Earlier quoted context omitted.
Pilot suicide by a long shot. There is no other alternative theory that comes even close. What was interesting is to see them piece the theory together from the very fragmentary and little evidence (what is even more mind-blowing to know how little evidence there was to play with given we are talking about a 747). The true mystery left is how did he execute the suicide and why. How did he dispatch the co-pilot? (Ther…
did you chance upon @MentourPilot on youtube and his breakdown of the MH370 investigation + recent update? If not, I am afraid you may have another hour to spend, but its very likely you have already seen this.
Ask HN: What rabbit hole(s) did you dive into recently?
261–270 of 443 posts
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#262Mine all feel like "we do these not because they're easy, but because we thought they would be easy".
Turning a thousand-page book - PAIP - into a stack of Markdown files in a git repo, readable online. The print book received more editing and revisions than the ebook. I converted an ebook's ... odd formatting ... into Markdown, remade diagrams, generated new ePub and pdf files, and had the spine cut off a print copy to make a fresh scan. Working on that scan, I made Scantailor, an X program, easier to access from a Mac, via Docker. I tried different OCR engines, and pored over the diffs, incorporating dozens (hundreds?) of improvements. I got to find so many differences between Markdown engines. I have ideas on how to make Pandoc links between chapters. There's still a lot to do!
My current WIP: Lars Wirzenius posted about file systems with a billion (empty) files. I started exploring because I was curious, if I was remembering correctly, how well a mostly empty image file would recompress - like, drive_image.gz.gz. Lars offered a Rust program; I was curious about how other methods compared. Like, how about nested shell loops, tar, and touch? And, hey, how well can we archive and compress them? I've gotten to see some issues, bottlenecks, and outright failure modes with SMR hard drives, Samba re: sparse files, and parallel gzip compression. I've accumulated some shell script boilerplate to make it easier to go back and verify my processes, and harder to accidentally wipe out past work if I rerun it.
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#263Writing a beginner intro to wealth tax and assemblng and organizing all the Ressources I had consumed in years. https://start.me/p/1997pL/inequality-for-the-pragmatic-ideal...
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#264Bartending / cocktails / "mixology" .
It's more fun than I thought because whipping up every cocktail you've ever heard of is actually quite simple. There's also some cool generalizations to uncover so that you can Pareto principle your way to knowing how to do almost everything with a few tricks and ~10 liquids. I could have someone knowing more than 2/3 of bartenders (most are just a job / basics) in an evening. Then once you've got a good handle on all the basics, there's an endless adventure into variations and history. There are a lot of flavors out there you wouldn't believe existed; many concoctions of herbs and botanicals. It's a great social activity too.
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#265I’ve fallen into the plant tissue culturing rabbit hole. I was selling excess trimmings of aquarium plants locally on Facebook marketplace and made a surprising amount of money, and my kids really enjoyed it (they got a cut for helping me out). I thought hmm, this could be a great excuse to make a little business around this, teach them some skills, get them thinking more constructively and feeling a sense of agency…
This is really interesting! Wondering if there’s any good reading/books about it you’d recommend?
I started with “Plants from Test Tubes: An Introduction to Micro-Propagation”. After reading that I’ve perused various sites, YouTube, and I find research papers are remarkably plentiful and useful when you’ve got a specific question.
For example, I want to culture some plant. How do I get the best tissue from the plant and which media and hormones seem to work best? Should I use agar, gellan, multiply in a temporary immersion bioreactor, are there any special deflasking notes, etc. The information is out there for a ton of species!
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#266Texas Hold'em. I know there are probably plenty of experts here but after decades avoiding it, I'm getting into it because I found a group of friends that played online. I first discovered that there are tables (and tables and tables) of preflop card combinations that tell you whether to raise/call/fold based off of where you are in the dealing order and how many players are active. Then I learn that's basically deri…
Did you write an algorithmic betting software?
Nah. When playing solitaire I just use a Kelly calculator. I plug in estimated equity and pot odds, and get a recommendation of what percentage of my stack to bet. It's just to get a sense of how to make riskier bets when the pot is large.
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#267PDF files, and why the heck they are so slow to read. Hours upon hours of perf(1) and fiddling with ugly things in C. My main takeaway is everyone in the world is doing things HORRIBLY wrong and there's no way to stop them. (Digression: did you know libpng, the one everyone uses, is not supposed to be an optimized production library—rather it's a reference implementation? It's almost completely unoptimized, no really…
> The worst offender (so far) is the JBIG2 format (several major libraries, including jbig2dec), a very popular format that gets EXTREMELY high compression ratios on bilevel images of types typical to scanned pdfs. But: it's also a format that's pretty slow to decompress—not something you want in a UI loop, like a PDF reader is! And, there's no way around that—if you look at the hot loop, which is arithmetic coding, it's a mess of highly branchy code that's purely serial and cannot be thread- nor SIMD- parallelized.
