Jung used a single point source S, a brightly lit small hole in an opaque screen. Behind this screen Jung placed a second screen in which he made two small holes S1 and S2 at equal distances from S. The wave from source S simultaneously reached the holes in the second screen. According to Huygens’ principle, these holes became sources of secondary waves. These waves are coherent because they were generated by a single wave. Overlapping each other, they formed an interference pattern on the screen.
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.