[Sorry for the late response to this and other threads. I was overwhelmed by the job market & allowed inboxes to pile up. Hope to catch up soon. RH]
James Annis' article, "An Astrophysical Explanation for the
`Great Silence'" JBIS 52:19-22 1999, is thoughtful and interesting.
Gamma ray bursts do seem a plausible component of the total
"great filter" that stands between dead matter and expanding
lasting life. Some critiques, however:
But clearly if life appeared quickly in most every system, and if civilizations expanded at .1c, then most of the universe would now be colonized if gamma ray bursts were the only problem. (A simulation could be constructed if anyone doubts this.) Thus this can't be the whole filter. So how much of the filter can it be?
Btw, I actually found Annis' *other* paper in the same issue to be more interesting. That is:
James Annis JBIS 52:33-36, 1999.
A civilization that uses the bulk of a galaxy's starlight for its own power requirements is a remarkably obvious entity. This is because galaxies naturally obey scaling laws between the surface brightness, the radius of the stellar distribution and the thermal velocities of the stars. The latter two quantities reflect the mass and its resulting gravitational potential, while the formal is the result of this same mass emitting light as stars. If civilization takes that light for its own purposes, the scaling laws are broken and the galaxy becomes an outlier on plots showing the scaling laws. For a sample of 137 galaxies, no such outliers are found.
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