Looking at the jbig2dec code, there appears to be some room for improvement. If my observations are correct, each segment has its own arithmetic decoder state, and thus can be decoded in its own thread. The main reader loop[1] is basically a state machine which attempts to load each segment in sequence[2], but it should not need to. The file has segment headers which contains the segments offsets and sizes. It should be possible to first decode the header and populate the segment headers, then spawn N-threads to decode N-segments in parallel. Obviously, you don't want the threads competing for the file resource, so you could load each segment into its own buffer first, or mmap the whole file into memory.
[1]:https://github.com/ArtifexSoftware/jbig2dec/blob/master/jbig...
[2]:https://github.com/ArtifexSoftware/jbig2dec/blob/master/jbig...
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#268Ham radio!
I got into it through wanting some cheap radios to keep in my house, so I wouldn't have to go all the way upstairs when I needed to communicate with my daughter.
Well let me tell you Baofeng radios are extremely cheap but really flexible. I got these things for the simplest possible use case but after realizing their potential I just had to learn more about the space. You can adjust their configuration with a tool called Chirp and you're off to the races!
I attended a local severe weather awareness event where I met some hams who were part of an emergency response network. It's really cool to learn about how these communities operate. It's legal to receive even without a license - you only need the license to transmit.
I plan to take the technician test soon and get my license so I can help out at a nearby bike event. The area is incredibly rural so there's no cell coverage and the ham operators are really helpful in coordinating things.
Anyway, I feel like the hobby is a bit of a dying art, but it's something that seems like it would have a lot of appeal to the programmer crowd.
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#269PDF files, and why the heck they are so slow to read. Hours upon hours of perf(1) and fiddling with ugly things in C. My main takeaway is everyone in the world is doing things HORRIBLY wrong and there's no way to stop them. (Digression: did you know libpng, the one everyone uses, is not supposed to be an optimized production library—rather it's a reference implementation? It's almost completely unoptimized, no really…
> The worst offender (so far) is the JBIG2 format (several major libraries, including jbig2dec), a very popular format that gets EXTREMELY high compression ratios on bilevel images of types typical to scanned pdfs. But: it's also a format that's pretty slow to decompress—not something you want in a UI loop, like a PDF reader is! And, there's no way around that—if you look at the hot loop, which is arithmetic coding,…
- "If my observations are correct, each segment has its own arithmetic decoder state, and thus can be decoded in its own thread."
Yeah, but real-world PDF JBIG2's seem to usually have one segment! One of the first things I checked—they wouldn't have made it that easy, the world's too cruel.
It's sort of a generic problem with compression formats—lots of files could easily be multiple segments that decompress in parallel, but aren't—if people don't encode them in multiple segments, you can't decompress them in multiple segments. Most formats support something like that in the spec, but most tools either don't implement that, or don't have it as the default.
e.g. https://news.ycombinator.com/item?id=33238283 ("pigz: A parallel implementation of gzip for multi-core machines" —fully compatible the gzip format and with gzip(1)! No one uses it).
Re: Ask HN: What rabbit hole(s) did you dive into recently?
#270I’ve fallen into the plant tissue culturing rabbit hole. I was selling excess trimmings of aquarium plants locally on Facebook marketplace and made a surprising amount of money, and my kids really enjoyed it (they got a cut for helping me out). I thought hmm, this could be a great excuse to make a little business around this, teach them some skills, get them thinking more constructively and feeling a sense of agency…
Sweet. I spent a few years cultivating mushrooms and found the hobby to be very rewarding. One can grow (legal) medicinal and gourmet mushrooms on a small scale with very little money. I recommend people interested give it a go because it's fun and offers a lot to learn. :)
Mushrooms are what gave me the confidence to try tissue culturing! I’d grown mycelium from spores, made liquid cultures, and generally figured out the sterile workflows and understood the gist of things. I figured it shouldn’t be too different or difficult.
Plants have been slightly more challenging, but not as much as I expected. If you aren’t optimizing for profits to keep a facility open, mediocre results are still awesome and you’ve got plenty of time to keep experimenting. I guess it’s much the same with mushrooms. If you don’t get 5 pounds on your first flush, it’s still great fun. The beauty of mycelium is that turn around times are an order of magnitude shorter. Tissue cultures are very, very slow.