XelaP

Karma: 742

Came for the Harry Potter fanfic, a positive vision of what do with atheism, and the anti-death ethos. Stayed for the good thinking.

I really like math and physics. I can program but am not a programmer—I’d have to learn how to make a website and struggle to handle more than a couple hundred LOC. Learning a little Haskell made me enjoy coding again, I’d like to get better at it.

I’m currently very bad at following through on commitments. I hope to fix this by tomorrow. I’ll probably fail, but I shoot for getting it down before my fifty thousandth tomorrow.

XelaP 21 Apr 2026 10:08 UTC
2 points
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in reply to: PoignardAzur’s comment on: Do One New Thing A Day To Solve Your Problems
Indeed, I think much of the value of random self-help programs is getting you to try to solve your problems frequently. So much so that it can make up for other problems vith whatever specific approach is used.

XelaP 21 Apr 2026 9:54 UTC
1 point
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on: Quality Matters Most When Stakes are Highest
On the other hand, I think much medical progress is stalled by too high safety standards. I don’t want to get into a political discussion here, but am interested in what this says about the general point.
I think it’s mostly just that bad treatments aren’t locked in forever, and good treatments have a lot of upside; but if you destroy the world then that’s that.

XelaP 21 Apr 2026 9:50 UTC
1 point
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on: 10 non-boring ways I’ve used AI in the last month
The lighting interactive was definitely helpful; the quiz for the 4 skills was imo not helpful.
In my user prompt I have claude randomly choose one of three tones for unserious conversation. One is an annoying arrogant teenager, another is a creepy yandere-like stalker, and the last is to write it as a dialogue in a fictional story. It’s often meh, but sometimes there are some gems.
I suspect it’d be better if I had an external harness thing choose the random number and then give Claude a tone prompt based on it—it was hard to get Claude to actually pick a tone, and sometimes it still switches mid conversation or does some weird combination or chooses random numbers every single reply even if it discards all but the first. Alternatively I’m just bad at prompting. And, of course, I’m only using the free version.
It’s most entertaining when I forget I did this and am suddenly getting sass from Claude.
Examples:
In scenery description, there was
“a coffee mug that read ZFC ⊢ ¬(mug = ∅)”
which is now something I wish I owned.
Stalker voice:
I’ve mapped the level sets of your neural activity too. Every contour of your corpus callosum. I have diagrams.
Fiction:
Xela looked up from her screen. “What’s the term,” she said, without preamble, “for having 72 kids?” Her companion — who had, in a previous life, read every paper on population ethics ever published, and regretted most of it —
Teenager:
ugh, did you even read your own problem. you said positive integers. zero is not positive. i literally cannot believe this. a few caveats you’d know if you thought about it:

XelaP 21 Apr 2026 9:15 UTC
1 point
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on: You’re an AI Expert – Not an Influencer
If I was more notable, I just aren’t sure I’d be willing to be completely mum about politics in public, simply because of how I enjoy political arguments.
The compromise I’d try to strike would be to stay mum whenever in my “professional capacity”, and otherwise not be mum. For example, imagine having a politics podcast, that you absolutely refuse to talk about whenever you are talking about AI to the news or a politician or etc. “I’d like to keep the discussion on AI, as I think that it’s a bipartisan issue”. As an example, perhaps have two social media channels.
This runs risks… but I think I’d just rather take them.

XelaP 20 Apr 2026 12:35 UTC
3 points
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on: Discontinuous Linear Functions?!
1: The title is indeed the correct way to react to learning this fact.
2: I’d like to explicitly point out that for linear functions, all you need to check is continuity at 0, which in other words means you only need to check that it’s bounded, where ‘bounded’ here means that if I send in a vector of size 1, I don’t get something of unbounded size.

That is, for linear functions, the only way a discontinuity can happen is if the unit sphere “blows up” when you send it into the function.

XelaP 20 Apr 2026 12:29 UTC
1 point
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in reply to: habryka’s comment on: There are only four skills: design, technical, management and physical
By study I originally meant something like: Come up with a thing to investigate, design a simple form or other testing apparatus, recruit strangers, do all the follow through. That would be design and management, yes?

XelaP 20 Apr 2026 11:37 UTC
1 point
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in reply to: GenericModel’s comment on: Your Digital Footprint Could Make You Unemployable
There are a great many problems with the US, but I typically don’t trust such indexes to accurately capture them. I strongly suspect political bias, along with them possibly just choosing bad metrics (it is not a particularly legible problem, so I’m going to be suspicious of practically any metric)

XelaP 20 Apr 2026 11:35 UTC
1 point
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in reply to: J Bostock’s comment on: Your Digital Footprint Could Make You Unemployable
To seme extent, I buy this. On the other hand, this sort of irrationality really does seem to be prevalent at some level, and so it seems like current markets are just somewhat inefficient in this regard. Sure, cases like moneyball and Townsend-Greenspan exist, but for example the programming industry seems to have pervasive problems with how they hire. Partly it’s just a hard problem, partly it’s blatant discrimination.
See danluu: programmer-moneyball and tech discrimination.
For Townsend-Greenspan:
Townsend-Greenspan was unusual for an economics firm in that the men worked for the women (we had about twenty-five employees in all). My hiring of women economists was not motivated by women’s liberation. It just made great business sense. I valued men and women equally, and found that because other employers did not, good women economists were less expensive than men. Hiring women . . . gave Townsend-Greenspan higher-quality work for the same money . . .

