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Transfers from Infrequent to Frequent Vehicles

Imagine yourself taking a train somewhere, and imagine the train is big and infrequent. Let’s say it’s the commuter train from New York down the Northeast Corridor to Newark Airport, or perhaps a low-cost OuiGo TGV from Lyon to Paris. Now imagine that you change trains to a small, frequent train, like the AirTrain to […]

via Pedestrian Observations January 20, 2020

Veganism and restrictive eating

I’m reading the book Intuitive Eating, which I highly recommend. I was looking for something like it that could get me back to trusting my biological hunger without worrying that I need to control myself or my weight. It’s raised my consciousness to the ways I had a “diet mentality” even though I’ve only rarely restricted […]

via Holly Elmore January 17, 2020

Cops on Public Transportation

I wrote a post about American moral panics about fare evasion two months ago, which was mirrored on Streetsblog. I made a mistake in that post that I’d like to correct – and yet the correction itself showcases something interesting about why there are armed police on trains. In talking about BART’s unique belts-and-suspenders system […]

via Pedestrian Observations January 17, 2020

The Different Travel Markets for Regional Rail

At a meeting with other TransitMatters people, I had to explain various distinctions in what is called in American parlance regional rail or commuter rail. A few months ago I wrote about the distinction between S-Bahn and RegionalBahn, but made it clear that this distinction was about two different things: S-Bahns are shorter-distance and more […]

via Pedestrian Observations January 14, 2020

Why Do Public Transportation Commuters Outearn Car Commuters in Some American Cities?

More than a year ago, I compared Los Angeles with a number of other large American cities. I brought up issues of public transportation ridership, city center job concentration, and income differences, as in the Los Angeles region people who commute by public transit average barely half the earnings of people who drive alone. One […]

via Pedestrian Observations January 6, 2020

A foolish consistency

“The other terror that scares us from self-trust is our consistency; a reverence for our past act or word, because the eyes of others have no other data for computing our orbit than our past acts, and we are loath to disappoint them. But why should you keep your head over your shoulder? Why drag […]

via Holly Elmore January 5, 2020

Algorithms interviews: theory vs. practice

When I ask people at trendy big tech companies why algorithms quizzes are mandatory, the most common answer I get is something like "we have so much scale, we can't afford to have someone accidentally write an O(n^2) algorithm and bring the site down"1. One thing I find funny about this is, even though a decent fraction of the value I've provided for companies has been solving phone-screen level algorithms problems on the job, I can't pass algorithms interviews! When I say …

via Posts on Dan Luu January 5, 2020

Queens Bus Redesign

New York City Transit has just released its draft redesign for the Queens bus network. It’s a further-reaching reform than what was planned for the Bronx. I’m still seriously skeptical about a number of aspects, but this redesign is genuinely a step forward. The required changes are for the most part tweaks, with just one […]

via Pedestrian Observations December 31, 2019

The unreasonable effectiveness of one-on-ones

When I started dating my partner, I quickly noticed that grad school was making her very sad. This was shortly after I’d started leading an engineering team at Wave, and so the “obvious” hypothesis to me was that the management (okay, “management”) one gets in graduate school is totally …

via benkuhn.net December 28, 2019

Maybe it’s not me– it’s grad school

Just a low effort post. I would love a mutually supportive comment discussion about it (because I’m not on facebook). Twitter replies would be nice, too.  I appreciated this post from Ben Kuhn, Grad school is worse for public health than STDs. In it he calculates that the disability-adjusted life years (DALYs) caused by grad school […]

via Holly Elmore December 11, 2019

No need to explain

I haven’t been posting much lately for several reasons, but mainly I just haven’t felt the desire to post. My posts usually come from trying to figure something out through reflection, or to explain myself to myself. I haven’t felt the need to explain myself much recently. This has also been a time of high […]

via Holly Elmore December 8, 2019

Grad school is worse for public health than STDs

(The way you can *really* tell something is horribly wrong is that grad students find PhD Comics darkly funny, not just dark.)

via benkuhn.net December 8, 2019

Your room can be as bright as the outdoors

The effect was huge: I became dramatically more productive between 3:30pm and whenever I turned off the light. I estimate the lamp bought me between half an hour and two hours a day, depending on how overcast it was.

