Fig.72  Two sources of waves are in the nodes of the standing wave theyíve created. The nodes are areas of stable balance for the sources. In these areas the gradient of the wave field energy is absent.


Fig.73.  Attempts to bring the wave sources closer, i.e. to take them out of potentialís holes, lead to the reaction of the standing wave aimed at bringing the sources apart. The reaction lasts till the sources are again in the balance areas.


Fig.77  Moving away from the center under the influence of the pulling apart forces, the sources will soon form another two standing waves and slide into new nodes, i.e. new areas of stable balance (potentialís holes).