Stepan — LessWrong

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Stepan — LessWrong

Replying toThe Most Common Bad Argument In These Parts

The Most Common Bad Argument In These Parts

I'm going to treat the actual fact-of-the-matter as having been resolved by Scott Alexander here.

I don't think Scott Alexander himself considers the matter resolved, nor did it appear resolved to me or, I expect, most other readers.

Replying to[Intuitive self-models] 1. Preliminaries

Stepan3mo

[Intuitive self-models] 1. Preliminaries

That makes sense, thanks!

Replying to[Intuitive self-models] 1. Preliminaries

Stepan5mo

[Intuitive self-models] 1. Preliminaries

Thank you for that series! Learnt about it from Scott's book review, and decided to read the original.

The first half of this post is the conventional basic knowledge from neuroscience, as I understand it. I was following and nodding along and thinking "yeah this is cool, makes sense" until section 1.4, where the solid before logic started breaking down a bit, or at least it seems so to me.

Before that, when you were talking about predicting, you were talking about predicting sensory input. There is some suspiciously car-shaped sensory input on my retina, then I get engine-and-tires-shaped sensory input in my ears. I would be less surprised to hear "wrrrr" after I... (read 364 more words →)

Replying toX explains Z% of the variance in Y

Stepan7mo*

X explains Z% of the variance in Y

It really is an important, well-written post, and I very much enjoyed it. I especially appreciate the twin studies example. I even think that something like that should maybe go into the wikitags, because of how often the title sentence appears everywhere? I'm relatively new to LessWrong though, so I'm not sure about the posts/wikitags distinction, maybe that's not how it's done here.

I have a pitch for how to make it even better though. I think the part about "when you have lots of data" vs "when you have less data" would be cleaner and more intuitive if it were rewritten as "when $X$ is discrete vs continuous". Now the first example (the "more... (read more)

Replying toX explains Z% of the variance in Y

Stepan7mo*

X explains Z% of the variance in Y

Is it correct to say that the mean is a good estimator whenever the variance is finite?

Well, yes, in the sense that the law of large numbers applies, i.e.

lim n \to \infty Pr {| ¯ x - E [X] | < ε} = 1 \forall ε > 0

The condition for that to hold is actually weaker. If all the $x_{i}$ are not only drawn from the same distribution, but are also independent, the existence of a finite $E [X]$ is necessary and sufficient for the sample mean to converge in probability to $E [X]$ as $n$ goes to infinity, if I understand the theorem correctly (I can't prove that yet though; the proof with a finite variance is easy). If $x_{i}$ aren't independent, the necessary condition is still weaker than the finite variance, but it's cumbersome and impractical, so finite variance is... (read more)

Replying toX explains Z% of the variance in Y

Stepan7mo

X explains Z% of the variance in Y

Consequently, we obtain

Technically, we should also apply Bessel's correction to the denominator, so the right-hand side should be multiplied by a factor of $(1 - \frac{1}{2 N})$ . Which is negligible for any sensible $N$ , so doesn't really matter I guess.

Replying toThe Boat Theft Theory of Consciousness

Stepan8mo*

The Boat Theft Theory of Consciousness

Well, here ya go. Apparently, the mirror-test shrimp are Myrmica ants.

The article is named Are Ants (Hymenoptera, Formicidae) capable of self recognition?, and the abstract could've been "Yes" if the authors were fond of brevity.

(Link: https://www.journalofscience.net/html/MjY4a2FsYWk=, link to a pdf: https://www.journalofscience.net/downnloadrequest/MjY2a2FsYWk=.)

I remember hearing a claim that the mirror test success rate reported in this article is the highest among all animals ever tested, but this needs checking, can easily be false.

This is quite an extraordinary claim published in a terrible journal. I'm not sure how seriously I should take the results, but as far as I know nobody took them seriously enough to reproduce, which is a shame. I might do it one day.

Replying toThoughts on seed oil

Stepan1y*

Thoughts on seed oil

Well, EB article you linked doesn't state directly that fatty acids are made out of carbon atoms linked via hydrogen bonds. It has two sentences relevant to the topic, and I am not entirely sure how to parse them:

Unsaturated fat, a fatty acid in which the hydrocarbon molecules have two carbons that share double or triple bond(s) and are therefore not completely saturated with hydrogen atoms. Due to the decreased saturation with hydrogen bonds, the structures are weaker and are, therefore, typically liquid (oil) at room temperature.

The first sentence is (almost)^[1] correct.

The second sentence, if viewed without the first one, may technically also be correct, but for what I know it's not and... (read more)

Replying toThoughts on seed oil

Stepan2y*

Thoughts on seed oil

Great post, enjoyed it!

A technical mistake here: "Fat is made of fatty acids—chains of carbon atoms linked via hydrogen bonds". They are linked via covalent bonds, not hydrogen bonds.

For those who don't know: covalent bond is a strong chemical bond that forms when two atoms provide one electron each to form an electron pair. These are normal bonds that hold molecules together. They are shown as sticks when one draws a molecule. Hydrogen bond is a much weaker intermolecular bond that forms when one molecule has an atom with an unshared electron pair and the other has a hydrogen atom that sort-of has an orbital to fit this electron pair.

And also having a chain of carbon atoms is about "fatty" part, and the "acid" part means that at the end of this chain there is a carboxyl group. I know that's not the point of this post, it just hurts a little, I'm sorry.