November 25th, 2009
My friend and fellow astronomer/science fiction writer Valentin Ivanov pointed me at these abstracts saying they reminded him of Star Dragon (which has creatures living in an accretion disk):
Title: Accretion disk civilization 1: Habitable zone around accretion disks at galactic nuclei. Authors: Fukue, J. Publication: Astron. Her., Vol. 88, No. 5, p. 199 – 205 Publication Date: 00/1995 Origin: ARI ARI Keywords: Galaxies: Planetary Systems, Planetary Systems: Accretion Disks Bibliographic Code: 1995AstHe..88..199F
The space density of stars, and therefore, the possible number of planets are expected to be high in the central region of galaxies. While the galactic nuclei may be rather wild places due to the existence of the supermassive black holes and the surrounding accretion disks. As the first step to investigate the advanced civilizations in the galactic nuclei, the author examines the equilibrium temperature and related problems of possible planets in the vicinity of accretion disks.
Title: Accretion disk civilization 2: From sunhook to photon floater. Authors: Fukue, J. Publication: Astron. Her., Vol. 88, No. 6, p. 244 – 253 Publication Date: 00/1995 Origin: ARI ARI Keywords: Accretion Disks: Black Holes, Accretion Disks: Energies Bibliographic Code: 1995AstHe..88..244F
An accretion disk surrounding a supermassive black hole at the active galactic nuclei radiates tremendous energy. In order to utilize energy of the accretion disk system, the author investigates the configuration and stability of a floating platform – photon floater – above the accretion disk, which is supported by the radiation pressure of the disk radiation. In the case of the far-floater, which is located far from the disk, there exists a critical floating angle, where the gravitational force of the central black hole is balanced with radiation pressure. In the case of the near-floater, which is located very close to the disk, there exists a critical floating height, where the gravity is balanced with radiation. It is demonstrated that this floating height is dynamical stable. Finally, in the case of the axis-floater, which is located on the axis of the disk, the photon floater is unstable.
Now, these papers are not available online, apparently, and I don’t know the author personally, or the journal, but they sound like a lot of fun and some hard science on which to base an advanced civilization at the (or a) galactic core.