All of garethrees's Comments + Replies

Deaths per cyclist per kilometre of road is a crazy unit of measurement. I mean, sometimes you have to report the statistic you've got rather than the statistic you'd like, but I don't see what possible practical significance this has.

The statistic we'd like to know is deaths per kilometre cycled. The average person in the UK cycles about 60 km a year (source: Department for Transport) and the population of London is about 8.5 million (source: Wikipedia), so the 19 deaths in 2006 correspond to about 3.5 deaths per 100 million kilometres cycled.

This is slig... (read more)

In Japanese, these aren't noun suffixes but number suffixes, known as counters or classifiers. You don't say, "*ninjin ga san" [three carrots], but rather, "ninjin ga sanbon" [three-cylinder-shaped carrots].

Mass nouns behave in a similar way in English: you don't say "*three breads", but rather, "three loaves of bread". Also, "head of cattle", "slices of toast", "sheets of paper", "items of cutlery", etc.

In Navajo, the classifiers are verb stems.

This proposal seems like it would run aground on the actual complexity and changeability of river systems. The River Great Ouse, to take an example that's local to me, runs in four channels between Earith and its outflow at Kings Lynn (the Old and New Bedford Rivers, the Great Ouse proper, and an unnamed flood relief channel). But this is a relatively recent configuration: the Great Ouse formerly turned west at Littleport (rather than north as at present), reaching a confluence with the River Nene before flowing into the Wash at Wisbech, while the Little Ouse flowed north to Kings Lynn.

Gung cnegvphyne nzovtenz, fher. (Vg'f nyfb qvsvphyg gb svaq zhygvcyr zrffntrf jvgu gur fnzr unfu.) Ohg Qreera Oebja hfrq guvf nzovtenz va uvf 2007 frevrf "Gevpx be Gerng" jvgu ng yrnfg gur nccrnenapr bs fhpprff (gubhtu nf nyjnlf jvgu Oebja, vg'f cbffvoyr ur jnf sbbyvat hf engure guna gur cnegvpvcnag).

Creuncf gur fyvc bs cncre ybbxrq fbzrguvat yvxr guvf. (Qrfvtavat na nzovtenz jbhyq or nanybtbhf gb svaqvat zhygvcyr zrffntrf jvgu gur fnzr unfu.)

I once attended an apologetical talk given by the Christian Union at my college. (They were offering free food.) The invited speaker presented a version of C. S. Lewis's trilemma: liar, lunatic or lord? (a kind of proof by alliteration).

I spoke to the speaker afterwards and took him to task for presenting such a silly argument, which I said was hardly likely to convince anyone not already a Christian. He freely admitted the logical flaws in the trilemma argument, and said that his own personal justifications for belief were quite different—he appealed, if ... (read more)

I have never been able to get the Socratic Method to work on the Internet. In theory the Socratic Method is effective because the student has to reason their own way to the conclusion, and so they end up knowing it more deeply and thoroughly than if they were just told the conclusion by the teacher. But somehow it never works for me.

I think part of the problem is that the Socratic Method relies on the participants agreeing to take on the appropriate roles in the discussion. In particular, the "student" has to agree to play the role of the student... (read more)

I think gwern is teasing us: there is no such quotation in Sluga's Heidegger's Crisis, or at least I cannot find it in the Google Books version. Perhaps gwern has taken the Wittgenstein/Malcolm story and swapped Britain for Germany to make a point about the universal applicability of the philosopher's rebuke.

But for what it's worth:

• The date in the Heidegger version of the story is very suspicious: in 1939 Churchill was First Lord of the Admiralty; he did not become Prime Minister until May 1940 and it is only with hindsight that we see his significance (

"Biggest fan" here is hyperbole for "a very big fan".

You say that my explanations "aren't valid" because I "have to assume" various facts. Why do I have to make these assumptions? Your argument is that these tricks must be fair puzzles. But Derren is not in the business of making fair puzzles, he is in the business of entertaining television audiences. He is under no obligation to play fair, and he is quite willing to use your belief that he plays fair in order to fool you.

My explanations for tricks two and three don't just explain the effect, but also a number of details of the presentat... (read more)

For the record, I thought of "spade" and then "orange" (perhaps because of an association of spades with the merchant B&Q, whose logo and branded materials are orange, though of course this is post-hoc rationalization on my part).

The reason why I think concentrating on "suggestion" is often an indication that you've missed something, is that suggestion is not reliable enough for magicians to use it as the sole mechanism for an effect, especially in settings like live television where the stakes are high. Magicians prefer t... (read more)

It's an example of Derren Brown's brilliant use of misdirection. Here you're misdirected as to the whole nature of the trick, and if you start your analysis by asking yourself, "how does he manage to read the woman's mind?" then you've already swallowed the false assumption. You have to take a step back and start from the question, "how does he manage to convince me, the viewer, that he read the woman's mind?"

