I meant to include this link as an example of what appears to be an outlier in main sequence star solar systems as an example of why I don't believe the assumption that all life in the universe would have started at about the same time is a good one:
http://www.physorg.com/news/2012-03-planetary-early-universe.html --Doug On Mon, Apr 2, 2012 at 12:08 PM, Douglas Roberts <[email protected]>wrote: > 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 > > -- 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
