Geography Phenomenom

Rainbow
Rainbow or bianglala are optical and meteorological symptoms in the form of parallel, multicolored light seen in the sky or other mediums. In the sky, a rainbow appears as a light arc with its tip pointing towards the horizon during a light rain. Pelangi can also be seen around heavy waterfalls.


Sunlight is polycromatic light (consisting of many colors). The white color of sunlight is actually a combination of various lights with different wavelengths. The human eye is able to perceive at least seven colors contained in sunlight, which will be seen in the rainbow: red, orange, yellow, green, blue, indigo and violet.

The wavelength of this light forms a band of parallel lines, each color with a color next to it. This ribbon is called the color spectrum. In the color spectrum, the red line is always on one side and blue and violet on the other, and this is determined by the difference in wavelength.


Pelangi is a large, circular color spectrum arc that occurs due to refraction of sunlight by water grains. When sunlight passes through water droplets, it refracts like when it pierces a glass prism and comes out into the rainbow color spectrum. So in water droplets, we have got different colors lined up from one side to the other side of the water droplets. Some of this colored light is then reflected from the far side of the water droplets, back and out again from the water droplets. The light comes out again from the water droplets in different directions, depending on the color. The colors in this rainbow are arranged with red at the top and purple at the bottom of the rainbow.

Rainbow is seen as an arc from the surface of the earth because of the limited viewpoint of the eye, if the point of view in a high place, for example from an airplane, can be seen as a complete color spectrum, which is circular. The rainbow can only be seen when it rains along with the sun shining, but from the opposite side of the observer. The position of the observer must be between the sun and water droplets with the sun behind the person. The sun, the eye of the observer, and the center of the rainbow arc must be in a straight line.