5 ms·

A turtle on the Galápagos Islands in 1450AD could use the same reasoning to conclude that no seafaring civilizations existed.

hansbo 5y ago
Yeah, but if humans keep existing for millions of years, then the probability for a turtle on the Galápagos Islands to live in the time between when humans started seafaring and when humans visited the islands would be extremely small compared to any other time period.
- addingnumbers 5y ago
  Since we know the conclusion to be false, any reasoning that would support this hypothetical turtle's conclusion that no seafarers existed in 1450 is inarguably an example of bad reasoning.
  - gpm 5y ago
    No, because the turtle is concluding that it's likely false, not definitely false. There happens to be a cosmic coincidence working against the turtle, but that doesn't mean that it was bad reasoning to conclude that the cosmic coincidence was very unlikely.
    - addingnumbers 5y ago
      The turtle is saying with certainty, not likelihood, that no seafarers exist, analogous with the explicit conclusion (3) in the top level comment
      - gpm 5y ago
        People are lazy when they speak, it's best to understand basically every claim as probabilistic (and meaning "almost certainly") even when it isn't stated as such. Certainly no-one would make the claim that "there are (definitely) no aliens in the galaxy" when we can't disprove the idea that aliens traveling at the speed of light just reached the galaxy (with our current understanding of physics). That doesn't mean you can't make the claim "there are (almost definitely) no aliens in the galaxy (because I just created the most amazing telescope ever and looked at every particle of matter in the galaxy and there were no aliens there)". The principle of charity demands that understand the bare claim that "there are no aliens in the galaxy" to mean something that is plausible, such as "there are almost certainly no aliens in the galaxy".
        addingnumbers 5y ago
        A line of reasoning that tells our turtles something totally false doesn't deserve validation for doing it with slight uncertainty.
        indrax 5y ago
        You have to weight the validity of the reasoning across all turtle observers through history. If you reject probabilistic reasoning because it sometimes tell you things that are wrong, then you have no way to reason about uncertainty.
        addingnumbers 5y ago
        If your reasoning about uncertainty tells you there's a 99% chance something is false while it's true, what good is it? All the math in the world won't save you from the specious premises in this no-seafarers argument.
        epivosism 5y ago
        "If your reasoning suggests you shouldn't play the lottery, but playing the lottery actually results in you winning, what use is your math?" Well, what matters is expectation. The fact that some people win the lottery doesn't prove that playing the lotto is profitable. In fact it isn't money-profitable. The fact that people sometimes win doesn't change the nature of reality, that even for them, the win is unexpected and playing was negative expectation for them. You seem to be confusing expected value with results. Do you revise your decision process every time you get unlucky? On a meta level, sure, paying attention to unexpected failures is important to look for systematic errors. But randomly getting unlucky on 99% certainties does not automatically disprove your decision method.
  - RupertEisenhart 5y ago
    That is incorrect. Good reasoning can lead to conclusions that are strictly false. For example, when asked to be more granular, the turtle could say 'I reason that there is only a 1 in 10 chance that seafaring civilizations exist'. The existence of seafaring civilizations doesn't make the turtle wrong in this case. If the turtle concluded that 'there can not possibly be any seafaring civilizations, because I don't see any' then you could accuse it of bad reasoning.
    - addingnumbers 5y ago
      > If the turtle concluded that 'there can not possibly be any seafaring civilizations, because I don't see any' The hypothetical turtle did exactly that, loyally following suit with the commenter who I replied to.
jameshart 5y ago
The turtle would be working with considerably less data, though. Does he know how old his island is? Does he have conclusive evidence of the existence of other islands? Is he aware of the similarity or difference of other islands compared to his own? Would he be able to observe if seafarers were living on a nearby island or does he need to wait for them to actually land on his beach? Does he have a reasonable estimate for the size of the earth? The amount of ocean? For the distribution of islands across the ocean? Also, since he’s a turtle, he doesn’t, presumably, yet actually know how hard it is to make a boat. The argument for determining whether or not you are the only seafaring species depends, first, on you having attained the ability to travel the seas… All of that seems necessary before he can conclude whether or not he should consider it ‘surprisingly late’ for his island not to have been reached yet by any seafarers. But the interesting part of the analogy is maybe that the turtle might fool himself into thinking he understands the parameters well enough to estimate this probability - after all, he’s paddled around off the beach and even made it to a nearby rock - so he reckons he’s got a pretty good handle on how hard it must be to travel between islands.
- addingnumbers 5y ago
  I wonder how I failed to express my position so badly that people who seemingly agree with me think they don't. Ignorance and misestimation of the true underlying factors isn't a trait unique to these hypothetical turtles. Or, perhaps you have a much higher confidence than I do in humans' assessment of the factors involved in your questions. I'm saying we are over-confident in the underlying premises of our understanding, just like the turtles would be. The more of the questions you pose that go partly unsolved, the more unsubstantiated the conclusion. Their probability calculations are pointless -- garbage in, garbage out. As demonstrated by the patent wrongness of their conclusion. If you are confident that we've got solid answers to the interstellar corollaries of all your questions with the evidence we can gather at this point, then we aren't on the same page at all. This idea, that our observations of the universe are a properly representative sample from which to form conclusions about the unobserved universe, makes as much sense to me as the thinking-turtles assuming you need a small green island to and a thick shell to enable sentience because that's what their observations show.
jandrese 5y ago
It's not a matter of limited perspective, it's a matter of the laws of physics. The rocket equation is a harsh mistress. Without FTL or reactionless drives the physics of going to a distant solar system is absurdly unfavorable. It takes many decades/centuries, is a one way trip, and the ability to build a self contained self powered ecosystem that can survive the entire trip without support. Once you have that why bother going to a distant solar system? You have a perfect orbital habitat.

