Are you looking for a project where you could substantially improve indoor air quality, with benefits both to general health and reducing pandemic risk?

I've written a bunch about air purifiers over the past few years, and its frustrating how bad commercial market is.

The most glaring problem is the widespread use of HEPA filters. These are very effective filters that, unavoidably, offer significant resistance to air flow. HEPA is a great option for filtering air in single pass, such as with an outdoor air intake or a biosafety cabinet, but it's the wrong set of tradeoffs for cleaning the air that's already in the room. Air passing through a HEPA filter removes 99.97% of particles, but then it's mixed back in with the rest of the room air. If you can instead remove 99% of particles from 2% more air, or 90% from 15% more air, you're delivering more clean air. We should compare in-room purifiers on their Clean Air Delivery Rate (CADR), not whether the filters are HEPA.

Somerville Porchfest was a lot of fun this year, and we got a great crowd:

Showing some pictures to Claude it guesses there might have been 600 people. Very glad the city gave us permission to close the street! [1]

I recently read a blog post that concluded with:

When I'm on my deathbed, I won't look back at my life and wish I had worked harder. I'll look back and wish I spent more time with the people I loved.

Setting aside that some people don't have the economic breathing room to make this kind of tradeoff, what jumps out at me is the implication that you're not working on something important that you'll endorse in retrospect. I don't think the author is envisioning directly valuable work (reducing risk from international conflict, pandemics, or AI-supported totalitarianism; improving humanity's treatment of animals; fighting global poverty) or the undervalued less direct approach of earning money and donating it to enable others to work on pressing problems.

Last year at NEFFA we mostly bought food. We brought a range of cold options, but they weren't very tasty and the kids weren't very excited about them. This time we've mostly eaten food we brought. Why? The miCARwave!

At work we've recently been using zstd as a better-compressing alternative to gzip, and overall I've been pretty happy with it. A minor documentation gripe, though, is that the behavior around multithreaded compression is a bit unclear. I understand it's chunking the work and sending chunks to different threads to parallelize the compression process, and this means that I should expect to see better use of threads on larger files because there are more chunks to spread around, but what is the relationship?

When I look in man zstd I see that you can set -B<num> to specify the size of the chunks, and it's documented as "generally 4 * windowSize". Except the documentation doesn't say how windowSize is set.

The Effective Altruism community has encouraged a range of different approaches to doing good over time. Initially there was more focus on frugality as a way to increase how much you could donate, which was mostly supplanted by emphasis on earning more. In late 2015 this started to shift towards doing things that are directly useful, which accelerated in 2021. Then the market fell in 2022, FTX turned out to be a fraud, and there haven't been new donors near the scale of Open Phil / Good Ventures. Among many changes, people are thinking more about frugality again: the less you can live on, the more you can stretch a given amount of funding. [1]

To encourage myself to live more frugally and to give an example of what I thought was a pretty fulfilling life at relatively low cost for the US, I used to calculate numbers for how much we spent on ourselves. This included housing, food, transportation, medical, etc but not donations, taxes, or savings. At one point there were some news stories comparing our spending to our income, and it was nice to have a simple number to point at.

I was thinking it might be nice to start calculating these numbers again, but when I looked back at why I stopped it's mostly that it's actually a pretty tricky accounting question and I'm not sure there are ways to draw the lines that make much sense. For example: