Alex_Altair

Karma: 5,680

Alex_Altair 31 Oct 2025 22:22 UTC
2 points
0
in reply to: Alex_Altair’s comment on: Resampling Conserves Redundancy & Mediation (Approximately) Under the Jensen-Shannon Divergence
(I have no idea what y’all are using KL-divergence for, so I have no opinion about whether you should have been using it in this theorem.)

Alex_Altair 31 Oct 2025 22:21 UTC
9 points
7
on: Resampling Conserves Redundancy & Mediation (Approximately) Under the Jensen-Shannon Divergence
a metric, a feature sorely lacking from $D_{K L}$
I have a pet peeve around this, which is hopefully a useful comment for someone to read; KL-divergence should not be symmetric, because of the whole thing that it is. If you’re using KL-divergence and thinking to yourself “I wish this was symmetric”, then that should be a red flag that you’re using the wrong tool!
I think it’s easy for people to think, “hm, I’d like a way to quantify the how different two probability distributions are from each other” and then they grab the nearest hammer, which happens to be KL-divergence. But mathematical definitions are not for things, instead they mean things.
You should use KL-divergence when you want to measure the cost of modelling a true distribution using a false distribution. The asymmetry comes from the fact that one of them is the true one (and therefore the one that you take the expected value with respect to).

Alex_Altair 19 Oct 2025 19:19 UTC
4 points
0
on: I wasn’t confused by Thermodynamics
I enjoyed reading this post quite a bit, but the exact reason why eludes me. I think I’ve had or almost had a lot of these thoughts before, and this post clarified them for me.
I have a tendency to be constantly asking something like “but what is the real thing going on?”. This is obviously very useful overall, but as in the post, it is sometimes also to useful to say “within this context, let’s only reason as if this is all that’s going on” and then try to improve my understanding of something that way. I think this would have significantly improved my experience of learning thermo and stat mech.
For anyone who’s interested in going deeper on a formalism of thermo with no stat mech, I once found this niche book that seems to do exactly that: A First Course in the Mathematical Foundations of Thermodynamics. (It’s published by Springer so it’s probably legit, but I didn’t actually get that far into it, so this isn’t a recommendation per se.)

Alex_Altair 11 Oct 2025 20:41 UTC
2 points
0
on: Subscribe to my Inkhaven feed!
Oops, I said two things.

Alex_Altair 11 Oct 2025 18:11 UTC
2 points
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in reply to: RobertM’s comment on: RobertM’s Shortform
Er, bug report, the right-click menu is where my spell-check’s suggestions were. So now I get a red underline telling me a word is not in the dictionary, but to correct it I have to just, try to type the correct spelling. Or google it I guess.

Alex_Altair 10 Oct 2025 20:33 UTC
5 points
0
on: Stars are a rounding error
Turing completeness, let alone error correction, has not been shown for leptonic matter on its own.
Curious if you have a citation for this!

Alex_Altair 3 Oct 2025 21:17 UTC
33 points
10
on: Alex_Altair’s Shortform
There are, as far as I can tell, no book-length biographies of Kolmogorov’s life. The world is worse for it! His life was long, and his accomplishments innumerable and broad-reaching. An aspiring biographer could establish a career with such a book.
(There are a few different compilations of essays about Kolmogorov, but they’re by fellow academics, and largely focus on his work rather than him.)

Alex_Altair 1 Oct 2025 23:17 UTC
7 points
5
on: Halfhaven virtual blogger camp
“Inkhaven” is already modifying the name of the campus “Lighthaven” (which is already a modification of “Lightcone”). Since you’re still doing the “ink” part by writing, but not doing the haven part (by not being at Lighthaven) I’d recommend a different name.
May I suggest “Inkhalven”/”Inkhalfen”? Maybe the verb “Inkhalfing”?

Alex_Altair 20 Sep 2025 16:42 UTC
5 points
1
in reply to: Alex_Altair’s comment on: Alex_Altair’s Shortform
Now that I think about it, it could be useful to have a timed sequence of posts that are just for discussing the book chapters, sort of like a read-along.

