X-Message-Number: 11203
From: 
Date: Sun, 31 Jan 1999 11:50:17 EST
Subject: probably not GRB

Joe Strout (#11196) notes that galaxy-killing gamma ray bursts (GRB) may occur
every few hundred million years on average, and that since the last one in our
galaxy, several or many advanced civilizations may have developed, but not yet
had time to reach us. Seems a bit of a stretch to me, for the following
reason.

Suppose it takes, on average, half a billion years for a civilization to
develop after a GRB. Randomness should assure a variation on the order of at
least 10 million years, so there should be at least one that is several
million years ahead of us, thus should have reached us by now. Our galaxy has
a radius on the long axis of around 50,000 light years, so probes half a
galaxy away, traveling at 0.01 c, could reach us within 5 million years. Not
conclusive, of course, but suggestive. 

One other point: If the GRB only lasts a few seconds, and underground life
would be spared, then eradication of the advanced civilization seems unlikely.
Even if there was no warning, as long as there was only one source, half the
people would be on the safe side of the planet, or of some other planet, and
some would be underground.

The simplest explanation seems to me the most likely--we haven't seen advanced
aliens here because they aren't here, and they aren't here because they aren't
anywhere. Nor do we need catastrophes to explain their absence; our
development could easily be a unique event (in a finite universe), as Dr.
Hart's calculations suggest. After all, even our UNIVERSE (out of all
imaginable universes, in terms of the constants of physics such as the charge
of the electron, the magnitude of Planck's constant, etc.) is staggeringly
unlikely, as calculated by Hoyle and other cosmologists. 

Aint nobody here but us chickens. Guess I'll have to do it myself, said the
little red hen.

Robert Ettinger
Cryonics Institute
Immortalist Society
http://www.cryonics.org

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