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I feel like a lot of people here are pontificating about something they don't understand. It smells like few people here are mathematicians, and yet they're spe

• freshhawk 5y ago
  It certainly uses a logical structure that requires independent variables when we have strong evidence to believe these things are not independent. "if other sentient species exist, we should expect ours to have an unusually high population" Except that sentience evolving is, as far as we know, extremely tied to population numbers and then afterwards sentient agents will have strong incentives to manage their population in some way (or you could say: the odds of them deciding to exactly match their pre-sentient population levels, now that they can make a choice, is small). The underlying explanation of the principle of mediocrity and a mathematical intuition for it is pretty good. Maybe people in 2021 are just extremely skeptical about "if we assume the most likely thing every step and pretend each choice is independent we can build a prediction that we can assume is maximally accurate, which means it is meaningfully accurate" chains of reasoning? That's how you get "Roko's Basilisk scenarios scaring people" type outcomes. It certainly is the source of my distaste and bias against it if I'm being honest with myself.
  • natosaichek 5y ago
    The ability to solve widespread coordination problems is... probably orthogonal to consciousness? Bees and ants do it without consciousness, and humans clearly suck at it. Or you could say: The odds of them being capable of using their sentience to solve their desire to have a controlled population level is small.
    • plutonorm 5y ago
      “Bees and ants do it without consciousness” do they? Prove it.
    • freshhawk 5y ago
      Our population changed radically when we gained sentience. I don't see how it is reasonable to assume a species will gain sentience and not alter their behaviour in a way that alters their population. That is a "big" threshold to cross in terms of ability to alter your surroundings. It doesn't have to be controlled, it just has to change significantly because of the gain of sentience for this argument to not be valid.
• ldb 5y ago
  I am not a mathematician either and only read the “Quick Intro” but that left me with the following question: What happens if I replace the Earth’s populations with that of France and the Earth’s countries with the French cities? If I do that and then follow the logic in the Quick Intro then it makes sense to me that it is likely that I would be born in Paris, but I do not understand how I can follow from this that France is a high population country. What do I miss?
  • srcreigh 5y ago
    You would be wrong, but lots and lots of people following the same logic from China, India, USA would be right.
    • ldb 5y ago
      Thanks, that makes sense. Do you know if there is any "mathematical trick" to quantify the likelihood of me being wrong (without knowing the population numbers of the other countries)?
    • notahacker 5y ago
      I think the main problem is piling up the estimates. If I use anthropic reasoning to conclude that I am from an extremely populous country like India, I am wrong, but 2 billion Chinese and Indian people would be right, and the majority of people making the estimation would in fact be from larger than average countries But if someone starts drawing conclusions like "due to the correlation between population size and landmass, it is therefore unlikely any country is more than 20% larger than mine", there is a 98% chance they are not Russian and therefore incorrect (and there is a 100% chance that their country is dwarfed by either population or landmass by some other country). The probability of them being the largest country is roughly the same as the probability of them being from a small island group like the UK or Japan If the principle falls apart when applied to the human populations whose population density relationships its estimated from, how can we assert 95% certainty that the circumference of planets supporting very different civilisations will be no more than 20% greater than Earth?
      • 5y ago
• Jorengarenar 5y ago
  > It smells like few people here are mathematicians, and yet they're speaking with reddit levels of hubris, attributing simpletons' logical fallacies to a published astrophysicist. I fully understand the need of respecting the authority of experts, but it doesn't automatically mean they are always right or are immune to logical fallacies. Prime example is a persona of Linus Pauling - a Nobel Prize winner, who despite being called one of the 20 greatest scientists of all time, was the one behind a huge popularity of pseudoscience around vitamin C. And funny how you mentioned Reddit, because I have a PhD biology researcher who spammed his research paper on several unrelated subreddits and had audacity to talk back when called out for it. Heck, he was upset with moderators of r/eli5 [sic!], because his post (academic paper!) was removed. You can see my argument with him here: https://www.reddit.com/r/programming/comments/lezh2o https://www.reddit.com/r/programming/comments/lezh2o
  • canadianfella 5y ago
    Why do you have a researcher?
