Beauty,Spring 2005
Second Web Papers
On Serendip

As I watched the rainbow morph and arc as we drove along, my mind wandered from the simple beauty of the colors to the science of a rainbow. I asked myself why we were able to see the full arc this time when we had never seen it before. To answer myself, I took what I knew of rainbows and angles to try and understand. I knew that rainbows were a phenomenon that occur when the sun is out while it is raining. The sunlight hits the rain drops at a certain angle which allows the light to be refracted, creating the visible spectrum of colors. What we were witnessing, I deduced from my limited knowledge, was the rain from different angles. The path of the light from the sun was not moving, the rain was not moving (at least not side to side), but we in the bus were. The bus was changing our angle of vision. The refracted light was coming at us from a different angle, causing the rainbow to look like it was arching to follow us. The simple science of understanding what was happened enhanced my experience. Since I knew mundanely what was happening to cause me to see the full arch of the rainbow, I was able to realize how truly beautiful it was. Not only that, but I felt pleased that I was able to understand it, at least a little. I get a similar satisfaction when I am able solve a complex math problem. While I may not know all about the angles and arcs and why we see it like that, I could still find the science of the experience beautiful.

I was moved to write about this experience when I read a chapter from Philip Fishers book Wonder, the Rainbow, and the Aesthetics of Rare Experiences. The way he described a rainbow spoke to me and enhanced my personal experience. He describes seeing a rainbow as a rare and unexpected experience. We see them enough to know what they are, but not enough to be bored with them (Fisher 34). They still hold a certain "awe" value. Although we are aware that they are the product of sun during the rain, they retain a certain magical quality about them. We associate them with leprechauns and pots of gold and Dorothy's dream, and maybe our dream too. But we find them beautiful and intriguing not only because of the myths and stories that we were brought up on, but also because of the simple wonder and the colors of the rainbow. Inevitably when someone sees one he or she shouts out "Wow! A rainbow! Look!". It is just like when it starts to snow. No matter how many times you've seen snow, the experience of seeing it fall is still awe-inspiring. We all feel the need to point it out to each other. It so strikingly beautiful that you want everyone else to experience the beauty as well.

The most amazing thing about my recent rainbow experience was not the "awe" value or the colors, but the actual arc of the rainbow and the science behind it. I was fascinated with the arc of a rainbow in a way I had never been before. As Fisher explains, it was the arc that helped scientists explain the rainbow. For the Greeks, geometry was the meeting point for science and ascetics. It was the beauty and wonder of the arc that made it accessible for geometry. It is the arc, Fisher explains, that led to our understanding of the rainbow. "Just as the rainbow drew and held attention, it seemed, in the geometrical regularity of the shape, to point out the path by which it could be understood" (Fisher 36). The beauty of the semicircle allowed the Greeks to figure out that it "was a phenomenon of light rather than matter. This made it unique among the objects of beauty, noble in a way that the material beauty of flowers or of a human face could never be" (Fisher 36). The arc is symmetrical and perfect, too perfect for nature. That is how they knew that they could explain it with geometry. This quote also helps explain why we find them so beautiful. The shape is so unique and perfect that it is impossible to not find it beautiful. We are drawn to its shape in a way that we could never be drawn to a flower.

Even though Fisher explains the importance of the arc, I still want to know more about it - like why it forms a nearly perfect semicircle. It was in 1637 that the mathematician and philosopher Rene Descartes fine tuned the ideas of how a rainbow works. He did this by simplifying the problem from many raindrops to one. He asks that we imagine light being refracted in one drop:
Imagine how light is refracted as it enters the raindrop, then how it is reflected by the internal, curved, mirror-like surface of the raindrop, and finally how it is refracted as it emerges from the drop. If we then apply the results for a single raindrop to a whole collection of raindrops in the sky, we can visualize the shape of the bow. (my.unidata.ucar.edu)
So the sun hits the curved surface of the drops and reflects the light back out to create the bow. To see the refraction, you must have your back to the sun which must be hitting the drops at a special angle, known as the Descartes or rainbow ray. If we are viewing the rainbow along this angle, then we can see the rainbow brightening. That is why as we moved in the bus, we were able to see the full arc. Our angle changed in respect to the rain and different parts of the rainbow got brighter while others parts faded. The shape is also deeply connected with where the viewer is in respect to the source of light. As we changed in position, the angle also changed. The angle is essential: it is the difference between seeing the rainbow and just seeing rain. Other factors in the shape of the arc is what time of day it is, since that changes the angle of the sun. It made sense to me to learn that the best time to see the full arc is at sunset, which is the exact time we saw the full rainbow arc.

The angle also effects how we see a rainbow and causes each individual to see a different rainbow. Where you are standing in relation to the sun and the rainbow ray determines how bright or how much of the rainbow you are going to see. It is because of this reflection that each person sees a different rainbow. Fisher says "Each person's rainbow, like his or her reflection in a pool of water, is uniquely determined by the point where he or she stands, by the angle between eye, raindrop, and sun" (Fisher 36-37). Each rainbow is unique to us, since it is not a tangible thing. It is the product of light, reflection, and our eyes. I would think that this would diminish my finding it beautiful, but it does not. Even though we know they do not exist, they are no more than reflections- a creation of ours eyes. That they "can have no reality but mere appearance" (Fisher 37), as Roger Bacon says. Without us, there would be no such thing as a rainbow. Other animals cannot see them, even though they have similar eyes. We are the creators of our own personal rainbow. Perhaps that why we are still so fascinated by them. When our eyes react to the refracted light, they create a rainbow that only we see. And what we create is beautiful, symmetrical, and unique. Or perhaps we will never really know exactly why each of us finds a rainbow so beautiful. All I can say is that for myself, understanding the workings of a rainbow has made them all the more beautiful.

References

Fisher, Philip. Wonder, the Rainbow, and the Aesthetics of Rare Experiences. London: Harvard University Press. 1998.

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