1. Stephen Baxter, “The Planetarium Hypothesis: A Resolution of the Fermi Paradox,” JBIS, Vol. 54 (2001), 210–216.
2. Padgen, 49.
3. Edward Harrison, review of The Anthropic Cosmological Principle, American Scientist, Vol. 75 (January-February 1987), 72–73. Also see Edward Harrison, Masks of the Universe, New York, MacMillan, 1985, 65.
4. Stephen Eales, “Smoking Supernovae and Dusty Galaxies,” Sky and Telescope, August 2004, 36–42.
5. George Musser, “Growing Pains,” Scientific American, July 2004, 32–33.