Figure 4. There are four images. These graphics show two wave sources interfering in two dimensions. In image A, only a wave interference pattern is created. In image B, the two central wave sources begin to overlap. When this overlap happens, a compound wave source begins to appear, as in image B. The closer these central wave sources coincide, the more obvious a compound wave source appears. See images C and D. This means a compound wave source emerges as these central wave sources, with a diameter of a ½ wavelength, start to overlap. This parallels the emergence of compound particles. The force that pulls compound particles together (the nuclear strong force) emerges as the particles, with ½ wavelength diameters, begin to intersect [7, 8].