Alex_Altair 20 Sep 2025 16:39 UTC
8 points
13
on: Alex_Altair’s Shortform
Is there any plan to post the IABIED online resources as a LW sequence? My impression is that some of the explanations are improved from the authors’ previous writings, and it could be useful to get community discussion on more of the details.

Alex_Altair 14 Sep 2025 19:42 UTC
3 points
0
on: LASR Labs: Applications Open
FYI on your website it says “Applications are now closed” and links to an expression of interest form, but I assume that just hasn’t been updated with the new application link yet?

Alex_Altair 8 Sep 2025 21:16 UTC
2 points
0
in reply to: Ben Pace’s comment on: henryaj’s Shortform
It’s not national, so I might just go with BloWriMo.

Alex_Altair 30 Aug 2025 23:14 UTC
15 points
7
in reply to: PhilGoetz’s comment on: Should you make stone tools?
FWIW I currently think it’s bad practice to paste LLM output in a forum. It’s like pasting the google search results for something. Anyone can ask an LLM, and the reason I’m here reading comments on a forum is to talk to humans, who have separate identities, reputations, and tons of cultural context of the forum.

Alex_Altair 30 Aug 2025 23:11 UTC
3 points
0
in reply to: Thomas Kwa’s comment on: Should you make stone tools?
Oooh yeah dude I think you want to un-buy the obsidian. That is almost literally glass. You want chert!

Alex_Altair 29 Aug 2025 7:02 UTC
4 points
0
in reply to: DanielFilan’s comment on: Somebody invented a better bookmark
I don’t think I’ve ever had one fall off in a bag! The only time I can recall them falling off/catching is if I start flipping through the book and the page facing the “back” of the dart slips into the tiny fold and pops it off.

Alex_Altair 29 Aug 2025 6:17 UTC
4 points
5
on: Von Neumann’s Fallacy and You
There are several stories of him being able to read a book once and then repeat it back, word for word, until he was told to stop.
This is an aside, but I roll to disbelieve this

Alex_Altair 22 Aug 2025 13:26 UTC
2 points
0
in reply to: Cleo Nardo’s comment on: Alex_Altair’s Shortform
Ooh, I love this.

Alex_Altair 21 Aug 2025 23:38 UTC
13 points
1
in reply to: sunwillrise’s comment on: Agent foundations: not really math, not really science
By contrast, if “it’s hard to even think of how experiments would be relevant to what I’m doing,” you have precisely zero means of ever determining that your theories are inappropriate for the question at hand.
Here, you’ve gotten too hyperbolic about what I said. When I say “experiments”, I don’t mean “any contact with reality”. And when I said “what I’m doing”, I didn’t mean “anything I will ever do”. Some people I talk to seem to think it’s weird that I never run PyTorch, and that’s the kind of thing where I can’t think of how it would be relevant to what I’m currently doing.
When trying to formulate conjectures, I am constantly fretting about whether various assumptions match reality well enough. And when I do have a theory that is at the point where it’s making strong claims, I will start to work out concrete ways to apply it.
But I don’t even have one yet, so there’s not really anything to check. I’m not sure how long people are expecting this to take, and this difference in expectation might be one of the implicit things driving the confusion. As many theorems there are that end up in the dustbin, there is even more pre-theorem work that end up in the dustbin. I’ve been at this for three and change years, and I would not be surprised if it takes a few more years. But the entire point is to apply it, so I can certainly imagine conditions under which we end up finding out whether the theory applies to reality.

Alex_Altair 21 Aug 2025 22:36 UTC
3 points
0
in reply to: Jon Garcia’s comment on: Agent foundations: not really math, not really science
I am not personally working on “equipping AI with the means of detecting and predictively modeling agency in other systems”, but I have heard other people talk about that cluster of ideas. I think it’s in-scope for agent foundations.

Alex_Altair 21 Aug 2025 22:33 UTC
2 points
−5
in reply to: gjm’s comment on: Agent foundations: not really math, not really science
I’m not very confident about this, but it’s my current impression. Happy to have had it flagged!