9 ms·

The Weakness of Anthropic Arguments

41 points by srl 6y ago

sullyj3 6y ago
Max Tegmark goes into detail on the potential pitfalls of anthropic arguments in "Our Mathematical Universe". Very interesting book.
alexpetralia 6y ago
Does anyone know if panpsychism is an anthropic argument?
- tmp0192847475 6y ago
  Why would it be ?
- falseprofit 6y ago
  If anything, it uses Occam's razor, reducing {conscious matter, unconscious matter} to {conscious matter}.
m4r35n357 6y ago
Isn't this just a form of "survivor bias"? I don't get why anthropic arguments are considered "weak". The article seems to just be complaining that anthropic arguments cannot explain the precise _value_ of the fine structure constant. Well, nor can Occam's Razor, but we don't seem to have a problem quoting that!
- rbanffy 6y ago
  My understanding is that they are an attempt to explain away something that may or may not be random. We wouldn't be debating it if the universe were substantially different, but that doesn't explain why the universe we observe is the way it is.
  - m4r35n357 6y ago
    OK fair enough, to me the opposition to the weak AP just seems to be people "unhappy" that a physical constant should need to be that precise. In other words, for some reason they expect the universe to be more "understandable" or "sensible" than this . . . Of course the strong AP is ludicrous in the extreme ;)
    - XorNot 6y ago
      It wraps up a concern that there are these seemingly random constants in our models that don't seem to be a product of our measurement system. There's no number system you can invent where the fundamental constants turn into simple integers or have obvious ratios. So why do they have those values? What gave them those values? The anthropic principle is disliked because it rejects further inquiry and progress.
      - greatquux 6y ago
        I don't think we can reject it though. We may not / shouldn't "like" it, and we can sort of shove it to the background and try to come up with other explanations or theories that are more explanatory, but we do have to acknowledge that at least the weak form does make a kind of sense and we can't ignore it.
        rbanffy 6y ago
        AP can't really make sense because it doesn't explain anything. We know a universe with our values works because we are observing one. Any set of values that "work" in this sense will have someone to make the same observation. Unfortunately, that doesn't explain how these values are generated. That is the important question.
    - coldtea 6y ago
      >OK fair enough, to me the opposition to the weak AP just seems to be people "unhappy" that a physical constant should need to be that precise. No, their opposition is to the fact that a physical constant is a mere accident, a mere facet coming with the universe as a set, and not explained by some more fundamental mechanism.
- catawbasam 6y ago
  I don't think it is just survivor bias, since the claim applies to all life as we understand it and not just life in human form. "Anthropic Principle" is kind of a poor name for it.
- coldtea 6y ago
  >Well, nor can Occam's Razor, but we don't seem to have a problem quoting that! Well, Occam's Razor is just a heuristic, not a logical necessity. Sometimes the more complex answer is actually the correct.
- Keysh 6y ago
  Well, nor can Occam's Razor, but we don't seem to have a problem quoting that! Occam's Razor is not an argument or explanation. It's a heuristic for discriminating among different arguments/explanations. And anthropic arguments amount to "there isn't any explanation for the precise value of the fine structure constant!" Or "you should just give up trying to explain why it has the value it has!"
flerchin 6y ago
It seems to be the final answer in a game of "why"? with a 2 year old.
- falseprofit 6y ago
  I think that game should end at the question of https://en.wikipedia.org/wiki/Why_there_is_anything_at_all https://en.wikipedia.org/wiki/Why_there_is_anything_at_all. I don't actually think the anthropic principle is capable of tackling that one.
  - Izkata 6y ago
    "Because nothingness was bored." ( Original intention of the backstory of https://andromeda.fandom.com/wiki/Trance_Gemini https://andromeda.fandom.com/wiki/Trance_Gemini ) (Yeah, not quite anthropic principle, but definitely popped into my mind as something to give a 2-year-old)
    - falseprofit 6y ago
      My attempt at an answer would be that emptiness/nothingness is just a made-up concept. Not a good answer, I know, but idk what else to think.
jankotek 6y ago
》This would prevent carbon-based life from existing, sure; but would it prevent intelligent life from existing? We are yet to find another primitive carbon based life form. Anthropic principle works just fine with Occam's razor.
metalliqaz 6y ago
But I thought the purpose of the Anthropic principle was not to answer, "why is this thing?" but rather, "why is this thing so perfect for us?". Those are very different questions.
- throwaway_pdp09 6y ago
  As our n=1, how can you claim that it is indeed the best of all possibilities ("so perfect")?
  - harshitaneja 6y ago
    We need a large number of samples when we lack sufficient understanding of the system in study. But if we assume our current knowledge of physics and biology are good enough then we should be able to find the best(whatever definitions is used) without needing multiple samples. We use multiple samples to create a model but if a model exists then non-contradicting samples add nothing. Although we could have a large discussion about bayesian epistemology regarding my last statement.
    - throwaway_pdp09 6y ago
      > But if we assume our current knowledge of physics and biology are good enough That's a bloody big if, but let us let it ride for now > we should be able to find the best(whatever definitions is used) Agreed it hinges on that, assuming the preceding if is accepted. What 'best' do you nominate? I have no idea what it might be.
      - harshitaneja 6y ago
        It is a big if. My choice of words was very deliberate as I didn't wish to convey that our knowledge is sufficient. But the question here doesn't hinge on real knowledge(our ability to ever gain it is in itself a huge question) but rather on belief in possessing the said knowledge. Otherwise every real world calculation of probability is meaningless as physical systems can't have proofs but rather more and more tested models acting as the prior in our calculations. I don't nominate any best. I don't have an idea either. I merely used a word used by a parent. Best could be minima, maxima or any other criteria of the function they choose to refer here. My point is if you have a belief that your model is good enough, you don't need a large number of trials to calculate a probability on whatever characteristic you choose. The accuracy of this result is a question but the question would remain similar to the scenario where you calculate the probability from a larger number of trials.
ggambetta 6y ago