hansbo 5y ago

Yeah, but if humans keep existing for millions of years, then the probability for a turtle on the Galápagos Islands to live in the time between when humans started seafaring and when humans visited the islands would be extremely small compared to any other time period.

addingnumbers 5y ago
Since we know the conclusion to be false, any reasoning that would support this hypothetical turtle's conclusion that no seafarers existed in 1450 is inarguably an example of bad reasoning.
- gpm 5y ago
  No, because the turtle is concluding that it's likely false, not definitely false. There happens to be a cosmic coincidence working against the turtle, but that doesn't mean that it was bad reasoning to conclude that the cosmic coincidence was very unlikely.
  - addingnumbers 5y ago
    The turtle is saying with certainty, not likelihood, that no seafarers exist, analogous with the explicit conclusion (3) in the top level comment
    - gpm 5y ago
      People are lazy when they speak, it's best to understand basically every claim as probabilistic (and meaning "almost certainly") even when it isn't stated as such. Certainly no-one would make the claim that "there are (definitely) no aliens in the galaxy" when we can't disprove the idea that aliens traveling at the speed of light just reached the galaxy (with our current understanding of physics). That doesn't mean you can't make the claim "there are (almost definitely) no aliens in the galaxy (because I just created the most amazing telescope ever and looked at every particle of matter in the galaxy and there were no aliens there)". The principle of charity demands that understand the bare claim that "there are no aliens in the galaxy" to mean something that is plausible, such as "there are almost certainly no aliens in the galaxy".
      - addingnumbers 5y ago
        A line of reasoning that tells our turtles something totally false doesn't deserve validation for doing it with slight uncertainty.
        indrax 5y ago
        You have to weight the validity of the reasoning across all turtle observers through history. If you reject probabilistic reasoning because it sometimes tell you things that are wrong, then you have no way to reason about uncertainty.
        addingnumbers 5y ago
        If your reasoning about uncertainty tells you there's a 99% chance something is false while it's true, what good is it? All the math in the world won't save you from the specious premises in this no-seafarers argument.
        epivosism 5y ago
        "If your reasoning suggests you shouldn't play the lottery, but playing the lottery actually results in you winning, what use is your math?" Well, what matters is expectation. The fact that some people win the lottery doesn't prove that playing the lotto is profitable. In fact it isn't money-profitable. The fact that people sometimes win doesn't change the nature of reality, that even for them, the win is unexpected and playing was negative expectation for them. You seem to be confusing expected value with results. Do you revise your decision process every time you get unlucky? On a meta level, sure, paying attention to unexpected failures is important to look for systematic errors. But randomly getting unlucky on 99% certainties does not automatically disprove your decision method.
- RupertEisenhart 5y ago
  That is incorrect. Good reasoning can lead to conclusions that are strictly false. For example, when asked to be more granular, the turtle could say 'I reason that there is only a 1 in 10 chance that seafaring civilizations exist'. The existence of seafaring civilizations doesn't make the turtle wrong in this case. If the turtle concluded that 'there can not possibly be any seafaring civilizations, because I don't see any' then you could accuse it of bad reasoning.
  - addingnumbers 5y ago
    > If the turtle concluded that 'there can not possibly be any seafaring civilizations, because I don't see any' The hypothetical turtle did exactly that, loyally following suit with the commenter who I replied to.

jameshart 5y ago

The turtle would be working with considerably less data, though. Does he know how old his island is? Does he have conclusive evidence of the existence of other islands? Is he aware of the similarity or difference of other islands compared to his own? Would he be able to observe if seafarers were living on a nearby island or does he need to wait for them to actually land on his beach? Does he have a reasonable estimate for the size of the earth? The amount of ocean? For the distribution of islands across the ocean? Also, since he’s a turtle, he doesn’t, presumably, yet actually know how hard it is to make a boat. The argument for determining whether or not you are the only seafaring species depends, first, on you having attained the ability to travel the seas… All of that seems necessary before he can conclude whether or not he should consider it ‘surprisingly late’ for his island not to have been reached yet by any seafarers. But the interesting part of the analogy is maybe that the turtle might fool himself into thinking he understands the parameters well enough to estimate this probability - after all, he’s paddled around off the beach and even made it to a nearby rock - so he reckons he’s got a pretty good handle on how hard it must be to travel between islands.

addingnumbers 5y ago
I wonder how I failed to express my position so badly that people who seemingly agree with me think they don't. Ignorance and misestimation of the true underlying factors isn't a trait unique to these hypothetical turtles. Or, perhaps you have a much higher confidence than I do in humans' assessment of the factors involved in your questions. I'm saying we are over-confident in the underlying premises of our understanding, just like the turtles would be. The more of the questions you pose that go partly unsolved, the more unsubstantiated the conclusion. Their probability calculations are pointless -- garbage in, garbage out. As demonstrated by the patent wrongness of their conclusion. If you are confident that we've got solid answers to the interstellar corollaries of all your questions with the evidence we can gather at this point, then we aren't on the same page at all. This idea, that our observations of the universe are a properly representative sample from which to form conclusions about the unobserved universe, makes as much sense to me as the thinking-turtles assuming you need a small green island to and a thick shell to enable sentience because that's what their observations show.

jandrese 5y ago

It's not a matter of limited perspective, it's a matter of the laws of physics. The rocket equation is a harsh mistress. Without FTL or reactionless drives the physics of going to a distant solar system is absurdly unfavorable. It takes many decades/centuries, is a one way trip, and the ability to build a self contained self powered ecosystem that can survive the entire trip without support. Once you have that why bother going to a distant solar system? You have a perfect orbital habitat.