via benkuhn.net November 26, 2019

git-subtrac: all your git submodules in one place

Long ago, I wrote git-subtree to work around some of my annoyances with git submodules. I've learned a lot since then, and the development ecosystem has improved a lot (shell scripts are no longer the best way to manipulate git repos? Whoa!). Thus, I bring you: git-subtrac. It's a bit like git-subtree, except it uses real git submodules. The difference from plain submodules is that, like git-subtree, it encourages you to put all the contents from all your submodules into your superproject r…

via apenwarr November 24, 2019

Pieces of time

My friend used to have two ‘days’ each day, with a nap between—in the afternoon, he would get up and plan his day with optimism, whatever happened a few hours before washed away. Another friend recently suggested to me thinking … Continue reading →

via Meteuphoric November 11, 2019

Ethical experimentation

I suggested experimenting with different settings on personal characteristics that aren’t obviously good or bad. For instance, trying out being more or less perfectionistic for a day. A particular variety of this that interests me is experimentation with different ethical … Continue reading →

via Meteuphoric November 10, 2019

For the metaphors

I make use of a lot of analogies, for instance ‘like dancing’ and ‘the ice skating thing’ are particular phenomena I often think about, and I get value from thinking about meta-ethics as if it were romance, or saving the … Continue reading →

via Meteuphoric November 8, 2019

Self policing for self doubt

Sometimes it seems consequentially correct to do things that would also be good for you, if you were selfish. For instance, to save your money instead of giving it away this year, or to get yourself a really nice house … Continue reading →

via Meteuphoric November 7, 2019

Wild animal welfare in Hans Christian Andersen

Continuing the theme of wild animal suffering in children’s lit… Hans Christian Andersen’s stories involve a lot of suffering of both human and animal varieties. “The Ugly Duckling” takes a brief detour from describing the duckling’s repeated social humiliations to describe being a waterfowl in winter: The winter grew cold – so bitterly cold that […]

via The whole sky November 7, 2019

My fantasy grunge band has the best name

Ever since I first heard that Wonderland was the outbound end of the Blue Line (of the Boston T), I thought “Blue Line to Wonderland” was the perfect blend of whimsy, mundanity, locality, and a perverse children’s story allusion to IV drug use with which to entitle a grunge band. Even with so many musicians […]

via Holly Elmore November 6, 2019

Personal quality experimentation

Different people seem to have different strategies, which they use systematically across different parts of their lives, and that we recognize and talk about. For instance people vary on: Spontaneity Inclination toward explicit calculations Tendency to go meta Skepticism Optimism … Continue reading →

via Meteuphoric November 6, 2019

Why and how to start a for-profit company serving emerging markets

Wave1 is a for-profit, venture backed startup building cheap, instant money transfer to and within Africa. Since launching in 2015, we’ve become by far the biggest remitter to Kenya and Ghana, saving our users and recipients over $100 million so far. Our biggest source of expected future impact …

via benkuhn.net November 4, 2019

Prediction markets for internet points?

Using real money in prediction markets is all-but-illegal, and dealing with payments is a pain. But using fake money in prediction markets seems tricky, because by default players have no skin in the game. Here’s a simple proposal that I think might work reasonably well without being too hard to try: Create a service that … More Prediction markets for internet points?

via The sideways view October 27, 2019

What do executives do, anyway?

An executive with 8,000 indirect reports and 2000 hours of work in a year can afford to spend, at most, 15 minutes per year per person in their reporting hierarchy... even if they work on nothing else. That job seems impossible. How can anyone make any important decision in a company that large? They will always be the least informed person in the room, no matter what the topic. If you know me, you know I've been asking myself this question for a long time. Luckily, someone sent me a link to a …

via apenwarr September 29, 2019

Taxing investment income is complicated

How should a state tax investment income if it wants to maximize its citizens’ welfare? This sounds like a simple question but I find it surprisingly hard to think about. Here are some of the positions I’ve moved through over the last few years: Taxing investment has distortionary effects, but we should have non-zero investment … More Taxing investment income is complicated

via The sideways view September 22, 2019

Reframing the evolutionary benefit of sex

From the perspective of an organism trying to propagate its genes, sex is like a trade: I’ll put half of your DNA in my offspring if you put half of my DNA in yours. I still pass one copy of my genes onto the next generation per unit of investment in children, so it’s a … More Reframing the evolutionary benefit of sex

via The sideways view September 14, 2019

Bear store

A preschool game that’s been particularly popular and versatile with my kids. Materials: Pennies Collection of counting bears or any other small objects One person is the storekeeper and sets out the bears in any way they want. The other people are customers and bring some pennies. The storekeeper sells the bears to the customers. […]