> In this universe, where α ≈ 0.007297352569, you’re reading an article about the anthropic principle; in the universe where α ≈ 0.007297352569, at the very least, it’s reasonable to guess that you would not be. (Good news: in that universe, you’re a billionaire playboy philanthropist!) Both values of α look identical to me, but the text implies that they're subtly different - is this a typo in the article, or am I missing something?
- couchand 6y ago
  I read this as putting all the weight on the wavy approximate equals; the alternate universe described is incredibly similar to, but not quite the same as, ours.
  - leephillips 6y ago
    I’m sure he must have meant to change the last digit, but something went wrong. We exist because of a typo!
    - TheSpiceIsLife 6y ago
      Thereby exposing God as nothing more than an average copy editor.
- coldtea 6y ago
  The ≈ means "aproximately", so they might or might not be the same. In this case they're meant as not the same. The author intents to make a point, this values, which approximate to the same degree of x decimals, are supposed to be explained by "if the first wasn't true we wouldn't be here to ask this question".
- srl 6y ago
  Yeah of course this is a typo. I've fixed. (But I appreciate the other commenters trying to interpret this in a way that makes sense.)
laszlokorte 6y ago
`Why is this question encoded as string of 385 characters and why is there a set of 385 character long strings? I mean there could be just a set of strings of length 95 and the question could instead ask "why is this question of exactly 95 letters long and why is there a set of 95 char long strings?" but still this specific question is asking why it is 385 chars long, why is that so?`
- squibbles 6y ago
  One answer to "Why is this question..." is because we have defined it so. And why did we define it so? One could make an argument that notions of sets, counting, length, and so on are anthropomorphisms -- we project our bodies onto the universe around us so we can reason about the environment using our specialized brains. (Human brains are specialized to operate in the context of our bodies.) In fact, the Whorf hypothesis [0][1][2] addressed this subject in the context of linguistics. [0] https://en.wikipedia.org/wiki/Linguistic_relativity https://en.wikipedia.org/wiki/Linguistic_relativity [1] https://plato.stanford.edu/entries/linguistics/#SoCalSapWhoHyp https://plato.stanford.edu/entries/linguistics/#SoCalSapWhoH... [2] https://www.sciencedirect.com/science/article/pii/B0080430767030424 https://www.sciencedirect.com/science/article/pii/B008043076... , https://doi.org/10.1016/B0-08-043076-7/03042-4 https://doi.org/10.1016/B0-08-043076-7/03042-4
lordnacho 6y ago
The thing about the fine structure constant always bothered me. If it were slightly different, our universe would be very different. But how do we quantify how different is different enough to warrant investigation? How do we know what the range of such a number could be?
- at_a_remove 6y ago
  Ah, well, about a four percent change and you no longer can produce carbon during regular fusion. You need atoms capable of making at least three bonds to produce structure more complex than a chain. Carbon can do four, is lovely, otherwise you would have to make do with boron and nitrogen. Crank the value up to .1 and you get no fusion at all. This one is super-interesting, because no fusion means no photonic pressure keeping silly large accumulations of gases up and so you will crank your way to neutron stars and black holes much faster, as well as resulting in a universe whose only light is the remaining cosmic background radiation. No more supernovae creating shockwaves and the like. In the other direction and you have a different problem -- molecules won't molecule and you will just have a bunch of disconnected atoms incapable of covalent bonds.
  - lordnacho 6y ago
    Yes but how do we know what the numbers could have been? It's not like we have a generating theory that says it had to be between a and b, and thus it being x is really unlikely.
    - at_a_remove 6y ago
      Ah, okay, that's a different question. Aside from common sense ("this being negative would be self-contradicting") for a given number and sets of inter-relations, that's out of my wheelhouse. I very dimly recollect some work on allowable sets of constants somewhere in the nineties, something to do with superstrings, but that was never a huge interest of mine. I will admit that such a generating theory may exist and I am just unaware of it. In some sense, each constant represents a bit of embarrassment to physics. Having this rather large set of adjustable parameters calls to mind the von Neumann quote "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." Why this seemingly arbitrary number? Can we take multiple constants and find some smaller set from which they are derived? Can I make a constant emerge from a physical law, devoid of measurement?
maroonblazer 6y ago
Sean Carroll (theoretical physicist) and Nick Bostrom (philosopher with a very technical background) discuss Anthropic arguments on Sean's Mindscape podcast a few weeks ago. https://www.youtube.com/watch?v=EffcY6tnbcA https://www.youtube.com/watch?v=EffcY6tnbcA
roenxi 6y ago
If we start with the theory that universal constants are random (big if) then the question he is pushing towards doesn't make any sense. Why does a random number take on a specific value? That is a question for philosophers, not physicists. If we were observing a truly random number then it doesn't mean anything for it to be a specific value. It is a fair point if nobody has proven (or indeed, can prove) that something in physics is a random number. But alas that does not mean the theory is weak. It is perfectly consistent with the evidence, and mathematically satisfying. It would be quite exciting if someone can find a reason why we observe specific values and rule out the random number idea. But at some point we know we'll run up against the impossible questions of "why does anything exist at all?", "is it possible for something to not exist?" and "what separates existence from non-existence?". We can't expect to find causal answers for everything.
goodside 6y ago
I feel like the challenge of explaining fundamental constants understates the strength of anthropic reasoning. Most regions in space are empty voids — why aren’t we in such a void right now? Being anywhere near the orbit of a star is extremely unlikely a priori. Why are we on a planet with oceans teeming with other life forms, instead of a barren rocky desert, which seems to be the norm for planets in general? Why are we exactly on the surface of that planet, as opposed to being 1,000 kilometers up in the sky or down underground, swimming in hot magma? These are the questions where “Because those are the only conditions suitable for your existence to happen” is so obviously correct the questions make you roll your eyes. Applying the anthropic principle to fundamental constants is a speculative extension that might be right or wrong, but there are plenty of mundane coincidences that have no other answer.
