Stupid Questions Open Thread Round 2

Michaelcurzi's How to avoid dying in a car crash is relevant. Bentarm's comment on that thread makes an excellent point regarding coronary heart disease.

There is also Eliezer Yudkowsky's You Only Live Twice and Robin Hanson's We Agree: Get Froze on cryonics.

Good question.

Its probably easier to list things they shouldn't be doing that are known to significantly reduce life expectancy (e.g. smoking). I would guess it would mainly be obvious things like exercise and diet, but it would be interesting to see the effects quantified.

I follow the "Bulletproof" diet.

Donate to SENS.

Basically, any effective plan boils down to diligence and clean living. But here are changes I've made for longevity reasons:

You can retain nervous control of your muscles with regular exercise; this is a good place to start on specifically anti-aging exercise.

Abdominal breathing can significantly reduce your risk of heart attacks. (The previously linked book contains one way to switch styles.)

Intermittent fasting (only eating in a 4-8 hour window, or on alternating days, or a few other plans) is surprisingly easy to adopt and maintain, and may have some (or all) of the health benefits of calorie restriction, which is strongly suspected to lengthen human lifespans (and known to lengthen many different mammal lifespans).

In general, I am skeptical of vitamin supplements as compared to eating diets high in various good things- for example, calcium pills are more likely to give you kidney stones than significantly improve bone health, but eating lots of vegetables / milk / clay is unlikely to give you kidney stones and likely to help your bones. There are exceptions: taking regular low doses of lithium can reduce your chance of suicide and may have noticeable mood benefits, and finding food with high lithium content is difficult (plants absorb it from dirt with varying rates, but knowing that the plant you're buying came from high-lithium dirt is generally hard).

“Everyone” is tricky, since the main causes of mortality vary with your age. Anyway, I'd say, not smoking, exercising, not being obese (nor emaciated, but in the parts of the world where most Internet users are, short of anorexia nervosa this isn't likely to be a problem), driving less and in a less aggressive way, not committing suicide... Don't they teach this stuff in high school?

Well, that doesn't seem too difficult -

(one that doesn't originate with a cryonics institute)

Oh.

So, who exactly do you expect to be doing this analysis? The most competent candidates are the cryobiologists, and they are ideologically committed to cryonics not working and have in the past demonstrated their dishonesty\*.

* Literally; I understand the bylaw banning any cryonicists from the main cryobiology association is still in effect. ** eg. by claiming on TV cryonics couldn't work because of the 'exploding lysosomes post-death' theory, even after experiments had disproven the theory.

chronopause.com/index.php/2011/02/23/does-personal-identity-survive-cryopreservation/#comment-247

I've been finding ChronoPause.com to be a very insightful blog. I can't speak to the degree of bias of the author, but most of the posts I've read so far have been reasonably well cited.

I found it sort of terrifying to read the case reports he links in that comment - I read 101, 102, and 103, and it largely spoke to this being a distinctly amateur organization that is still running everything on hope and guesswork, not precise engineering/scientific principles.

Case 101 in particular sort of horrifies me for the aspects of preserving someone who committed suicide, without any consent from the individual in question. I can't help but feel that "patient must be held in dry ice for at least two weeks" is also a rather bad sign.

Feel free to read them for yourself and draw your own conclusions - these reports are straight from CI itself, so you can reasonably assume that, if anything, they have a bias towards portraying themselves favorably.

Only one technical analysis of cryonics which concludes it won't work has ever been written: http://blog.ciphergoth.org/blog/2011/08/04/martinenaite-and-tavenier-cryonics/

Morality is good because goals like joy and beauty are good. (For qualifications, see Appendices A through OmegaOne.) This seems like a tautology, meaning that if we figure out the definition of morality it will contain a list of "good" goals like those. We evolved to care about goodness because of events that could easily have turned out differently, in which case "we" would care about some other list. But, and here it gets tricky, our Good function says we shouldn't care about that other list. The function does not recognize evolutionary causes as reason to care. In fact, it does not contain any representation of itself. This is a feature. We want the future to contain joy, beauty, etc, not just 'whatever humans want at the time,' because an AI or similar genie could and probably would change what we want if we told it to produce the latter.

This comment by Richard Chappell explained clearly and concisely Eliezer's metaethical views. It was very highly upvoted, so apparently the collective wisdom of the community considered it accurate. It didn't receive an explicit endorsement by Eliezer, though.

Let me try...

