Researchers have confirmed the mass of a free-floating planet thanks to a lucky convergence of ground- and space-based telescopes
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1 January 2026 7:00PM GMT
Nicolas Solerieu in On wearables:
The marketing is a mishmash of sport, lifestyle, health value propositions fading in a goodness mush, rarely delivering much beyond a wrist-mounted stream of numbers.
Couldn't agree more. After a few years of wearing my sports watch 24/7, I realised that the data and the way it was presented did my head in, and had no positive effect on my health and fitness. For the past couple of years I've worn an analogue watch, only switching to my sports watch to track my actual workouts.
I am unreasonably proud of getting this right in the workout log before actually getting there and seeing that something was off.
Calendar years and ISO weeks don't really intermingle. Can't wait for the scramble at work on Monday as people start trying to figure out what's what because of this fact.
Hey all,
I'm not dropping this on the actual newsletter feed because it's a little self-indulgent and I'm not sure 88,000 or so people want an email about it.
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The last day of the year is coming to a close. As I begin drafting this post, four more hours remain until the year of our lord twenty twenty five is but a memory.
I didn't plan on writing a "year in review" for this year. Don't get me wrong, I love it when those posts pop up in my feed reader and I wish more people would write them. This was just a particularly ordinary year on my end. There isn't all that much to report.
But with the four year old in bed and asleep, and the seven year old upstairs playing Minecraft with his mother in an attempt to stay awake until the new year rolls around, I'm suddenly sat in the living room. Alone and with time to spare. So I thought I'd give myself a small challenge. Write and publish a post. Right here, right now, before the year ends. I don't know what it will become. Call it a "word vomit" inspired by Meadow and let's see what comes out.
There was absolutely nothing of particular note to report from my 2025. It was a year without big stories, inspirational turnarounds, remarkable comings of age and uncomfortable upheavals. A good thing, in most respects.
Both children continued to prosper and grow. At seven and four, we're now reaching that phase of their lives where they might begin to encounter problems outside the little bubble of the world their mother and I can influence. Parental duties so far have been challenging, yes, but rewarding. When their challenges are "small"1 and manageable, you come a long way by just showing up and being there. At the same time, I know that as they continue to expand their contact surface with the world, they will begin to face challenges beyond our immediate control.
I can't help but feel ill equipped to guide them through these situations.
Watching my kids apply themselves to an activity is my favourite thing. Both are active and participate in several activities. The boy plays football and handball, while the girl (despite my continued lobbying that she should start playing football) loves dancing. To see them practice with passion and make headway gives me great joy. I have no aspirations on their behalves, I'm just there for the ups and downs and all that'll teach them.
After battling cancer for over a year, my grandmother passed this fall. It was sad and I miss her. Given she'd been living with cancer for so long, I thought it would lessen the impact of her parting. It didn't. Her passing was also the oldest kid's first real experience with mortality. He was absolutely devastated at her funeral. It was a hard day.
Savne deg, mor.
As shown in my reading log for 2025, I read 18 books this year.2 Eight of them I read aloud to one of my children. Of those, the Narnia books (which I had been wanting to read for many years) were my favourites. I wrote a post with my thoughts on the series.
Of the books I read on my own, Jonathan Strange & Mr Norrell was a particular highlight. In a post about the book I shared some of my thoughts and my favourite excerpts.
What I did not write about was the Liveship Traders books. Late last year, I read Ship of Magic before setting aside the trilogy for Wind and Truth (which left me a bit disappointed). I though Ship of Magic was OK, but it really set the scene for the rest of the story. And what a story it was! The Mad Ship was excellent before the trilogy concluded with the even better Ship of Destiny. I think these three books combined is perhaps my favourite work of fantasy writing. If you haven't read them yet, you should! Although they work fine as a stand-alone trilogy, they are part of Robin Hobb's Elderling universe. You'll probably appreciate them even more if you begin with Hobb's Farseer trilogy.