via The whole sky September 9, 2019

Graveyard Shift at Dawn Dance

I would say I’m alllmost recovered from the all-nighter I pulled this weekend calling the graveyard shift (4AM–7AM)—but heck, what a blast! Here’s the program I called (most of these walked through minimally or not at all): 50/50 — Bob Isaacs Fiddler’s Fling — Cary Ravitz (Will Mentor var.) Maliza’s Magical Mystery Motion — Cary Ravitz Rollin’ to the Grey Eagle — Hank Morris Read Between the Lines — Bob Isaacs The Young Adult Rose — David Kaynor Treasure of the Soda Bar — Maia McCormick Cheat Lake Twir…

via Maia Calls Dances September 4, 2019

Some open problems in P2P routing

Imagine a world where some pairs of whom want to talk to each other—each person has a unique n-bit identity (e.g. 64-bit strings), and wants to send a message to someone with a particular identity. The number of people is ballpark exp(n), I’m imagining ~10 billion. We’ll start with a graph G, where people know how to … More Some open problems in P2P routing

via The sideways view August 25, 2019

How replaceable is public key crypto?

Suppose that there were was no number theory, no elliptic curves, no lattice-based crypto. Perhaps because our universe was rigged against cryptographers, or perhaps because our society had never decided to explore abstruse mathematics. How bad would this be? Would electronic commerce be impossible? Would modern society crumble? In this post I’ll explore the possibility that … More How replaceable is public key crypto?

via The sideways view August 24, 2019

Absolute scale corrupts absolutely

The Internet has gotten too big. Growing up, I, like many computery people of my generation, was an idealist. I believed that better, faster communication would be an unmitigated improvement to society. "World peace through better communication," I said to an older co-worker, once, as the millenium was coming to an end. "If people could just understand each others' points of view, there would be no reason for them to fight. Government propaganda will never work if citizens of two w…

via apenwarr August 19, 2019

Traces

At naptime Anna listens to recordings of novels recorded by Jeff’s grandmother. It is the main way she will know Winnie, as it is the main way I have ever known Winnie. Some of the recordings are missing parts, and Suzie often fills in the first few sentences, her cadence echoing the distinctive pattern of […]

via The whole sky August 18, 2019

Insect ethics for parents

I walk past the neighbor’s garden and feel habitual comfort at the sight of bees clustering in the Russian sage. Bees are good. Bees are pollinators. Why is that good? Because I want my apple tree to bear fruit. Is it good to be a bee? What is it like? I have no idea. I […]

via The whole sky August 6, 2019

Interpersonal rules for preschoolers

(which we hope they will carry into adulthood) Consequences matter. If you were kicking your legs near your sister and you didn’t exactly mean to kick her but your foot did crash into her, you’re being reckless. You never need to give hugs or kisses if you don’t feel like it. No complaining or threatening […]

via The whole sky July 22, 2019

Files are fraught with peril

This is a psuedo-transcript for a talk given at Deconstruct 2019. To make this accessible for people on slow connections as well as people using screen readers, the slides have been replaced by in-line text (the talk has ~120 slides; at an average of 20 kB per slide, that's 2.4 MB. If you think that's trivial, consider that half of Americans still aren't on broadband and the situation is much worse in developing countries. Let's talk about files! Most developers seem to think tha…

via Posts on Dan Luu July 12, 2019

*Why Nations Fail* and the long-termist view of global poverty

Within the effective altruism community, people often talk about “long-termist” vs “short-termist” worldviews. The official distinction between the two is that short-termists prioritize problems by how they affect people alive today, while long-termists prioritize problems by how they could affect humanity’s entire future trajectory. In practice, people usually treat …

via benkuhn.net July 7, 2019

The log/event processing pipeline you can't have

Let me tell you about the still-not-defunct real-time log processing pipeline we built at my now-defunct last job. It handled logs from a large number of embedded devices that our ISP operated on behalf of residential customers. (I wrote and presented previously about some of the cool wifi diagnostics that were possible with this data set.) Lately, I've had a surprisingly large number of conversations about logs processing pipelines. I can find probably 10+ already-funded, seemingly successf…

via apenwarr April 26, 2019

Reflections on My First Techno Contra

Last weekend, I called my first techno contra (as part of a double dance at CDNY to celebrate the wedding of two of our lovely dancing humans 😍). It turns out, to no one’s surprise, that calling techno is a fair bit different from calling a regular evening dance. Here are my reflections on calling my first techno (including a bunch of great advice from folks on SharedWeight’s Callers’ Listserv). + If you can, listen to the tracks in advance! I worked with DJ Flourish (Mark Moore) from Philly—he’…

