------------------------------------------------------Merged from the "Do you think we are alone in the Milky Way?" topic------------------------------------------------------
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I agree with most of what you've said, but this part seems problematic. For a sample size of 1, the very notion of doing statistics on it is nonsensical. For example, the standard deviation would be undefined (as in it would involve a division by N-1 with N=1).
I would instead argue that we cannot make any strong conclusions about where to place ourselves in the context of life elsewhere in the universe. Maybe we are "average", or maybe we are exceptional outliers.
Ah, forgive me. I was rushed when I typed this out and so didn't get the point across properly. I was (rather clumsily now that I read it again) trying to invoke the Principle of Mediocrity
here in regard to our presence on this planet, communicating the idea that if we represent a certain outcome (intelligence in organisms), then that outcome should statistically be pervasive throughout the cosmos. If it was not, then we wouldn't be here, or at least make it this far in our development. An opposing counter to this would be the anthropic weak principle; that we observe the universe in the first place because a certain environment was fined tuned for us to observe it, via survivor bias
(or a supernatural force, if one is religiously inclined, which of course is not the case here). This just strikes me as a very narrow view of the universe. A neutral stance would be the one you pointed out (and to be honest I lean toward as well), that there is only 1 sample and so not a lot of predictive implications can be made.
Not at all. It seems like you are arguing from the extremist side of the Great Filters theory (something that I follow as well): certain factors inhibit life in the universe from developing intelligence that can achieve space travel and communicative abilities with other alien species. That is all well and good, but if you couple the effects that natural filters of cosmic and planetary environments (Great Filters) have on life on the extreme side of that theory (that the Filters knock down life more then we expect) with human-centered confirmation bias
, you can end up manufacturing an elaborate world-view that results in you seeing all events leading to the existence of intelligent life as humans being the ONLY way we (or other lifeforms) can evolve. You admit this here:
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One thing I've learned from Space Engine is there are no planets prettier or better for us than Earth is.
A good point, and SE is very useful for exploring this concept. But I hope that you are aware of the fact that the game engine's generation of exoplanetary environments in v0980 and prior editions is NOT very realistic. An obvious example would be the lethal amounts of SO2
in the atmospheres of planets with life. You and I both know about the huff on this forum concerning these ridiculous ratios of gas. Thankfully, SE 0990 appears to have remedied this - if Harbinger's streams are anything go by. Inaccuracies go deeper then that of course, but in time SE will more accurately match geological, chemical and even biological models for exoplanets.
In addition, just because an alien environment is inhospitable to our organism, doesn't mean that it is the only possible environment for life to develop. Indeed, I predict that the rule of thumb for the galaxy will be that each life-bearing planet will have enough chemical dissimilarities between them that biology on one couldn't function on the other. I discussed this idea elsewhere on the forum.
Also, Earth is not all that great for life. I know, that seems an idiotic statement, but the idea is based on actual observations, and we must remember the several times life was almost shook off our world. But back to the theory: Astronomers know two things about the universe: that K dwarf stars are far more common in the universe then our homey G-dwarf stars (both are outnumbered by M-dwarfs, but that isn't relevant here) and that super-earth worlds are far more common then 1 Earth-mass planets (it is worth noting that this is a selection bias on our part, because we can't detect far-out Earth-mass planets as well as super-earths). K-dwarf stars (and lower-class G-stars) are calmer then our sun, and have potentially double the lifespan. They don't flare like their smaller M-dwarf cousins, and many support solar-systems. If even a fraction of these have some gas-giants in their outer systems, then debris interrupting developing life on an inner super-earth would be averted. The super-earth would need just the right mass to support tectonics and not drown in a global ocean or become desert. Further, it wouldn't need a moon, because tides would be offered by its closer star. A larger, geologically active planet would have stronger magnetic fields, so solar-radiation would not be a big an issue as it is here on Earth, coupled with a thick atmosphere. This, combined with a stable, long-lived sun, would give life a comfortable and safe home. Jump to intelligence evolving on that planet, and Dirigible technology could be more effect because of the thicker atmosphere. That would be your 'stepping stone' to high atmospheric exploration, then to low-earth orbit and beyond. There are a lot of nuances to this premise, as other forum readers will be quick to point out, but you get the picture. Earth is just good enough
to let us live.
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Not only has humanity busted though Great Filters of the Fermi Paradox, but we've done so with flying colors.
Not really. Yes we have survived, but for context 99% of all life that has existed on this planet went extinct over 4 billion years, including most of our closest relatives in the hominid group. Homo sapiens
itself came VERY close becoming extinct several times. "Barely scraped by" would be a term I'd use, not "flying colors". If we were so successful and lucky, it stands to reason that other species on Earth would have too, regardless of intelligence. Again, this is a survivor-bias fallacy. Do bear in mind that we are not out of the woods yet and a lot of things in the universe could kill us or knock us back into the stone age, permanently.
, this post turned out longer then I expected, so humor me. I think when the James Webb and other instruments turn starward, we can answer some of these questions with more concision. Then we can debate this more! It's pretty fun