I only managed to finish two non-fiction books this year. Ray Bradbury's Zen in the Art of Writing (thoughts) and Ceasar by Adrian Goldsworthy. I want to double that next year.
Going through my workout log for 2025 I was surprised to find that I had the most active days in a year since I began tracking my workouts in 2017. 312 active days is nine up from the previous high in 2021. My sessions are shorter on average than back then, and total active time of 323 hours is not near the 379 hours of my peak years of 2023 and 2018.
Although it was a good year of physical activity, I am not quite satisfied. I "only" managed 55 hours of strength training. Now in my forties, I think working a wide range of muscles to reduce age-induced decay will only become more important. An hour a week is a little less than where I want to be.
I caught the running bug again earlier this year. It should therefore come as no surprise that running, at 244 hours, made up the bulk of my active time. Going out for a run in quiet surroundings, on trails or a back country road, gives me great joy. I'm also acutely aware of the fact that window of opportunity for bettering my personal bests is closing quickly. Realistically, I have three to five years to do it.
That in mind, I am gearing up for giving improving my personal bests one last go. This year was all about getting back to it. I got back to regular workouts, and increased my volume significantly compared to 2024. However, I'm still around 1500 kilometres behind for the year compared to where I need to be to get close to my PBs. In 2026 I will attempt to get back to that training volume and positioning myself to run a (hopefully) fast marathon in 2027.
In 2024 I transitioned to a new role internally. This year was all about fully settling and coming to grips with the expectations and deliverables of this role. It's taken longer than I'd expected, but after a year and a half, I believe I'm starting to get there. The role is quite different to what I'd expected. And, to be frank, it doesn't exactly play to my strengths. The responsibilities are less direct deliverables, and more mediation, meeting room influencing and stakeholder management than I'm comfortable with
There's a lot to learn and plenty of room to grow in a situation like this. The upside is that the team around me is great. My colleagues keep inspiring me to do my best and evolve my skills to better handle the role. That said, I find it hard to see myself in this role for the long term. If an opportunity that better matches my skill set presents itself, I will consider it. That might happen in 2026, or beyond.
The new year is still two hours away. But I'm ready to go to bed. What next year brings will have to wait until tomorrow.
Happy new year!
As a parent, and a human being in general, I think it's important to remember that what might seem small to you can be mountainous and incomprehensible to a child. Or any other person, for that matter. ↩
I've also spent more than half the year working my way through Letters from a Stoic. I still have a few letters left. Because I count all books as read in the year that I finish them, it'll show up as read in 2026. ↩
Soundtrack: Lynyrd Skynyrd — Free Bird
This piece is over 19,000 words, and took me a great deal of writing and research.
Ruslan Osipov in Home is where my stuff is:
Some of these versions of myself are still relevant. Some aren’t. The hard part isn’t identifying which is which - it’s accepting that letting go of the object means letting go of that version of me. Admitting that I’m not that person anymore. Or that I never became the person I bought that thing for.
I never became the guitarist I thought that fancy guitar would make me. But I'll never, ever let it go.
When I last made some updates to the workout log and wrote about it, I said:
The only thing remaining to make it a proper replacement is some more data on the activity level. Heart rate details (cookie diagram for zones or just a line chart), elevation numbers and line chart plus, possibly, a map of some sort. For the last one, I'm not sure, because I'm loath to introduce third party content on the site. And building a map engine isn't exactly on my list of things I want to tackle.
But I'll keep thinking about that. Either way, I think I want to make some changes to how I'm handling workout data upstream before I tackle any of those. To make the solution a bit more robust.
