gjm

• gjm 21 May 2020 11:11 UTC

  6 points

  in reply to: Adele Lopez's comment on: Com­ment on “En­doge­nous Epistemic Fac­tion­al­iza­tion”

  Re­lat­edly, in the sce­nario (in some ut­terly ab­surd coun­ter­fac­tual world en­tirely un­like the real world) where agents some­times mis­rep­re­sent the ev­i­dence in a di­rec­tion that favours their ac­tual be­liefs, it seems like the policy de­scribed here might well do bet­ter than the policy of up­dat­ing fully on all ev­i­dence you’re pre­sented with.

  Given the limi­ta­tions of our abil­ity to in­ves­ti­gate oth­ers’ hon­esty, it’s pos­si­ble that the only op­tions are fac­tion­al­ism or naivety and that the lat­ter pro­duces worse re­sults than fac­tion­al­ism; e.g., if we hap­pen to start with more peo­ple favour­ing (A,A,A) than (B,B,B) then re­ject­ing “dis­trust those who dis­agree” may end up with ev­ery­one in the (A,A,A) cor­ner, which is prob­a­bly worse than hav­ing fac­tions in all eight cor­ners if the re­al­ity is (B,B,B).

  As Zack says, what we want is a de­gree of trust that matches agents’ trust­wor­thi­ness. But that may be ex­tremely hard to ob­tain, and if all agents are some­what un­trust­wor­thy (but some hap­pen to be right so that their un­trust­wor­thi­ness does lit­tle harm) then hav­ing trust match­ing trust­wor­thi­ness may pro­duce ex­actly the sort of fac­tional re­sults re­ported here.

  So I think the most in­ter­est­ing ques­tion is: Are there strate­gies that, even when agents may be un­trust­wor­thy in their re­port­ing of the ev­i­dence, man­age to con­verge to the truth over a rea­son­able por­tion of the space of un­trust­wor­thi­ness and ac­tual-ev­i­dence-strength? My guesses: (1) yes, there kinda are, and the price they pay in­stead of fac­tion­al­ism is slow­ness; (2) if there is enough un­trust­wor­thi­ness rel­a­tive to the ac­tual strength of ev­i­dence then no strat­egy will give good re­sults; (3) there are plenty of ques­tions in the real world for which #2 holds. But I’m not ter­ribly con­fi­dent about any of those guesses.

• gjm 21 May 2020 8:46 UTC

  2 points

  in reply to: lombertini's comment on: Sig­nal­ing: Why Peo­ple Have Conversations

  My per­sonal the­ory is that not all talk is sig­nal­ling, but al­most all talk about sig­nal­ling is. (It sig­nals “I am smart, so­phis­ti­cated, not eas­ily fooled, and will­ing to face un­com­fortable re­al­ities; I see be­low the care­fully groomed sur­face of things to the ugli­ness be­neath.”)

  In the par­tic­u­larly promi­nent case of Literal Robin Han­son, it seems pos­si­bly sig­nifi­cant that the un­com­fortable re­al­ities he un­cov­ers are gen­er­ally much more un­com­fortable for one of the two ma­jor poli­ti­cal fac­tions in the US than for the other, and that the “other” one is the one re­spon­si­ble for a lot of his fund­ing over the years (though I think he may no longer be af­fili­ated with the Mer­ca­tus Cen­ter now?).

  (Only pos­si­bly sig­nifi­cant, and I do ac­tu­ally mean that. Ob­vi­ously things that are poli­ti­cally con­ve­nient for the per­son say­ing them can also be true.)

• gjm 20 May 2020 13:00 UTC

  5 points

  in reply to: Purplehermann's comment on: Sus­pi­ciously bal­anced evidence

  A prob­a­bil­ity mea­sure is a mea­sure $\mu$ (on a $\sigma$-alge­bra $A$ on a set $A$) such that $\mu \left(A\right)=1$.

  A mea­sure on a $\sigma$-alge­bra $A$ is a func­tion $\mu :A\to R$ with prop­er­ties like “if $A\cap B=\varnothing$ then $\mu (A\cup B)=\mu \left(A\right)+\mu \left(B\right)$” etc.; the idea is that the el­e­ments of $A$ are the sub­sets of $A$ that are well-enough be­haved to be “mea­surable” and then if $X$ is such a sub­set then $\mu \left(X\right)$ says how big $X$ is.

