4 ms·

Hopefully we find evidence for post-great-filter life too…

echelon 10mo ago
Speaking of "great filter", I often wonder about the hypothetical case that we live in a fragile universe. Whatever the first civilization is to cause something like vacuum collapse could destroy the entire universe at the speed of light. Maybe it's already happened somewhere and is currently propagating our way.
- datameta 10mo ago
  Maybe it even is happening but will never reach us from their local observable sphere.
  - gerad 10mo ago
    Guess it's good that space expands faster than the speed of light.
- exe34 10mo ago
  if you haven't read Schild's ladder, you're in for a treat :-D
GoblinSlayer 10mo ago
Great filter might involve harsh tradeoffs like "no stupidity allowed". Do you really want to know it?
- octopoc 10mo ago
  Yes because the alternative is extinction, any price is worth avoiding that
mikkupikku 10mo ago
Earth life may already be post-filter. Also, I would bet on there being lots of little filters rather than one great one. Stack a dozen or so independent filters that only 1% of upstart life can develop through, and you can easily explain the apparent absence of life capable of broadcasting their existence, making life as developed as humanity extremely rare. Maybe only 1% of stellar systems are arranged appropriately with a Jovian planet to sweep the inner system clean of killer comets and meteors. Maybe the conditions for unicellular life only occur on 1% of nominally terrestrial worlds. Maybe only 1% of unicellular life develops in a way that has a hereditary mechanism that is susceptible to random mutation, so evolution has something to work with. Maybe the jump from unicellular to multicellular is extremely unlikely to occur; it did take billions of years on Earth after all, its clearly not something that you can count on happening a week later. And maybe the chance that multicellular life develops in a direction that will eventually develop animals capable of making advanced tools is extremely rare too. Real life evolution isn't like a game of Spore, it's not a computer game with a defined goal that some force is working towards. Evolution likes robust reproducers like bugs a lot more than it likes clever monkeys. Maybe when intelligent animals do happen to evolve, they, like dolphins or octopus or corvids, almost always lack the physical characteristics necessary to put their brains towards the problem of the scientific method and industrialization. Maybe when such species even do exist, they usually socially stagnate in preindustrial times, as humanity did for a long time, and get stuck there because their culture values social stability more than innovation. Maybe only 1% manage to not nuke themselves out of existence within a few years of inventing nukes. Stack a few of these sort of considerations up, and before long Fermi's "paradox" stops seeming very paradoxical.
- neom 10mo ago
  You can generate arbitrarily low probabilities for anything by stacking arbitrary fractions. If evolution has no goal, then the absence of radio loud civilizations does not demand explanation, it is only paradoxical if you implicitly believe that intelligence plus technology is a natural attractor state.
  - mikkupikku 10mo ago
    Yes, agreed. Furthermore, high tech tool makers not being a goal of evolution is certain, not merely a supposition, there's no anthropomorphic force driving life in that direction. The natural attractor states of evolution can safely be assumed to be the niches evolution has repeatedly discovered and recreated on Earth numerous times, the cases of convergent evolution. If we were digging up fossils of technology created a hundred million years ago by a high tech species of birds or something, and more from another period from yet another totally different lineage, that would substantially change the math. But all the evidence on Earth points to a species like ours being a very rare thing for evolution to create.
    - neom 10mo ago
      Agree. And also: The universe contains multiple substrates, degrees of freedom, organizational proprties etc that could support advanced intelligence while being effectively totally invisible to a species/civilization like ours.
    - Xss3 10mo ago
      Despite our advantages intelligent hominids were an endangered species confined to a small pocket of africa for ~80,000 years.
      - mikkupikku 10mo ago
        Absolutely. The advantages provided by advanced intelligence matter a lot less when when technology is still primitive, and during that period an intelligent species is likely to be quite vulnerable. At least, we were.

Speaking of "great filter", I often wonder about the hypothetical case that we live in a fragile universe. Whatever the first civilization is to cause something like vacuum collapse could destroy the entire universe at the speed of light. Maybe it's already happened somewhere and is currently propagating our way.

datameta 10mo ago
Maybe it even is happening but will never reach us from their local observable sphere.
- gerad 10mo ago
  Guess it's good that space expands faster than the speed of light.
exe34 10mo ago
if you haven't read Schild's ladder, you're in for a treat :-D

GoblinSlayer 10mo ago

Great filter might involve harsh tradeoffs like "no stupidity allowed". Do you really want to know it?

octopoc 10mo ago
Yes because the alternative is extinction, any price is worth avoiding that

mikkupikku 10mo ago

Earth life may already be post-filter. Also, I would bet on there being lots of little filters rather than one great one. Stack a dozen or so independent filters that only 1% of upstart life can develop through, and you can easily explain the apparent absence of life capable of broadcasting their existence, making life as developed as humanity extremely rare. Maybe only 1% of stellar systems are arranged appropriately with a Jovian planet to sweep the inner system clean of killer comets and meteors. Maybe the conditions for unicellular life only occur on 1% of nominally terrestrial worlds. Maybe only 1% of unicellular life develops in a way that has a hereditary mechanism that is susceptible to random mutation, so evolution has something to work with. Maybe the jump from unicellular to multicellular is extremely unlikely to occur; it did take billions of years on Earth after all, its clearly not something that you can count on happening a week later. And maybe the chance that multicellular life develops in a direction that will eventually develop animals capable of making advanced tools is extremely rare too. Real life evolution isn't like a game of Spore, it's not a computer game with a defined goal that some force is working towards. Evolution likes robust reproducers like bugs a lot more than it likes clever monkeys. Maybe when intelligent animals do happen to evolve, they, like dolphins or octopus or corvids, almost always lack the physical characteristics necessary to put their brains towards the problem of the scientific method and industrialization. Maybe when such species even do exist, they usually socially stagnate in preindustrial times, as humanity did for a long time, and get stuck there because their culture values social stability more than innovation. Maybe only 1% manage to not nuke themselves out of existence within a few years of inventing nukes. Stack a few of these sort of considerations up, and before long Fermi's "paradox" stops seeming very paradoxical.

neom 10mo ago
You can generate arbitrarily low probabilities for anything by stacking arbitrary fractions. If evolution has no goal, then the absence of radio loud civilizations does not demand explanation, it is only paradoxical if you implicitly believe that intelligence plus technology is a natural attractor state.
- mikkupikku 10mo ago
  Yes, agreed. Furthermore, high tech tool makers not being a goal of evolution is certain, not merely a supposition, there's no anthropomorphic force driving life in that direction. The natural attractor states of evolution can safely be assumed to be the niches evolution has repeatedly discovered and recreated on Earth numerous times, the cases of convergent evolution. If we were digging up fossils of technology created a hundred million years ago by a high tech species of birds or something, and more from another period from yet another totally different lineage, that would substantially change the math. But all the evidence on Earth points to a species like ours being a very rare thing for evolution to create.
  - neom 10mo ago
    Agree. And also: The universe contains multiple substrates, degrees of freedom, organizational proprties etc that could support advanced intelligence while being effectively totally invisible to a species/civilization like ours.
  - Xss3 10mo ago
    Despite our advantages intelligent hominids were an endangered species confined to a small pocket of africa for ~80,000 years.
    - mikkupikku 10mo ago
      Absolutely. The advantages provided by advanced intelligence matter a lot less when when technology is still primitive, and during that period an intelligent species is likely to be quite vulnerable. At least, we were.