Lo and behold, in ToDo-WindrunnerSSG.md, my to do list for my static site generator, were the following entries:
( )Workout log improvements:( )Add splits bar chart (ala Strava where bar width = duration, bar height = pace)( )Heart rate graph( )Elevation profile( )GPS coordinates route to SVG( )Refactor title and notes to support unified workout data storage
The workout log has been the defining project of 2025 for me. With the end of the year in sight, I was motivated to take a stab at solving these last remaining features. And now I have. The most recent update in the version log for my static site generator:1
0.2.5
22.12.2025
- Updated
workoutlog_processingto include more data per activity. This includes splits, route, heart rate plot and elevation plot illustrations. Code was also refactored to adjust for upstream changes in workout data storage. The script is now pulling data from individual text files per activity. Minor changes togenerate_feeds.pyandwindrunner.pyto account for logic changes.- No remaining items in
ToDo-WindrunnerSGG.md. Is this thing feature complete?
True to form, I'll spend this post going through my thought process when attempting to solve each of these. The post will be long, boring and only suitable the particularly peculiar persons who wants to know how I've "vibe coded"2 my way to a fully functional Strava replacement as a component of my own static site generator.
If you read my initial post about the workout log you probably remember (lol) that my data flow was as follows:
This worked OK. But it had two glaring issues:
I routinely messed up the CSV file and caused errors by being sloppy with commas and escaping. Adding even more data for visualisations would require changing the setup. The second point was also nagging me. My workout data was not unified in one place. The .fit activity files were stored in one place, while my notes on the workouts existed only in the CSV file. Manually added workouts existed only as a row in the CSV file.
As directly enriching the activity files is not possible, my idea was to create companion files for each activity file. These files would be identically named text files (only with a differing extension, .md in this case) and they would contain key details of the workout as well as my notes on each workout.
This solved both issues. Editing a single text file with dedicated lines to the title and notes is easier than fiddling with a CSV file. Likewise, it centralises all of my workout data in a single location: The directory where my activity files are stored. Each workout is now merely a text file with a few data points, and — if I happened to be wearing a device to capture more detailed data during the workout — there will be an identically named .fit alongside it containing all additional data like a GPS track, heart rate stream and more.
Next, I had to figure out how to approach generating the workout log based on this new data structure. My initial idea was to keep the CSV as the source for generating the workout log. Intuitively, this seems significantly more efficient than accessing thousands of individual files each time I generate the site. Some testing confirmed that to be true. Generating the workout log based on data in a single CSV file was around an order of magnitude faster than fetching the same data from 3000+ individual text files.
While that may seem like a lot, in practice we're talking about going from 100-200 milliseconds to 1-2 seconds. It was a cost I was willing to swallow. Because introducing a middle layer meant increasing the complexity of the setup significantly. This because there is more often than not a time delay from when the workout file is created and I get around to adding a title and notes. So when do I generate the CSV file to ensure that it is current? My site is rarely generated more than a couple of times per day, either way. The solution can only be "every time a workout file is updated" for there to be any significant resource savings.
Not worth the added complexity.
That said, xan and his followers need not worry. There is still a CSV file. I recently created a workouts feed for anyone who wants to keep up with my workouts.3 Like Strava, only built on an open protocol! To avoid having to access thousands of files twice every time I generate my site, the script creates a CSV index while accessing the files on the first go. This index is then used when generating the workouts feed later in the build process.
(X)Refactor title and notes to support unified workout data storage
Routes have been on my mind since I first began working on the workout log. The context provided by a visual illustration of where you've run (or biked, skied, skated or anything else) simply cannot be replaced.
But there were some immediate stumbling blocks. Maps, for one. I do not want to introduce third party components on my site, even if there are great options out there. Self-hosting tiles seemed like too much hassle. Plus, there's this privacy thing. While I've been privileged to never really have to worry too much about that since, well, forever, openly sharing my exact geo-location every single day seems a step too far.
Because of this, I left routes alone. When I, thanks to Josh Comeau's excellent friendly introduction to SVG began to wrap my head around SVGs, the solution seemed obvious: Generate an SVG showing the path. This way I can provide some context of what the run was like by showing the route without revealing everything. And I must say, I'm really happy with the result.