Something is green if it emits or scatters much more light between 520 and 570 nm than between 400 and 520 nm or between 570 and 700 nm. That's what green means, and it also applies to places where there are no humans: it still makes sense to ask whether the skin of tyrannosaurs was green even though there were no humans back then. On the other hand, the reason why we find the concept of ‘something which emits or scatters much more light between 520 and 570 nm than between 400 and 520 nm or between 570 and 700 nm’ important enough to have a word (green) for it is that for evolutionary reasons we have cone cells which work in those ranges; if we saw in the ultraviolet, we might have a word, say breen, for ‘something which emits or scatters much more light between 260 and 285 nm than between 200 and 260 nm or between 285 and 350 nm’. This doesn't mean that greenness is relative, though.

Likewise, something is good if it leads to sentient beings living, to people being happy, to individuals having the freedom to control their own lives, to minds exploring new territory instead of falling into infinite loops, to the universe having a richness and complexity to it that goes beyond pebble heaps, etc. That's what good means, and it also applies to places where there are no humans: it still makes sense to ask whether it's good for Babyeaters to eat their children even though there are no humans on that planet. On the other hand, the reason why we find the concept of ‘something which leads to sentient beings living, to people being happy, to individuals having the freedom to control their own lives, to minds exploring new territory instead of falling into infinite loops, to the universe having a richness and complexity to it that goes beyond pebble heaps, etc.’ important enough to have a word (good) for it is that for evolutionary reasons we value such kind of things; if we valued heaps composed by prime numbers of pebbles, we might have a word, say pood, for ‘something which leads to lots of heaps with a prime number of pebbles in each’. This doesn't mean that goodness is relative, though.

I have recently read this post and thought it describes very well how I always thought about morality, even though it talks about 'sexiness'.

Would reading the metaethics sequence explain to me that it would be wrong to view morality in a similar fashion as sexiness?

One part of it that did turn out well, in my opinion, is Probability is Objectively Subjective and related posts. Eliezer's metaethical theory is, unless I'm mistaken, an effort to do for naive moral intuitions what Bayesianism should do for naive probabilistic intuitions.

I think it's just Meta-ethical moral relativism.

My summary is pretty close to yours.

I would summarize it as:

• All questions about the morality of actions can be restated as questions about the moral value of the states of the world that those actions give rise to.
• All questions about the moral value of the states of the world can in principle be answered by evaluating those world-states in terms of the various things we've evolved to value, although actually performing that evaluation is difficult.
• Questions about whether the moral value of states of the world should be evaluated in terms of the things we've evolved to value, as opposed to evaluated in terms of something else, can be answered by pointing out that the set of things we've evolved to value is what right means and is therefore definitionally the right set of things to use.

I consider that third point kind of silly, incidentally.

Would anyone dare summarise it?

Morality is a sense, similar to taste or vision. If I eat a food, I can react by going 'yummy' or 'blech'. If I observe an action, I can react by going 'good' or 'evil'.

Just like your other senses, it's not 100% reliable. Kids eventually learn that while candy is 'yummy', eating nothing but candy is 'blech' - your first-order sensory data is being corrected by a higher-order understanding (whether this be "eating candy is nutritionally bad" or "I get a stomach ache on days I just eat candy").

The above paragraph ties in with the idea of "The lens that sees its flaws". We can't build a model of "right and wrong" from scratch any more than we could build a sense of yumminess from scratch; you have to work with the actual sensory input you have. To return to the food analogy, a diet consisting of ostensibly ideal food, but which lacks 'yumminess', will fail because almost no one can actually keep to it. Equally, our morality has to be based in our actual gut reaction of 'goodness' - you can't just define a mathematical model and expect people to follow it.

Finally, and most important to the idea of "CEV", is the idea that, just as science leads us to a greater understanding of nutrition and what actually works for us, we can also work towards a scientific understanding of morality. As an example, while 'revenge' is a very emotionally-satisfying tactic, it's not always an effective tactic; just like candy, it's something that needs to be understood and used in moderation.

Part of growing up as a kid is learning to eat right. Part of growing up as a society is learning to moralize correctly :)

I am wondering if risk analysis and mitigation is a separate "rationality" skill.

Two related points that I think are very important and not dealt with:

• Exploration vs. exploitation (or when to stop doing research).
• Judgment under uncertainty (or how to deal with unpredictable long term consequences).

Suppose (just to fix ideas) that you are at rest, in some coordinate system. Call FLC(t) your future light cone from your space-time position at time t.