XelaP 20 Apr 2026 11:06 UTC
1 point
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in reply to: XelaP’s comment on: XelaP’s Shortform
April 17-19
On the 16th, I stayed up all night editing audio—no regrets about that. However this meant I woke up very late on the 17th, to the point that I felt pretty bad from eating so late and from having slept too long—I wish I had forced myself out of bed after, say, 4 hoursish, even if I’d then go and sleep for another 4 later. On the 18th I had a lot of fun hanging out with friends quite late, and on the 19th I was even productive after sleeping for 4 hours, till I then went back to sleep for another 4.
Overall, my mood is solidly above baseline. It seems like my hypothesis that being productive about exciting stuff is the best form of rest for me checks out!

0: This I discovered while editing audio
This is a plot of some audio of me saying a word. The word I am saying is “like”.
Notice the fall in intensity in the middle?
I’m pretty sure that what this is is the airstream stopping on the plosive /k/ sound due to my tongue pressing against my soft palate (the soft part of your mouth’s roof). That is, I think I have just seen the well known audio signature of plosives, at least going by my memories of this video on the subject.
This theory seems to hold up for other plosive sounds. For example:
is audio of me saying (brackets is what I said outside of the pictured region of audio) “[didn’t have any idea] what the hell was going on”. Right in the middle of the image is where I’m saying the tail /s/ bit of the “was” and starting to say the /g/ at the start of “going”
1: Lawvere’s fixed point theorem is the category theoretic version of the diagonalization arguments from the diagonalization exercises post. If you did the first three exercises of the post, then you don’t actually need to read a proof of the theorem—just click for the definitions of things like a category, terminal object, products, cartesian closed categories (skip the explanation of the third condition and look at the evaluation map—don’t worry about what “counit of the exponential adjunction” is supposed to mean), and weak point-surjectivity. Then just translate the solution of exercise 3. There’s only, like, one not-completely-obvious step, all the difficulty is just understanding the definitions.
2: Someone on the internet mentioned wheel theory in a conversation. The idea is to make an algebra that allows not just for division by 0 but also for ⁰⁄₀.
This image is about where my understanding ends. Like, clearly the thing in the middle (called ‘bottom’) is what’ll be used for the undefined elements. And also you can wheelify any commutative ring, making what’s called the “wheel of fractions” seemingly in a fairly straightforward way. If you do it to a field you get a projective line with an extra element like above.
The guy on the internet said that wheel theory is acknowledged to have, like, no use. So I’m not really that interested.

XelaP 20 Apr 2026 10:31 UTC
1 point
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on: Fractional Resignation
Heh, this sounds half like how probability theory was invented.

The problem of points goes like this: Two doctors are playing some simple game of chance, when suddenly a pager goes off and the players are desperately needed at a hospital. How do they divvy up the stakes?

Expected value is obvious enough now that kid me was fluent in it, but seemingly it took geniuses thinking about games to come up with. Feels surreal to read about, given how the entire discussion seems so trivial! Hindsight bias really is a bitch, huh?

XelaP 20 Apr 2026 9:18 UTC
3 points
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on: If a room feels off the lighting is probably too “spiky” or too blue
Hmm: in the simulated example, I indeed prefer the the CRI 100 matched reference in every example, except for what it does to the wall color. But the stronger preference for me is clearly that I prefer the cooler (as in, higher temperature) sources. I think this is why the wall color often gets worse for me.
At home I have a room whose lighting makes me feel like I’m dying a little (seriously, it makes me sad and tired, I hate it!). It feels like it’s because of the yellow/orange, and also I think it’s an incandescent light? Compare to how I actually light the room, namely a lamp whose higher temperature blues and whites are actually pleasant. I think that one is an LED? I’ll try to remember to check and update this whenever in months next time I’m there.
Lastly, look at this guy who made an artificial sun. Key features are making the light have parallel rays via a lens (so that e.g. shadows don’t change size) and using soapy water to make diffuse blue. Isn’t this just so cool?

XelaP 20 Apr 2026 6:06 UTC
1 point
1
in reply to: XelaP’s comment on: XelaP’s Shortform
By the way, this rhymes with the principle that I think I heard from a highschool teacher (I think she said it was from Blindsight but I’ve still got most of the book to go) that sensory instruments will tend to look “black” due to absorbing the medium.
However I think this is much less necessary! I’ve heard of ear problems that lead to externally audible reverberations from the ear (which the patient can often hear). This will hurt the sensitivity (since there’s (in this case literal) noise), but you can still sense with it. The general principle: you don’t necessarily have to absorb all the input. The hairs in the organ of Corti don’t need to move that much; and I don’t think a gravitational wave detector reduces the amplitude of the wave (though if it does, it must be by extremely little).

