Spiritual/Political/Philosophical Blog on the Nature of Truth and Falsehood and Heaven
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| Sunny Days in Heaven Spiritual/Political/Philosophical Blog on the Nature of Truth and Falsehood and Heaven |
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Monday, April 01, 2002 Home Alone - the Galaxy For a long time I've been telling SETI types that if there were other people (or sentient beings) in the universe, we would have already encountered them (unless we are absolutely the very first). The science types would all scoff at me. Well, First Things has a great article on that and illustrates that the proof I used to state was eponymously called , Fermi's Paradox: "Fermi’s Paradox—Back in Style. Fermi’s Paradox, a SETI-challenge that was tried and found wanting in the 1950s, has been given a retrial. This time, expert witnesses on propulsion technologies have been called in, claiming that if life sprung up in our galaxy many millions of years ago, then our galaxy should have been entirely colonized by now. It all started over a Los Alamos lab lunch in the summer of 1950, when renowned Italian physicist Enrico Fermi had one of those napkin-scribbling epiphanies. His conclusion stemmed from the indisputable premise that there are billions of stars in our galaxy that are older than our sun, and that life routinely develops under favorable conditions. Exhausted planet resources and dying stars would provide good motives for exploration and homesteading. Some cultures, like our own, would find other motives for colonizing, and it would only take one enterprising population to begin exponential expansion. Fermi showed that, even assuming modest speeds, every habitable star system in the galaxy should have been colonized within mere millions, not billions, of years. Complete colonization could take place in the relative twinkling of a cosmic eye, many times over, in a ten-billion-year-old galaxy like the Milky Way. "So," asked Fermi, "where are they?" Also: " Figuring on a cruising speed of 10 percent that of light and periods of four hundred years’ settling time between migrations, astronomers say it would take just five million years for one colonizing group to reach every star system across the Milky Way’s 100,000 light-years. In the 1970s, four astrophysicists—Michael Hart, David Viewing, Frank Tipler, and Ronald Bracewell—independently published studies concluding that the Fermi Paradox was difficult to escape. Today, as NASA lays the groundwork for new propulsion strategies, the thought that older cultures should have developed these long ago lends added weight to Fermi’s argument. "The implication is clear," wrote British astronomer Ian Crawford last year: "The first technological civilization with the ability and the inclination to colonize the galaxy could have done so before any competitors even had a chance to evolve." There's lots more in the essay. posted by Mark Butterworth | 9:14 PM | |
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