An object that is with you at t=0 cannot exit FLC(0), no matter how it moves from there on. But it can accelerate in a way that its trajectory is entirely outside FLC(T) from some T>0. Then it makes sense to say that the object has exited your future light cone: nothing you do after time T can affect it.

Well, every object is separated from you by a spacelike interval. If some distant object starts accelerating quickly enough, it may become forever inaccessible.

Also, an object distant enough on way-bigger-than-galaxy-superclaster scale can have Hubble speed more than c relative to us.

If not, why do people speak as if the lack of such a derivation were a point against MWI?

The primary argument in favor of MWI is that it doesn't require you to postulate additional natural laws other than the basic ones we know for quantum evolution. This argument can pretty easily be criticized on the grounds that yes, MWI does require you to know an additional fact about the universe (the Born rule) before you can actually generate correct predictions.

On occasion people will speak of some object "exiting one's future light cone". How is it possible to escape a light cone without traveling in a spacelike direction?

Usually people do include traveling in a spacelike direction as a component of the 'exiting'. But the alternative is for the objects ('you' and 'the other thing') to be at rest relative to each other but a long distance apart - while living in a universe that does stuff like this.

ie. Imagine ants on the outside of a balloon that is getting blown up at an accelerating rate.

Nobody has derived the Born rule, though I think some have managed to argue that it is the only rule that makes sense? (I'm not sure how successful they were). I think people may count it against mwi because of either simple double standards or because it's more obvious as an assumption since it's the only one MWI needs to make. (In other theories the rule may be hidden in with the other stuff like collapse, so it doesn't seem like a single assumption but a natural part of the theory. Since MWI is so lean, the assumed rule may be more noticeable, especially to people who are seeing it from the other side of the fence.)

It's not an acronym. It's an onomatopoeia for what happens when an AI self-recursively improves and becomes unimaginably powerful.

(A regular explosion goes BOOM; an intelligence explosion goes FOOM.)

I added it to the jargon page.

It's the sound of an AI passing by, I guess.

Very rapid increase/acceleration. Originally it's the sound you hear if you pour gasoline on the ground and set fire to it.

Friends Of Ol' Marvel. It means that a self-improved unfriendly AI could turn into Galactus and eat the planet.

"Acausal" is used as a contrast to Causal Decision Theory (CDT). CDT states that decisions should be evaluated with respect to their causal consequences; ie if there's no way for a decision to have a causal impact on something, then it is ignored. (More precisely, in terms of Pearl's Causality, CDT is equivalent to having your decision conduct a counterfactual surgery on a Directed Acyclic Graph that represents the world, with the directions representing causality, then updating nodes affected by the decision.) However, there is a class of decisions for which your decision literally does have an acausal impact. The classic example is Newcomb's Problem, in which another agent uses a simulation of your decision to decide whether or not to put money in a box; however, the simulation took place before your actual decision, and so the money is already in the box or not by the time you're making your decision.

"Acausal" refers to anything falling in this category of decisions that have impacts that do not result causally from your decisions or actions. One example is, as above, Newcomb's Problem; other examples include:

• Acausal romance: romances where interaction is impossible
• The Prisoner's Dilemma, or any other symmetrical game, when played against the same algorithm you are running. You know that the other player will make the same choice as you, but your choice has no causal impact on their choice.

There are a number of acausal decision theories: Evidential Decision Theory (EDT), Updateless Decision Theory (UDT), Timeless Decision Theory (TDT), and Ambient Decision Theory (ADT).

In EDT, which originates in academia, casuality is completely ignored, and only correlations are used. This leads to the correct answer on Newscomb's Problem, but fails on others- for example, the Smoking Lesion. UDT is essentially EDT, but with an agent that has access to its own code. (There's a video and transcript explaining this in more detail here).

TDT, like CDT, relies on causality instead of correlation; however, instead of having agents chose a decision that is implemented, it has agents first chose a platonic computation that is instantiated in, among other things, the actual decision maker; however, is is also instantiated in every other algorithm is equal, acausally, to the decision maker's algorithm, including simulations, other agents, etc. And, given all of these instantiations, the agent then choses the utility-maximizing algorithm.

ADT...I don't really know, although the wiki says that it is "variant of updateless decision theory that uses first order logic instead of mathematical intuition module (MIM), emphasizing the way an agent can control which mathematical structure a fixed definition defines, an aspect of UDT separate from its own emphasis on not making the mistake of updating away things one can still acausally control."

