Rainbows, Mirages, and Sky

Julia Davis Period 1
The fascination of rainbows, mirages, and the color of the sky can be seen by many as simply a miracle. For those with the knowledge of physics, this “unexplainable” phenomenon is simply explained by physics concepts that are working together to form such an astonishing site. These concepts, including dispersion and refraction, not only form the images we see daily, but also the beauty in rainbows and other spectacular occurrences in nature.
Rainbows only appear after rainstorms or any other precipitation. The sunlight strikes the water droplets and does three things: reflects, refracts, and disperses among the sky. The rays of the sun, also known as white light, that are refracted form the colors of the rainbow seen by the human eye. Therefore each raindrop is an individual prism that separates the white lights by refracting it back into the sky. The different colors are the result of the light being reflected at different degrees. The less the light is refracted the closer to red the light appears. Therefore if a color bends greatly it become the violet in the rainbow. A point that is 180 degrees from the sun, commonly referred to as the antisolar point, is instrumental in determining where the rainbow is formed. There is also the instance where one sees a double rainbow. This occurs when rays are reflected twice inside the raindrop therefore refracting back into the atmosphere twice, giving the appearance of a double, or secondary rainbow.
Mirages are often explained as optical illusions, but it has since been proven that they are more of a physics phenomenon than anything else. Mirages are most often seen in the desert or the artic. The most commonly seen mirage is water in the desert. This image is formed by the refraction of light along the barrier between two layers of air. Boundaries between layers of warm and cold air is often bent therefore forming images. Cold air is denser therefore sinks below hot air forming a boundary. Images appear more complex, such as a UFO, when more light is refracted. Physics simply explains mirages as the boundary between air.
When the sun is rising and setting it forms different colors that make a beautiful sky. The law of scattering light in the atmosphere can best explain why the sky appears blue during the day and reddish in the morning and evening. The sky is blue because the scattered light has the wavelength of the blue visible light spectrum. Red and orange are the most often seen colors of the spectrum that the human eye sees. The colors blue and red are seen by the eye at different times, blue light is rarely seen due to refraction. The more direct colors, including red, orange, and yellow are more often seen during sunrise and sunsets.
Physics can explain these natural wonders such as rainbows, mirages, and the color of the sky. Reflection, refraction, and dispersion of light explains these natural occurrences therefore explaining what otherwise would be thought of as miracles.

The National Center for Atmospheric Research & the UCAR Office of Programs. "AboutRainbows." 2/29/2008 .
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Young, Andrew T. "Introduction." An Introduction to Mirages. 2008.