For mirage, after finding an event corresponding to the original scene, we can know that mirage is by no means a projection of parallel space, nor is it caused by the distortion of time and space. If a mirage reflects a landmark, it is easy to find it. For example, in 2015, the mirage that appeared on the Xin &;anjiang River in Huangshan City, Anhui Province was recognized by local witnesses, that is, the buildings near Tunxi District not far from where the mirage appeared. Moreover, in the evening, when the riverside buildings are lit up, the virtual buildings refracted in the mirage are also lit up. Mirages don&;t last long, mostly 5 minutes to 25 minutes, and there are many kinds of scenery, especially peaks and tall buildings. The conditions for mirage are very harsh, and the distribution of air temperature leads to a great difference in air density in different air layers, so the sunlight reflected by objects is easy to refract here and form a virtual image. Therefore, such a natural phenomenon is really common.