One must distinguish different varieties of MWI. There is an old version of the interpretation (which, I think, is basically what most informed laypeople think of when they hear "MWI") according to which worlds cannot interact. This is because "world-splitting" is a postulate that is added to the Schrodinger dynamics. Whenever a quantum measurement occurs, the entire universe (the ordinary 3+1-dimensional universe we are all familiar with) duplicates (except that the two versions have different outcomes for the measurement). It's basically as mysterious a process as collapse, perhaps even more mysterious.

This is different from the MWI most contemporary proponents accept. This MWI (also called "Everettianism" or "The Theory of the Universal Wavefunction" or...) does not actually have full-fledged separate universes. The fundamental ontology is just a single wavefunction. When macroscopic branches of the wavefunction are sufficiently separate in configuration space, one can loosely describe it as world-splitting. But there is nothing preventing these branches from interfering in principle, just as microscopic branches interfere in the two-slit experiment. There is no magical threshold of branch size/separation where the Schrodinger equation no longer permits interference. And in MWI understood this way, the Schrodinger equation is all the dynamics there are. So yeah, MWI does allow for the interaction of "worlds" in principle. The reason we never see this happening at a macroscopic scale is usually explained by appeal to special initial conditions (just like the thermodynamic arrow of time).

ETA: And in some sense, all the separate worlds are actually interacting all the time, just at a scale that is impossible for our instruments to detect.

Also, if MWI hypothesis is true, there's no way for one branch to interact with another later, right? If there are two worlds that are different based on some quantum event that occurred in 1000 CE, those two worlds will never interact, in principle, right?

To expand on what pragmatist said: The wavefunction started off concentrated in a tiny corner of a ridiculously high-dimensional space (configuration space has several dimensions for every particle), and then spread out in a very non-uniform way as time passed.

In many cases, the wavefunction's rule for spreading out (the Schrödinger equation) allows for two "blobs" to "separate" and then "collide again" (thus the two-split experiment, Feynman paths and all sorts of wavelike behavior). The quote marks around these are because it's not ever like perfect physical separation, more like the way that the pointwise sum of two Gaussian functions with very different means looks like two "separated" blobs.

But certain kinds of interactions (especially those that lead to a cascade of other interactions) correspond to those blobs "losing" each other. And if they do so, then it's highly unlikely they'll accidentally "collide" again later. (A random walk in a high-dimensional space never finds its way back, heuristically speaking.)

So, as long as the universe has relatively low entropy (as it will until what we would call the end of the universe), significant interference with "blobs" of wavefunction that "split off of our blob" in macroscopic ways a long time ago would be fantastically unlikely. Not impossible, just "a whale and a petunia spontaneously appear out of quantum noise" degree of improbability.

What do people mean here when they say "acausal"?

As I understand it: If you draw out events as a DAG with arrows representing causality, then A acausally effects B in the case that there is no path from A to B, and yet a change to A necessitates a change to B, normally because of either a shared ancestor or a logical property.

Having seen the exchange that probably motivated this, one note: in my opinion, events can be linked both causally and acausally. The linked post gives an example. I don't think that's an abuse of language; we can say that people are simultaneously communicating verbally and non-verbally.

Broadly, branches become less likely to interact as they become more dissimilar; dissimilarity tends to bring about dissimilarity, so they can quickly diverge to a point where the probability of further interaction is negligible. Note that at least as Eliezer tells it, branches aren't ontologically basic objects in MWI any more than chairs are; they're rough high-level abstractions we imagine when we think about MWI. If you want a less confused understanding than this, I don't have a better suggestion than actually reading the quantum physics sequence!

I found an excellent answer here

Also, if MWI hypothesis is true, there's no way for one branch to interact with another later, right? If there are two worlds that are different based on some quantum event that occurred in 1000 CE, those two worlds will never interact, in principle, right?

I think it depends on perspective. We notice worlds interfering with each other in the double slit experiment. I think that maybe once you are in a world you no longer see evidence of it interfering with other worlds? I'm not really sure.

Also, if MWI hypothesis is true, there's no way for one branch to interact with another later, right?

Basically, if two of them evolve into the same "world", they interfere. It could be constructive or destructive. It averages out to be that it occurs as often as you'd expect, so outside of stuff like the double-slit experiment, they won't really interact.

What do people mean here when they say "acausal"?

Non-traditional notions of causality as in TDT such as causality that runs backwards in time.

"Acausal" means formal or final as opposed to efficient causality.

It's from psychology: it's where an intelligence develops a model of a thing and then mentally simulates what will happen to it given X. Caledionian crows are capable of developing mental models in solving problems, for example. A mental model of a person is basically where you've acquired enough information of them to approximate their intentions or actions. (Or you might use existing archetypes or your own personality for modeling--put yourself in their shoes.) For example, a lot of the off color jokes by Jimmy Carr would seem malicious from a stranger, misogynist, or racist, whereas you can see with someone like Carr that the intention is to derive amusement from the especially offensive rather than to denigrate a group.

Not a conscious technique. When you get to know a person you form some kind of brain structure which allows you to imagine that person when they aren't around, and which makes some behaviors seem more realistic/in character for them than some other behaviors. This structure is your mental model of that person.

I use this phrase a lot; in my case it's just a turn of phrase. Can't speak for anyone else, though.

Sorta both. Basically your mental model of someone is anything internal that use to predict their (re)actions.

I'm a guy.

Let it be OpenThreadGuy and OpenThreadLady, by turns.

Nope.

ZF is consistent with many negations of strong choice. For example, ZF is consistent with Lebesgue measurability of every subset in R. Well-ordering of R is enought to create unmeasurable set.

So, if ZF could prove existence of such a formula, ZF+measurability would prove contradiction, but ZF+neasurability is equiconsistent with ZF and ZF would be inconsistent.

It is very hard to say anything about any well-ordering of R, they are monster constructions...

ZF does not imply well ordering of R, ZFC does. ZF with the Axiom of Choice.

Strictly speaking.

Yes. In ZF one can construct an explicit well-ordering of L(alpha) for any alpha; see e.g. Kunen ch VI section 4. The natural numbers are in L(omega) and so the constructible real numbers are in L(omega+k) for some finite k whose value depends on exactly how you define the real numbers; so a well-ordering of L(omega+k) gives you a well ordering of R intersect L.

I'm not convinced that R intersect L deserves the name of "the-real-numbers-as-we-know-them", though.

Is this a correct statement of what a well-ordering of R is?

%20\land%20\forall%20B%20(B%20\subseteq%20\mathbb{R}%20\land%20B%20\neq%20\emptyset%20\implies%20\exists%20x%20\in%20B%20\forall%20y%20\in%20B%20((x%20\preceq%20y)%20\in%20A)))%0A%0A\forall%20A%20\forall%20B%20(\text{total-order}(A,%20B)%20\iff%20\forall%20a%20\forall%20b%20\forall%20c(a,%20b,%20c%20\in%20B%20\implies%20(((a%20\preceq%20b)%20\in%20A%20\lor%20(b%20\preceq%20a)%20\in%20A)%20\land%20((a%20\preceq%20b)%20\in%20A%20\land%20(b%20\preceq%20a)%20\in%20A%20\implies%20a%20=%20b)%20\land%20((a%20\preceq%20b)%20\in%20A%20\land%20(b%20\preceq%20c)%20\in%20A%20\implies%20(a%20\preceq%20c)%20\in%20A)))))

I wrote that line in the jargon file quoting the first line of the relevant wiki page. The phrase was there in the first revision of that page - put there by an IP. If that IP is still present and could explain ...

I could come up with surmises as to what it could plausibly mean, but I'd be making them up and it isn't actually clear to me in April 2012 either.

It's the process of changing your mind about something when new evidence on something comes your way.

The different jargon acts as a reminder that the process ought not be an arbitrary one, but (well, in an ideal world anyway) should follow the evidence in a way defined by Bayes theorem.

I don't think there's any particular definition of what constitutes, belief, opinion and cognitive structure. It's all just beliefs, although some of it might then be practised habit.

I like this (long) informal explanation, written by Yvain.

See also.

• Each possible world-state has a value
• The value of a world-state is determined by the amount of value for the individuals in it
• The function that determines the value of a world state is monotonic in its arguments (we often, but not always, require linearity as well)
• The function that determines the value of a world state does not depend on the order of its arguments (a world where you are happy and I am sad is the same as one where I am happy and you are sad)
• The rightness of actions is determined wholey by the value of their (expected) consequences.

and then either

• An action is right iff no other action has better (expected) consequences

or

• An action is right in proportion to to the goodness of its consequences

Welcome to LW! You pose an interesting question.

My initial question is perhaps about the social psychology of the site. Why are two popular subjects here (1) extending lifespan, including cryogenics, (2) increasingly powerful AIs leading to a singularity. Is there an argument that concern for these things is somehow derivable from a Bayesian approach? Or is it more or less an accident that these things are of interest to the people here?

