We've been stuck on the red line between Porter and Harvard for 70min. They're working on hooking up a rescue train. Intercom: "when you get up to the front, take off the sleet scraper" Random passenger in our car: "will do!"

My house has radiators for heat. There are fewer heating loops than rooms, and it's not very well balanced. Fixing this properly involves hiring a plumber, but we can make it much better by just putting a small fan on the radiator where we want more output.

Far-UVC is something people have talked about for years in a "that would be great, if you could buy it" sort of way. But the future is now, and it costs $500. I think we're now at the point where dances, churches, offices, rationalist group houses, schools, etc. should consider them.

I move my music pedalboard around in a suitcase. A few months ago I used spray adhesive to attach foam padding to the case instead of having it loose. It's still good and tight!

I used to need to take my access card out of my wallet to tap it, but then I realized I could tape a piece of tinfoil to the back. I often put up with annoyances instead of thinking about how to fix them (which overall makes my life better!) but in this case I should have done something sooner.

On a road trip, you can call in an order to a pizza place you'll be driving past in half an hour. Combining the benefits of food that takes a while to make with not having to wait around!

Anthropic has many employees with an EA-ish outlook, who may soon have a lot of money. If you also have that kind of outlook, money donated sooner will likely be much higher impact.

It can be hard to get the kids to practice their instruments. Sometimes they're having trouble focusing, don't like their assigned piece, or are just grumpy. One thing I'll offer them in these cases is "busking practice", where instead of practicing their assigned piece we pretend we're busking.

We clean drinking water all the time, not just in response to cholera outbreaks. To have clean air in emergencies, we need to figure out how to have clean air every day. The benefits of widespread deployment of air purifiers, far-UVC, etc are very high even before you count the biosecurity impact.

I wanted to link an explanation of how far-UVC works, why you might want to use it to clean indoor air, and what we know about its safety. I didn't find anything I liked, so I made something: faruvc.org Background: jefftk.com/p/introducing-faruvc-org

The kids told me they wanted to watch a "blue E" but Disney wasn't working. I told them I could solve their problem, but they weren't amused.

Looking up the history, apparently this is not a pun!

Picking up checked bags at Logan. Old displays say carousel 4. New ones say 6. Announcer repeatedly says 3. Bags came out on 2.

Getting ready for far UVC starting tomorrow at BIDA! blog.bidadance.org/2025/11/maki...

When I saw the recent Atlantic article on Florida train deaths I guessed we were making a big deal over it because it was the train was big and new, and actually we're better off overall. Turns out no: Brightline is just really deadly, not just for a train, but even relative to driving.

For deploying far UVC to clean the air at a dance event, I modeled the difference between putting a lamp in each corner (theoretical ideal) vs one stand with four lamps on stage (logistically better). Efficacy goes down 5.6%, but it's within safety limits.

I've had a lot of people reach out to me who are interested in working on biosecurity, but have a background in software. I keep having to say "sorry, I don't see a place for you right now." This has changed: we're now hiring for junior engineers (NAO in Boston; AI remote). Consider applying?

What would honest advice to contra dance newcomers look like if communities took their "fragrance free" policies seriously? Not very welcoming:

The situation in the contra dance world with "fragrance free" is a mess. Many dances have very strict policies, but they don't advertise this. So they're not dances that work for people who need the strict policies, but then also put careful people through a lot of work in avoiding common products.

We surveyed our dance community on reducing infection risk from COVID, flu, and other airborne pathogens using far UVC and glycol vapors. Far UVC was very popular; glycol vapors were popular but more mixed.

This popped back in my head today, and I'm still not sure if this commenter was trolling me

Estimating the chance of future natural pandemics, without even taking into account the increasing risk from AI-assisted engineering, I get that a good reusable mask is worth about $14k. Since they cost $30-$60, they're well worth buying to keep on hand!

Does anyone remember who I lent my Far UVC lamp to? I'm completely blanking on it. It was one of these: aerolamp.net

How should BIDA reduce airborne infections? Masks, far UVC, glycol vapors? Some combination? Nothing? Let us know what you'd like to see!

Mask optional dances had 9% higher attendance on average, but (via permutation testing!) it was just p=0.2.

We tried glycol vapors and far UVC at BIDA last night, for reducing inhalation of infectious aerosols. No issues with either! I also stayed after to make an estimate of how much ventilation we're getting; looks like ~24 CFM/person.

Our cats are in the paper! Two-year-old siblings Clementine and Nix are running for mayor and vice-mayor respectively. Their owner Lily, 11, says the pair’s goals are lengthy: ...