- leephillips 6y ago
  There is an interesting book called _The Fallacy of Fine-Tuning: Why the Universe Is Not Designed for Us_ by Victor J. Stenger where he shows that most of the fundamental constants that people may think can only be explained with some kind of anthropic principle, or more to the point, intelligent design, are really more constrained than that.
  - nicoffeine 6y ago
    A great subject is also the cosmological constant. Introduced by Einstein, who later claimed it was the biggest blunder of his life, that has returned to make the math work for cosmological observations made in the 90s. As explained by Susskind[1], a sort of negative force that by one measurement is 2.88 x 10^-122 [2] and if it were only slightly different, the universe as we know it would not exist. Add in the "need" for observers in Wheeler's Participatory Anthropic Principle[3], I would say that some extraordinary minds have recognized and proposed some strong anthropic arguments. In any case, the older I get, the more I realize I don't know a damn thing. As a poet once sang: Now, I wish I could write you a melody so plain That could hold you, dear lady, from going insane That could ease you and cool you and cease the pain Of your useless and pointless knowledge [1] https://www.youtube.com/watch?v=2cT4zZIHR3s&fbclid https://www.youtube.com/watch?v=2cT4zZIHR3s&fbclid [2] https://en.wikipedia.org/wiki/Cosmological_constant https://en.wikipedia.org/wiki/Cosmological_constant [3] https://en.wikipedia.org/wiki/John_Archibald_Wheeler https://en.wikipedia.org/wiki/John_Archibald_Wheeler
squibbles 6y ago
I find the argument against anthropic arguments to be weak. * The terms life and intelligence lack formal definitions. * The predicate why lacks a formal definition. * The argument does not address the maximum number of possible configurations of the universe, which dilutes any quantitative arguments. Most importantly, the cardinality of the maximum number of possible configurations is not addressed. For example, the possibility of an aleph number [0] was not addressed. * The argument does not address qualitatively different structures of the universe, such as universes with discontinuous lengths or types of affine spaces [1] where measurement as we understand it does not exist. The list of concerns above is not exhaustive, and I don't think addressing them individually will necessarily salvage the argument. While stronger arguments for or against the anthropic principle are possible, I think they deserve much more rigor. [0] https://en.wikipedia.org/wiki/Aleph_number https://en.wikipedia.org/wiki/Aleph_number [1] https://en.wikipedia.org/wiki/Affine_space https://en.wikipedia.org/wiki/Affine_space
AgentME 6y ago
I think this post's assumption that intelligent life is inevitable is unsupported. Just because lots of systems are Turing complete doesn't at all imply that intelligent life or even life in general is likely to arise from a random initial state. There's no support in the post for this jump in logic. I think the solution to the Fermi paradox is that intelligent life is just spectacularly unlikely, and that we're the only intelligent life in the observable universe. I think most people reason that we're probably not that special, that our conditions aren't too rare, and that the likelihood of intelligent life given those conditions must be somewhat good, but I don't think any of this reasoning is valid given the anthropic principle. I think the fact that we find ourselves in a world where we're alone is evidence for the sheer unlikelihood of life. If there were many values of the fine structure constant that could create a universe with any life at all, then I would guess that across that range of values, there would be more variation where some values would create a universe with rare lonely life and some values would create a universe where life was more plentiful. In that case, we would be more likely to find ourselves in a universe where life was more plentiful. But if there were a tighter range of possible constant values that create a universe with any life at all, then I would expect less variation with only universes with rare lonely life. Given that we find ourselves in a universe with rare lonely life, that seems like evidence that there isn't much room for variation in the constants while staying life-supporting.
- coldtea 6y ago
  >but I don't think any of this reasoning is valid given the anthropic principle And that concludes the circle in your circular argument in support of the antrhopic principle :-)
  - AgentME 6y ago
    In that paragraph, I was trying to argue that the observation of us being alone and the anthropic principle are compatible and related in a way that if either one were missing, we should be skeptical of the other. I think that's valid and distinct from a circular argument. (And then in the last paragraph, I wasn't trying to argue for the anthropic principle, but to argue that given the anthropic principle and the observation we're alone, then I think it's correct to believe that the specific values of physical constants that we observe are likely to be necessary for intelligent life.)
njarboe 6y ago
The Anthropic principle idea that this universe's physical properties can't vary much and produce carbon/hydrogen/oxygen (CHO) based life on the surface of planets is probably not correct and was just popularized many decades ago when the understanding of nuclear physics was not as complete as it is now. The possible paths to a CHO universe with acceptable planet surface conditions were not well explored. From the linked article: "Suppose the fine structure constant were in fact 10% different — enough to prevent stellar fusion from producing carbon." This is an old idea and is probably false (I am not an astro/nuclear physicist) but the author of this in-depth paper is[1]. Fred Adams is at the Physics and Astronomy departments at the University of Michigan and in this 2019 paper[1], with over 500 references, states the fine structure constant can vary by 4 decades/orders of magnitude (decade=log10(max value/min value)). See table two on page 140 for that range and ranges of some other fundamental values. The most constrained value ranges still vary by an order of magnitude (down quark mass and the up-down quark mass difference). [1]https://arxiv.org/pdf/1902.03928.pdf https://arxiv.org/pdf/1902.03928.pdf
golemotron 6y ago
Honestly, I think this article about anthropic arguments is weak. Expressing discomfort with an argument isn't an argument.
mensetmanusman 6y ago
If intelligence is ‘extremely resilient’ then we will find it everywhere in our universe. If you use the cellular automata analogy that is being alluded to, ‘intelligence’ is being essentially equated to some limit of ‘complexity’ This is all very hand-wavey so it doesn’t appear to add much to the discussion?
- goatlover 6y ago
