Re: >H Re: The Great Filter
Sat, 15 Mar 1997 02:11:24 -0500 (EST)

Forrest Bishop writes (on the transhuman list):
>Colliding binary neutron stars may provide a hefty element of the
>"Great Filter". An article in the April, 1997 issue of *Astronomy*
>magazine reports astrophysicists theorise that these events produce
>the gamma ray bursters, and goes on to say that "in Milky Way-like
>galaxies, such explosions would destroy advanced life on every nearby
>Earth-like planet on the average every 100 million years." Nearby is
>implied to be between 1500 and 3000 light years.

This is a compelling image, but I don't quite understand how this could wipe
out. Gamma-ray bursts are very brief events and planets are excellent
gamma-ray shields. The burst would sterilize half the planet but the other
half would be unaffected. This is far less damage than the end-Cretaceous
meteor strike, which killed all large animal species on the planet. I
suppose ther could be atmospheric effects from decomposing tissue, but
offhand this seems like it wouldn't be enough.