Sunday, August 31, 2008

What Do Rainbows Mean?

In our scientific age, we tend to see the rainbow as a purely optical phenomenon, or we might think of the end of the rainbow as the place where leprechauns hide the elusive pot of gold.

The Greeks believed the rainbow was a path between the earth and heaven. In Norse mythology the rainbow was seen as a bridge between Ásgard and Midgard, the realms of the gods and mankind respectively. In Chinese mythology, the rainbow was regarded as as a slit in the sky sealed with stones of five different colors.

In the story of Noah, the rainbow serves as a sign of God’s promise that the earth will never again be flooded. In the Stuppach Madonna by Matthias Grünewald (c.1475-1528), above, or the painting by Joseph Anton Koch (1768-1839), below, it serves more broadly as a symbol of God’s covenant.

Durer’s famous engraving Melancholia features a rainbow, though scholars differ on whether to read it as a hopeful or a pessimistic sign.

Next week we’ll look at rainbows in more scientific terms. But for now we might notice that Grünewald breaks a basic optical law of rainbows, namely that the colors of the rainbow should always be lighter than the background, because the colored light of the rainbow is added to the light in the scene behind it.
More about rainbows in my book: More in my book: Color and Light: A Guide for the Realist Painter
Previously: The Science of Rainbows
Further Reading: Rainbow Bridge by Raymond Lee, link.


Anonymous said...

Hmm, looks to me as if Grunewald uses the rainbow also as some kind of halo for Maria and Jesus. Seems also that this trick does push the view of the beholder into the centre. At least to me. The scene is overloaded with details, but the two heads seems different, lighter; the faces are the calm spot but still alive. Strange but effective.

Jared Shear said...

I had the opportunity to observe a rainbow yesterday, and in looking at it, I noticed that the sky in the inner circle of the rainbow seems to be a lighter value than the sky on outside of the rainbow. I was curious if you some of the other readers have ever observed this phenomenon at all?....and was curious for the reason why?? Looking at a few photos of rainbows, I noticed this phenomenon popping up again.

James Gurney said...

Alandiras--good observations.

Jared, you're absolutely right, the region inside the rainbow is lighter. I'll try to address that either next week or the week after.