Everyone who's run the Berlin Marathon will immediately recognise the route and probably get an emotional response when seeing it in the activity from when I ran it back in 2019:
Similarly, here's a point to point example when I ran Ecotrail Oslo the same year:
I think it provides a lot of context for the activity. Even if it doesn't reveal the exact location, it conveys something about what the run was like that is difficult to get across with words alone. Especially paired with the next point.
(X)GPS coordinates route to SVG
You can describe an activity with numbers such as metres climbed and descended. But, like with routes, an illustration can give an intuitive understanding of what the activity was like that is difficult to replicate with words. To add a simple chart to show the elevation profile of my activities, therefore, seemed obvious.
After sorting out the route illustration, I decided to use the same approach for the elevation profile: A simple SVG. It is responsive and works fine. Let's look at what this looks like for the same activities mentioned above. First, the Berlin Marathon:
One flaw in this implementation is that the elevation changes are all relative. Meaning that the elevation profile for the pancake flat Berlin Marathon (total metres climbed is 74 metres) looks quite hilly. On the other hand, the Ecotrail Oslo 50k looks like a straight drop by comparison:
Even if Ecotrail has a significant net drop, the total metres climbed is 896 metres and more than ten times as much as Berlin. You wouldn't know just looking at these two charts.
My first iteration was just the lines chart. To add a little more context to the chart, I decided to add labels for the highest and lowest points. Although this doesn't quite solve the relativity issue, it helps mitigate it. And I prefer it to a "fixed height" approach, because the most important point is to get a feel for the relative changes within a particular activity rather than comparing activities.
(X)Elevation profile
For the heart rate chart, I reused the exact same approach as for the elevation profile. And it works well. Just have a look at the chart from this 8 x 1000m workout from earlier this year:
Although not a tool for detailed analysis of a workout, the chart illustrates how the heart rate fluctuates throughout the workout. It goes up throughout the reps, dipping sharply during the standing rests. With the label for the highest value, we can see that it peaks during the last rep at 177 beats per minute.
(X)Heart rate graph
The last thing I wanted to implement was a bar chart illustrating the pace and duration of the workout splits. Splits, or laps, are segments of a workout. For a regular jog, I use auto split per kilometre. If I'm doing a structured workout, I will manually split at the beginning and end of each repetition.
Looking at these splits is my preferred method of quickly assessing a workout afterwards. For many years, I paid for a Strava premium subscription because I liked their bar charts better than anything else I had found. Suffice it to say, I wanted to get these right.
Conceptually, the bar chart is quite simple:
My first implementation used a relative approach. The fastest split was set at the max height, the slowest at the minimum height, and everything else was given height relative to these two outer points. It worked… OK.
The first thing that bothered me was that for a workout where everything was fairly evenly paced, it would look like pace varied significantly. I could live with that. But, as soon as I looked at a structured workout, I knew I had to improve the approach. Just look at this:
What's interesting here is the variance between the tall bars, which represents the 1000 metre repetitions. Because the rest intervals (walking rest) are so slow by comparison, there is absolutely no granularity between the reps. I am instead wasting space illustrating the meaningless differences between the walking rests. This won't do!
I need a way to scale these bars that will preserve the granularity at the faster end at the expense of the slower end. Bonus points if it solves the issue of exaggerated differences during a run with fairly even splits. To someone smarter than me (low bar!) the solution is likely obvious. My first thought, however, was introducing some kind of fixed pace range. Where 3:00 min/km or faster is set to max height and 7:00 min/km or slower is set to minimum height.
This would work… OK. For running. But if I go for a bike ride, it wouldn't because the paces won't fit that range. A more flexible approach would be better. After consulting with my friendly neighbourhood Claude, the light bulb went on. I can maintain a "relative" approach by anchoring the scale to the fastest lap split pace and capping the slow end based on some factor. In other words, anything X percent slower than the fastest split gets drawn as the lowest bar. For everything in between, I use the available canvas.
In theory, this should solve both issues — as long as I can find the correct multiplier.