  A $\sigma$-alge­bra on a set $A$ is a set $A$ of sub­sets of $A$ that (1) in­cludes all-of-$A$, (2) when­ever it in­cludes a set $X$ also in­cludes its com­ple­ment $A-X$, and (3) when­ever it in­cludes all of countably many sets $X_i$ also in­cludes their union.

  And now prob­a­bil­ity the­ory is the study of prob­a­bil­ity mea­sures. (So the mea­sure-the­o­retic defi­ni­tion of “prob­a­bil­ity” would be “any­thing satis­fy­ing the for­mal prop­er­ties of a prob­a­bil­ity mea­sure”, just as the math­e­mat­i­cian’s defi­ni­tion of “vec­tor” is “any­thing ly­ing in a vec­tor space”.)

  “Bayesian” prob­a­bil­ity the­ory doesn’t dis­agree with any of that; it just says that one use­ful ap­pli­ca­tion for (mostly the more el­e­men­tary bits of) the the­ory of prob­a­bil­ity mea­sures is to rea­son­ing un­der un­cer­tainty, where it’s use­ful to quan­tify an agent’s be­liefs as a prob­a­bil­ity mea­sure. Here $A$ is the set of ways the world could be; $A$ is some­thing like the set of sets of ways the world could be that can be de­scribed by propo­si­tions the agent un­der­stands, or the small­est $\sigma$-alge­bra con­tain­ing all of those; $\mu$, more com­monly de­noted $P$ or $P$ or $P$ or some­thing of the sort, gives you for any such set of ways the world could be a num­ber quan­tify­ing how likely the agent thinks it is that the ac­tual state of the world is in that set.

  You can work with prob­a­bil­ity mea­sures even if you think that it’s in­ap­pro­pri­ate to use them to quan­tify the be­liefs of would-be ra­tio­nal agents. I guess that’s PP’s po­si­tion?

• gjm 20 May 2020 9:35 UTC

  2 points

  in reply to: PP's comment on: Open & Wel­come Thread—May 2020

  I as­sume it means an image used in the train­ing pro­cess by which the robots learned to rec­og­nize things.

• gjm 20 May 2020 9:33 UTC

  4 points

  in reply to: PP's comment on: Sus­pi­ciously bal­anced evidence

  You don’t need any­one’s for­give­ness. But it turns out that quan­tify­ing de­grees of be­lief is use­ful some­times, and that rep­re­sent­ing them as num­bers from 0 to 1 that be­have like prob­a­bil­ities is a good way to do that. (There are the­o­rems that kinda-sorta say it’s the only way to do that, if you want var­i­ous nice-sound­ing things to be true, but how much you care about those nice-sound­ing things is up to you.) So you may be miss­ing out on some use­ful think­ing tools.

• gjm 19 May 2020 11:17 UTC

  4 points

  on: Open & Wel­come Thread—May 2020

  In the space of four frames, to­day’s SMBC comic touches on un­friendly AI, fun the­ory, and overfit­ting in ma­chine learn­ing.

• gjm 13 May 2020 15:12 UTC

  6 points

  in reply to: Miguel Cisneros's comment on: Stud­ies On Slack

  No one is eras­ing other peo­ple’s com­ments here un­less they’re out­right abu­sive.

  As for the “ir­re­ducible com­plex­ity” ar­gu­ment, you may no­tice that it has con­vinced ap­prox­i­mately zero per­cent of ac­tual biol­o­gists. You may find “they’re all brain­washed athe­ists so com­pletely un­der Satan’s thumb that they can’t form ra­tio­nal opinions” a more con­vinc­ing ex­pla­na­tion for that than “the ar­gu­ment is ac­tu­ally not very strong”, but I don’t agree.

  (I agree with the biol­o­gists; I think Behe’s ar­gu­ment is bad. But I don’t think ar­gu­ing about that ar­gu­ment is par­tic­u­larly on topic here.)

  Also, no one is claiming that Fran­cis Ba­con is any­one’s moral foun­da­tion. I think you may not have been read­ing what Scott wrote very care­fully.