  Yeah, there needs to be evidence backing up a claim to extreme resilience. Invoking scifi scenarios and Turing completeness does not count. One can easily counter with the Fermi Paradox and only one species on Earth asking anthropic questions.
tunesmith 6y ago
This is a little new to me, but as described, isn't it like a form of a proof by contradiction? I mean, it doesn't have to bring in "we wouldn't be here" questions of survival, it seems to be just of the form of... (1) Question whether A is true. (2) If A were not true, then it would necessitate that B is true. (3) B is clearly impossible. (4) Therefore... A must be true.
- tuatoru 6y ago
  Proof by contradiction only applies to mathematical/logical theorems, which are also known as tautologies. It's useless for statements about the physical universe. Edit: IIRC the form is !(!A || B) && !B which reduces as (A || !B) && !B (A && !B) && (!B && !B) A && !B && !B Given B == false A && true && true A
mensetmanusman 6y ago
Are we comfortable admitting that this can never actually be answered with the scientific method? This puts all realms of the discussion in the metaphysical, which is fine, but it should be noted :)
- srl 6y ago
  It's perfectly fair to complain that these discussions are untestable, at the very least, but unfortunately they're inescapable. We need some heuristic for evaluating which anomalies/patterns are likely to be hints of "new physics" (and are thus worth investing resources in exploring further), and which ones are just coincidence or otherwise not worth investigating. Anthropic arguments seem to provide a reason to be uninterested in a large class of apparent surprises. Should we invest in investigating those surprises, or not? The discussion may be metaphysical, but the decision has real-world consequences.
  - mensetmanusman 6y ago
    Thanks for the comment. I am by no means trying to downplay metaphysical discussions, most lived human experience is in that realm (“what should I wear/eat/do/etc.”), so one could argue it is more important than many scientific/engineering endeavors looking to find new ways to serve advertisements :) I love the discussion of complexity and automata, and I struggle to think how our limited minds will ever work around the problem of unbounded complexity...
dcanelhas 6y ago
Why is intelligent life held as such an inevitable outcome these scenarios? Could it not be the case that we look around and see billions of species (just on Earth) that are no smarter than ants (i.e. pencils lying around) and draw the conclusion that it was just luck instead?
tuatoru 6y ago
The article gives a crude statement of the principle as > The universe is the way it is because if it weren’t, we wouldn’t be here to discuss the issue. That can't be right. That statement says we are here as a consequence of the way the universe is. It says nothing about causes (of the universe being the way it is). What's a better statement of the principle?
Veedrac 6y ago
The key most people miss about the anthropic principle, and that seems to be the confusion here, is that when you're filtering out false hypotheses (those inconsistent with the observed facts), all remaining consistent explanations increase in probability equally. This means, for example, if you want to explain how Derren Brown won the lottery, the probability that he cheated raises in line with the probability that he just got lucky, which is exponentially low, hence it is almost certain he cheated. The base probability is, as always, based on some form of Solomonoff induction, which is invariant to ‘scale’, hence why we can explain away seemingly-arbitrarily low probability events (α≈0.007297352569) by talking about universes that contain a continuum of different α. In the lottery example, the hypothesis ‘lots of people tried’ is simple, even if the probability of each individual winning the lottery is low. You might ask instead, but what's the probability that that specific person won the lottery? Surely that is exponentially less likely? Yes, indeed, but unlike the Derren Brown case, where P(Derren Brown cheats the lottery) is fairly high prior to him winning the lottery given the public attempt, P(that random guy cheats the lottery) is very low, as most people don't cheat the lottery. Thinking about alternative observers and question-asking is a distraction. Other people asking other questions are not you, so they are not compatible with your observations.
DDaa 6y ago
Anthropic principle has been used by too many people to meaning too many different ideas. It really should just refer to the mere tautology that "I can only find myself exist, and the world in a state compatible with my existence". That is a perspective specific statement. It answers questions formulated from my/our first-person perspective: "why do I find the fundamental constants compatible with my existence?". However, it does not apply to questions formulated objectively (i.e. when it requires a perspective invariant response), for example "why are the fundamental constants have these values?". That question calls for an impartial causal model or scientific answer. Anthropic principle simply isn't it. That doesn't mean AP is wrong, it is a tautology, correct by definition. Neither is AP useless. It is the correct counter to teleological arguments such as fine-tuning. However, treating it as a scientific explanation is not correct. That being said, that confusion is totally understandable. The current state of anthropic reasoning is quite messy. There are contending theories on many related paradoxes. The sleeping beauty problem, the doomsday argument, the fine-tuned universe, the simulation argument, etc. Like before, I find these paradoxes are caused by ignoring the role of perspectives as well. I explained my solution to the related debate on my website https://www.sleepingbeautyproblem.com https://www.sleepingbeautyproblem.com if anyone is interested.
webmaven 6y ago
Perhaps I am missing something, but doesn't the presumed "existential robustness" of intelligent life mean that any affected anthropic principle arguments just devolve to the "well it had to take some value" answer mentioned at the very beginning?
flatfilefan 6y ago
Were you guys ever curious as to what the word “anthrop” means exactly? Here’s an interesting explanation from Socrates:” Socrates I will tell you. The name “man” (ἄνθρωπος) indicates that the other animals do not examine, or consider, or look up at (ἀναθρεῖ) any of the things that they see, but man has no sooner seen—that is, ὄπωπε—than he looks up at and considers that which he has seen. Therefore of all the animals man alone is rightly called man (ἄνθρωπος), because he looks up at (ἀναθρεῖ) what he has seen (ὄπωπε).” http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname=GreekFeb2011&getid=1&query=Pl.%20Cra.%20399c http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname... And yet the English “man”, Spanish “hombre”, Russian Мужик mean the same yet different thing, namely a (working) hand. As in “how many hands do you have in your factory?”

