This is really interesting. In Principal Component Analysis, eigen values greater than one could be perceived as factors after a rotation (verimax/promax). Eigen in German means self or one's perception (sometimes from the self) (via wikipedia, not me). The translation of eigengrau means self gray/ashen or one's perception of darkness. Pretty cool word and it would make and awesome band name. Nice fact of the day!
Does this all mean that we need contrast to experience the color black, and if that is the case, does black even exist? Or is it simply that we only see eigengrau but that it seems darker because of the contrast? If that is the case, black isn't even a figment of our imagination, it is a physical creation of our shitty eyes? I mean, if we are in complete darkness and see something lighter, that seems to be the case to me.
I kind of know where to go with this post but I don't want to write a wall of text. As a young Blumperz, I remember reading this article on color vision and the evolution therein.
http://www.imaging.org/ist/publications/reporter/issues/Reporter20_1.pdf In general, humans see black, white and red similarly. Variations exists with other colors, but perception of colors is remarkably stable across cultures. The famous work of Berlin and Kay (1969)
http://en.wikipedia.org/wiki/Basic_Color_Terms:_Their_Universality_and_Evolution points out that color categories are indeed universal. Color combinations are subject to cultural limitations which is what relativism proposes. Black does exist, but not within our perception. Take a dog whistle as an example. You don't hear the high pitch frequency because it is beyond our perception, but the frequency exists. Black is no different.
Things get even more bizarre when culture/language shapes what we actually hear (
http://www.ncbi.nlm.nih.gov/pubmed/6747097). Because most of us only speak English, we can only perceive English based phonemes and syntax. Crazy stuff. As an adult, it is difficult for me to even perceive Mandarin Chinese because I lack the cognitive structures to actually hear it. I gotta stop or I'll write a freaking thesis here.
