Nigemizu (English: inferior mirage, road mirage) is a phenomenon in which water appears to be in the distance on asphalt roads on sunny, hot days with no wind. It is also called a "mirror". One of the summer traditions.
A type of submirage in which an object appears to be below its actual location. As a condition, it is necessary to form an air layer having a lower refractive index as it approaches the ground surface. Light has the property of bending in the direction of cold air, which has a high refractive index. When the light exits the target object, it curves downward and enters the field of view. looks like
When approached, it recedes away, and it looks like water running away, hence the name "running water".
In the "Scattered Poetry Collection" (circa 1128), it is said that ``Even if you escape from the water that is said to be on the east road, you will pass the world.'' It is also used as a season word for spring in haiku.
heat haze (weather phenomenon)
Mizuno (Sayama City) - There is a place name called Nagemizu derived from a phenomenon as a small character in Mizuno, which is located in Sayama City, Saitama Prefecture.
"Escape water" - Koto bank