via Maia Calls Dances April 7, 2019

Programmer migration patterns

I made a little flow chart of mainstream programming languages and how programmers seem to move from one to another. There's a more common kind of chart, which shows how the languages themselves evolved. I didn't want to show the point of view of language inventors, but rather language users, and see what came out. It looks similar, but not quite the same. If you started out in language A, this shows which language(s) you most likely jumped to next. According to me. Which is not very scie…

via apenwarr March 18, 2019

You have more than one goal, and that's fine

When people come to an effective altruism event for the first time, the conversation often turns to projects they’re pursuing or charities they donate to. They often have a sense of nervousness around this, a feeling that the harsh light of cost-effectiveness is about to be turned on everything they do. To be fair, this is a reasonable thing to be apprehensive about, because many youngish people in EA do in fact have this idea that everything in life should be governed by cost-effectiveness. I&…

via Giving Gladly February 19, 2019

Randomized trial on gender in Overwatch

A recurring discussion in Overwatch (as well as other online games) is whether or not women are treated differently from men. If you do a quick search, you can find hundreds of discussions about this, some of which have well over a thousand comments. These discussions tend to go the same way and involve the same debate every time, with the same points being made on both sides. Just for example, these three threads on reddit that spun out of a single post that have a total of 10.4k comments. On …

via Posts on Dan Luu February 19, 2019

Improve Your Community With This One Weird Trick!

Hey experienced contradancers! Have you been looking for a new way to contribute to your dance community? Here’s one that I’ve been trying. It’s really small, and has the potential to make a really big impact on the quality of our dances, especially as more and more of us get on board with it. Ready? Here it is: Be quiet when the caller starts talking, and don’t talk through the walkthrough. That’s it. Really. If you want to go one step further, you can be the person who gently reminds people to …

via Maia Calls Dances January 31, 2019

Words Don't Help Beginners

I’ve been contradancing for over eight years, and can jump into even the most complex and falling-apart of contras and still have some idea of what’s going on. But last summer at English-Scottish-Contra Week at Pinewoods, I tried Scottish Country Dance for the first time and I had an experience I haven’t had for quite a while: I was completely at sea in a set dance. Scottish isn’t too different from contra and English, and I got along okay when I had a walkthrough. (Not great, mind you, but I ma…

via Maia Calls Dances January 21, 2019

No one is a statistic

I’m late to the party, but I've been thinking about the documentary “The Life Equation” about how people use data to decide make life-and-death decisions. The central example is a woman named Crecencia, a mother of seven who lives in rural Guatemala and has cervical cancer. The doctor treating her knows that screening other women for cancer is more cost-effective than treating this woman, and that the community doesn’t have enough money to fully fund both. The filmmaker writes: “Crecencia’s…

via Giving Gladly October 10, 2018

On Finding Purpose

We’re often taught about the importance of “finding your purpose” as you set out into the world and choose your pathway forward. The words change–sometimes it’s ‘purpose’, but you might also find your ‘bliss’, your ‘passion’, your ‘voice’, your ‘career’, or your ‘calling’–but the narrative remains the same. Whatever it is, you’ve gotta find it. And … Continue reading On Finding Purpose → The post On Finding Purpose appeared first on Hollis Easter.

via Hollis Easter April 13, 2018

Computer latency: 1977-2017

I've had this nagging feeling that the computers I use today feel slower than the computers I used as a kid. As a rule, I don’t trust this kind of feeling because human perception has been shown to be unreliable in empirical studies, so I carried around a high-speed camera and measured the response latency of devices I’ve run into in the past few months. Here are the results: computerlatency(ms)yearclock# T apple 2e3019831 MHz3.5k ti 99/4a4019813 MHz8k custom haswell-e 165Hz5020143.5 GHz2G commo…

via Posts on Dan Luu December 24, 2017

How good are decisions?

