[ExI] After the Great Filter

[John Grigg]

Rafal  Smigrodzki wrote:
"We are on the last millionth part of the last sprint of the longest race
in our galaxy, the race to space-colonizing intelligent life. I sure hope
we don't trip up at the last possible moment."

If we can just make it through the next one-hundred years, I would think we
would be okay in terms of having enough people and infrastructure
off-planet to continue civilization should the human society on Earth
collapse.

I am a huge Edgar Panghorn fan, who wrote the classic sf novel, Davy, which
many consider the work of a grandmaster. As I read it and the follow-up
book, I was horrified to learn that when the big global nuclear war
happened, they not only destroyed all the cities of the world, but also the
large Moon colony which had been established. And so the spark of advanced
civilization was completely extinguished. It might have been cool in the
sequel to have had colonists from the Moon show up in exo-skeletons, to see
how the poor backward humans left on Earth were doing.

https://en.wikipedia.org/wiki/Edgar_Pangborn.

John


On Tue, Dec 15, 2020 at 11:46 PM BillK via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> On Tue, 15 Dec 2020 at 07:45, Rafal Smigrodzki via extropy-chat
> <extropy-chat at lists.extropy.org> wrote:
> >
> > A recent article in Communications Earth & Environment:
> >
> > https://www.nature.com/articles/s43247-020-00057-8
> >
> > attempts to model the likelihood of Earth-like planets to remain
> continuously habitable for 3 billions of years and comes to the conclusion
> that the overall success rate would be very low (0.0145). I have doubts
> about the approach, in part because I don't really understand how the
> results were generated and I am too lazy to read the Methods section where
> the assumptions are explained. Well, actually I skimmed through the methods
> and I think one assumption is a major blooper - that 3 By of continuous
> habitability are needed for intelligent life to evolve. That really doesn't
> make sense. The whole modeling effort seems like trying to squeeze way too
> much knowledge out of way too little data. Or maybe I am not sophisticated
> to see the general applicability of the method?
> >
> > Still, the article's conclusion is probably correct - even on planets
> blessed with all the right ingredients there is going to be a lot of
> instability, due to various instantaneous perturbations (asteroids,
> supervolcanism) and the interplay of long-term forcings. We know that
> complex life on Earth was reset multiple times, so it's plausible that the
> same is happening everywhere. Life-sustaining planets most likely all have
> plate tectonics, since this is a very powerful stabilizing mechanism
> without which the chemical composition of the atmosphere would almost
> certainly degrade continuously until water is lost (Mars) or a runaway
> heating occurs (Venus). But plate tectonics implies mantle convection and
> convection is likely to produce plumes which trigger supervolcanism. So
> every living planet is most likely primed to erase large animals on a
> regular basis.
> >
> > I do not believe that dinosaurs or the theriodonts were in some
> substantial way more primitive than modern mammals - most likely they were
> functionally equivalent to the bulk of modern mammals and the only reason
> they did not give rise to intelligent forms is because they got creamed by
> climate perturbations too early.
> >
> > Intelligence most likely appears randomly with some reasonable
> probability once you have large animals running around long enough - but
> exactly how long is the average time to first evolved sophont is unclear.
> Probably not less than 100 million years (Myr), since there were two epochs
> on Earth when large animals evolved uninterrupted, more or less, for
> similar periods (the above-mentioned theriodonts and dinosaurs) and still
> did not manage to evolve intelligence. If we are a lucky throw of the dice,
> and the average time to intelligence is e.g. 500 Myr, then even on lucky
> planets with all the right ingredients for life there would never be
> intelligent life because random resets due to supervolcanism would happen
> too frequently.
> >
> > Too much uncertainty, too little data. Anyway, my guess, which I
> mentioned here before, is that Earth already passed through the Great
> Filters. We are just a couple of decades away from spreading to other
> planets. I don't believe that superintelligent AI is a filter, at least not
> a filter preventing intelligence survival - even if all humans perish in
> the robot wars, intelligence of the inorganic variety will still survive
> and spread.
> >
> > We are on the last millionth part of the last sprint of the longest race
> in our galaxy, the race to space-colonizing intelligent life. I sure hope
> we don't trip up at the last possible moment.
> >
> > Rafal
> > _______________________________________________
>
>
> This article implies that not only the habitability of Earth depended
> greatly on random chance, but Evolution itself did as well.  Every so
> often, random events wiped out great swathes of species from the
> earth.
> The idea that humans are the peak of a steady step by step improving
> evolution is just not right. It is more like evolution is making the
> best of a bad job, making do with what was left after disasters
> struck.
>
> If there are other habitable planets out there evolution probably took
> a rather different path. I quite fancy being an evolved Tyrannosaurus
> Rex, after evolving bigger arms of course.
>
>
> BillK
>
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