I think there is a purely sociological explanation. LW was started by Eliezer Yudkowsky, who is a transhumanist and an AI researcher very concerned about the singularity, and his writings at Overcoming Bias (the blog from which LW was born by splitting) naturally tended to attract people with the same interests. But as LW grows and attracts more diverse people, I don't see why transhumanism/futurism related topics must necessarily stay at the forefront, though they might (path-dependence effect). I guess time will tell.

Examples of other things that might be of interest could be (a) "may I grow firmer, quieter, warmer" (rough paraphrase of Dag Hammarskjold), (b) I want to make the very best art, (c) economics rules and the key problem is affording enough for everyone. I'm not saying those are better, just that they're different. Are there reasons people here talk about the one set and not the other?

If you have something interesting to say about these topics and the application of rationality to them, by all means do! However, about topic (c) you must bear in mind that there is a community consensus to avoid political discussions, which often translates to severely downvoting any post that maps too closely to an established political/ideological position.

Why are two popular subjects here (1) extending lifespan, including cryogenics

This is factually false. I suspect if you looked through the last 1000 Articles or Discussion posts, you'd find <5% on life extension (including cryonics) and surely <10%.

Cryonics does not even command much support; in the last LW survey, 'probability cryonics will work' averaged 21%; 4% of LWers were signed up, 36% opposed, and 54% merely 'considering' it. So if you posted something criticizing cryonics (which a number of my posts could be construed as...), you would be either supported or regarded indifferently by ~90% of LW.

Why are two popular subjects here (1) extending lifespan, including cryogenics, (2) increasingly powerful AIs leading to a singularity. Is there an argument that concern for these things is somehow derivable from a Bayesian approach? Or is it more or less an accident that these things are of interest to the people here?

The short answer is that the people who originally created this site (the SIAI, FHI, Yudkowsky, etc) were all people who were working on these topics as their careers, and using Bayesian rationality in order to do those things. So, the people who initially made up the community were made up, in large part, of people who were interested in those topics and rationality. There is a bit more variation in this group now, but it's still generally true.

You're thinking according what pragmatist calls the “old version” of MWI. In the modern understanding, it's not that an universe splits into several when a quantum measurement is performed -- more like the ‘universes’ were ‘there’ all along but the differences between them used to be in degrees of freedom you don't care about (such as the thermal noise in the measurement apparatus).

You-measure is conserved in each branch, I believe. You can't make more of it, only more fragments of it.

Re: utilitarianism: Is there any known way to resolve the Utility Monster issue?

Yes, don't be utilitarian. Seriously. The "utility monster" isn't a weird anomaly. It is just what utilitarianism is fundamentally about, but taken to an extreme where the problem is actually obvious to those who otherwise just equate 'utilitarianism' with 'egalitarianism'.

The first comment says that the double slit experiment is feasible under both hypothesis, but the second adds on that it is just as likely with MWI as waveform collapse.

Analogy: There are two possible bags arrangements, one filled with 5 green balls and 5 red balls, and the other with 4 green balls and 6 red balls. It's true that drawing a green ball is consistent with both, but it's more likely in the with first bag than the second.

wait, that was easier to search than I thought. http://lesswrong.com/lw/kn/torture_vs_dust_specks/

Yes, it is Knuth's arrow notation.

If they interrupt and disagree then that obviously that's evidence in favor of them disbelieving. However, if they don't, then is that evidence in favor of them believing?

If X is evidence of A, then ~X (not-X) is evidence of ~A. They are two ways of looking at the same thing - it's the same evidence. This is called conservation of expected evidence.

So if your premise is true, then your conclusion is necessarily also true.

Please note that this says nothing about whether your premise is indeed true. If you have doubts that "not disagreeing indicates belief", that is exactly the same as having doubts that "disagreeing indicates disbelief". The two propositions may sound different, one may sound more correct than the other, but that is an accident of phrasing: from a Bayesian point of view the two are strictly equivalent.

The standard utilitarian argument for pursuing knowledge

So why should we seek additional knowledge is we can't use it to make ourselves happier? Surely we should live in a state of blissful ignorance as much as possible.

Because I'm not utilitarian. I'll care about being happy to whatever extent I damn well please. Which is "a fair bit but it is not the most important thing".

"The opposite of happiness is not sadness, but boredom." --Tim Ferris.

I wonder if all we really should ask of them is that they

, why rock their boats?

What boat-rocking are you talking about? Do you know a lot of people who "ask of" religious people that they do something?