• moralestapia 5y ago
  >attributing simpletons' logical fallacies to a published astrophysicist Funny how you fell into a very common logical fallacy by trying to make a statement about the arguments made against the author. See: https://en.wikipedia.org/wiki/Argument_from_authority https://en.wikipedia.org/wiki/Argument_from_authority
  • setr 5y ago
    The logical fallacy would be “he’s clearly correct, because he’s an astrophysicist”. But that’s not OP’s claim; rather it’s that “he’s probably not an idiot, because he’s an astrophysicist” — that is, if he’s wrong, it’s probably not for reasons you’d attribute to a simpleton off the street. It is not a logical fallacy to assume a relevantly credentialed person would give a stronger argument. It would be a fallacy to assume that he must give stronger arguments.
    • moralestapia 5y ago
      Kindly read and ponder about the first two sentences under "Use in science" on the wikipedia page I referenced.
      • setr 5y ago
        Sure. My point still stands. They assumed the argument was correct, because of who said it, rather than reviewing the argument itself. OP does not make this mistake. He assumes the argument is probably not idiotic, because the author is probably not an idiot (in this subject). Again, the fallacy is in assuming it must be correct (thereby bypassing the argument itself). Probably correct is a very different thing, and is why we have credentials in the first place. An idiot will likely make an idiot’s argument. It doesn’t mean he can’t have a spur of brilliance... but it’s not likely. Alternatively, from a programmer perspective... the compiler is probably not the one that’s wrong. It could be, but it’s probably you. Authority has no place in evaluating an argument is correct, or not. That doesn’t mean it has no place is evaluating whether the argument is likely to be constructed well and without trivial mistakes. It also doesn’t mean authority is useless, just that it’s in no way the final say (the argument of course should hold up on its own)
• gadf 5y ago
  Theoretical explanation for observed reactions: Lemma 1: alien topic is like religion, not a great amount of data, but very high stakes. Lemma 2: There's a lot of intellectual "soccer mums" on HN eager to find an outlet for their unrealized (?) intellectual prowess. Corollary: Alien topic seems like fair game, because low risk associated to bring wrong, and hard to disprove with facts or experts. Theory: this topic manifold provides attractive attachment site for brains looking to engage in intellectual proving games and leads to lots of low signal comments intended to make others wrong to achieve a sense of being right. It will take HN some time to adopt the correct posture to discuss leading edge questions in areas with lots of ambiguity. QED. But this theory shouldn't be controversial at all: A random sample taken from any distribution is more than likely to be representative of that distribution. It's a basic idea but I like how he's illustrated it here with lots of examples and connected it to the alien notion. Meaning it leads to a good insight. Namely why most described encounters of aliens detail beings that are a lot like ourselves. The so-called five star pattern: a head, two arms, two legs. And hands with fingers. In fact the ideas advanced in this essay are so fundamental they're like informational entropy or enthalpy/thermodynamics in that they are basic but insightful and sometimes counterintuitive principles that advanced reasoners can use to figure about the world. I wish more people knew of them. I'm so blown away by this essay. in a limit sense I think this type of reasoning represents the best that you can possibly do starting from a position of ignorance. And as essay says that position is the safest one to start at. Sure you can apply a bunch of priors and constraints to limit the variations of different populations to what you think is right but really in this topic those things are just distortions. so the conclusions arrived at in this paper I think are in the limit sense the best that you can possibly do from the intellectually honest position of almost totally ignorance about this. it's telling that so many people want to instinctively reject this and instead blindly impose their own priors while being blissfully unaware that's exactly what they're doing, resisting the general purpose conclusions of this essay and trying to pass off their own beliefs as truth.
  • simiones 5y ago
    > Namely why most described encounters of aliens detail beings that are a lot like ourselves. The so-called five star pattern: a head, two arms, two legs. And hands with fingers. The reason why ALL described alien encounters have happened has nothing to do with the statistics of possible alien life in the universe, it has everything to do with the human psyche - as they are all either delusions, lying, false memories etc.
