5 ms·

"Chance of life forming from non life * age of the universe * number of stars * the chance a star has an earth like planet, is far from zero" You have no proof

by zeteo 16y ago

"Chance of life forming from non life * age of the universe * number of stars * the chance a star has an earth like planet, is far from zero" You have no proof for this, and things can well be the other way round. Let n = age of the universe * number of stars * the chance a star has an Earth like planet n is a number that we currently have a pretty good guess at. Let p = chance of life forming from non life on Earth-like planet within a given year. We are basically clueless as to the value of p. p may well be much less than 1/n, which would make our biosphere very special indeed.

eof 16y ago
I have no proof for it, but I don't need it. The burden of proof is not on me. They are making the claim that 'complex life only happened once'. Life certainly does exist so p > 0. Since our understanding (or I should say, my under standing of 'our' understanding) of n is approaching infinity, it stands to reason that p x n is > 0.
- zeteo 16y ago
  You've made a statement that a certain quantity is far larger than zero, so you do incur a burden of proof for that statement. p * n > 0 doesn't imply p * n >> 0, not even for large values of n (and "approaching infinity" doesn't apply to constants).
  - eof 16y ago
    Sorry, 'far from zero' is really meaningless and I shouldn't have said it that way. I don't actually mean to make a positive statement about the existence of complex life elsewhere in the universe, though intuitively I think it's absurd to believe our little planet is the only one with life on it. I mean, why would we believe that other than residual religious dogma? Our understanding of n is not a constant.
    - jerf 16y ago
      "I mean, why would we believe that other than residual religious dogma?" Because when we look out into the universe, it looks like we expect it to look when it is dead, not full of life, some significant percentage of which becomes intelligent. Nothing that looks like Dyson spheres of any form (recalling that the "solid shell" is actually only a special case), nothing that looks like curated stellar evolution (very high-end stuff but a truly advanced civilization will not want to leave stars just randomly flying around a galaxy and exploding), very very little that could even conceivably be a ship traveling between the stars (which turns out with any physically-plausible propulsion mechanism to be visible from a very long ways away and would show very clear blue/red shift changes), nothing that doesn't appear entirely natural. This isn't the whole story (maybe they're hiding, maybe our idea of the top end of tech is wrong, maybe they're all virtual, maybe they escaped into another, friendlier dimension, maybe they all kill themselves, maybe the universe is soaked with simple life but this article is essentially correct and complex intelligent life really is a 10^-1000 event, etc.), but it is not true that the claim that complex life must be hard is some sort of stupid idea in light of the size of the universe. Arguably it's actually the claim best supported by the evidence at this time. People are really bad at thinking about small probabilities even on the scale of one out of a million, and it's not impossible that complex intelligent life turns out to be one out of 10^1000 or worse; we simply don't know. It is not hard to come up with calculations that plausibly set the odds of advanced life occurring even once in the universe as less than 50/50 without having to make stuff up. Our ignorance dominates our knowledge here.
      - eof 16y ago
        Where exactly would we be seeing all this stuff? I mean, how closely can we even look on planets in our galaxy? We are still discovering trillions of new galaxies here and there. Our reach is virtually zero in the context of the universe. It seems from our vantage point, I would expect the universe to look exactly the same whether it was bustling with life or we were the only ones. I had never thought about searching for Dyson spheres (it made me replay a part from The Big Lebowski where the dude says, "We'll that's fucking interesting man."), but they strike me as a incredibly hard thing to search for. Don't we see into the universe with the energy escaping from stars, galaxies, etc..? If some species were able to actually harvest the output of a star to anything approaching 100%, wouldn't it be exactly the type of thing we would never see? > Arguably it's actually the best claim supported by evidence Unless I am fundamentally wrong about the resolution of our map of the universe, I don't think there is any evidence either way unless you believe in any 'encounters'
- weavejester 16y ago
  They are making the claim that 'complex life only happened once'. They're saying that on Earth, complex life only happened once: "It suggests that complex alien life-forms could only evolve if an event that happened just once in Earth's history was repeated somewhere else."
  - eof 16y ago
    aye ye ye. Yeah I was definitely reading that wrong. That's a helluva claim! I guess I am out of my league to say anything about it though.

