GALACTIC POSITION OF OUR SUN AND THE OPTIMIZATION OF SEARCH STRATEGIES FOR DETECTING EXTRATERRESTRIAL CIVILIZATIONS

This contribution makes use of some stellar astronomical results based on the galactic distribution of open clusters of various ages on C. C. Lin's gravitational density wave theory of the large-scale galactic spiral structure. Relying upon the cluster distribution it is possible to determine the pitch angle (i) and angular velocity ( OMEGA //p) of the spiral pattern. It turns out that the orbit of the Sun is close to the so-called co-rotation circle. Consequently, if we assume that the case of mankind is about average and accept the idea that the longevity of a civilization might be limited with high probability by catastrophic events threatening during the crossing of galactic arms, intelligent life is presumably concentrated on a belt in the Galaxy which is a narrow annulus including the co-rotation circle and the galactic orbit of our Sun.