Example of Explanation Text

How Mirage (Fata Morgana) is Formed

source of picture:http://www.academia.edu/6547321/Seminar_Fisika_Proses_Terjadinya_Fatamorgana

Mirage is a pseudo-shadow (not real) that usually occurs in a large field such as desert or ice field. Mirage is also common in the streets. Often, mirage resembles lakes or oily water. This is actually a reflection of the sky because of the hot air. This hot air serves as a mirror.

Mirage occurs due to the difference in density between cold and hot air. Cold air has a density that is more concentrated and heavier than hot air. In fact, the hot air layer that is near the ground is trapped by a cooler layer of air above it. Light is refracted horizontally and the view ends upward due to total internal influence. The total internal reflection is the reflection process of a light on the boundary surface between one medium and another medium where the index is usually smaller if the angle to the second medium exceeds a certain angle. Thus, light travels within a medium having a high refractive index such as water, glass, and plastic onto a medium having a lower refractive index such as air. As a result, the image of the false and inverted nature will form a fata morgana. There are two kinds of mirage : superior and inferior mirages. Superior mirages occur above the horizon, while inferior mirages are more common around us.

Scientifically, mirage is classified in a unique natural phenomenon, because it is formed from natural processes that form a beautiful thing in nature. Often, people who do not understand the process of mirage, think that it is caused by eyestrain, but actually it can be seen without eyestrain, even can be captured directly.