There are more possible effects if we are working on a galactic scale.
For example, the radial galactic metallicity gradient determines isotope concentrations, silica and magnesium concentrations, etc., all of which are important for forming habitable planetary systems.
A simple density modulated sinusoidal model is imposed on the data to guide the reader regarding the galactic distribution of objects.
The passage times through an arm are simple multiples of published results on impact and fossil record periodicity and galactic plane half-periods.
This confirms an earlier study correlating human breast cancer mortality and galactic cosmic rays.
In conclusion, a coherent pattern of mass extinction emerges with galactic forcing as the ultimate causal mechanism.
As well as being nurseries for stars, galactic outer spiral arms are also the ideal location for the formation of the molecules necessary for life.
The study of rarefied anisotropic-pressure plasmas is important for the solar wind, galactic spiral arms, star formation, plasma jets and fusion research.