• gjm 9 May 2020 13:37 UTC

  6 points

  in reply to: Giammi T's comment on: Open & Wel­come Thread—May 2020

  It’s true that lawters aren’t re­quired to take ev­ery client who comes along, but I think gen­er­ally the le­gal pro­fes­sion strongly en­courages them to be will­ing to take unattrac­tive cases. For in­stance, the ABA Model Code of Pro­fes­sional Re­spon­si­bil­ity has var­i­ous things to say, of which I’ve ex­cerpted the bits that seem to me most im­por­tant (on both sides of the ques­tion):

  A lawyer is un­der no obli­ga­tion to act as ad­viser or ad­vo­cate for ev­ery per­son who may wish to be­come his client; but in fur­ther­ance of the ob­jec­tive of the bar to make le­gal ser­vices fully available, a lawyer should not lightly de­cline proffered em­ploy­ment. The fulfill­ment of this ob­jec­tive re­quires ac­cep­tance by a lawyer of his share of ten­dered em­ploy­ment which may be unattrac­tive both to him and the bar gen­er­ally.

  [...]

  When a lawyer is ap­pointed by a court or re­quested by a bar as­so­ci­a­tion to un­der­take rep­re­sen­ta­tion of a per­son un­able to ob­tain coun­sel, whether for fi­nan­cial or other rea­sons, he should not seek to be ex­cused from un­der­tak­ing the rep­re­sen­ta­tion ex­cept for com­pel­ling rea­sons. Com­pel­ling rea­sons do not in­clude such fac­tors as the re­pug­nance of the sub­ject mat­ter of the pro­ceed­ing, the iden­tity or po­si­tion of a per­son in­volved in the case, the be­lief of the lawyer that the defen­dant in a crim­i­nal pro­ceed­ing is guilty, or the be­lief of the lawyer re­gard­ing the mer­its of the civil case.

  So they don’t quite say that lawyers should never re­fuse to rep­re­sent clients just be­cause they think they’re guilty. But they do say that lawyers should be will­ing to take “unattrac­tive” cases, and that if a court as­signs a lawyer to rep­re­sent some­one who can’t af­ford to pay for his own lawyer then that lawyer shouldn’t re­fuse just be­cause they think the client is guilty.

  So my ear­lier state­ment goes too far, but I think it’s more right than wrong: in gen­eral lawyers aren’t sup­posed to re­fuse to defend you just be­cause they think you’re prob­a­bly guilty. Even though they are al­lowed to re­fuse to defend you.

• gjm 9 May 2020 10:55 UTC

  3 points

  in reply to: Giammi T's comment on: Open & Wel­come Thread—May 2020

  What do you mean by “know­ing that both ways are le­git”? Only one way is le­git: when some­one comes to you need­ing defence and will­ing to pay your fees, you defend them.

  (I think the ac­tual sys­tem is a lit­tle differ­ent: a lawyer isn’t ex­pected to defend their client if they’re sure the client is guilty; in that case they would ask them to find an­other lawyer, or some­thing. But that isn’t be­cause those clients don’t de­serve defend­ing, it’s be­cause they de­serve defend­ing bet­ter than some­one who’s sure they’re guilty is likely to man­age.)

• gjm 1 May 2020 15:52 UTC

  6 points

  on: Reopen Protest Sign Survey

  It’s worth not­ing that what some­one puts on a sign doesn’t nec­es­sar­ily in­di­cate what they re­ally care most about, es­pe­cially if what’s on the sign is more so­cially ac­cept­able than what they re­ally care about. So I don’t think the find­ings here are in­con­sis­tent with what an­nacaf­feina says. (They are prob­a­bly, albeit not very strong, ev­i­dence against what she says, though. Only “prob­a­bly” be­cause it could be that the other sign-slo­gans—es­pe­cially the more gener­i­cally-poli­ti­cal ones—are ev­i­dence about the sort of per­son wav­ing the sign; maybe some of those slo­gans are more char­ac­ter­is­tic of wealthier peo­ple who want the ser­vice in­dus­try serv­ing them again than of poorer ser­vice-in­dus­try em­ploy­ees who want to be at work again.)