I'll ROT-13 my own answers to the questions, but I strongly recommend that you do your best to figure out your own answers to them before decrypting mine. Trying to figure out plausible mechanisms for magic tricks is a way of calibrating your rational thinking skills, in the presence of an adversary (the magician) who is trying to use all your perceptual biases and cognitive shortcuts against you. If you find yourself seriously considering hypotheses like micromuscle reading or subliminal suggestion, then that's probably because the magician has managed to... (read more)

I think it's worth taking a step back from the details of any one of Derren Brown's effects, and looking at the nature of stage magic. A stage magician employs a set of techniques called misdirection to mislead the audience as to how a trick is performed, to direct their attention to irrelevant aspects of the performance, or to encourage them to misinterpret relevant aspects.

An important technique in misdirection is to provide the audience with a false explanation for how the trick is done. A magician who says that a trick is done by magic encourages you w... (read more)

This is an excellent question. grouchymusicologist above has it right that "music enjoyment is a remarkably multifaceted phenomenon", and I would like to expand on this.

Michael J. Parsons, in How we understand art: a cognitive developmental account of aesthetic experience, identifies a sequence of developmental stages in the appreciation of visual art. This is of necessity a very rough and un-nuanced summary since I don't have the book to hand, but I think this sequence is: first, colour ("this painting is red"); second, subject matter ... (read more)

The paper

• David Archer & Andrey Ganopolski (2005), "A movable trigger: Fossil fuel CO2 and the onset of the next glaciation", Geochemistry Geophysics Geosystems 6:5.

provides evidence that periods of glaciation begin when northern hemisphere insolation (which varies due to changes in the precession, obliquity and eccentricity of Earth's orbit) falls below a "trigger" level that depends on the amount of CO2 in the atmosphere. Archer & Ganopolski suggest that we're currently approaching a solar minimum, but we've already release... (read more)

If I can't get this study published in the traditional way, I'll "publish" it myself on the internet.

There's always the Journal of Articles in Support of the Null Hypothesis.

Blues understand Green arguments but aren't persuaded by them (presumably because they have counterarguments), whereas Greens don't understand Blue arguments and this makes it unlikely they have counterarguments.

This is a restatement of the hypothesis under discussion. (That inability to imitate convincingly is caused by lack of understanding.)

your third objection amounts to "sometimes the people defending the incorrect position are homogeneous, this gives them a large advantage in the test".

You've failed to imitate my position. My third o... (read more)

I find it very plausible that Christians are better able to pretend to be atheists than vice versa. But what follows from that?

Caplan claimed in his original piece:

the ability to pass ideological Turing tests—to state opposing views as clearly and persuasively as their proponents—is a genuine symptom of objectivity and wisdom.

Caplan gives little in the way of argument in support of this claim, and I'm not at all sure that it's true. "Genuine symptom of objectivity and wisdom", really? My objections follow.

First, there's only one way to be rig... (read more)

"Post-utopian" is a real term, and even in the absence of examples of its use, it is straightforward to deduce its (likely) meaning, since "post-" means "subsequent to, in reaction to" and "utopian" means "believing in or aiming at the perfecting of polity or social conditions". So post-utopian texts are those which react against utopianism, express skepticism at the perfectibility of society, and so on. This doesn't seem like a particularly difficult idea and it is not difficult to identify particular text... (read more)

Front page: missing author

The front page for Facing the Singularity needs at the very least to name the author. When you write, "my attempt to answer these questions", a reader may well ask, "who are you? and why should I pay attention to your answer?" There ought to be a brief summary here: we shouldn't have to scroll down to the bottom and click on "About" to discover who you are.

The tables of contents for Science magazine are online. Looking through these might jog your memory. But there are quite a lot of issues.

Recently in another topic I mentioned the "two bishops against two knights" chess endgame problem. I claimed it was investigated over two decades ago by a computer program and established that it is a win situation for the two bishops' side. Then I was unable to Google a solid reference for my claim.

I believe that subject to the ambiguity in what is meant by "a win situation for the two bishops", your recollection is correct.

The 6-piece pawnless endgames were were first analyzed systematically by Lewis Stiller starting in the late 19... (read more)

Spelling Latin with u has always been there (but as a tiny minority of texts). Here are some occurrences of omnia uincit amor over the years: 1603, 1743, 1894, 1974.

If you compare the frequencies of vincit and uincit on Google Ngram viewer, you'll see that the u spelling has always been present at a low frequency. There doesn't seem to be any noticeable recent trend (other than the general decline of Latin as a proportion of printed material). I tried a few other Latin words and got similar results.

The earliest reference I can track down is from 1952. In Roger Sessions: a biography (2008), Andrea Olmstead writes:

[In 1952] Sessions published "Some notes on Schoenberg and the 'method of composing with twelve tones'." At the head of the article he quoted from one of Schoenberg's letters to him: "A Chinese philosopher speaks, of course, Chinese; the question is, what does he say?" Sessions [had performed] the role of a Chinese philosopher in Cleveland.

