The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox.

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

The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, “If life is so easy, someone from somewhere must have come calling by now.”

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

Personally I think it’s photosynthesis. Life itself developed and spread but photosynthesis started an inevitable chain of ever-greater and more-efficient life. I think a random chain of mutations that turns carbon-based proto-life into something that can harvest light energy is wildly unlikely, even after the wildly unlikely event of life beginning in the first place.

I have no data to back that up, just a guess.

  • rsuri@lemmy.world
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    4 months ago

    There’s a lot of possibilities.

    My top contender would be a desire to explore, which probably requires consciousness. Given that we have pretty much no idea what leads to consciousness, it can be guessed (dubiously) that if it arose more easily then we’d have an explanation by now. It could be that it’s an extremely rare phenomenon, and there may even be other planets with “intelligent” but mechanistic beings that act entirely for their own survival and don’t build civilizations or explore much.

    Second would be intergalactic and to a lesser degree interstellar travel. If we assume both 1) intelligent civilizations are extremely rare and 2) faster-than-light transportation is impossible, it could be that everyone is just too spread out to make contact.

    Third, and the one I most feel is right but it requires pretending I understand quantum physics (which I don’t) and probably offending many that do, is the notion that the concrete universe is not large but small and has no objective existence independent of our respective perceptions, and any part of the universe that’s invisible is a mere wave function that will only have concrete reality upon our perceiving it. I make the further dubious assumption that conscious beings can’t be part of the wave function. So there.

    • Cethin@lemmy.zip
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      4 months ago

      For your final point, that’s not what that means. It’s not “observation” that collapses the wave function, at least as you’re understanding the word. It’s any interaction that requires the information to be known. That includes any particle interactions. It’s not consciousness that matters. When we “make a measurement” it’s only recording information of an interaction. It doesn’t actually matter that we record it, only that there was an interaction. There is zero metaphysical consciousness mumbo-jumbo involved.

      • ammonium@lemmy.world
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        4 months ago

        That’s what I thought too, but according to Sabine Hossenfelder there actually is, we just choose not to speak about it. I don’t really know enough about quantum physics to make my own judgement.

    • KevonLooney@lemm.ee
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      4 months ago

      conscious beings can’t be part of the wave function

      That’s not how any of this works. Your brain is made out of regular matter, not special fancy matter.

      • rsuri@lemmy.world
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        4 months ago

        I don’t know if the type of matter matters, rather I’m basing in on the idea that measurement collapses the wave function, and consciousness does measure things

        • KevonLooney@lemm.ee
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          4 months ago

          Your brain isn’t what “collapses the wave function”, it’s the measuring device that you use. You can do a double slit experiment and watch it with your eyes the whole time. Light will still act as a wave until you interact with it experimentally.

          You are reading too much Deepak Chopra. Your brain is just a computer made out of meat. It’s not magic.

    • Cryophilia@lemmy.worldOP
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      4 months ago

      Second would be intergalactic and to a lesser degree interstellar travel. If we assume both 1) intelligent civilizations are extremely rare and 2) faster-than-light transportation is impossible, it could be that everyone is just too spread out to make contact.

      Not just too spread out to make contact, too spread out to even detect each other’s presence