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 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11203