• gjm 29 Apr 2020 23:41 UTC

  2 points

  on: On “COVID-19 Su­per­spreader Events in 28 Coun­tries: Crit­i­cal Pat­terns and Les­sons”

  Na­ture ar­ti­cle giv­ing some ev­i­dence for aerosol trans­mis­sion. More speci­fi­cally, what it gives ev­i­dence of is that in some cir­cum­stances you can find aerosolized SARS-CoV-2 where there are in­fected peo­ple, which doesn’t seem very sur­pris­ing. It doesn’t say any­thing about how effec­tively that causes in­fec­tion, or about the rel­a­tive im­por­tance of this mode of trans­mis­sion com­pared with oth­ers. It also has some dis­cus­sion of the sizes of aerosol par­ti­cles and how they got that way, and of what cir­cum­stances make it more likely for there to be non-neg­ligible amounts of SARS-CoV-2 in the air.

  The least ob­vi­ous things there, to me: Toi­lets are pretty bad (lots of peo­ple, each there for a while, small space). In hos­pi­tals, one source of SARS-CoV-2 in the air (in smaller aerosol par­ti­cles—do these stay around longer?) may be from PPE af­ter it’s been taken off. In the pub­lic ar­eas they looked at, only the most densely used ones had sub­stan­tial amounts of SARS-CoV-2 in the air. [EDITED to add:] “Least ob­vi­ous” does not mean “very not-ob­vi­ous”; most of these are pretty un­sur­pris­ing. I don’t know that I’d have guessed the thing about dis­carded PPE, though.

• gjm 28 Apr 2020 22:58 UTC

  7 points

  on: A Book Review

  I think you mean oc­ca­sional weirdly out-of-place fuck­ing cuss words.

• gjm 20 Apr 2020 0:51 UTC

  3 points

  in reply to: Jay Molstad's comment on: Far-Ul­travi­o­let Light in Public Spaces to Fight Pan­demic is a Good Idea but Premature

  Oops! The per­ils of hand-tran­scribing URLs.

  I think I may have been un­clear; I wasn’t say­ing “let’s not use blue light for any­thing” or any­thing like that, just giv­ing a bit of con­text. It shouldn’t be so sur­pris­ing that blue light can kill some microor­ganisms, given that it can harm hu­mans too.

• gjm 17 Apr 2020 11:32 UTC

  4 points

  in reply to: Jay Molstad's comment on: Far-Ul­travi­o­let Light in Public Spaces to Fight Pan­demic is a Good Idea but Premature

  It’s not go­ing to kill us. But high-in­ten­sity blue light will, in the long term, dam­age your reti­nas. See e.g. http://​​pho­to­biol­ogy.info/​​Rozanowska.html .

  [EDITED to fix a typo in the URL; sorry about that]

• gjm 16 Apr 2020 14:30 UTC

  4 points

  in reply to: Kirby Sikes's comment on: Far-Ul­travi­o­let Light in Public Spaces to Fight Pan­demic is a Good Idea but Premature

  Short-wave­length blue light is harm­ful to hu­mans too. In par­tic­u­lar, it’s harm­ful to the eyes. I would be highly un­sur­prised if it were slightly car­cino­genic but I don’t know any­thing about that.

• gjm 15 Apr 2020 17:58 UTC

  3 points

  on: The one where Quir­rell is an egg

  I en­joyed read­ing it on r/​HPMOR but I con­fess I think it should have stayed there.

• gjm 14 Apr 2020 14:15 UTC

  2 points

  in reply to: kithpendragon's comment on: Why don’t we tape sur­gi­cal masks to the face to seal them air­tight?

  Right. Though the pa­per by Davies et al that Chris­tian found sug­gests that at least some pa­per masks may not be so wretched at keep­ing out tiny par­ti­cles.

• gjm 14 Apr 2020 14:14 UTC

  2 points

  in reply to: ChristianKl's comment on: Why don’t we tape sur­gi­cal masks to the face to seal them air­tight?

  Davies et al is en­courag­ing as re­gards the benefits of sur­gi­cal masks. Still, let­ting 10% in is a lot worse than let­ting 5% in, and the fact that the Wikipe­dia page about N95 masks says “Col­lec­tion effi­ciency of sur­gi­cal mask filters can range from less than 10% to nearly 90% for differ­ent man­u­fac­tur­ers’ masks when mea­sured us­ing the test pa­ram­e­ters for NIOSH cer­tifi­ca­tion” sug­gests that maybe Davies et al got lucky in which sur­gi­cal masks they tested.

• gjm 14 Apr 2020 9:32 UTC

  13 points

  on: Why don’t we tape sur­gi­cal masks to the face to seal them air­tight?

