Alternating layers or zones of syntropic and entropic forces such as are seen in galaxy or hurricane images of light and dark arms or swirls as also in gas discharge tubes.
Dark and Light Spiral Arms of a Galaxy
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(courtesy University of Science and Philosophy)
See Also
Birkeland Currents
Differential Densities
Stria
Striation
Vortex
3.6 - Differential Densities Begin to Form