After trying various multipliers on for size, I settled on 2. That is, anything that's half the pace of the fastest split gets suppressed at the lowest height. It is a fair compromise between detail at the pointy end, and lack of detail at the slow side. Going back to the same workout we saw above, here's what it looks like with the new approach:
There's clear separation between the repetitions, while maintaining a visual distinction between the warm up and cool down splits. A more aggressive cap, like 1.5, resulted in even more granularity between the fast repetitions, but at the cost of any distinction between the warm up and cool down splits. This compromise works.
Looking at a recent run, it also solves the problem of fairly even splits coming across as wildly different:
Paces here range from 5:50 min/km to 5:36 min/km. With the old approach, the bars would've given the (completely erroneous) impression of a aggressive progression run.
I can now confidently proclaim that this bar chart illustration of workout splits is equal to that which I used to Strava for the privilege of using. It is also fully responsive and works on mobile.
(X)Add splits bar chart (ala Strava where bar width = duration, bar height = pace)
As I wrote in the changelog, there are now exactly zero remaining items on my to do list. Not just for the workout log, but for the entire static site generator that powers this website. A year after finishing the first iteration, I have implemented everything that I had the idea of doing "sometime" when I first began working on this thing. That probably warrants a post of its own. As does the question of whether or not it is complete.
What I can declare with absolute certainty, however, is that the workout log is finished. It does exactly what I want it to do. Nothing more, nothing less. I have no desire for new features or additional elements. If I have to stick to one way of tracking and analysing my workouts for the rest of my life, I am perfectly content with this being it.
That's a nice feeling. And a good note on which to end a year.
Yes, like a proper wannabe developer sans actual developer skills, of course I keep a changelog for this thing. And the version numbering is, naturally, completely made up. Whenever I make a change I just ask myself "what do I want to call this version?" before landing on a number. It's pretty cool. ↩
Back when I began using LLMs to put together a static site generator that matched my mental model of how these things should work, the term "vibe coding" didn't exist. But now it does, and I suppose it fits what I'm doing here. ↩
Not so much because I think that anyone would want to subscribe to my workouts in their feed reader, but, rather, because I have a dream of lots and lots of people tracking their workouts in a way that lets me follow their workouts in my feed reader. Because I get a lot of motivation from seeing other people getting out there and doing the work, and I really miss that aspect of Strava. Be the change you want to see and all that. ↩
I was buying a couple of albums to add to my growing collection of legally acquired music. After completing the purchase over at Qobuz, they hit me with this warning:
Certain works may be withdrawn from the service for legal reasons, such as a revocation of rights. The titles purchased will then no longer be available for re-download. Download your purchases quickly.
Don't mind if I do!
Appreciated this frank message. It perfectly captures exactly why someone would consider building a music collection in 2025, instead of trying to hide the reality and instead push you towards platform dependency.
PS: I bought two albums. Young, Loud and Snotty and We Have Come for Your Children, both by the late 70s by American punk rockers Dead Boys.
Recommended listening!
Cast iron waffle maker. Fry waffles straight on the fire. 10/10 will do again!
One apropos: Not ideal with impatient kids running around anticipating a big stack of waffles asap. This is slow food and you’ll be enjoying every heart.
Backing up Spotify - Anna’s Blog:
Anna’s Archive normally focuses on text (e.g. books and papers). We explained in “The critical window of shadow libraries” that we do this because text has the highest information density. But our mission (preserving humanity’s knowledge and culture) doesn’t distinguish among media types. Sometimes an opportunity comes along outside of text. This is such a case.
This is a magnificent effort by the people at Anna's Archive. 86 million music files archived, with metadata for 256 million tracks.
As I've begun constructing my own music library recently, it feels like the people at Anna's and I are kindred spirits of a sort. My library is currently at 50 artists, 69 albums and 708 songs. Good to know that I'm not running out of options for stuff to add any time soon.
Via.
Some years ago, I had a frustrating and largely fruitless encounter with the politics of policing. As a member of an oversight commission, I was particularly interested in the regulation of urban surveillance.
