Comments on: All Hail William Napier http://www.overcomingbias.com/2009/11/all-hail-william-napier.html Overcoming Bias is economist Robin Hanson’s blog, on honesty, signaling, disagreement, forecasting, and the far future. Sun, 12 Feb 2012 01:09:57 +0000 hourly 1 http://wordpress.org/?v=3.1.3 By: Overcoming Bias : Alien Life Info, But Not Status, Found http://www.overcomingbias.com/2009/11/all-hail-william-napier.html#comment-467635 Overcoming Bias : Alien Life Info, But Not Status, Found Sun, 06 Mar 2011 15:15:53 +0000 http://www.overcomingbias.com/?p=20280#comment-467635 [...] by volume, comets seem the most likely place to find such life, and so meteorites from comets would be the most likely [...] [...] by volume, comets seem the most likely place to find such life, and so meteorites from comets would be the most likely [...]

]]> By: Michael Caton http://www.overcomingbias.com/2009/11/all-hail-william-napier.html#comment-435740 Michael Caton Wed, 11 Nov 2009 10:50:44 +0000 http://www.overcomingbias.com/?p=20280#comment-435740 Now that we're up to about 100 amino acids in the Murchison meteorite - not to mention nucleobases - and in the first glance at the material returned from the Stardust mission, glycine - I would imagine these views are becoming much more mainstream. To make it as mundane as possible, the first replicators had to come from somewhere, whether it was RNA in a shallow lake on the young Earth or in a gravity-churned reservoir inside a warm comet. I think there's a point here beyond that of our <em>own</em> origins, that if this kind of chemistry is really so widespread in the galaxy, it confounds our search for extraterrestrial intelligence in the form of von Neumann probes. The reason is that I think we're more likely to find such probes that are based on biology-like replicator chemistry than on the iron-age technology which one brand of vertebrates has temporarily found useful (and tends to write about in science fiction). And if von Neumann probes are around, they surely won't be concentrated at the bottom of a gravity well, from whence we're all reading this. They'll be on comets and asteroids. But there is noise in any system, and after enough time the von Neumann probes you would see more of would be the ones that breed the fastest, and to hell with their original function, so you would have a hard time distinguishing von Neumann probes from "natural" replicators. Either may accumulate at the bottom of gravity wells, and that may well be how things on Earth got rolling. For more: http://speculative-nonfiction.blogspot.com/2009/02/where-to-find-von-neumann-probes-and.html Now that we’re up to about 100 amino acids in the Murchison meteorite – not to mention nucleobases – and in the first glance at the material returned from the Stardust mission, glycine – I would imagine these views are becoming much more mainstream. To make it as mundane as possible, the first replicators had to come from somewhere, whether it was RNA in a shallow lake on the young Earth or in a gravity-churned reservoir inside a warm comet.

I think there’s a point here beyond that of our own origins, that if this kind of chemistry is really so widespread in the galaxy, it confounds our search for extraterrestrial intelligence in the form of von Neumann probes. The reason is that I think we’re more likely to find such probes that are based on biology-like replicator chemistry than on the iron-age technology which one brand of vertebrates has temporarily found useful (and tends to write about in science fiction). And if von Neumann probes are around, they surely won’t be concentrated at the bottom of a gravity well, from whence we’re all reading this. They’ll be on comets and asteroids. But there is noise in any system, and after enough time the von Neumann probes you would see more of would be the ones that breed the fastest, and to hell with their original function, so you would have a hard time distinguishing von Neumann probes from “natural” replicators. Either may accumulate at the bottom of gravity wells, and that may well be how things on Earth got rolling.

For more:

http://speculative-nonfiction.blogspot.com/2009/02/where-to-find-von-neumann-probes-and.html

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