Footnotes:1. The excerpt entitled "The Origin of the Drake Equation" was adapted and updated for "Astronomy Beat" from "Is Anyone Out There? The Scientific Search for Extraterrestrial Intelligence" (Delacorte Press, 1992) by Frank Drake and Dava Sobel.2. From author Paul McAuley's Introduction to "Is Anybody Out There?" co-edited by Nick Gevers and Marty Halpern (Daw Books, 2010): "The galaxy contains between one hundred billion and four hundred billion stars: even if only a small fraction possess planets capable of supporting life, and technological civilisations arise on only a few of those life-bearing planets, there should still be a large number of civilisations capable of communicating with us. And although the distances between stars are very large, and even if exploration of the galaxy is limited to speeds below that of light, exponential multiplication of interstellar colonies would mean that a determined star-faring civilisation would be able to visit or colonise every star in the galaxy within 5 to 50 million years, a trivial span of time compared to the lifetime of the galaxy. From these basic assumptions and calculations, Fermi concluded that Earth should have been visited by aliens long ago, and many times since. But where was everybody?"One additional note: Seth Shostak, the SETI Institute's senior scientist, is author of Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence (National Geographic, 2009).
Sunday, July 27, 2014
One Is The Lonliest Number
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On 11:41 PM
Footnotes:1. The excerpt entitled "The Origin of the Drake Equation" was adapted and updated for "Astronomy Beat" from "Is Anyone Out There? The Scientific Search for Extraterrestrial Intelligence" (Delacorte Press, 1992) by Frank Drake and Dava Sobel.2. From author Paul McAuley's Introduction to "Is Anybody Out There?" co-edited by Nick Gevers and Marty Halpern (Daw Books, 2010): "The galaxy contains between one hundred billion and four hundred billion stars: even if only a small fraction possess planets capable of supporting life, and technological civilisations arise on only a few of those life-bearing planets, there should still be a large number of civilisations capable of communicating with us. And although the distances between stars are very large, and even if exploration of the galaxy is limited to speeds below that of light, exponential multiplication of interstellar colonies would mean that a determined star-faring civilisation would be able to visit or colonise every star in the galaxy within 5 to 50 million years, a trivial span of time compared to the lifetime of the galaxy. From these basic assumptions and calculations, Fermi concluded that Earth should have been visited by aliens long ago, and many times since. But where was everybody?"One additional note: Seth Shostak, the SETI Institute's senior scientist, is author of Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence (National Geographic, 2009).
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