41 points by srl 6y ago

Max Tegmark goes into detail on the potential pitfalls of anthropic arguments in "Our Mathematical Universe". Very interesting book.

alexpetralia 6y ago

Does anyone know if panpsychism is an anthropic argument?

tmp0192847475 6y ago
Why would it be ?
falseprofit 6y ago
If anything, it uses Occam's razor, reducing {conscious matter, unconscious matter} to {conscious matter}.

m4r35n357 6y ago

Isn't this just a form of "survivor bias"? I don't get why anthropic arguments are considered "weak". The article seems to just be complaining that anthropic arguments cannot explain the precise _value_ of the fine structure constant. Well, nor can Occam's Razor, but we don't seem to have a problem quoting that!

rbanffy 6y ago
My understanding is that they are an attempt to explain away something that may or may not be random. We wouldn't be debating it if the universe were substantially different, but that doesn't explain why the universe we observe is the way it is.
- m4r35n357 6y ago
  OK fair enough, to me the opposition to the weak AP just seems to be people "unhappy" that a physical constant should need to be that precise. In other words, for some reason they expect the universe to be more "understandable" or "sensible" than this . . . Of course the strong AP is ludicrous in the extreme ;)
  - XorNot 6y ago
    It wraps up a concern that there are these seemingly random constants in our models that don't seem to be a product of our measurement system. There's no number system you can invent where the fundamental constants turn into simple integers or have obvious ratios. So why do they have those values? What gave them those values? The anthropic principle is disliked because it rejects further inquiry and progress.
    - greatquux 6y ago
      I don't think we can reject it though. We may not / shouldn't "like" it, and we can sort of shove it to the background and try to come up with other explanations or theories that are more explanatory, but we do have to acknowledge that at least the weak form does make a kind of sense and we can't ignore it.
      - rbanffy 6y ago
        AP can't really make sense because it doesn't explain anything. We know a universe with our values works because we are observing one. Any set of values that "work" in this sense will have someone to make the same observation. Unfortunately, that doesn't explain how these values are generated. That is the important question.
  - coldtea 6y ago
    >OK fair enough, to me the opposition to the weak AP just seems to be people "unhappy" that a physical constant should need to be that precise. No, their opposition is to the fact that a physical constant is a mere accident, a mere facet coming with the universe as a set, and not explained by some more fundamental mechanism.
catawbasam 6y ago
I don't think it is just survivor bias, since the claim applies to all life as we understand it and not just life in human form. "Anthropic Principle" is kind of a poor name for it.
coldtea 6y ago
>Well, nor can Occam's Razor, but we don't seem to have a problem quoting that! Well, Occam's Razor is just a heuristic, not a logical necessity. Sometimes the more complex answer is actually the correct.
Keysh 6y ago
Well, nor can Occam's Razor, but we don't seem to have a problem quoting that! Occam's Razor is not an argument or explanation. It's a heuristic for discriminating among different arguments/explanations. And anthropic arguments amount to "there isn't any explanation for the precise value of the fine structure constant!" Or "you should just give up trying to explain why it has the value it has!"

flerchin 6y ago

It seems to be the final answer in a game of "why"? with a 2 year old.

falseprofit 6y ago
I think that game should end at the question of https://en.wikipedia.org/wiki/Why_there_is_anything_at_all https://en.wikipedia.org/wiki/Why_there_is_anything_at_all. I don't actually think the anthropic principle is capable of tackling that one.
- Izkata 6y ago
  "Because nothingness was bored." ( Original intention of the backstory of https://andromeda.fandom.com/wiki/Trance_Gemini https://andromeda.fandom.com/wiki/Trance_Gemini ) (Yeah, not quite anthropic principle, but definitely popped into my mind as something to give a 2-year-old)
  - falseprofit 6y ago
    My attempt at an answer would be that emptiness/nothingness is just a made-up concept. Not a good answer, I know, but idk what else to think.

jankotek 6y ago

》This would prevent carbon-based life from existing, sure; but would it prevent intelligent life from existing? We are yet to find another primitive carbon based life form. Anthropic principle works just fine with Occam's razor.

metalliqaz 6y ago

But I thought the purpose of the Anthropic principle was not to answer, "why is this thing?" but rather, "why is this thing so perfect for us?". Those are very different questions.

throwaway_pdp09 6y ago
As our n=1, how can you claim that it is indeed the best of all possibilities ("so perfect")?
- harshitaneja 6y ago
  We need a large number of samples when we lack sufficient understanding of the system in study. But if we assume our current knowledge of physics and biology are good enough then we should be able to find the best(whatever definitions is used) without needing multiple samples. We use multiple samples to create a model but if a model exists then non-contradicting samples add nothing. Although we could have a large discussion about bayesian epistemology regarding my last statement.
  - throwaway_pdp09 6y ago
    > But if we assume our current knowledge of physics and biology are good enough That's a bloody big if, but let us let it ride for now > we should be able to find the best(whatever definitions is used) Agreed it hinges on that, assuming the preceding if is accepted. What 'best' do you nominate? I have no idea what it might be.
    - harshitaneja 6y ago
      It is a big if. My choice of words was very deliberate as I didn't wish to convey that our knowledge is sufficient. But the question here doesn't hinge on real knowledge(our ability to ever gain it is in itself a huge question) but rather on belief in possessing the said knowledge. Otherwise every real world calculation of probability is meaningless as physical systems can't have proofs but rather more and more tested models acting as the prior in our calculations. I don't nominate any best. I don't have an idea either. I merely used a word used by a parent. Best could be minima, maxima or any other criteria of the function they choose to refer here. My point is if you have a belief that your model is good enough, you don't need a large number of trials to calculate a probability on whatever characteristic you choose. The accuracy of this result is a question but the question would remain similar to the scenario where you calculate the probability from a larger number of trials.

