Random (alien civilizations) • d*******s@n**.********e.com 02/05/1996 00:00:000 UTC On May 01, 1996 20:54:14 Brian McGuinness wrote: (crap about computers deleted, because I don't care) >Regarding intelligent life in space, I haven't seen any discussion in the texts >of how long ago the first civilizations could have arisen. But there are old >Population I stars about five billion years older than the Sun in the galactic >bulge, so a figure of one billion years ago seems reasonably conservative. >Now, if we say that the first civilizations appeared one billion years ago, >then the probability of any civilization being within one hundred years of us >in age (up to 100 years older or 100 years younger), is 200 / 1,000,000,000 or >1 in 5,000,000. If we take our own rate of technological development as >average, then this is also the probability of a given alien civilization being >within 100 years of us in development. All such calculations are very speculative. You have a long equation with a lot of estimated parameters, and a huge cumulative error. Assuming our rate of development is "average", for instance, may be wildly inaccurate (although I don't have a better idea for an estimate). >A typical science fiction television series might have, say, about eight or >ten civilizations at about our level of development (e.g. Vulcans, Andorians, >Tellarites, Klingons, Romulans, Tholians, Gorn, Orion pirates), implying the >existence of perhaps 40-50 million civilizations in our galaxy. But the >civilizations in these shows are not randomly scattered around the galaxy; >they are all found in the vicinity of the Earth, implying an even higher >density of civilizations; well over a billion in our galaxy alone. Such >densities seem unrealistically large. Well, they are TV shows, and meant to entertain, not inform. Go back and look at early Star Trek shows. We can confidently say that the probability of the future being anything like that is very near zero. (Women officers wearing mini-skirts? Computers with meaningless blinking lights? Salt shakers used as medical scanners?? Huge numbers of alien species that look exactly like humans wearing makeup???) >It is true that the recent discovery of other planetary systems, and the Space >telescope observations of protoplanetary disks, imply that planetary systems >are quite common in the galaxy. But this does not imply that civilizations >are equally common. A planetary system might not have any planets in the >habitable zone, or its habitable planet might be bombarded frequently by large >meteorites, preventing life from evolving, or life on a planet might not >happen to evolve beyond the bacterial stage. Yes, of course. but it's awfully hard to tell from here. And visiting another solar system just to see what's up there seems awkward. Unmanned probes with onboard AI, that's the only way to go. >It would be better if the civilizations in these shows were spread out over a >wider variety of technological levels. Babylon 5 does this better than the >other series I've seen, but even they have a lot of civilizations similar in >development to humanity (e.g. the League of Nonaligned Worlds). If by "better" you mean "more realistic", yes. TV shows are set up the way they are for the sake of interesting plots. The civilizations on Star Trek were set up the way they were, not just for the sake of a plot, but to make some moral message! >One interesting possibility that no one seems to have explored in television >or films is a future in which all of the civilizations we have encountered are >vastly older than ourselves, and thus incomprehensibly alien, but where the >roles normally given to alien civilizations are filled by various groups of >genetically engineered humans in a wide variety of forms. Perhaps these >people were engineered to survive on normally inhospitable worlds, or perhaps >they were bizarre experiments or art forms. These groups of humans would tend >to associate more with their own kind than with the rest of humanity, leading >to a number of separate blocs analogous to the Earth Alliance, Minbari, >Centauri, Narn, and so on, without the need to introduce an implausibly high >density of alien civilizations. It's an interesting idea. Wouldn't such aliens, from our point of view, be essentially gods? Certainly the idea of Earth as a "bizarre experiment or art form" sounds like something out of Douglas Adams. ("I did the fiddly bits around the fjords. Got an award for Norway." ) It's only recently that SF has gone more towards avoiding implausible situations. Moving away from Tom Swift / Star Trek towards, well, cyberpunk, was a step toward reality. Cyberpunk generally keeps its noir feel precisely in that it feels plausible. The most important part is that people still act like people. Hey, anybody remember "Venus on the Half Shell" by Kilgore Trout? Now there was a great book in the Old School of Science Fiction! No pretense of plausibility! >Smedley's Law: Someone else's keyboard never feels quite right. I've noticed. What's with that? ---------- David Hodges • s******j@**.com 02/05/1996 00:00:000 UTC Regarding how old the oldest civilization could be: Given Brian's statement that the oldest Population I stars (which, for the uninformed, are actually younger thatn Population II stars) are about 5.5 billion years old, I think it's possible for civilizations to have been around as long as 4 billions years back. Life on Earth started around 3.5 billion years ago, when the planet was around a billion years old. However, it (life) spent about 2.8 billion years doing NUTHIN. It wasn't until the Cambrian, about 700 million years ago, that complex multicellular critters showed up and the "road" down which our ancestors travelled began. It's conceivable that the equivalent of the "Cambrian Explosion" could occur much closer to the origin of life on a world (there's guarantee that it will EVER happen, but that's another story). It's also possible that creatures complex enough to be sapient could have evolved faster. So, between an older star and planet, and a good luck on the evolutionary front, sapeients could have been coursing around the stars before life started on Earth. IMHO, it's probably that were the only folks around, and that life elsewhere is either really simple or just didn't travel down paths that would take it to sapience. See Stephen Jay Gould's WONDERFUL LIFE for more details. Stefan -- +-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+ ***@***.com ~ s*****s@a*****.***u.edu ~ s******j@**.com http://www.ini.cmu.edu/~sjones/