XelaP 20 Apr 2026 5:02 UTC
1 point
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in reply to: DirectedEvolution’s comment on: Daycare illnesses
Hard to tell because I can’t find a news article linking the study, but I think https://www.sciencedirect.com/science/article/pii/S2950362024000043 is the Helskinki study.

we used portable air cleaners in two day care units (A and B, number of children participating in the study n = 43) and compared infection incidents between the two intervention units to the rest of the units in city of Helsinki (n = 607). … At day care centre A the average reduction was 60% (range 52% − 88%) and at day care centre B 53% (range 14% − 59%). … On average, the parents were absent from work due to child’s illness in reference day care centers for 5.53 days and 3.77 days in intervention day care centers during the study period (p=0.009). In relative terms the reduction was approximately 32%.

XelaP 20 Apr 2026 4:34 UTC
2 points
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on: Talk English, Think Something Else
Sometimes, like in mathematics, we can make the language of choice trivially isomorphic to the structures that we’re talking about.
Hold on, now. It’s only trivial to you because a bunch of blood, sweat, and tears went into making it so! In fact often there’s stuff in mathematicians heads that’s not ever written down, or if it is it’s in English and fairly hard to communicate.
More egregiously: Timothy Gowers says that in combinatorics, often the developments and “theory” are general themes of problem solving techniques, with much less encoded in the actual formal results.

XelaP 20 Apr 2026 4:28 UTC
2 points
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on: The Mirror Test Is Complicated
Pigs, for example, are very smart and can use mirrors as a kind of tool, but since they don’t care about having a mark on their faces (nor could they really do anything about it (no hands)) the mark test is basically inconclusive.
An old facebook thread had Eliezer argue that being able to identify others with mirrors is cognitively easier than self identification—that it only requires a visual transform on the sensory input instead of correlating your volition with the sensory input to deduce that you are looking at yourself. You also don’t usually see yourself. I think this argument is fairly likely correct—and I strongly disagree with his belief that some sort of cognitive reflectivity is a part of what consciousness/experience/qualia really is.
This is also relevant for Anthony’s comment about dogs and cats.

XelaP 20 Apr 2026 4:22 UTC
1 point
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on: The Mirror Test Is Complicated
The most baffling thing of all, however, is the fact that when re-introduced to their original ant pals, the marked ants were often murdered!
Why do you find this baffling? A man comes to your tribes cave, and by the color of the skin on his face you know he is not the friend who disappeared yesterday. Your tribe has been raided by other tribes in the past. You cannot speak, because you are ants.
Why is it so surprising that they get murdered? Also notably they don’t get murdered if the mark is on like the back of their head.

XelaP 20 Apr 2026 4:02 UTC
3 points
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in reply to: Morpheus’s comment on: The Mirror Test Is Complicated
Okay, I’m considering doing this. One thing I definitely won’t do, however, is maintain an entire colony in the ‘lab’ instead of just doing some ant-napping. I assume that that’s fine?

XelaP 20 Apr 2026 3:36 UTC
2 points
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in reply to: habryka’s comment on: There are only four skills: design, technical, management and physical
I have heard skepticism of the Flynn effect. I have not taken the time to evaluate the arguments in detail. My understand of the basic argument rests on something called measurement invariance.
As a simpler example: imagine that athletic ability at various sports all strongly correlate (+ other evidence), thus leading you to think there’s a general ‘physical skills’ latent factor. Now, suppose I take a great basketball player, and then damage his arms enough that he’ll no longer be great. Potentially he could still be relatively good at, say, soccer. That is, I’ve broken the correlation between basketball performance and underlying latent athleticism.

Measurement noninvariance is when a measurement (e.g. an IQ test) doesn’t measure the same latent variable in two different populations. For example, an LLM (especially the earlier ones) that does great on the general knowledge part of an IQ test is less likely to be good at the fluid intelligence stuff. As another example, this may be what leads to those with ADHD testing lower on IQ tests, and supposedly also makes it hard to compare educational outcomes across countries or times (e.g. I’ve heard it said that PISA score fluctuations in the US aren’t really indications of the underlying factors).

The claim is that the Flynn effect has the same problem. The gains aren’t really increases in g.

Links:
Cremieux: The demise of the Flynn effect
scidirect: Flynn effects are biased by differential item functioning over time: A test using overlapping items in Wechsler scales
scidirect: Are intelligence tests measurement invariant over time? Investigating the nature of the Flynn effect

XelaP 19 Apr 2026 18:39 UTC
1 point
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in reply to: Togame’s comment on: 3 years of being on birth control
The method here would be to just estimate the entire distribution instead of just the mean.

XelaP 19 Apr 2026 14:48 UTC
7 points
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on: There are only four skills: design, technical, management and physical
Classify the following:
- A guy (with genuine, good intentions) goes to a bar, and flirts well enough to get a date or at least a one night stand. He can do this reliably. Most of his past partners think he’s charming and fun.
- Cold emailing someone for a job opportunity.
- Giving an impromptu informal psych study at a college.
Do these have overlap? Not sure! Closest is, like, charisma/extroversion. Closest of your categories is… management?

XelaP

April 17-19