I'm working out the logistics for trialing triethelyne glycol for pathogen control at a contra dance, and ran some tests to figure out how much to dilute it to get the right amount of vapor. www.jefftk.com/p/calibratin...

Before having kids I thought teaching them to clean up would be similar to the rest of parenting: once they're physically able to do it you start practicing with them, and after a while they're independent and do it reliably. Tidying has not been one of these.

The numbers printed on pasta boxes for cooking time generally seem way high, even on the low end. I ran an experiment on some "13-15min" Rigatoni and we liked it best around 10min30s.

This year you can order the nasal spray flu vaccine to your house, and self-administer. I just ordered for our whole family: $18 for five people, delivered. I expect the kids to strongly prefer this to needles, and it's much easier logistically.

I play by ear, and when I write tunes I normally save them by making a recording. Since other people use dots, I'd like to have transcriptions, but this is hard. I had a go at this with AI tooling without success, and then did reasonably well writing four tunes out manually.

BIDA has now finished its second year alternating whether dances required N95s. Over 44 dances, mask-required averaged 166 (median 160) vs mask-optional at 190 (median 184).

As we go into winter, the BIDA dance is thinking about infection reduction. Our primary approaches are requiring high-filtration masks at half our dances and bringing in large amounts of outside air, but at our 2025-09-07 dance we'll be testing far UVC and glycol vapors.

Here's an update of an older post, laying out an example sound system for a contra dance. The big changes are a switch to a digital mixer (XR18) and going from K10s to HD10As for speakers. Overall it's about $3.2k, 37% cheaper than 2014 in real terms.

I rebuilt my pedalboard, saving 9.3lb (23%) which means it now all fits in a 50lb checked bag. It's also no longer falling apart, and should last more than a year.

I'm on various mailing lists, and the archives are a trove of niche knowledge. A dance calling list I'm on is considering making archives subscriber-only, to keep AI bots from snarfing up this data. But I think this harvesting is overall a good thing: I'd prefer future LLMs gave good dance advice.

When something doesn't go well with the kids a "do over" can offer a chance to try again. It quickly breaks the bad pattern and replaces it with a better one. You're not digging into what should have happened, you just jump back and try again. It works whether they, I, or both of us messed up.

I fly to a lot of gigs, and check my pedalboard. Out of a budget of 50lb, how little can I allocate to the suitcase? It looks like all the <7lb options are Samsonite: Lite-Shock (5.5lb), Cosmolite 3.0 (5.8lb), C-Lite (6.3lb), Firelite (6.7), Proxis (6.8). All way expensive, but maybe one used?

Don't substitute polyethylene glycol (Miralax) for propylene glycol (fog juice) if you're trying to reduce airborne pathogens. It turns out the syllables mean something.

The most common feedback I get about my writing is that people like my posts but the fraction of interesting posts is too low. I currently cross-post everything to a bunch of places; I'm going to switch my Substack mirror to just getting the best 10-25% of posts, about 2-4 per month.

@juliawise.bsky.social and I know drowning is the biggest risk to US children under 5, and we try to take this seriously. But yesterday our 4yo came very close to drowning in a fountain. (She's fine now.)

Subway pm2.5 levels peak closer to 75 ug/m3 than 1,000 ug/m3, and aren't something I'd wear a mask for. The post I shared earlier was misreading (my own) graph. Sorry!

I've started masking on the subway again. Not because of covid or anything we've found at the NAO, but because of the extremely high pm2.5 levels from brake dust.

Imagine you load up your seatback entertainment, and one of the options is a burrito. But there's only one. You can put in a bid, and 1/3 of the way into the flight the person who bids the most gets it. Even if profitable, though, I expect this would be widely hated.

The legal term "affordable housing" is actually a decent operationalization of whether housing is something regular people can afford. If the area median income (AMI) is $100k, then a "50% AMI" unit is priced so someone earning 50% of the AMI ($50k) spends <1/3 of their income ($1,390/month).

At the NAO, we’ve created new estimates on how well wastewater sequencing detects different pathogens. SARS-CoV-2 is again highly detectable, but common cold viruses are harder to detect. We will use this research to compare wastewater sequencing to other detection strategies.

In sequencing wastewater we see slightly higher than advertised output for Illumina (~28B read pairs on a 25B flowcell), but much lower for ONT (~3Gbp on a PromethION where we'd hope to get 200Gbp).

Metagenomic sequencing data is fundamentally relative: each observation is a fraction of all the observations in a sample. If you want to understand whether there's been an increase in the number of people with some infection you need to calibrate these observations: ...