I’ve read most of that paper (I think I’ve seen it before, although there could be something else near-identical to it; I know I’ve read multiple[1] papers that claim to solve the Fermi Paradox and do not live up to their hype). TBH, I feel like it can be summed up as “well, there might be a Great Filter somewhere along the line, therefore no paradox”. I mean, no shit there’s probably a Great Filter somewhere, that’s the generally-proposed resolution that’s been going for decades now. The question is “what is the Filter?”. And saying “a Filter exists” doesn’t answer that question.
We’ve basically ruled out “Earthlike planets are rare”. “Abiogenesis is rare” is possible, but note that you need “no lithopanspermia” for that one to hold up since otherwise one abiogenesis event (the one that led to us and which is therefore P = 1, whether on Earth or not) is enough to seed much of the galaxy. “Intelligence is rare” is a possibility but not obviously-true, ditto “technology is rare”. Late filters (which, you will note, the authors assume to be a large possibility) appear somewhat less plausible but are not ruled out by any stretch. So yeah, it’s still a wide-open question even if there are some plausible answers.
The other one I recall, besides Grabby Aliens, was one saying that Earthly life is downstream of a lithopanspermia event so there’s no Fermi paradox; I don’t get it either.
TBH, I feel like it can be summed up as “well, there might be a Great Filter somewhere along the line, therefore no paradox”.
Yep, this is the point, we should not be surprised to see no aliens, because there is a likely great filter, or at least a serious mistake in our calculations, and thus it doesn’t matter that we live in a large universe, since there is quite a high probability that we are just alone.
But they also isolate the Great Filter to “Life is ridiculously rare”, and they also isolate the Great Filter to the past, which means that there’s not much implications other than “life is rare” from seeing no aliens.
The earliness of life appearing on Earth isn’t amazingly-consistent with life’s appearance on Earth being a filter-break. It suggests either abiogenesis is relatively-easy or that panspermia is easy (as I noted, in the latter case abiogenesis could be as hard as you like but that doesn’t explain the Great Silence).
Frankly, it’s premature to be certain it’s “abiogenesis rare, no panspermia” before we’ve even got a close look at Earthlike exoplanets.
I’ve read most of that paper (I think I’ve seen it before, although there could be something else near-identical to it; I know I’ve read multiple[1] papers that claim to solve the Fermi Paradox and do not live up to their hype). TBH, I feel like it can be summed up as “well, there might be a Great Filter somewhere along the line, therefore no paradox”. I mean, no shit there’s probably a Great Filter somewhere, that’s the generally-proposed resolution that’s been going for decades now. The question is “what is the Filter?”. And saying “a Filter exists” doesn’t answer that question.
We’ve basically ruled out “Earthlike planets are rare”. “Abiogenesis is rare” is possible, but note that you need “no lithopanspermia” for that one to hold up since otherwise one abiogenesis event (the one that led to us and which is therefore P = 1, whether on Earth or not) is enough to seed much of the galaxy. “Intelligence is rare” is a possibility but not obviously-true, ditto “technology is rare”. Late filters (which, you will note, the authors assume to be a large possibility) appear somewhat less plausible but are not ruled out by any stretch. So yeah, it’s still a wide-open question even if there are some plausible answers.
The other one I recall, besides Grabby Aliens, was one saying that Earthly life is downstream of a lithopanspermia event so there’s no Fermi paradox; I don’t get it either.
Yep, this is the point, we should not be surprised to see no aliens, because there is a likely great filter, or at least a serious mistake in our calculations, and thus it doesn’t matter that we live in a large universe, since there is quite a high probability that we are just alone.
But they also isolate the Great Filter to “Life is ridiculously rare”, and they also isolate the Great Filter to the past, which means that there’s not much implications other than “life is rare” from seeing no aliens.
The earliness of life appearing on Earth isn’t amazingly-consistent with life’s appearance on Earth being a filter-break. It suggests either abiogenesis is relatively-easy or that panspermia is easy (as I noted, in the latter case abiogenesis could be as hard as you like but that doesn’t explain the Great Silence).
Frankly, it’s premature to be certain it’s “abiogenesis rare, no panspermia” before we’ve even got a close look at Earthlike exoplanets.