Good old puzzles

While I’m on the subject of bad puzzles from 1995, I want to briefly share one of my favorite good puzzles from the time. Around 1995, I received a book titled 100 Perceptual Puzzles by Pierre Berloquin. It’s apparently a newer edition of an older book titled 100 Geometric Games, copyright 1976.

The book contains a wide variety of puzzles, mostly of the sort that rely on pictures, or require you to draw pictures. Many people are familiar with the puzzle where you have a 3×3 grid of dots, and you’re asked to draw four straight lines through all the points without lifting your pencil. That puzzle is not in this book, and instead it includes multiple harder versions!

Other puzzles include: mazes, spot the difference, match moving puzzles, shape counting puzzles, and knot puzzles. The knot puzzles! I will share one knot puzzle.

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Risk neutrality in EA

Effective Altruism (EA) is a community focused on donating money to create the greatest good in the world. This is mostly (?) unobjectionable–but there’s problems. The EA community has a number of philosophical viewpoints that most external observers would consider absurd, and which materially affect their donating behavior.

In particular, many people in EA believe that the most efficient way to create the greatest good is by preventing extinction caused by AI. EA surveys suggest that about 18% of community members donate to “Long term & AI” causes, compared to 62% that donate for global health & development. Clearly concern about AI is not a unanimous viewpoint in EA, but you have to imagine the kind of community where everyone takes it seriously.

EA has been under the spotlight in current news because Sam Bankman-Fried–recently arrested for massive fraud at his cryptocurrency exchange FTX–was a vocal proponent of EA. More than a vocal proponent, he founded the FTX Future Fund, which committed $160M in charitable grants to various EA causes. At the top of Future Fund’s cause list? AI.

Although I’m critical of EA, I actually think it’s a bit unfair to pretend that they’re directly responsible for SBF’s fraudulent behavior. Instead I wanted to focus on some of SBF’s philosophical views, which are shared by at least some parts of the EA community. Specifically, let’s talk about the idea that charitable causes are risk-neutral.

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Musical maturity and bad statistics

Among music-likers, it’s often said that your musical tastes are defined by what we enjoyed at age 14, or that our favorite music came out when we were 14. This claim comes from a 2018 article in the New York Times titled “The Songs That Bind” (paywalled). This article contains dubious statistical analysis, and its claims are probably false.

The article uses Spotify data, “on how frequently every song is listened to by men and women of each particular age.” There are two distinct ways of analyzing this data:

  1. The person level – Look at each individual, and see which songs they listen to most.
  2. The song level – Look at each song, and see which individuals listen to them the most.

So let’s read the article carefully and determine which analysis was used.
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Regulating data science with explanations

Data science has an increasing impact on our lives, and not always for the better. People speak of “Big Data”, and demand regulation, but they don’t really understand what that would look like. I work in one of the few areas where data science is regulated, so I want to discuss one particular regulation and its consequences.

So, it’s finally time for me to publicly admit… I work in the finance sector.

These regulations apply to many different financial trades, but for illustrative purposes, I’m going to talk about loans. The problem with taking out a loan is that you need to pay it back plus interest. The interest is needed to give lenders a return on their investment, and to offset the losses from other borrowers who don’t pay it off. Lenders can increase profit margins and/or lower interest rates if they can predict who won’t pay off their debt, and decline those people. Data science is used to help make those decline decisions.

The US imposes two major restrictions on the data science. First, there’s anti-discrimination laws (a subject I might discuss at a later time) (ETA: it’s here). Second, an explanation must be provided to people who are declined.

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Xenharmonic music theory part 3: Tuning theory

This is the final part of a series introducing xenharmonic music theory. In the first part, I talked about musical perception, especially the perception of microtones. In the second part, I explained roughness theory, which is an empirical theory of dissonance independent of musical tradition. The first two parts overlap with conventional music theory, but in this third part, I finally reach the music theory that is more particular to the xenharmonic tradition.

I’m just going to scratch the surface here, with an eye towards how you would actually use it in practice, if you were a composer. Most readers, I imagine, are not composers. It’s okay if it’s just a hypothetical for you, as long as you learn something.

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Xenharmonic music theory part 2: Dissonance Theory

See part 1

Dissonance in music is analogous to conflict in a story. Dissonance sounds “unpleasant” in the same way that conflict is unpleasant to the characters within the story, but then it would be an odd to have a story without any conflict. The opposite of dissonance is called consonance. Music commonly alternates between dissonance and consonance–creating tension, and then resolving it.

Conventional musical theory comes with a bunch of ideas about what’s consonant or dissonant. 400 cents, the major third, is considered consonant; 300 cents, the minor third, is considered dissonant. There’s some physical basis for these ideas, but arguably a lot of it has to do with tradition. 300 cents is more dissonant than 400 cents because that’s the meaning we’ve absorbed from our musical culture.

When you go outside the usual tuning system, musical tradition offers less guidance on what’s more or less dissonant. So this is the part of my intro to xenharmonic theory where I discuss a theory of dissonance that is independent of musical tradition.

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Xenharmonic music theory part 1: Perception of microtones

Microtonal music is music that goes outside of the standard western 12-tone tuning system. There are many microtonal traditions throughout history and the world, but xenharmonic music refers to a specific modern musical tradition that makes a point of being microtonal.  If you’d like to listen to examples, I have a list of popular xenharmonic artists. Xenharmonic music is associated with music theories that might be considered heterodox. Heterodoxy is good though because conventional music theory is too narrowly focused on a certain European classical music tradition, and we could use an alternate perspective.

This is part of a short series introducing xenharmonic theory. Part 1 is about the perception of sound, with a particular focus on small differences in pitch. Part 2 is about dissonance theory. Part 3 is about tuning theory. The first two parts overlap with conventional music theory, but focus on aspects that are independent of tuning. Part 3 is where we get into theory that’s more specific to the xenharmonic tradition.

I freely admit that I don’t know everything, I just know enough to point in some interesting directions. The idea here is not to write an authoritative intro to xenharmonic music theory (which might be better found in the Xenharmonic Wiki), but to write an accessible intro with a bit of a slant towards what I personally think is most important.

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