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>The silence implied by Fermi's paradox (“Where is everybody?”) may mean that we are not the most attention-worthy cookies in the jar. I've always thought of F

by cortic 6y ago

>The silence implied by Fermi's paradox (“Where is everybody?”) may mean that we are not the most attention-worthy cookies in the jar. I've always thought of Fermi's paradox as ultimately a math problem, assuming a conservative amount of time between a civilization in one star system colonizing a neighboring star system, over billions of years every star system in the galaxy should be colonized by now. The fact that we are not getting signals from the considerable number of stars that are within a reasonable distance is concerning. It does point to a great filter that we are not seeing or understanding. Or at least an enormous misconception about our universe.

bluGill 6y ago
I just assume that space is filled with enough junk that you cannot actually get between stars without getting hit by random chance and destroyed.
drichel 6y ago
We might as well be among the first ones. I find the idea quite fascinating, it kind of puts the Earth back into the center and makes us special in a way.
- cortic 6y ago
  If we are the first, then its likely the 'great filter' is behind us. And it means we will never find life that isn't related to us.
  - drichel 6y ago
    I can't quite follow how the "early bloomers" theory would imply either of those two conclusions. What I meant is the concept that our galaxy is young and the conditions just became right for ingelligent life to form, and here we are.
    - cortic 6y ago
      I've never heard of any theories that earth like conditions are new or unique, in fact half of all stars like ours are over 9 billion years old. And the universe has almost stopped making new stars. If you believe it takes, on average 9 billion years X 100 billion star systems to create 1 civilization, then you believe in some kind of 'filter' that stops life almost completely. A filter that we have passed to be the first. And by the time any other life statistically emerges we will have colonized the galaxy many times over.
      - drichel 6y ago
        There is indeed as far as I know some evidence that we are early bloomers https://hubblesite.org/contents/news-releases/2015/news-2015-35.html https://hubblesite.org/contents/news-releases/2015/news-2015... Half of the stars might be 9 billion years old, but for heavy emelents fo form, you need already certain conditions like neutron star mergers need to have occured. Our galaxy might be just old enough for that.
        cortic 6y ago
        That is interesting, and it changes my math a bit, though not to your favor; >Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe. So for us to be near the first, near enough not to trip on Fermi's paradox, and allowing a short 5 billions years for these planets to have existed on average; we are (1000 billion X 5 billion) to 1. Which still needs one hell of a filter to explain.
        drichel 6y ago
        Well actually you are starting to convince me of the opposite. My horizon is limited to the galaxy. The hypothesis here is that the Earth is an early bloomer in the Milky Way. Then we are dealing with 1 billion Earth-sized planets, only a fraction of which is orbiting stars capable of sustaining life, only a fraction of which in the habitable hone around their stars... They also need to be in the right region of the galaxy in which heavy stars were formed and died with the right conditions to produce heavy elements. Candidate planets also need to be far enough from sources of gamma ray bursts. And finally, even if they have life, it still needs to develop in the right direction for it to be complex enough and interested in reaching out and colonizing the galaxy. So, the odds are a billion times a tiny fraction to one, a sustainable hypothesis as far as I am concerned. I believe I saw a model somewhere, predicting that most habitable planets are yet to form in our galaxy, but I did not bother to look hard enough for references.
krapp 6y ago
>I've always thought of Fermi's paradox as ultimately a math problem, assuming a conservative amount of time between a civilization in one star system colonizing a neighboring star system, over billions of years every star system in the galaxy should be colonized by now. I've never found this argument particularly compelling, as it seems too simplistic and ignores a vast number of possible confounding variables such as stars not being equally amenable to colonization, or even equidistant to each other, and the likely stability of civilizations over such timescales. It seems far more likely to me that any civilization that colonizes another star sees diminishing returns given the risk and reaches some limit rather than seeking infinite, exponential expansion. >The fact that we are not getting signals from the considerable number of stars that are within a reasonable distance is concerning. It does point to a great filter that we are not seeing or understanding. Or at least an enormous misconception about our universe. For one thing, the observable universe contains billions of galaxies, which means the vast majority of stars are unreasonably distant.
- cortic 6y ago
  What you are proposing is a great filter of confounding variable and diminishing returns. You really think these limitations are so overwhelming that practically no civilization could expand exponentially? Cause that's what you need to be saying, if even one in a trillion could then they should be everywhere by now.
  - krapp 6y ago
    >You really think these limitations are so overwhelming that practically no civilization could expand exponentially? Yes, including the set of all civilizations that chose not to continue to expand exponentially as well as those that tried and eventually failed, due to any number of factors. I think interstellar expansion (to say nothing of infinite exponential expansion) turns out to be just that hard and, for the relatively few civilizations that may actually advance to the point of even being capable of considering the effort, not worth the effort.

