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Such a mechanism would make complex life even more rare in the universe. Better this solution to the Fermi paradox than that sentient species tend to destroy th

Such a mechanism would make complex life even more rare in the universe. Better this solution to the Fermi paradox than that sentient species tend to destroy themselves with technology.

pfdietz 2y ago
We want the Great Filter to be behind us.
- rbanffy 2y ago
  I very much love the idea the Great Filter being behind us, but, just in case, we shouldn't ignore the possibility of multiple Great Filters.
  - pfdietz 2y ago
    Every time a SETI search comes up empty, I am happy.
    - rbanffy 2y ago
      Every time it comes up empty I think of how many filters we still have to clear.
      - pfdietz 2y ago
        If we find abundant ET life, it's evidence we're fucked, since at least one filter is in front of us. Only by having little or no ET within cosmological distances would the possibility remain open there's no GF ahead of us.
        wholinator2 2y ago
        Please explain because i would intuit the opposite. The less life's we see, the less likely that life survives to/through technological ages that would allow them to talk to us. If we see abundant life the it must be very easy to survive, thus less filters
        pfdietz 2y ago
        If life is abundant, there must have been something to prevent it from spreading, now or in the distant past. The fact that we evolved in an apparently empty universe, rather than in one that's been totally colonized, implies something stops this from happening. This thing is called the Great Filter, and it's apparently extremely effective. If the GF is in front of us, in a universe with lots of ETI, our chances of evading it are extremely small. After all, no one else has; why would we be so special? Nick Bostrum has called detection of ETI, or even complex ET life, the worst news mankind would ever receive. It would be a death sentence for our future. https://nickbostrom.com/papers/where-are-they/ https://nickbostrom.com/papers/where-are-they/
        svnt 2y ago
        You can have abundant life that is functionally isolated by physics, or said differently, by the degree of technological and societal advancement required to traverse the space between. Great distances and inherent speed limits seem like a decent way to accomplish that.
        pfdietz 2y ago
        I think it's clear that interstellar travel, while not trivial, should be possible for a civilization just a bit more advanced than our own. The energy or material resources required for interstellar colonization are very small compared to the resources available. It doesn't even require relativistic speeds, although reaching (say) 0.01 c doesn't require outrageous engineering, just a large spacecraft and lots of hydrogen bombs. Now, perhaps it's universally true that civilizations don't advance much beyond where we currently are, or don't persist for sufficiently long for interstellar colonization to be successful. These would also be very depressing outcomes if they are imposed on us by the GF.
        rbanffy 2y ago
        Interstellar colonization is more difficult than it's commonly imagined. To build a colony ship you need the same resources you'd need to build a large habitat. There would be economic pressure to build habitats that'd compete with the building of colony ships. When a colony ship arrives to a new planet, it'll need to bootstrap a full industrial chain before it can build its own colony ships to expand to other systems. It's reasonable to assume there would be little incentive for that before the colony starts to require off-planet resources on their own system, and, therefore, has a compelling reason to build a space economy. For us, this would easily be in the thousands of years even if no terraforming is needed, and let's not even consider we'd need a consistent multi-century planning to get there. Precursor missions with automated in-situ resource collection and storage would allow colonists to arrive to a fully built and stocked colony, which would save some time. Existing biospheres might present issues of toxicity and biological risks: you really don't want to grow up on a (Dune's) Rossak (even if it grants you superpowers). So, let's say Earth manages to establish 10 successful extra-solar colonies over 5 thousand years. It'll be at least a good couple thousand years until those successful colonies can each establish 10 others and raise the number to 100 worlds. If we manage to diligently expand at that exponential ration, we'll soon bump into other intelligent space-faring species that also share this commitment to reproduce.
- api 2y ago
  I've always seen a problem with the idea of the great filter: why do we think the filter is one thing or one discrete barrier? Why couldn't there be a very large number of low-probability filters and/or a continuous probability of failure spread across billions of years? Add them all up and the cumulative effect would be the same as a single great filter, but there would not be one single primary hurdle that needs to be cleared. This and the Fermi paradox itself are really just speculations. We have only one data point, which makes it impossible to say anything definitive.
  - pfdietz 2y ago
    The Great Filter could indeed be an aggregate of subfilters, but this wouldn't change the argument.
pohl 2y ago
Wouldn't it potentially make it less rare, if it turns out to be an additional mechanism? (Isn't it possible that there'd be multiple paths?)
billiam 2y ago
I think the rare Earth hypotheses get it backward, it all looks unlikely when you only have one data point. I think that complex life finds a way and it all looks like a six cushion bank shot in retrospect.

