TNRTB Archive - Retained for reference information
Two Japanese astronomers have discovered why only a very few galaxies are candidates for the possible support of life. Life is possible only in a large galaxy, but for all but a few large galaxies the mass of their central black hole is too large. The astronomers found that stellar radiation in the galactic bulge drives the mass accretion (gas) on to the central black hole. Consequently, all large elliptical galaxies and all spiral galaxies with a large bulge will produce a central black hole too large to permit life’s survival. It seems no accident that the Milky Way is fine-tuned for life.
Nozomu Kawakatu and Masayuki Umemura, “Why Are Massive Black Holes Small in Disk Galaxies?” Astrophysical Journal Letters, 601 (2004), pp. L21-L24.
RTB article: Facts for Faith articles on the anthropic principle
RTB book: The Creator and the Cosmos, third edition
RTB: Journey Toward Creation, 2nd edition