A rainbow can appear during rain, before rain, or after rain, depending on how the clouds move in the sky. A rainbow is formed when sunlight passes through a drop of water. A parallel beam of light falling on the drop turns out to be strongly diverging when it leaves the drop. A rainbow can be created without rain – in the laboratory, a rainbow is obtained from a suspended drop of distilled water.
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.