Such a mechanism would make complex life even more rare in the universe. Better this solution to the Fermi paradox than that sentient species tend to destroy themselves with technology.

pfdietz 2y ago

We want the Great Filter to be behind us.

rbanffy 2y ago
I very much love the idea the Great Filter being behind us, but, just in case, we shouldn't ignore the possibility of multiple Great Filters.
- pfdietz 2y ago
  Every time a SETI search comes up empty, I am happy.
  - rbanffy 2y ago
    Every time it comes up empty I think of how many filters we still have to clear.
    - pfdietz 2y ago
      If we find abundant ET life, it's evidence we're fucked, since at least one filter is in front of us. Only by having little or no ET within cosmological distances would the possibility remain open there's no GF ahead of us.
      - wholinator2 2y ago
        Please explain because i would intuit the opposite. The less life's we see, the less likely that life survives to/through technological ages that would allow them to talk to us. If we see abundant life the it must be very easy to survive, thus less filters
        pfdietz 2y ago
        If life is abundant, there must have been something to prevent it from spreading, now or in the distant past. The fact that we evolved in an apparently empty universe, rather than in one that's been totally colonized, implies something stops this from happening. This thing is called the Great Filter, and it's apparently extremely effective. If the GF is in front of us, in a universe with lots of ETI, our chances of evading it are extremely small. After all, no one else has; why would we be so special? Nick Bostrum has called detection of ETI, or even complex ET life, the worst news mankind would ever receive. It would be a death sentence for our future. https://nickbostrom.com/papers/where-are-they/ https://nickbostrom.com/papers/where-are-they/
        svnt 2y ago
        You can have abundant life that is functionally isolated by physics, or said differently, by the degree of technological and societal advancement required to traverse the space between. Great distances and inherent speed limits seem like a decent way to accomplish that.
        pfdietz 2y ago
        I think it's clear that interstellar travel, while not trivial, should be possible for a civilization just a bit more advanced than our own. The energy or material resources required for interstellar colonization are very small compared to the resources available. It doesn't even require relativistic speeds, although reaching (say) 0.01 c doesn't require outrageous engineering, just a large spacecraft and lots of hydrogen bombs. Now, perhaps it's universally true that civilizations don't advance much beyond where we currently are, or don't persist for sufficiently long for interstellar colonization to be successful. These would also be very depressing outcomes if they are imposed on us by the GF.
        rbanffy 2y ago
        Interstellar colonization is more difficult than it's commonly imagined. To build a colony ship you need the same resources you'd need to build a large habitat. There would be economic pressure to build habitats that'd compete with the building of colony ships. When a colony ship arrives to a new planet, it'll need to bootstrap a full industrial chain before it can build its own colony ships to expand to other systems. It's reasonable to assume there would be little incentive for that before the colony starts to require off-planet resources on their own system, and, therefore, has a compelling reason to build a space economy. For us, this would easily be in the thousands of years even if no terraforming is needed, and let's not even consider we'd need a consistent multi-century planning to get there. Precursor missions with automated in-situ resource collection and storage would allow colonists to arrive to a fully built and stocked colony, which would save some time. Existing biospheres might present issues of toxicity and biological risks: you really don't want to grow up on a (Dune's) Rossak (even if it grants you superpowers). So, let's say Earth manages to establish 10 successful extra-solar colonies over 5 thousand years. It'll be at least a good couple thousand years until those successful colonies can each establish 10 others and raise the number to 100 worlds. If we manage to diligently expand at that exponential ration, we'll soon bump into other intelligent space-faring species that also share this commitment to reproduce.
api 2y ago
I've always seen a problem with the idea of the great filter: why do we think the filter is one thing or one discrete barrier? Why couldn't there be a very large number of low-probability filters and/or a continuous probability of failure spread across billions of years? Add them all up and the cumulative effect would be the same as a single great filter, but there would not be one single primary hurdle that needs to be cleared. This and the Fermi paradox itself are really just speculations. We have only one data point, which makes it impossible to say anything definitive.
- pfdietz 2y ago
  The Great Filter could indeed be an aggregate of subfilters, but this wouldn't change the argument.

pohl 2y ago

Wouldn't it potentially make it less rare, if it turns out to be an additional mechanism? (Isn't it possible that there'd be multiple paths?)

billiam 2y ago

I think the rare Earth hypotheses get it backward, it all looks unlikely when you only have one data point. I think that complex life finds a way and it all looks like a six cushion bank shot in retrospect.