michal.piekarczyk.xyz

Longer-form posts about whatever I'm exploring.

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  Coldest Feb 15, 2026

  Recently, myself and the rest of NYC went through a cold spell and news outlets reported2 the 13 day stretch of sub-zero weather, ending Feb 6th, was not longer than a 16 stretch in 1881. And this was shorter than a 1963 stretch, but tying a 2018-01-13 streak. But this recent winter sure felt extreme. I know there is a recency bias, but I figured, why not also compare the area under the curve too. So I ranked the coldest 14-day stretches, using available data of the past decade. And then tried to visualize the spans of the coldest years too.

• Looking Forwards Feb 7, 2026

  Email forwarding mystery solved Feeling several facepalms now that my michal@piekarczyk.xyz email finally forwards to my hey.com email inbox. After several sessions of tweaking, the answer was low tech! Registrar forwarding Originally, I setup mail forwarding on my domain registrar. Only $5 a year, okay why not. After proving to my registrar I owned my hey email, I was all set, but tests yielded silence. I spent several chat sessions with a support engineer at my registrar. He pointed out I was missing SPF and DKIM records for my custom domain and so he added those. Those have nothing to do with delivering mail to my address and only help to authenticate mail sent from my domain, but I figured what the heck let’s try something. That did not work.

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  Gardening time Dec 28, 2025

  Life’s a garden, can you dig it? That is what a colleague of mine had said very often when we worked together, about how you need to put time and effort into stuff. You know, get your hands dirty ! Picking up my shovel Today I finally took a first step to trying out this digital gardening concept on Maggie Appleton’s blog0. I came across back on haha I don’t know why but on 2025-07-04 , I guess it was a kind of independence day in my brain, from the march of chronology.

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  Skip the Jetlag Dec 11, 2025

  Came back from a flight from New Delhi , Monday morning, that left New Delhi just after midnight and 16 hours later arriving in New York around 5:30 am. And so far today, Thursday morning, I feel kind of fine, not really jet lagged, in the sense of wanting to wake or sleep at odd hours. The specific strategy I did in attempting to align meal time and sleep time with the destination time zone was to fast the day of the flight until lunch time arrival at my destination. It would have been ideal if I was able to sleep during the red eye though not doing so was also perhaps fine since by the time I crashed on Monday at around 19:00, I had about 16 + 16 + 12 = 44 hours of sleep pressure in the tank. And then when I slept for basically 12 hours, waking at 7 am on Tuesday, and getting the morning sun, I was basically back in my rhythm. And so far, sleep on Tuesday night and Wednesday night was pretty okay.

• Something is not Tracking Dec 10, 2025

  Recently I went on a trip to India where so much was going on I stopped using my meal tracking. And on this trip the other thing that happened was that half the time, I was in a plane, waiting for a plane, or on a bus –or on the back of a Maruti Suzuki offroad Jimny– or otherwise sedentary. And yet, after the brief 10 day trip, I carved off an inch and a half off my waist and dropped over 6 pounds on the scale. (Side note, I know that “intra-day” variability can be high, because I have personally seen a reset of 5 pounds , within a day’s worth of eating, answering the call of nature and exercising, and so on, but “inter-day” variability, should be lower, when you weigh-in at a consistent time of day).

Fleeting notes and thoughts that might take shape later.

• inter vs intra group variations Apr 21, 2026

  placeholder, inspired by conversation with a friend on a instagram post linking to a study [1] on visceral fat differences among two populations. Decent n, between “South East Asian” and , “white European origin”, n=677 vs n=2394 for liver fat comparison and n=697 vs n=2271 for subcutaneous and visceral fat comparisons . ( Using CT , and or MRI ). They measured more liver fat and more visceral fat at lower BMI .

• A Phone Call Apr 20, 2026

  Today I scratched an itch I have had for many years. I discovered this artist on sound cloud, Hot Sugar, some time ago. Their music spoke to me. In particular I recall around 2017-2018 listening to this simple song about a telephone call. I didnt remember the lyrics, but I had an impression about how a simple phone call is a very beautiful way to connect with people which my generation sadly avoids. its all about text messaging these days.

• try-planning-a-puzzle Apr 19, 2026

  spoiler alert. Dont read further if you want to enjoy a really cool jigsaw puzzle . Recently worked on this fun puzzle … [1] when we were nearing the end , someone was asking me hey want to do this nsxt? I said yea think we done in 5 minutes… Haha turns out nope references https://magicpuzzlecompany.com/products/the-happy-isles

• leaky capabilities Apr 15, 2026

  Mini reaction on people saying Mythos can find bugs in decade old code. I think similarly I was reading Mythos or maybe a different model is solving Erdos problems previously unsolved, yet it turned out they were solved but just lost into the internet and the model in question sort of performed a lookup as with stack overflow answers. Especially if folks are saying, Mythos is finding bugs in really old software, that begs the question are old bugs being resurfaced , recycled as novel.

• No, you grep ! Apr 12, 2026

  I recently1 discovered ugrep, and I have benefited a lot in using this to search my logseq journals. But recently I noticed I was getting fewer results and also confirmed some misses. My specific strange issue was that if I pointed directly to my miss, ug found it but not otherwise. I was consulting with microsoft copilot about this mystery. running into a weird ugrep issue where, ug -%% 'some blah' /some/foo/path , comes up dry , but if I am specific ug -%% 'some blah' /some/foo/path/more/specific/file.py , then I get results. Is there some index that needs to be poked for rebuilding?