Ok, after a night's sleep I can think about addressing your comments, Owen.
We appear to differ on the relevance of the scale of time since the big bang (presuming you believe in the big bang). The point I was trying to make was that human evolution occurred during a cosmological eye-blink of time, and "civilization" has lasted for even less than that. During the period since the big bang, cosmology indicates that opportunities for water-life sustaining environments elsewhere in the universe have existed for billions of years prior to the present. Even on earth, there has been a ~500 million year window that is proven to have been capable of sustaining life, with no proof that Homo Sap. is the first intelligent life to have evolved here. So I therefore immediately reject your seeming assumption that "all life in the universe started at the same time" as not having sufficient basis. Also, considering that red dwarf stars are very long-lived, it is possible that life could have evolved on a water-life-friendly planet circling one of those billions of years before even single-celled life had emerged on Earth. One additional note related to this from the following article: h ttp://www.dailymail.co.uk/sciencetech/article-2123974/IBM-building-powerful-history--hopes-unravel-origin-universe.html *"The SKA’s 15m-dishes, which will detect electromagnetic radiation emitted by objects in space, will be the most sensitive ever built - able to detect an airport radar on a planet 50 light years away."* Pretty impressive, yet when you consider that the radius of the observable universe is on the order of 45.7 billion light years it becomes obvious that we have no way of detecting any indicators of familiar 21st century earth-like technology usage other than in our immediate next-door stellar neighborhood. Summarizing, it is the issue of scale, both spatial and temporal that leads me to believe that your opinion of us perhaps being the first to the party is not defensible. As to stellar evolution, note that I only mentioned red dwarf stars above. But taking other main sequence starts into account only increases the potential for life. Even if you wish to preclude all but Sol-class main sequence stars, they have a life span of 10 billion years, which allows for plenty of evolution opportunities that could have occurred before we swaggered onto the scene. As to what period of time since the big bang would I be comfortable trimming down for consideration of when life could have evolved, anywhere: I have absolutely no idea. I suspect very few people do. --Doug On Sun, Apr 1, 2012 at 9:25 PM, Owen Densmore <[email protected]> wrote: > Doug: I'm not sure if we're on the same page. Let me be as simple as > possible. > > Because I had earlier belonged to the Sagan school of Billions being > Important, I had assumed the possibility of life was pretty much spread > over the era of galaxy formation. > > But after being a bit more analytic, it occurred to me that one could > reduce one of the billions .. the percent of the life of the universe w/in > life formation might occur .. by a considerable amount. > > What I found interesting was that (considering star generations of import) > that all life may be starting at about the same time .. w/in a billion or > two years of each other. > > Does that make sense? You keep blinding me with science and billions, > about which I am already aware. I'm interested in a different phenomenon > .. adding stellar evolution (and why would you presume I don't understand > evolution, of all things) and using that to be a bit more intelligent about > boundary conditions. > > I think the answer is: You don't care about trimming the era of life > formation from 12BY say, to 2-4BY. Right? > > -- Owen > > On Sun, Apr 1, 2012 at 7:16 PM, Douglas Roberts <[email protected]>wrote: > >> As to being the first, we've only been civilized, if you can call it >> that, for a mere 5,000 years - the working definition for that descriptive >> being the length of recorded history. Cripes, we've only existed as a >> unique species for ~20,000 year. At the rate we're going, I'd place even >> money on us no lasting another 20,000. >> >> So, given this, and the fact that there has been evolved multicellular, >> animate life on the planet for the last ~500 million years, who can state >> with authority that we are the first "intelligent" specie to evolve? >> >> Unless you don't believe in evolution... Oh wait, I guess we decided not >> to go there. Back to our main program. >> >> Anyhow, 500 million years on a geological time scale >> is sufficient for subduction to have completely >> obliterated sizable portions of earthly real estate. Evidence of some >> unfortunate prior specie's ephemeral 20,000 year claim to having become >> civilized could well never be found by today's archaeologists. >> >> This is not a new concept, several science fiction writers have written >> stories that transpire over geological time periods. Frederich Pohl, Larry >> Niven, and more recently, Michael Seimsen who wrote *The Dig* which >> addresses this very proposition. In his story, a hominid species rose to >> approximately iron-age levels of technology ~120 million years ago, before >> having been being wiped out in the Cretaceous era mass extinction. These >> unfortunate individuals had a rough go of it, what with all the dinosaur >> predators roaming around at the time (Sarah Palin would have *loved* this >> story, presuming she could have gotten past the 6,000 year issue). As a >> result of the relative hard times they were living in, these hominids did >> not expand to the point of becoming a global blight, unlike the current >> inhabitants. The did have art, though. >> >> On a much broader scale, we have what: 200 billion galaxies that we can >> see, each with tens to hundreds of billions of >> potentially habitable planets? I have a sneaky suspicion we are not the >> first to have experienced "the quickening", universally speaking. >> >> --Doug >> >> On Sun, Apr 1, 2012 at 12:42 PM, Owen Densmore <[email protected]>wrote: >> >>> Gentle readers, as much as I like /.-like digressions, interesting humor >>> (but not religious rants), has anyone anything to add to the idea that life >>> origins may be bound to the era after Population II star formation? >>> >>> If so, we may be among the first of these very young life forms, +/- a >>> billion years or so. >>> >>> -- Owen >>> >>> ============================================================ >>> FRIAM Applied Complexity Group listserv >>> Meets Fridays 9a-11:30 at cafe at St. John's College >>> lectures, archives, unsubscribe, maps at http://www.friam.org >>> >> >> >> >> -- >> Doug Roberts >> [email protected] >> [email protected] >> http://parrot-farm.net/Second-Cousins >> <http://parrot-farm.net/Second-Cousins> >> 505-455-7333 - Office >> 505-670-8195 - Cell >> >> >> ============================================================ >> FRIAM Applied Complexity Group listserv >> Meets Fridays 9a-11:30 at cafe at St. John's College >> lectures, archives, unsubscribe, maps at http://www.friam.org >> > > > ============================================================ > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > lectures, archives, unsubscribe, maps at http://www.friam.org > -- Doug Roberts [email protected] [email protected] http://parrot-farm.net/Second-Cousins <http://parrot-farm.net/Second-Cousins> 505-455-7333 - Office 505-670-8195 - Cell
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