Light in Nature
From sunsets to rainbows, from the blues and greens of the ocean to the remarkable range of colors of plants and animals, our first experiences of light and color are through what we see in the natural world. This page will contain resources and links to images so that you can see for yourself the wonderful range of light and color in the natural world and understand the science behind it.
A rainbow is a beautiful natural phenomena that occurs when drops of rainwater meet sunlight. The multi-color arch is produced by a fundamental process called refraction, or the “bending” of light. In optics, refraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle.
Perhaps one of the most frequently occurring visual displays of light in nature, sunsets are also a result of refraction. In astronomy, sunset is the point when the trailing edge of the Sun’s sphere disappears below the horizon. The brilliant array of colors that appear in the sky during sunset are created by scattered airborne particles passing through rays of white sunlight traveling through the atmosphere. Because the evening air contains more particles than morning air, sunsets are typically more radiantly colored than sunrises.
The process that converts energy in sunlight to chemical energy used by green plants and other organisms is called photosynthesis. Although it is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll pigments. A seemingly simple process, photosynthesis is actually quite complex and is the basis by which we grow all of our food and produce important resources such as fossil fuels.
Also known as the Aurora Borealis, the Northern lights is a natural light display that occurs in the sky in the arctic (northernmost) region on Earth. In fact, auroras be seen all over the world, but occur most frequently in high altitude regions. Caused by the collision of solar wind and magnetospheric charged particles with the high altitude atmosphere, most auroras occur in a band known as the auroral zone.
For a more information and full list of atmospheric phenomenon occurring in nature, visit Wikipedia.
NASA’s Astronomy Picture of the Day archive also includes some visually stunning instances of light in nature: