X-Message-Number: 14466 From: Date: Wed, 13 Sep 2000 16:41:07 EDT Subject: Re:Fermi etc... In Message #14443 From: : I read: >Thomas Donaldson remarks that the Fermi question (Where are all the ETs?) >becomes worse on the hypothesis of an infinite past and an infinite space. > >I certainly agree that no plausible reason has been given for the apparent >absence of advanced ETs on earth, given that they exist elsewhere. But I'm >not sure the problem is exacerbated by a universe infinite in space and time. > We don't know what the Universe content is, but we know about one of its point: the Earth. There is a mathematical operation called a Fourier transform who turn a sharp peak into a flat "curve" and a time coordinate into a space one (and vice versa). If we ask: what is the distance of the nearest ET civilization, we can answer that question by taking the Fourier's transform of the distribution density of civilizations. This transform is the time "distance" between two civilizations on Earth. Given that we are the first technological civilization here, we must enlarge the idea of civilization. A civilization could be defined as a biological group able to master its planet surface. With that definition the last group to master the Earth was the dinosaures, wipped out 65 000 000 years ago. Given that single example, we can take it as representative of the mean time between two civilizations. The Fourier's transform of that duration give us the distance of the nearest present day civilisation: Between 50 and 100 millions of light years away. This is far outside our Galaxy with its 200 billions stars and its 100 000 Lys in diameter. It is even beyond the Virgo super cluster centered at 28 millions lys. There could be neverthless up to one million of civilizations in the observable universe today, but each one is so far away of any other that for all practical purposes each is alone in the universe. There may be life on Mars or Europa, on billions of planets in the Galaxy but a civilization is quite another matter. Yvan Bozzonetti. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14466