ggambetta 6y ago

> In this universe, where α ≈ 0.007297352569, you’re reading an article about the anthropic principle; in the universe where α ≈ 0.007297352569, at the very least, it’s reasonable to guess that you would not be. (Good news: in that universe, you’re a billionaire playboy philanthropist!) Both values of α look identical to me, but the text implies that they're subtly different - is this a typo in the article, or am I missing something?

couchand 6y ago
I read this as putting all the weight on the wavy approximate equals; the alternate universe described is incredibly similar to, but not quite the same as, ours.
- leephillips 6y ago
  I’m sure he must have meant to change the last digit, but something went wrong. We exist because of a typo!
  - TheSpiceIsLife 6y ago
    Thereby exposing God as nothing more than an average copy editor.
coldtea 6y ago
The ≈ means "aproximately", so they might or might not be the same. In this case they're meant as not the same. The author intents to make a point, this values, which approximate to the same degree of x decimals, are supposed to be explained by "if the first wasn't true we wouldn't be here to ask this question".
srl 6y ago
Yeah of course this is a typo. I've fixed. (But I appreciate the other commenters trying to interpret this in a way that makes sense.)

laszlokorte 6y ago

`Why is this question encoded as string of 385 characters and why is there a set of 385 character long strings? I mean there could be just a set of strings of length 95 and the question could instead ask "why is this question of exactly 95 letters long and why is there a set of 95 char long strings?" but still this specific question is asking why it is 385 chars long, why is that so?`

squibbles 6y ago
One answer to "Why is this question..." is because we have defined it so. And why did we define it so? One could make an argument that notions of sets, counting, length, and so on are anthropomorphisms -- we project our bodies onto the universe around us so we can reason about the environment using our specialized brains. (Human brains are specialized to operate in the context of our bodies.) In fact, the Whorf hypothesis [0][1][2] addressed this subject in the context of linguistics. [0] https://en.wikipedia.org/wiki/Linguistic_relativity https://en.wikipedia.org/wiki/Linguistic_relativity [1] https://plato.stanford.edu/entries/linguistics/#SoCalSapWhoHyp https://plato.stanford.edu/entries/linguistics/#SoCalSapWhoH... [2] https://www.sciencedirect.com/science/article/pii/B0080430767030424 https://www.sciencedirect.com/science/article/pii/B008043076... , https://doi.org/10.1016/B0-08-043076-7/03042-4 https://doi.org/10.1016/B0-08-043076-7/03042-4

lordnacho 6y ago

The thing about the fine structure constant always bothered me. If it were slightly different, our universe would be very different. But how do we quantify how different is different enough to warrant investigation? How do we know what the range of such a number could be?

at_a_remove 6y ago
Ah, well, about a four percent change and you no longer can produce carbon during regular fusion. You need atoms capable of making at least three bonds to produce structure more complex than a chain. Carbon can do four, is lovely, otherwise you would have to make do with boron and nitrogen. Crank the value up to .1 and you get no fusion at all. This one is super-interesting, because no fusion means no photonic pressure keeping silly large accumulations of gases up and so you will crank your way to neutron stars and black holes much faster, as well as resulting in a universe whose only light is the remaining cosmic background radiation. No more supernovae creating shockwaves and the like. In the other direction and you have a different problem -- molecules won't molecule and you will just have a bunch of disconnected atoms incapable of covalent bonds.
- lordnacho 6y ago
  Yes but how do we know what the numbers could have been? It's not like we have a generating theory that says it had to be between a and b, and thus it being x is really unlikely.
  - at_a_remove 6y ago
    Ah, okay, that's a different question. Aside from common sense ("this being negative would be self-contradicting") for a given number and sets of inter-relations, that's out of my wheelhouse. I very dimly recollect some work on allowable sets of constants somewhere in the nineties, something to do with superstrings, but that was never a huge interest of mine. I will admit that such a generating theory may exist and I am just unaware of it. In some sense, each constant represents a bit of embarrassment to physics. Having this rather large set of adjustable parameters calls to mind the von Neumann quote "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." Why this seemingly arbitrary number? Can we take multiple constants and find some smaller set from which they are derived? Can I make a constant emerge from a physical law, devoid of measurement?

maroonblazer 6y ago

Sean Carroll (theoretical physicist) and Nick Bostrom (philosopher with a very technical background) discuss Anthropic arguments on Sean's Mindscape podcast a few weeks ago. https://www.youtube.com/watch?v=EffcY6tnbcA https://www.youtube.com/watch?v=EffcY6tnbcA

roenxi 6y ago

If we start with the theory that universal constants are random (big if) then the question he is pushing towards doesn't make any sense. Why does a random number take on a specific value? That is a question for philosophers, not physicists. If we were observing a truly random number then it doesn't mean anything for it to be a specific value. It is a fair point if nobody has proven (or indeed, can prove) that something in physics is a random number. But alas that does not mean the theory is weak. It is perfectly consistent with the evidence, and mathematically satisfying. It would be quite exciting if someone can find a reason why we observe specific values and rule out the random number idea. But at some point we know we'll run up against the impossible questions of "why does anything exist at all?", "is it possible for something to not exist?" and "what separates existence from non-existence?". We can't expect to find causal answers for everything.

goodside 6y ago

I feel like the challenge of explaining fundamental constants understates the strength of anthropic reasoning. Most regions in space are empty voids — why aren’t we in such a void right now? Being anywhere near the orbit of a star is extremely unlikely a priori. Why are we on a planet with oceans teeming with other life forms, instead of a barren rocky desert, which seems to be the norm for planets in general? Why are we exactly on the surface of that planet, as opposed to being 1,000 kilometers up in the sky or down underground, swimming in hot magma? These are the questions where “Because those are the only conditions suitable for your existence to happen” is so obviously correct the questions make you roll your eyes. Applying the anthropic principle to fundamental constants is a speculative extension that might be right or wrong, but there are plenty of mundane coincidences that have no other answer.