• user-the-name 5y ago
  > I see no fallacies "I am more likely to have been born in a high population country than a low population country" This is incorrect. If there is one country with one million people, and a hundred countries with a hundred thousand people, you are overwhelmingly more likely to have been born in a low population country.
  • dash2 5y ago
    Only if you aren't careful enough about what you mean by "low population". The argument is that you are probably born in a country with above the median population. This will also be the case in your example. The median population is 100K. Assume there are tiny deviations around the median. Then 50 x 100K people live in countries below the median population. And 49 x 100K people, plus 1 million, live in countries above the median. (And 100K people live in the median population country itself.) If you don't like the tiny deviations, then still, more people live in countries weakly above the median (everyone) than live in countries weakly below the median (everyone minus a million); and more people live in countries strictly above the median than strictly below.
    • user-the-name 5y ago
      But does "above the median population" actually tell you anything that is useful? I don't see that as being anything more than a truism.
      • gnramires 5y ago
        The claim being made here is what I call the "Existential inference hypothesis": that we are somehow, as individuals, sampled from a large ensemble of consciousness across space and time. There is some difficulty in defining the conscious cross-section that governs this sampling process (could you be born a mouse? Maybe yes, but then you probably couldn't be asking those questions... Could you be born a rock? That makes even less sense; but all that differs among those cases is their atomic configuration). I think the sampling in this case might be a soft measure among linguistically capable entities. What it does is allow some weak inference about the existential landscape, about everything that exists out there. I believe the author's refutal of 'inference from a single datapoint' is mostly wrong -- I believe indeed we're likely some kind of uniform sample, and single uniform samples don't reveal variance. But, there's not exactly a single variable here. We have a pretty large number of variables: population of the Earth, number of Neurons per individual, and so on. It's still not much though to give an accurate picture of the landscape. I would indeed be wary of taking any hard conclusions from the data. If you use hard knowledge from biology, physics and computational disciplines, you can probably use our "sample" to refine estimates about life in our own universe. Overall, the most I would conclude from this hypothesis is the following: "You and I probably (but not certainly) typical among numerical living beings in the entirety of existence.". The practical lesson I would take from that is to be thankful for what you have, and do the most of what you can for the world, because the basic donitions don't get much better than this.
• simiones 5y ago
  But the problem here is that the paper is obviously concluding too much from too little data. Their basic argument is right, but useless: it's true that, over all sentients in the universe, the sentients thinking they are on one of the most populous planets are more likely to be right; but there is no way to estimate what that likelihood is until you found out the actual distribution. So basically, to have any predictive power whatsoever, the argument depends entirely on the other arguments about the possible distributions, which are all bogus given how little we understand about what other forms of life are possible, and the extremely little we understand about what forms of life can develop human-like intelligence .
  • raducu 5y ago
    And if we know the actual distributions... we know the actual distributions and there's nothing predictive about this whole thing.
    • simiones 5y ago
      Exactly, that is why I'm saying that the statistical truism that the article puts front-and-center is useless.
• raducu 5y ago
  Is there anything useful out of this? All other species that don't know the actual distributions should expect that all other species are larger than themselves. If we base our search for alien intelligence on this assumption but it turns out that intelligent life is not possible on smaller stars because the habbitable distance also means the planet is tidally locked and some other filters, we're wasting our time. It's great for SCI-FI though.
• Grustaf 5y ago
  I don't even understand his main argument, but here's a random, incorrect argument he made. > For example, let's take Usain Bolt's 100m World Record of 9.58 seconds. Imagine that was the only data point we had regarding human running speed. Wth that one data point we could confidently make a powerful prediction, that anyone we pick from the world population will take more than 9.58 seconds to run 100 metres. This is not true at all. Either he's saying that the "single datapoint" is "Bolt ran 100 m in 9.58 s". If that is the datapoint, we can't draw any conclusions from that, for all we know he could be the slowest human in the world. If on the other hand he means that the single datapoint is "Bolt ran 100 m in 9.58 s and nobody has run faster" then sure, we can conclude that nobody is faster, but that's part of the datapoint so it's not very interesting.
