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Wouldn't advanced civilizations at least be doing what we've been doing recently, looking at the transit spectroscopy for distant planets to determine whether w

Wouldn't advanced civilizations at least be doing what we've been doing recently, looking at the transit spectroscopy for distant planets to determine whether we think they can support carbon-based life? Likewise, couldn't they detect changes in the mixture of gases on Earth and deduce that these changes would most likely occur in the presence of evolving life? If we posit that evolution typically leads to intelligence and intelligence leads to civilization, then extraterrestrial intelligence would have deduced that we were going to be coming along at some point. Maybe they could even deduce when that civilization-building life was going to spring up, perhaps within about a ~1M-year window, depending on what information they have and what they can reliably deduce from that information. So in a way we are already "known." The new information that you can glean from the pyramids is that we've just now hit the inflection point of civilization. Maybe now they're watching to see if we manage to make it past the Great Filter. Or they've already launched their relativistic missiles to snuff us out before we can possibly launch our relativistic missiles at them -- if you're inclined to presume the cosmic prisoner's dilemma motivates being the first to launch.

gmuslera 3y ago
Having free oxygen in the atmosphere (I don’t know, 500 M-year?) would already had put us as target for oxygen breathing advanced civilizations in a long enough radius. If they could be a realistic threat capable of wiping us, they should had been here even before mankind evolved. Maybe the great filter is the great promotion, acquiring a knowledge/technology powerful enough to not need to go to other solar systems or expand a lot. But as we are not yet there, we expect invasion fleets.
- steelframe 3y ago
  > If they could be a realistic threat capable of wiping us, they should had been here even before mankind evolved. One of my favorite sci-fi themes about that is that we've already been hit once, about 66 million years ago.
nicklecompte 3y ago
> If we posit that evolution typically leads to intelligence and intelligence leads to civilization, then extraterrestrial intelligence would have deduced that we were going to be coming along at some point. I see two big issues with this: 1) "evolution typically leads to intelligence" is only plausible after the evolution of multicellular life. I don't think there's any reason to suppose "evolution typically leads to multicellular life." Perhaps these aliens are used to a galaxy where 95% of habitable planets are full of primordial soup, where primitive multicellular forms struggle to find a niche. In particular, if most planets are less geologically active than earth, and most solar systems have less asteroids than ours, then perhaps most habitable planets have less extinction events, so there wouldn't be any ecological disruption to spur evolution. 2) "intelligence leads to civilization" is almost certainly false. Orcas have near-human intelligence, including culture and symbolic communication - in fact they might be "smarter" than humans, we don't really know enough about intelligence to answer that. But it will take a bizarre fluke of evolution for them to develop technological civilization, for the simple reason that they don't have hands and there's no selective pressure for them to evolve "proto-hands" - they need the flippers to be good flippers. This is in contrast to primates: we didn't evolve hands to build tools, we evolved hands to climb trees and grab fruits/nuts. It seems far more likely to me that intelligence tends towards super smart crows and dolphins: the physiological capability of building highly advanced tools is orthogonal to intelligence and does not seem inevitable. I'm not saying you're wrong. But my understanding of the almost-science is that the aliens would be wasting a lot of tachyon missiles if they fired at every planet with evidence of photosynthesis / fermentation / etc.

gmuslera 3y ago

Having free oxygen in the atmosphere (I don’t know, 500 M-year?) would already had put us as target for oxygen breathing advanced civilizations in a long enough radius. If they could be a realistic threat capable of wiping us, they should had been here even before mankind evolved. Maybe the great filter is the great promotion, acquiring a knowledge/technology powerful enough to not need to go to other solar systems or expand a lot. But as we are not yet there, we expect invasion fleets.

steelframe 3y ago
> If they could be a realistic threat capable of wiping us, they should had been here even before mankind evolved. One of my favorite sci-fi themes about that is that we've already been hit once, about 66 million years ago.

nicklecompte 3y ago

> If we posit that evolution typically leads to intelligence and intelligence leads to civilization, then extraterrestrial intelligence would have deduced that we were going to be coming along at some point. I see two big issues with this: 1) "evolution typically leads to intelligence" is only plausible after the evolution of multicellular life. I don't think there's any reason to suppose "evolution typically leads to multicellular life." Perhaps these aliens are used to a galaxy where 95% of habitable planets are full of primordial soup, where primitive multicellular forms struggle to find a niche. In particular, if most planets are less geologically active than earth, and most solar systems have less asteroids than ours, then perhaps most habitable planets have less extinction events, so there wouldn't be any ecological disruption to spur evolution. 2) "intelligence leads to civilization" is almost certainly false. Orcas have near-human intelligence, including culture and symbolic communication - in fact they might be "smarter" than humans, we don't really know enough about intelligence to answer that. But it will take a bizarre fluke of evolution for them to develop technological civilization, for the simple reason that they don't have hands and there's no selective pressure for them to evolve "proto-hands" - they need the flippers to be good flippers. This is in contrast to primates: we didn't evolve hands to build tools, we evolved hands to climb trees and grab fruits/nuts. It seems far more likely to me that intelligence tends towards super smart crows and dolphins: the physiological capability of building highly advanced tools is orthogonal to intelligence and does not seem inevitable. I'm not saying you're wrong. But my understanding of the almost-science is that the aliens would be wasting a lot of tachyon missiles if they fired at every planet with evidence of photosynthesis / fermentation / etc.