In calm seas, rivers, lakes, snowfields, deserts or Gobi, occasionally towering towers, city walls and trees appear in the air or "underground", which is called a mirage. This illusion often appears on the sea surface of Penglai, China. The ancients attributed it to the dragon, exhaling and forming the tower wall, hence the name.
Features:
1, repeated in the same place, for example, a mirage often appears over Alaska in the United States;
2. It appears simultaneously. For example, the mirage in Penglai, China often appears in May and June every year, the mirage near Zimlensk, Russia often appears in spring, and the mirage in Alaska, USA generally appears within 20 days after June 20th.
Extended data 1. Formation principle
1, light refraction
When light is obliquely incident from one medium to another, the propagation direction changes, so that light is deflected at the junction of different media.
Step 2 understand
The refraction of light, like the reflection of light, occurs at the junction of two media, except that the reflected light returns to the original medium and the refracted light enters the other medium. Because the propagation speed of light in two different substances is different, the propagation direction changes at the junction of two media, which is the refraction of light.
Second, the mirage record.
1, 2011May 10, Guang Zhouta once again became the "crown of the sky" spectacle, which experts called a mirage. 2011At about 4 pm on May 9, a mirage appeared along the coast of Haikou City, which lasted for about an hour.
2.2065438+On the afternoon of May 2, 2002, after a heavy rain, rolling mountains appeared in the sky in the northwest direction of Shantou Central Building, Guangdong Province, but they could not be seen from this angle at ordinary times, so they should be a mirage.
3.2065438+On April 30th, 2003, a "mirage" appeared on the sea surface of Jiuzhou Port in Zhuhai, and a "tower crane" floated on the sea surface. The upper part of the mountain range is very clear, while the lower part is a vast cloud of smoke connecting the sea. The mountains gradually blurred and disappeared, blending with the sky until they disappeared completely. The whole process lasted about 20 minutes.
Baidu encyclopedia-mirage