  I’m not sure you’re right about the ad­van­tages of N95 masks over sur­gi­cal masks. (Note: at pre­sent the ques­tion says ”… the prime ad­van­tage of sur­gi­cal masks over N95 masks …” but I as­sume that’s just a slip.)

  N95 masks have finer filters that keep out par­ti­cles smaller than sur­gi­cal masks’ filters do. If you tape a sur­gi­cal mask to your face in a way that seals it perfectly, then while you may be do­ing a bet­ter job of keep­ing out the par­ti­cles the mask can block you’re still not do­ing much for the smaller ones.

  N95 masks are no­to­ri­ously tricky to fit well, but so far as I know no one tapes those to their faces. What­ever the rea­sons for that, many of those rea­sons prob­a­bly ap­ply to sur­gi­cal masks (but more so, be­cause the benefit will be smaller, be­cause how­ever good the fit the sur­gi­cal masks are still not keep­ing out all the smaller par­ti­cles.) I don’t know those rea­sons, but I guess they in­clude the fol­low­ing, all of which seem like they ap­ply to sur­gi­cal masks:

  • Tap­ing a mask to your face is harder than it may sound. There isn’t that much available sur­face be­tween nose and eyes to tape to.

  • Your face is flex­ible and moves around as you talk, blink, smile, etc. Tape can peel off. Espe­cially if you have fa­cial hair, wrin­kles, dam­age from ear­lier mask-un­peel­ings, etc., rather than a perfect smooth sur­face to tape to.

  • Sur­gi­cal masks are also flex­ible and of­ten have folds ex­tend­ing to their edges, mak­ing it difficult to seal them effec­tively us­ing tape.

  • They also have straps. It seems to me that any way of tap­ing a mask on is go­ing to leave a “tun­nel” along the straps. You can tape the straps down but they’re in­evitably go­ing to move around in ways that tend to en­large that tun­nel.

  • Peel­ing tape off your face is painful and may do dam­age, es­pe­cially if you are do­ing it re­peat­edly and es­pe­cially if the tape is ex­tra-sticky so as not to peel off while you’re wear­ing the mask.

  • The slow and awk­ward peel­ing-off pro­cess keeps the mask, whose outer sur­face might be cov­ered in virus par­ti­cles or what­ever, close to your face for longer while you’re re­mov­ing it.

  None of this means that tap­ing down a sur­gi­cal mask won’t provide any benefit. My guess is that it does. But I sus­pect the benefit is small enough, and the pain and in­con­ve­nience large enough, that most peo­ple won’t con­sider it a good trade­off.

  As to whether that’s right in any given case, I don’t know. It would be in­ter­est­ing to have some ac­tual num­bers on this, but my guess is that no one’s done the stud­ies.

• gjm 13 Apr 2020 1:09 UTC

  5 points

  on: Law school taught me nothing

  Are you now work­ing as a lawyer?

  I think I can still re­mem­ber a lot of what I learned when study­ing math­e­mat­ics at uni­ver­sity. But (to what­ever ex­tent it’s ac­tu­ally true; I haven’t tested my­self) that may be be­cause af­ter study­ing math­e­mat­ics at uni­ver­sity I did a PhD in math­e­mat­ics, and then some math­e­mat­ics re­search, and I now work in the allegedly-real world as a math­e­mat­i­cian (though in prac­tice that work uses very very lit­tle of what I stud­ied at uni­ver­sity). If I’d finished my math­e­mat­ics de­gree and then gone off to be­come a painter or brick­layer or chef or some­thing, I would prob­a­bly now re­mem­ber a lot less of the math­e­mat­ics.

  (The com­par­i­son may be un­fair; my im­pres­sion is that learn­ing law and learn­ing math­e­mat­ics are quite differ­ent, and that one way they’re differ­ent is that learn­ing law in­volves a much larger pro­por­tion of mem­o­riz­ing brute facts that one couldn’t de­duce from other things one knows. Whereas in prin­ci­ple a suffi­ciently hy­per­in­tel­li­gent be­ing wouldn’t need to learn any­thing in math­e­mat­ics other than defi­ni­tions, ter­minol­ogy and no­ta­tion; the ac­tual the­o­rems could all be de­duced from first prin­ci­ples. It seems plau­si­ble to me that the first kind of knowl­edge de­cays faster when not in ac­tive use than the sec­ond.)