>H Re: The Great Filter

Robin Hanson (hanson@hss.caltech.edu)
Mon, 10 Mar 1997 11:14:00 -0800 (PST)

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.

It occurs to me that if the entire filter were due to events like this
then for 1000 light years around we should see planets with advancing
life. This would be a billion systems, so if we were the most
advanced, it wouldn't be by much.

Interesting - a star trek like universe out for 1000 light years, and
then a vast emptiness from there on.

Robin D. Hanson hanson@hss.caltech.edu http://hss.caltech.edu/~hanson/