The Riddle (?) Of The Rainbow
Just like practically everyone else, I was told very early in life that the rainbow has 7 colors (and learned their names by rote). Whenever I see a rainbow, I try to count. It is far from obvious to the average eye (to the best of my knowledge, my color-vision is pleasantly average) that there are actually seven colors - it could very well be 5 or 6 - especially at the blue end, it is very hard to clearly discern the triplet (violet, indigo, blue). We talk about human color perception here, not the ACTUAL number of colors - scientifically, there is of course, a continuum of visible frequencies in sunlight and in the rainbow.
I don't think in Indian languages, there are even words for 'indigo', 'orange' ... but mysteriously it appears even in ancient India, the rainbow was said to have 7 colors. More mysteries - to self - here: Does Surya's (the Sun God) chariot have actually 7 horses and if so did these 7 represent the colors of the rainbow or something else? More basically, did folks here in India know that the rainbow came from a play of Sunlight (unlikely)?
Is it the case that in some culture, some folk-tradition, the rainbow has a different number of colors?
Note 1: And here is an intriguing bit from the online wikipedia article on the rainbow:
It is commonly thought that indigo was included due to the different religious connotations of the numbers six and seven at the time of Isaac Newton's work on light, despite its lack of scientific significance.
Well, that, if true, thickens the plot quite a bit!
Note 2: Probably, most Indian languages have names only for very few colors. It is more like the same word stands for a whole range of colors - 'Nila' in Sanskrit can be blue or dark-blue-tending-to-black or anything in the middle. Does this skimpy color vocabulary indicate a lack of sensitivity to colors and their nuances? I don't think so, but must say, in view of this limited set of names, it even feels 'realistic' to suspect the Indian tradition originally assigned not 7 but probably only, say, 5 colors to the rainbow ('Panchavarnam')!