Physics Blog: Winter Break

Rainbows, Mirages, Sky

Rainbows, Mirages, and the color of sky at dawn and dusk are more than just a pretty site for one’s eye. They have a lot of physics behind them that can explain their nature and being. The leprechaun does not just find the pot of gold at the end of a rainbow, but can be enlightened by the physics that causes such a miracle. The refraction of various lights causes the colors that encompass our world. Many physics concepts such as dispersion, refraction, and others involve the explanation of the formation of rainbows, mirages, and the sky.
The topic of rainbows is very interesting, because the concepts involved are quite complex. Think about the time one sees rainbows; it is always after a rainstorm, light rain, or some type of precipitation. This is one of the factors that help form the rainbows. The sunlight that forms rainbows bounces off the water vapor and particles in the air and reflect back into your eyesight. The white light from the sun is not only reflecting off the water, but it is also refracting and dispersing from the drops. Only the refracted rays are actually seen in the eyes, because they form the colors and rainbow. Specifically, every raindrop shows one color of the rainbow. For example, every light reflected at 42 degrees is seen as red light. The various colors that make up a rainbow spectrum; red, orange, yellow, green, blue, indigo, violet, each have specific and different refractions. For example, blue light bends or refracts more so than the green light. The green light then refracts more than the red light, and so on. The prism that makes up the rainbow split into different colors, which form due to the refraction techniques. “Each rainbow is your own,” this is because each rainbow looks different compared to the rainbow seen from a friend’s companion (Rainbows: Lights and Optics).
Another physics phenomenon includes the mirages in a sky. Two layers of air at different temperatures form a mirage. Cold air is denser than hot air, therefore the boundary between the two layers can refract light. The easiest and most commonly known mirage is the pond of water in the desert. Examples of various mirages include a band of marching soldiers on a mountain, certain UFO spottings, and of course the water in the desert. Mirages on top of water are seen when the air temperature is much warmer than that of the water. When there are several boundaries between the air layers, the more light is refracted and the more complex the image appears. Some claim to have seen castles, cities, and buildings refracting off a cliff. There are many mirages seen in the desert as well as the Arctic especially. The smoothness, shape, and amount of boundaries all are factors of what make the mirage (Krystek).
Mirages are not in fact optical illusions but real physics phenomenon, and can be photographed. This chart explains the classification of a mirage: IMAGEEEEE? The refraction of a mirage includes terrestrial refraction, inside the atmosphere and astronomical refraction, beyond the atmosphere (Young). The various forms of refraction and the boundaries between airs form the physics marvel of a mirage.
Lastly, the final physics wonder seen throughout the atmosphere is why the sunset and sunrise are full of colors. The sun formulates this because of the way the optics of the human eye work. When the sun is rising or setting, it has to travel through much more atmosphere to reach the human eye. Most of the blue light scatters in other direction, leaving mostly the red and orange side of the spectrum to reach our eyes. The human eye relies on refraction and lens to see the images of the world. Because the red and blue lights are on the opposite side of the light spectrum, they come to they eye at different times. Due to the refraction of our eye, blue light is almost never seen, because it refracts in too many different directions. The red, orange, and yellow light is more direct and can be seen from far away at sunrise or sunset (Polarization).
Physics is a science full of interesting and incredible marvels. The science of rainbows includes dispersion, refraction, and reflecting. Mirages are all about boundaries between airs that create a real photographable image. Finally, the sun, the thing that lights the world is perceived through our eye due to the different wavelengths of color. Overall, each one of these topics includes a lot of interesting physics that make up their formation.










Works Cited
Krystek, Lee. "Mirages in the Sky." Mirages in the Sky. 1998. 1 Mar 2008 .
"Light and Optics." Patterns in Nature. 26 Dec 1999. Department of Physics and Astronomy: Arizona State University. 1 Mar 2008 .
"Polarization." Polarization; And the Human Eye. 1999. 4 Aug 1999 .
Young, Andrew T. "Introduction." An Introduction to Mirages. 2008. .