  • simonh 5y ago
    That's the entire point. With the right one piece of data, you can draw powerful and useful inferences. You don't need data on the 100m dash running speed of every single human being on Earth. That one item can be sufficient. It all depends on what the data is and what you're trying to infer. How is that incorrect?
    • Grustaf 5y ago
      What is the datapoint in this case? 1. Bolt runs 100m in 9.58s or 2. Bolt runs 100m in 9.58s and he’s the fastest ever
      • simonh 5y ago
        It's what he said: Usain Bolt's 100m World Record of 9.58 seconds.
        • Grustaf 5y ago
          And what can you infer from that?
          • 5y ago
• titzer 5y ago
  > It smells like few people here are mathematicians, and yet they're speaking with reddit levels of hubris, attributing simpletons' logical fallacies to a published astrophysicist. On the contrary, making bold assertions about the entire universe generalizing from one example is a worse hubris. Manipulating some numbers in equations and coming out with absolute certainties is hilarious bad when you step back from having your nose in it. It's not like someone else wrote that summary of his ideas. He wrote it. From those conclusions I really won't trust any line of reasoning, no matter how complicated the equations. It's worthwhile to note that HN isn't your average reddit crowd. There are educated people here, and mathematicians. There are also plenty of people who know philosophy and can spot dubious results easily. I posted elsewhere in the thread about it, but the whole line of reasoning about us being randomly distributed over...well, anything, really...is just flawed. By this reasoning we'd all be dead, Boltzmann brains, ants, or a whole host of absurd conclusions. And the fact that we live on the end of a chain of extremely improbable events means that you'd literally never get here if probability was your only tool. And that's just it. The only tool in the toolbag here is some probability equations. Stunningly bad reasoning.
  • shakezula 5y ago
    It's not really bad reasoning when, from the very start of the article, the author points out what their limitations are in their approach. This is like saying that the Drake Equations are "stunningly bad reasoning".
  • brabel 5y ago
    > Manipulating some numbers in equations and coming out with absolute certainties is hilarious bad The author went ouf of his way to make sure people understood that probabilities are NEVER certainties, they are just about chances of things being true... yet here we are.
• jjk166 5y ago
  The author goes far beyond just assuming power law distributions. > We don't yet know the breadth of planet sizes on which intelligent life exists. Some will be larger than others. The larger planets have a greater area, and receive more energy from their star. Therefore they are capable of sustaining larger populations, on average. It is a major leap to go from planets with larger surfaces sustain larger populations. For starters, increased planet size will increase gravity, which means everything needs to expend more energy and either animals or their food getting larger becomes more difficult. Then what effects will this larger planet have on plate tectonics and continent formation. Further, life does not spread out uniformly over a planet's surface, compare the land area of vietnam to siberia and ask where you would expect to find larger populations. > A similar connection between area and population is seen among countries on Earth. Those with a larger population also tend to have a larger area. Compare Canada to Bangladesh. The sizes of nations are an incredibly complex function of conquests and mergers where tiny feudal states tended to get gobbled up by larger polities who in turn became stronger and able to acquire more territory, which was critical to pre-industrial societies where population density was constrained by area and then break apart into smaller polities during industrial times when population densities were not so constrained. Planets have no analogous function - Earth doesn't get the moon's land area because it is more populous, nor does it break into tinier planets as humans gain technology. If instead of countries we looked at continents, we'd see 5 out of 7 do not match the prediction. On the topic of individual size, the author assumes that if a human is a normal member of a group with the variation in size of the great apes, the average size should be 320kg. Obviously though if you applied the exact same logic to the great apes, you'd be way off. Indeed looking at earth, most species tend to be small. The simple assumption that just because something results in a smaller population size means it should lead to more populations is clearly incorrect in this case, and likewise is questionable in other cases where there isn't a clear causal link. More generally, the author's logic is a permutation of the doomsday argument, which while being mathematically intriguing is widely critiqued as a method of making predictions about reality.