(The work that Sessions had performed this role in appears to have been Man who ... (read more)

It's hardly fair to call EY Egan's 'biggest fan'

I based this description on Yudkowsky's comments here, where he says of Permutation City, "This is simply the best science-fiction book ever written [...] It is, in short, my all-time favorite."

I don't see how those novels could have been an inspiration?

Yudkowsky describes Egan's work as an important influence in Creating Friendly AI, where he comments that a quote from Diaspora "affected my entire train of thought about the Singularity".

The Wikipedia page explains how a frequentist can get the answer ⅓, but it doesn't explain how a Bayesian can get that answer. That's what's missing.

I'm still hoping for a reference for "the Bayesian rules of forgetting". If these rules exist, then we can check to see if they give the answer ⅓ in the Sleeping Beauty case. That would go a long way to convincing a naive Bayesian.

I think this kind of proposal isn't going to work unless people understand why they disagree.

You're not obliged to give a lecture. A reference would be ideal.

Appealing to "forgetting" only gives an argument that our reasoning methods are incomplete: it doesn't argue against ½ or in favour of ⅓. We need to see the rules and the calculation to decide if it settles the matter.

If I understand rightly, you're happy with my values for p(H), p(D) and p(D|H), but you're not happy with the result. So you're claiming that a Bayesian reasoner has to abandon Bayes' Law in order to get the right answer to this problem. (Which is what I pointed out above.)

Is your argument the same as the one made by Bradley Monton? In his paper Sleeping Beauty and the forgetful Bayesian, Monton argues convincingly that a Bayesian reasoner needs to update upon forgetting, but he doesn't give a rule explaining how to do it.

Naively, I can imagine doing this ... (read more)

D is the observation that Sleeping Beauty makes in the problem, something like "I'm awake, it's during the experiment, I don't know what day it is, and I can't remember being awoken before". p(D) is the prior probability of making this observation during the experiment. p(D|H) is the likelihood of making this observation if the coin lands heads.

As I said, if your intuition tells you that p(H|D) = ⅓, then something else has to change to make the calculation work. Either you abandon or modify Bayes' Law (in this case, at least) or you need to disagree with me on one or more of p(D), p(D|H), and p(H).

Bayes' Law says, p(H|D) = p(D|H) p(H) / p(D) where H is the hypothesis of interest and D is the observed data. In the Sleeping Beauty problem H is "the coin lands heads" and D is "Sleeping Beauty is awake". p(H) = ½, and p(D|H) = p(D) = 1. So if your intuition tells you that p(H|D) = ⅓, then you have to either abandon Bayes' Law, or else change one or more of the values of p(D|H), p(H) and p(D) in order to make it come out.

(We can come back to the intuition about bets once we've dealt with this point.)

That's interesting. But then you have to either abandon Bayes' Law, or else adopt very bizarre interpretations of p(D|H), p(H) and p(D) in order to make it come out. Both of these seem like very heavy prices to pay. I'd rather admit that my intuition was wrong.

Is the motivating intuition beyond your comment, the idea that your subjective probability should be the same as the odds you'd take in a (fair) bet?

I did check both threads, and as far as I could see, nobody was making exactly this point. I'm sorry that I missed the comment in question: the threads were very long. If you can point me at it, and the rebuttal, then I can try to address it (or admit I'm wrong).

(Even if I'm wrong about why the problem is hard, I think the rest of my comment stands: it's a problem that's been selected for discussion because it's hard, so it might be productive to try to understand why it's hard. Just as it helps to understand our biases, it helps to understand our errors.)

The Sleeping Beauty problem and the other "paradoxes" of probability are problems that have been selected (in the evolutionary sense) because they contain psychological features that cause people's reasoning to go wrong. People come up with puzzles and problems all the time, but the ones that gain prominence and endure are the ones that are discussed over and over again without resolution: Sleeping Beauty, Newcomb's Box, the two-envelope problem.

So I think there's something valuable to be learned from the fact that these problems are hard. Here a... (read more)

I think it's both. "Brave New World" portrays a dystopia (Huxley called it a "negative utopia") but it's also post-utopian because it displays skepticism towards utopian ideals (Huxley wrote it in reaction to H. G. Wells' "Men Like Gods").

I don't claim any expertise on this subject: in fact, I hadn't heard of post-utopianism at all until I read the word in this article. It just seemed to me to be overstating the case to claim that a term like this is meaningless. Vague, certainly. Not very profound, yes. But meaningless, no.

Th... (read more)

Stanislaw Lem, "The Twenty-First Voyage of Ijon Tichy", collected in "The Star Diaries".

You write, “suppose your postmodern English professor teaches you that the famous writer Wulky Wilkinsen is actually a ‘post-utopian’. What does this mean you should expect from his books? Nothing.”

I’m sympathetic to your general argument in this article, but this particular jibe is overstating your case.

There may be nothing particularly profound in the idea of ‘post-utopianism’, but it’s not meaningless. Let me see if I can persuade you.

Utopianism is the belief that an ideal society (or at least one that's much better than ours) can be constructed, for ex... (read more)