In hot sunny weather, it seems that the forest behind a freshly plowed field is trembling. Why?

The rays of light coming from the forest, passing through an area of warm air rising from the freshly plowed field, are refracted. Since the forest is viewed for a certain period of time, the light from it comes all the time in different directions. That is why it seems that the forest is “trembling”.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.