exhibited in his prism experiments, as below and hard-wired into the synapses of every Pink Floyd fan alive.
Enter Goethe. Polymath, and probably most famous for his play Faust. Goethe was passionate about colour, and published a book on it that was one of his proudest, but in some ways least appreciated, achievements. History also hasn't been kind to Goethe's theory, either completely ignoring it or lavishing it with the patronising chuckle modern science usually reserves for any work done before the 20th century, or at a stretch the 19th. Like the mistake often made in understanding evolutionary theory, that it's all about 'progress' to more sophisticated forms over time, science is seen as unidirectional, from past to future, from ignorance to knowledge. But we have known many profound things over the centuries that we've since forgotten. And in other fields you don't have that same hubris - which modern dramatists for example think that Shakespeare was some sort of starting point, which we've improved ever since? Newton still reigns supreme, with of course many refinements in the centuries since he first published his own theories.
And yet as Mitchell Feigenbaum and other modern scientists have recently discovered, Goethe's theory is of a level of sophistication that can make you gasp. Get hold of a copy of Goethe's book and you'll find that it's a riveting read, which is not what most could say about Newton's Opticks. An added benefit is that many if not most of the experiments Goethe describes can be done with a minimum of equipment, at home and with very little skill. And the phenomena he describes are the complex, many-faceted experiences we have every day with colour, rather than the artificial world of the lab. And you'll start to see colours in completely new ways, and in places you'd never thought to look.
Modern science again being what it is, all of these strengths of Goethe's work are seen as its real weakness. It's not 'scientific' enough, meaning Goethe refused to channel the phenomena into the idealised and controllable world of the lab. Yes at times he does talk about constructed phenomena, but his most vehement disgust for Newton's work derived from that prism above. Goethe was aghast that Newton took the results of this experiment in particular and generalised it to all of nature. It was less a disgust with a theory or a result of an experiment than it was with a methodology. Yes light behaves like this, in that specific situation i.e. of a reasonably well defined beam of white light entering a highly specialised object (the prism). But to then extract from this the entire nature of colour and light seemed to Goethe an extraordinary conceit. It seems incredible that in all the years since it's Newton who has ridden the white horse of righteous knowledge, and Goethe has worn the dunce's cap, given this entirely practical and sensible objection.
For Newton again, white light comprises all of the colours of the rainbow. They are its components, which refraction through a prism reveals as the different wavelengths are (apparently) separated out. Of course there is much more to the Newtonian theory, which there isn't space for here, but this point is critical. For Goethe on the other hand it was all about the interaction of light and dark, with colour representing various degrees of darkening of light. This seems a bit weird at first, but if you read Goethe's section on coloured shadows you'll start to see where this is coming from. For example if you light a candle in twilight, and place a sheet of white paper on the opposite side of the candle to the setting sun, at a certain point in the setting of the sun the shadow the candle casts on the white paper will turn a breathtaking blue.
An interesting thing about Goethe's theory in comparison to Newton's, which I haven't seen much commentary on, is that it makes light and darkness coextensive with matter itself. For Newton light is what illuminates matter (or not, in which case you have darkness), like a torch or flame, as a separate thing. That makes colour and light a sort of surface, ephemeral thing, not part of things themselves but more a sort of veneer, or something 'on' things rather than in them. For Goethe colour is part of things themselves, in their very essence, and light and shade are states of matter itself. This is very close to the change Einstein wrought on ideas about matter and light, although the connection again isn't one I've seen made.
This theory may have something to do with Goethe's strong affiliation with the arts as well as science, for chiaroscuro in painting for example is all about the interplay between light and dark, and objects gain volume in the space of a painting via this interplay (beautifully shown in Jospeh Wright of Derby's A Philosopher Giving that Lecture on the Orrery, in which a lamp is put in place of the Sun, below).
You can see how the painting's volume derives largely from the sophisticated use of light and dark/shade. And even simple sketching with a pencil in art class teaches you that you add volume by adding shade (shading).
This has profound links with 3D vision as well, I'm now sure, and I was going to do a follow up on that shortly, because my own idea of what's going on there is getting a bit clearer, to me anyway.