by cortic 6y ago

bluGill 6y ago

I just assume that space is filled with enough junk that you cannot actually get between stars without getting hit by random chance and destroyed.

drichel 6y ago

We might as well be among the first ones. I find the idea quite fascinating, it kind of puts the Earth back into the center and makes us special in a way.

cortic 6y ago
If we are the first, then its likely the 'great filter' is behind us. And it means we will never find life that isn't related to us.
- drichel 6y ago
  I can't quite follow how the "early bloomers" theory would imply either of those two conclusions. What I meant is the concept that our galaxy is young and the conditions just became right for ingelligent life to form, and here we are.
  - cortic 6y ago
    I've never heard of any theories that earth like conditions are new or unique, in fact half of all stars like ours are over 9 billion years old. And the universe has almost stopped making new stars. If you believe it takes, on average 9 billion years X 100 billion star systems to create 1 civilization, then you believe in some kind of 'filter' that stops life almost completely. A filter that we have passed to be the first. And by the time any other life statistically emerges we will have colonized the galaxy many times over.
    - drichel 6y ago
      There is indeed as far as I know some evidence that we are early bloomers https://hubblesite.org/contents/news-releases/2015/news-2015-35.html https://hubblesite.org/contents/news-releases/2015/news-2015... Half of the stars might be 9 billion years old, but for heavy emelents fo form, you need already certain conditions like neutron star mergers need to have occured. Our galaxy might be just old enough for that.
      - cortic 6y ago
        That is interesting, and it changes my math a bit, though not to your favor; >Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe. So for us to be near the first, near enough not to trip on Fermi's paradox, and allowing a short 5 billions years for these planets to have existed on average; we are (1000 billion X 5 billion) to 1. Which still needs one hell of a filter to explain.
        drichel 6y ago
        Well actually you are starting to convince me of the opposite. My horizon is limited to the galaxy. The hypothesis here is that the Earth is an early bloomer in the Milky Way. Then we are dealing with 1 billion Earth-sized planets, only a fraction of which is orbiting stars capable of sustaining life, only a fraction of which in the habitable hone around their stars... They also need to be in the right region of the galaxy in which heavy stars were formed and died with the right conditions to produce heavy elements. Candidate planets also need to be far enough from sources of gamma ray bursts. And finally, even if they have life, it still needs to develop in the right direction for it to be complex enough and interested in reaching out and colonizing the galaxy. So, the odds are a billion times a tiny fraction to one, a sustainable hypothesis as far as I am concerned. I believe I saw a model somewhere, predicting that most habitable planets are yet to form in our galaxy, but I did not bother to look hard enough for references.

krapp 6y ago

>I've always thought of Fermi's paradox as ultimately a math problem, assuming a conservative amount of time between a civilization in one star system colonizing a neighboring star system, over billions of years every star system in the galaxy should be colonized by now. I've never found this argument particularly compelling, as it seems too simplistic and ignores a vast number of possible confounding variables such as stars not being equally amenable to colonization, or even equidistant to each other, and the likely stability of civilizations over such timescales. It seems far more likely to me that any civilization that colonizes another star sees diminishing returns given the risk and reaches some limit rather than seeking infinite, exponential expansion. >The fact that we are not getting signals from the considerable number of stars that are within a reasonable distance is concerning. It does point to a great filter that we are not seeing or understanding. Or at least an enormous misconception about our universe. For one thing, the observable universe contains billions of galaxies, which means the vast majority of stars are unreasonably distant.

cortic 6y ago
What you are proposing is a great filter of confounding variable and diminishing returns. You really think these limitations are so overwhelming that practically no civilization could expand exponentially? Cause that's what you need to be saying, if even one in a trillion could then they should be everywhere by now.
- krapp 6y ago
  >You really think these limitations are so overwhelming that practically no civilization could expand exponentially? Yes, including the set of all civilizations that chose not to continue to expand exponentially as well as those that tried and eventually failed, due to any number of factors. I think interstellar expansion (to say nothing of infinite exponential expansion) turns out to be just that hard and, for the relatively few civilizations that may actually advance to the point of even being capable of considering the effort, not worth the effort.