Magma-clustering and galaxy-clustering: a comparison

The analogies between clustering processes in magmas and clustering ones in galaxies are pursued. By using reasonable assumptions about the properties of the fluids in magmas and in the Earth's mantle, it is shown that: (1) in both processes instabilities are formed by density fluctuations; (2) in both phenomena the process of clusters is of the hierarchical kind; (3) magmas and galaxies both exhibit a simultaneous superposition of mass, momentum and energy transports; (4) coalescence occurring in magmas can be considered the corresponding phenomenon to the close encounters in the galactic groups; and (5) vorticity of the Taylor Proudman type in magmatic systems can be regarded as the corresponding phenomenon to cannibalism in the galaxies. It is suggested that there is a single transport mechanism that may be universally applicable.