-
Rainbow
What is a rainbow?
-
1 Reply
-
A rainbow is a meteorological phenomenon that appears as a multicolored arc in the sky, typically observed when raindrops or other water droplets are present in the air and sunlight shines through them. It forms a circular or semicircular shape, with the center of the circle or arc appearing opposite the direction of the sun.
The formation of a rainbow involves the refraction, reflection, and dispersion of sunlight within the water droplets. When sunlight enters a raindrop, it refracts (bends) as it moves from air into the denser water. Upon entering the droplet, the light undergoes multiple internal reflections, bouncing off the droplet’s inner surface. Some of the light is also refracted again as it exits the droplet.
As the light is internally reflected and refracted, it is also dispersed into its component colors (red, orange, yellow, green, blue, indigo, and violet) due to differences in the wavelengths of each color. When the dispersed light exits the droplet, it forms a spectrum of colors, creating the familiar band of colors that we perceive as a rainbow.
The size and intensity of a rainbow can vary depending on factors such as the size of the raindrops, the angle of sunlight, and the observer’s position. Sometimes, a double rainbow can be observed, with a fainter and broader arc appearing outside the primary rainbow. Double rainbows occur when light undergoes an additional reflection within the raindrops, resulting in a secondary arc with a reversed color order.