leephillips 6y ago
There is an interesting book called _The Fallacy of Fine-Tuning: Why the Universe Is Not Designed for Us_ by Victor J. Stenger where he shows that most of the fundamental constants that people may think can only be explained with some kind of anthropic principle, or more to the point, intelligent design, are really more constrained than that.
- nicoffeine 6y ago
  A great subject is also the cosmological constant. Introduced by Einstein, who later claimed it was the biggest blunder of his life, that has returned to make the math work for cosmological observations made in the 90s. As explained by Susskind[1], a sort of negative force that by one measurement is 2.88 x 10^-122 [2] and if it were only slightly different, the universe as we know it would not exist. Add in the "need" for observers in Wheeler's Participatory Anthropic Principle[3], I would say that some extraordinary minds have recognized and proposed some strong anthropic arguments. In any case, the older I get, the more I realize I don't know a damn thing. As a poet once sang: Now, I wish I could write you a melody so plain That could hold you, dear lady, from going insane That could ease you and cool you and cease the pain Of your useless and pointless knowledge [1] https://www.youtube.com/watch?v=2cT4zZIHR3s&fbclid https://www.youtube.com/watch?v=2cT4zZIHR3s&fbclid [2] https://en.wikipedia.org/wiki/Cosmological_constant https://en.wikipedia.org/wiki/Cosmological_constant [3] https://en.wikipedia.org/wiki/John_Archibald_Wheeler https://en.wikipedia.org/wiki/John_Archibald_Wheeler

squibbles 6y ago

I find the argument against anthropic arguments to be weak. * The terms life and intelligence lack formal definitions. * The predicate why lacks a formal definition. * The argument does not address the maximum number of possible configurations of the universe, which dilutes any quantitative arguments. Most importantly, the cardinality of the maximum number of possible configurations is not addressed. For example, the possibility of an aleph number [0] was not addressed. * The argument does not address qualitatively different structures of the universe, such as universes with discontinuous lengths or types of affine spaces [1] where measurement as we understand it does not exist. The list of concerns above is not exhaustive, and I don't think addressing them individually will necessarily salvage the argument. While stronger arguments for or against the anthropic principle are possible, I think they deserve much more rigor. [0] https://en.wikipedia.org/wiki/Aleph_number https://en.wikipedia.org/wiki/Aleph_number [1] https://en.wikipedia.org/wiki/Affine_space https://en.wikipedia.org/wiki/Affine_space

AgentME 6y ago

I think this post's assumption that intelligent life is inevitable is unsupported. Just because lots of systems are Turing complete doesn't at all imply that intelligent life or even life in general is likely to arise from a random initial state. There's no support in the post for this jump in logic. I think the solution to the Fermi paradox is that intelligent life is just spectacularly unlikely, and that we're the only intelligent life in the observable universe. I think most people reason that we're probably not that special, that our conditions aren't too rare, and that the likelihood of intelligent life given those conditions must be somewhat good, but I don't think any of this reasoning is valid given the anthropic principle. I think the fact that we find ourselves in a world where we're alone is evidence for the sheer unlikelihood of life. If there were many values of the fine structure constant that could create a universe with any life at all, then I would guess that across that range of values, there would be more variation where some values would create a universe with rare lonely life and some values would create a universe where life was more plentiful. In that case, we would be more likely to find ourselves in a universe where life was more plentiful. But if there were a tighter range of possible constant values that create a universe with any life at all, then I would expect less variation with only universes with rare lonely life. Given that we find ourselves in a universe with rare lonely life, that seems like evidence that there isn't much room for variation in the constants while staying life-supporting.

coldtea 6y ago
>but I don't think any of this reasoning is valid given the anthropic principle And that concludes the circle in your circular argument in support of the antrhopic principle :-)
- AgentME 6y ago
  In that paragraph, I was trying to argue that the observation of us being alone and the anthropic principle are compatible and related in a way that if either one were missing, we should be skeptical of the other. I think that's valid and distinct from a circular argument. (And then in the last paragraph, I wasn't trying to argue for the anthropic principle, but to argue that given the anthropic principle and the observation we're alone, then I think it's correct to believe that the specific values of physical constants that we observe are likely to be necessary for intelligent life.)

njarboe 6y ago

The Anthropic principle idea that this universe's physical properties can't vary much and produce carbon/hydrogen/oxygen (CHO) based life on the surface of planets is probably not correct and was just popularized many decades ago when the understanding of nuclear physics was not as complete as it is now. The possible paths to a CHO universe with acceptable planet surface conditions were not well explored. From the linked article: "Suppose the fine structure constant were in fact 10% different — enough to prevent stellar fusion from producing carbon." This is an old idea and is probably false (I am not an astro/nuclear physicist) but the author of this in-depth paper is[1]. Fred Adams is at the Physics and Astronomy departments at the University of Michigan and in this 2019 paper[1], with over 500 references, states the fine structure constant can vary by 4 decades/orders of magnitude (decade=log10(max value/min value)). See table two on page 140 for that range and ranges of some other fundamental values. The most constrained value ranges still vary by an order of magnitude (down quark mass and the up-down quark mass difference). [1]https://arxiv.org/pdf/1902.03928.pdf https://arxiv.org/pdf/1902.03928.pdf

golemotron 6y ago

Honestly, I think this article about anthropic arguments is weak. Expressing discomfort with an argument isn't an argument.

mensetmanusman 6y ago

If intelligence is ‘extremely resilient’ then we will find it everywhere in our universe. If you use the cellular automata analogy that is being alluded to, ‘intelligence’ is being essentially equated to some limit of ‘complexity’ This is all very hand-wavey so it doesn’t appear to add much to the discussion?

