Put coins in a bowl. What is the ancient poem describing this phenomenon?

shallow refraction reflection 5km When the water falls to a certain height, the light reflected by the coin in the bowl will be refracted when it enters the air through the water, and the refracted light will be far away from the normal line and deflected downwards, so the virtual image A' of the coin is shallower than the actual depth of the coin. "The pool is clear and the water bottom looks shallower, which is due to the refraction of light. Seeing the water bottom is opposite to the direction of light propagation. The "moon illuminated by pool water" is the image of the moon on the water surface, which belongs to the phenomenon of plane mirror imaging. The image of the plane in the sea formed by the reflection of light belongs to the phenomenon of plane mirror imaging. Its principle is the reflection of light. According to the imaging characteristics of plane mirror, the image formed is a virtual image. When the plane is 5km away from the sea surface, the distance from the image of the plane in the sea to the sea surface is also 5km.