by zeteo 16y ago

eof 16y ago

I have no proof for it, but I don't need it. The burden of proof is not on me. They are making the claim that 'complex life only happened once'. Life certainly does exist so p > 0. Since our understanding (or I should say, my under standing of 'our' understanding) of n is approaching infinity, it stands to reason that p x n is > 0.

zeteo 16y ago
You've made a statement that a certain quantity is far larger than zero, so you do incur a burden of proof for that statement. p * n > 0 doesn't imply p * n >> 0, not even for large values of n (and "approaching infinity" doesn't apply to constants).
- eof 16y ago
  Sorry, 'far from zero' is really meaningless and I shouldn't have said it that way. I don't actually mean to make a positive statement about the existence of complex life elsewhere in the universe, though intuitively I think it's absurd to believe our little planet is the only one with life on it. I mean, why would we believe that other than residual religious dogma? Our understanding of n is not a constant.
  - jerf 16y ago
    "I mean, why would we believe that other than residual religious dogma?" Because when we look out into the universe, it looks like we expect it to look when it is dead, not full of life, some significant percentage of which becomes intelligent. Nothing that looks like Dyson spheres of any form (recalling that the "solid shell" is actually only a special case), nothing that looks like curated stellar evolution (very high-end stuff but a truly advanced civilization will not want to leave stars just randomly flying around a galaxy and exploding), very very little that could even conceivably be a ship traveling between the stars (which turns out with any physically-plausible propulsion mechanism to be visible from a very long ways away and would show very clear blue/red shift changes), nothing that doesn't appear entirely natural. This isn't the whole story (maybe they're hiding, maybe our idea of the top end of tech is wrong, maybe they're all virtual, maybe they escaped into another, friendlier dimension, maybe they all kill themselves, maybe the universe is soaked with simple life but this article is essentially correct and complex intelligent life really is a 10^-1000 event, etc.), but it is not true that the claim that complex life must be hard is some sort of stupid idea in light of the size of the universe. Arguably it's actually the claim best supported by the evidence at this time. People are really bad at thinking about small probabilities even on the scale of one out of a million, and it's not impossible that complex intelligent life turns out to be one out of 10^1000 or worse; we simply don't know. It is not hard to come up with calculations that plausibly set the odds of advanced life occurring even once in the universe as less than 50/50 without having to make stuff up. Our ignorance dominates our knowledge here.
    - eof 16y ago
      Where exactly would we be seeing all this stuff? I mean, how closely can we even look on planets in our galaxy? We are still discovering trillions of new galaxies here and there. Our reach is virtually zero in the context of the universe. It seems from our vantage point, I would expect the universe to look exactly the same whether it was bustling with life or we were the only ones. I had never thought about searching for Dyson spheres (it made me replay a part from The Big Lebowski where the dude says, "We'll that's fucking interesting man."), but they strike me as a incredibly hard thing to search for. Don't we see into the universe with the energy escaping from stars, galaxies, etc..? If some species were able to actually harvest the output of a star to anything approaching 100%, wouldn't it be exactly the type of thing we would never see? > Arguably it's actually the best claim supported by evidence Unless I am fundamentally wrong about the resolution of our map of the universe, I don't think there is any evidence either way unless you believe in any 'encounters'
weavejester 16y ago
They are making the claim that 'complex life only happened once'. They're saying that on Earth, complex life only happened once: "It suggests that complex alien life-forms could only evolve if an event that happened just once in Earth's history was repeated somewhere else."
- eof 16y ago
  aye ye ye. Yeah I was definitely reading that wrong. That's a helluva claim! I guess I am out of my league to say anything about it though.