A statement I commonly hear in tech-utopian circles is that some seeming inefficiency can’t actually be inefficient because the market is efficient and inefficiencies will quickly be eliminated. A contentious example of this is the claim that companies can’t be discriminating because the market is too competitive to tolerate discrimination. A less contentious example is that when you see a big company doing something that seems bizarrely inefficient, maybe it’s not inefficient and you just lack…

via Posts on Dan Luu November 21, 2017

XLR Mic Mute Switch with LEDs – Proof of Concept

Purpose I play music on stage, and that usually means using amplification (PA) systems. The bands I play with (Frost and Fire, The Turning Stile+, and others) typically have a bunch of musicians playing a host of instruments, each with their own microphones. Consequently, we need a lot of mic mute switches. The enemy of … Continue reading XLR Mic Mute Switch with LEDs – Proof of Concept → The post XLR Mic Mute Switch with LEDs – Proof of Concept appeared first on Hollis Easter.

via Hollis Easter September 30, 2017

How to Test Thermostat/Thermal Fuse in Kitchen Tools

How to test thermostat and thermal fuse units on kitchen appliances (espresso machine, coffee maker, rice cooker, pressure cooker) with a multimeter. The post How to Test Thermostat/Thermal Fuse in Kitchen Tools appeared first on Hollis Easter.

via Hollis Easter September 14, 2017

Use Up That Zucchini – Googoots / Cucuzza Recipe

Delicious crispy caramelized zucchini with garlic, basil, mint, red wine vinegar, and olive oil. Easily scales up to use all the zucchini in the house, and it's quick! Googootz! The post Use Up That Zucchini – Googoots / Cucuzza Recipe appeared first on Hollis Easter.

via Hollis Easter August 27, 2017

Hotline Memes

Jennifer Battle asked the National Association of Crisis Organization Directors’ mailing list for some uplifting hotline memes to use in training, since there didn’t seem to be that many available. Here are my first responses. (please feel free to use these if you like)   The post Hotline Memes appeared first on Hollis Easter.

via Hollis Easter May 24, 2017

Two standard donations and one new one

Here are three places Jeff and I are donating this year. The first two are similar to what we’ve been doing for years, and the third represents a change.Direct workJeff and I want to support work that directly makes the world a better place. (Some arguments against falling into a “meta trap” here.) As usual for us, this year we’ve given just over half our donations to direct work. We made these donations to the Against Malaria Foundation, one of GiveWell’s top picks, except for small amounts th…

via Giving Gladly December 30, 2016

Practical steps for self-care

Last week the Boston Effective Altruism group had a discussion on self-care for altruists. I've written about the topic before, but I wanted to share some of the more practical advice people had. Think beyond day-to-day choicesSelf-care isn’t just short-term decisions like whether to make time for yoga tonight. It’s larger life decisions too, like what job to take, where to live, how to budget money, and how to make time for partners, friends, and family.For me, having children was self-car…

via Giving Gladly June 15, 2016

Why I pledged

Almost four years ago, I pledged with Giving What We Can. Members pledge 10% of their incomes to the best charities they can find (with students and those with no income pledging 1% of their spending money).In the time since, I've felt good about making this commitment. I like having it as part of my routine, something that I know is part of my plan in the years to come. It's a confirmation of what I value—a safe and healthy life not just for me and mine, but for all families around the…

via Giving Gladly December 16, 2015

An Interaction or Not? Understanding a Few ML Algorithms via an Example with No Evidence Either Way

My latest blog post helps to explain a few statistical/ML models by whether they learn an interaction in a toy example Since Github Pages is way nicer than Blogger, I'm writing over there at http://davidchudzicki.com now. To keep old posts alive, these pages at http://blog.davidchudzicki.com will remain as is.

via David Chudzicki's Blog March 4, 2015

Moved

I've moved here.

via David Chudzicki's Blog June 2, 2014

dithering

I was converting a PNG (which represented partials sums of the Weierstrass elliptic function) to a GIF and was confused about why the PNG looked fine at low resolution but the GIF looked bad. Then I learned that GIFs can only use 256 colors and we have to do something to map the many colors to the fewer colors. We could just use the closest available color in the new set of colors, but that results in sharp jumps and "color banding" where the colors change. So instead we use (and Image…

via David Chudzicki's Blog January 21, 2014

Interactive Lissijous Curves in d3

On a visit to San Francisco's Exploratorium, I saw an oscilloscope they had making Lissijous curves. So I decided to make a version in d3: You can play with it (and see the code) here

via David Chudzicki's Blog January 21, 2014

A Bayesian Model for a Function Increasing by Chi-Squared Jumps (in Stan)

This post will describe a way I came up with of fitting a function that's constrained to be increasing, using Stan. If you want practical help, standard statistical approaches, or expert research, this isn't the place for you (look up “isotonic regression” or “Bayesian isotonic regression” or David Dunson, whose work Andrew Gelman pointed me to). This is the place for you if you want to read about how I thought about setting up a model, implemented the model in Stan, and created graphic…

via David Chudzicki's Blog October 17, 2013

via openring