goatlover 6y ago
Yeah, there needs to be evidence backing up a claim to extreme resilience. Invoking scifi scenarios and Turing completeness does not count. One can easily counter with the Fermi Paradox and only one species on Earth asking anthropic questions.

tunesmith 6y ago

This is a little new to me, but as described, isn't it like a form of a proof by contradiction? I mean, it doesn't have to bring in "we wouldn't be here" questions of survival, it seems to be just of the form of... (1) Question whether A is true. (2) If A were not true, then it would necessitate that B is true. (3) B is clearly impossible. (4) Therefore... A must be true.

tuatoru 6y ago
Proof by contradiction only applies to mathematical/logical theorems, which are also known as tautologies. It's useless for statements about the physical universe. Edit: IIRC the form is !(!A || B) && !B which reduces as (A || !B) && !B (A && !B) && (!B && !B) A && !B && !B Given B == false A && true && true A

mensetmanusman 6y ago

Are we comfortable admitting that this can never actually be answered with the scientific method? This puts all realms of the discussion in the metaphysical, which is fine, but it should be noted :)

srl 6y ago
It's perfectly fair to complain that these discussions are untestable, at the very least, but unfortunately they're inescapable. We need some heuristic for evaluating which anomalies/patterns are likely to be hints of "new physics" (and are thus worth investing resources in exploring further), and which ones are just coincidence or otherwise not worth investigating. Anthropic arguments seem to provide a reason to be uninterested in a large class of apparent surprises. Should we invest in investigating those surprises, or not? The discussion may be metaphysical, but the decision has real-world consequences.
- mensetmanusman 6y ago
  Thanks for the comment. I am by no means trying to downplay metaphysical discussions, most lived human experience is in that realm (“what should I wear/eat/do/etc.”), so one could argue it is more important than many scientific/engineering endeavors looking to find new ways to serve advertisements :) I love the discussion of complexity and automata, and I struggle to think how our limited minds will ever work around the problem of unbounded complexity...

dcanelhas 6y ago

Why is intelligent life held as such an inevitable outcome these scenarios? Could it not be the case that we look around and see billions of species (just on Earth) that are no smarter than ants (i.e. pencils lying around) and draw the conclusion that it was just luck instead?

tuatoru 6y ago

The article gives a crude statement of the principle as > The universe is the way it is because if it weren’t, we wouldn’t be here to discuss the issue. That can't be right. That statement says we are here as a consequence of the way the universe is. It says nothing about causes (of the universe being the way it is). What's a better statement of the principle?

Veedrac 6y ago

The key most people miss about the anthropic principle, and that seems to be the confusion here, is that when you're filtering out false hypotheses (those inconsistent with the observed facts), all remaining consistent explanations increase in probability equally. This means, for example, if you want to explain how Derren Brown won the lottery, the probability that he cheated raises in line with the probability that he just got lucky, which is exponentially low, hence it is almost certain he cheated. The base probability is, as always, based on some form of Solomonoff induction, which is invariant to ‘scale’, hence why we can explain away seemingly-arbitrarily low probability events (α≈0.007297352569) by talking about universes that contain a continuum of different α. In the lottery example, the hypothesis ‘lots of people tried’ is simple, even if the probability of each individual winning the lottery is low. You might ask instead, but what's the probability that that specific person won the lottery? Surely that is exponentially less likely? Yes, indeed, but unlike the Derren Brown case, where P(Derren Brown cheats the lottery) is fairly high prior to him winning the lottery given the public attempt, P(that random guy cheats the lottery) is very low, as most people don't cheat the lottery. Thinking about alternative observers and question-asking is a distraction. Other people asking other questions are not you, so they are not compatible with your observations.

DDaa 6y ago

Anthropic principle has been used by too many people to meaning too many different ideas. It really should just refer to the mere tautology that "I can only find myself exist, and the world in a state compatible with my existence". That is a perspective specific statement. It answers questions formulated from my/our first-person perspective: "why do I find the fundamental constants compatible with my existence?". However, it does not apply to questions formulated objectively (i.e. when it requires a perspective invariant response), for example "why are the fundamental constants have these values?". That question calls for an impartial causal model or scientific answer. Anthropic principle simply isn't it. That doesn't mean AP is wrong, it is a tautology, correct by definition. Neither is AP useless. It is the correct counter to teleological arguments such as fine-tuning. However, treating it as a scientific explanation is not correct. That being said, that confusion is totally understandable. The current state of anthropic reasoning is quite messy. There are contending theories on many related paradoxes. The sleeping beauty problem, the doomsday argument, the fine-tuned universe, the simulation argument, etc. Like before, I find these paradoxes are caused by ignoring the role of perspectives as well. I explained my solution to the related debate on my website https://www.sleepingbeautyproblem.com https://www.sleepingbeautyproblem.com if anyone is interested.

webmaven 6y ago

Perhaps I am missing something, but doesn't the presumed "existential robustness" of intelligent life mean that any affected anthropic principle arguments just devolve to the "well it had to take some value" answer mentioned at the very beginning?

flatfilefan 6y ago

Were you guys ever curious as to what the word “anthrop” means exactly? Here’s an interesting explanation from Socrates:” Socrates I will tell you. The name “man” (ἄνθρωπος) indicates that the other animals do not examine, or consider, or look up at (ἀναθρεῖ) any of the things that they see, but man has no sooner seen—that is, ὄπωπε—than he looks up at and considers that which he has seen. Therefore of all the animals man alone is rightly called man (ἄνθρωπος), because he looks up at (ἀναθρεῖ) what he has seen (ὄπωπε).” http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname=GreekFeb2011&getid=1&query=Pl.%20Cra.%20399c http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname... And yet the English “man”, Spanish “hombre”, Russian Мужик mean the same yet different thing, namely a (working) hand. As in “how many hands do you have in your factory?”