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The galaxy is billions of years old. Human civilization is a few thousand. Human civilization with a significant radiometric footprint above noise is less than

The galaxy is billions of years old. Human civilization is a few thousand. Human civilization with a significant radiometric footprint above noise is less than a hundred. And there's some not unreasonable concern that if we don't change our behavior en mass, the human race might cease to exist in a couple hundred to a thousand years. If that comes true, all of our human achievements will be a percent of a percent of a percent all throughout time. I personally think there was civilized life long ago, but it died out fairly quickly, the same way ours might. Time and space are so vast that there can easily be million-year and trillion-mile gaps in between each attempt at life that gets far enough to meaningfully search for the existence of other life elsewhere. Our universe is brutal and doesn't have any bias towards sentient life surviving. It does not care.

encoderer 4y ago
Yeah this is the heart of why the Fermi paradox does not convince me. The vastness of space and time mean that there might have been millions of other civilizations that have reached our current level of technical advancement with no real overlap.
- bullfightonmars 4y ago
  The fermi paradox is a question, not an answer. The answer may indeed be one of probability of timing.
- LarryMullins 4y ago
  The number of stars in the observable universe is really big, but perhaps not as big as you are thinking. Wolfram Alpha gives it as 10^24, which seems like a ludicrously huge number. But suppose for the sake of argument that intelligent human life on Earth were the consequence of just five independent "one in a million" chances. That's 1 in 10^30. Just five independent "one in a million" hurdles to clear makes intelligent life unlikely to occur anywhere in the universe at all. Now consider that advanced human life took a very long time to develop on Earth, even after multicellular life took off, which itself took a very long time to happen. Assuming that evolution inevitably converges onto something like humans is anthropocentric. It may be the case that life is reasonably common but intelligent life such as us is an absurdly rare fluke of luck.
  - encoderer 4y ago
    The sun is apparently 4.6 billion years old, but the Milky Way is 3x that. Hominids for 6 million years? It’s not just about looking back in time, which our telescopes are pretty great at, but observing the place at the right slice of time which becomes much harder. We see proxima b as it was ~4 years ago. That star system might be 6 billion years old. What if their extinction event was 50 million years ago? Or 500 million? Or 3 billion?
- yamtaddle 4y ago
  I dunno—there's a lot that had to go right with the Earth for it to support not just life, but complex, high-energy life, which enables (expensive-in-energy-terms) intelligence. And it still came close to getting stuck in bad states that may have prevented that, at least a couple times. It's way more than just being the right size, the right distance from a not-too-dangerous star, and having water. I'd be surprised if life isn't fairly common, but wouldn't be surprised if complex life is very rare.
  - wizeman 4y ago
    > there's a lot that had to go right with the Earth for it to support not just life, but complex, high-energy life, which enables (expensive-in-energy-terms) intelligence Like what? > It's way more than just being the right size, the right distance from a not-too-dangerous star, and having water. Besides that and having carbon (and nitrogen, I suppose), perhaps some small amounts of other elements, what are you referring to?
    - krapp 4y ago
      If it hadn't been for the K-T event wiping out the dinosaurs and creating a niche for mammals and eventually primates to thrive, we probably wouldn't be here. It doesn't get discussed enough how much of a factor blind stupid luck was in the one example we have of the evolution of intelligence in the universe.
      - wizeman 4y ago
        But the question was not whether we would be here. What's to say that in the absence of the K-T event, some dominant dinosaur species wouldn't have eventually evolved their intelligence to our level? Perhaps even earlier? It's not like the K-T event is a prerequisite for "general" intelligence, is it? Perhaps in such an alternative universe where the K-T event didn't happen you'd be a dinosaur posting on Dinohacker News right now.
        krapp 4y ago

encoderer 4y ago

Yeah this is the heart of why the Fermi paradox does not convince me. The vastness of space and time mean that there might have been millions of other civilizations that have reached our current level of technical advancement with no real overlap.

bullfightonmars 4y ago
The fermi paradox is a question, not an answer. The answer may indeed be one of probability of timing.
LarryMullins 4y ago
The number of stars in the observable universe is really big, but perhaps not as big as you are thinking. Wolfram Alpha gives it as 10^24, which seems like a ludicrously huge number. But suppose for the sake of argument that intelligent human life on Earth were the consequence of just five independent "one in a million" chances. That's 1 in 10^30. Just five independent "one in a million" hurdles to clear makes intelligent life unlikely to occur anywhere in the universe at all. Now consider that advanced human life took a very long time to develop on Earth, even after multicellular life took off, which itself took a very long time to happen. Assuming that evolution inevitably converges onto something like humans is anthropocentric. It may be the case that life is reasonably common but intelligent life such as us is an absurdly rare fluke of luck.
- encoderer 4y ago
  The sun is apparently 4.6 billion years old, but the Milky Way is 3x that. Hominids for 6 million years? It’s not just about looking back in time, which our telescopes are pretty great at, but observing the place at the right slice of time which becomes much harder. We see proxima b as it was ~4 years ago. That star system might be 6 billion years old. What if their extinction event was 50 million years ago? Or 500 million? Or 3 billion?
yamtaddle 4y ago
I dunno—there's a lot that had to go right with the Earth for it to support not just life, but complex, high-energy life, which enables (expensive-in-energy-terms) intelligence. And it still came close to getting stuck in bad states that may have prevented that, at least a couple times. It's way more than just being the right size, the right distance from a not-too-dangerous star, and having water. I'd be surprised if life isn't fairly common, but wouldn't be surprised if complex life is very rare.
- wizeman 4y ago
  > there's a lot that had to go right with the Earth for it to support not just life, but complex, high-energy life, which enables (expensive-in-energy-terms) intelligence Like what? > It's way more than just being the right size, the right distance from a not-too-dangerous star, and having water. Besides that and having carbon (and nitrogen, I suppose), perhaps some small amounts of other elements, what are you referring to?
  - krapp 4y ago
    If it hadn't been for the K-T event wiping out the dinosaurs and creating a niche for mammals and eventually primates to thrive, we probably wouldn't be here. It doesn't get discussed enough how much of a factor blind stupid luck was in the one example we have of the evolution of intelligence in the universe.
    - wizeman 4y ago
      But the question was not whether we would be here. What's to say that in the absence of the K-T event, some dominant dinosaur species wouldn't have eventually evolved their intelligence to our level? Perhaps even earlier? It's not like the K-T event is a prerequisite for "general" intelligence, is it? Perhaps in such an alternative universe where the K-T event didn't happen you'd be a dinosaur posting on Dinohacker News right now.
      - krapp 4y ago