Hacker News: jdranczewski

New comment by jdranczewski in "SpaceX launches Starship v3 rocket"

jdranczewski — Sat, 23 May 2026 21:42:31 +0000

They were originally planning to not do hot staging, aiming instead for a somewhat funny approach where they spin the ship and booster slightly so they are passively separated by centrifugal forces. A bunch of things went wrong in the first test flight, so this was never attempted, and they switched to the "simpler" hot staging in flight 2.

New comment by jdranczewski in "Hand Drawn QR Codes (2025)"

jdranczewski — Tue, 05 May 2026 08:11:46 +0000

I've really enjoyed reading the Grid World piece linked at the bottom of the post: https://alex.miller.garden/grid-world/

New comment by jdranczewski in "I rendered 1,418 confusables over 230 fonts. Most aren't confusable to the eye"

jdranczewski — Fri, 27 Feb 2026 09:02:13 +0000

The article mentions this only briefly, but browsers already do this kind of heuristic protection! See https://en.wikipedia.org/wiki/IDN_homograph_attack#Defending... or https://chromium.googlesource.com/chromium/src/+/main/docs/i... for a Chrome-specific blog post.

I think the lack of exploration of the context around the problem and current mitigations is an issue with the article - it spends a lot of time talking about the possible threat, but very little time on whether the attack is actually practical with modern mitigations.

New comment by jdranczewski in "Google Street View in 2026"

jdranczewski — Thu, 26 Feb 2026 22:51:09 +0000

On Android they've actually rolled out the 3D view in Maps recently! Took them long enough. I now have an "aerial" button in the bottom left corner when viewing Street View imagery that switches between the two.

New comment by jdranczewski in "The Perils of ISBN"

jdranczewski — Wed, 18 Feb 2026 23:01:32 +0000

If anyone in the comments is in a similar predicament to the author and would like a book logging app, I will say that I disagree on their judgement of StoryGraph - I've found it a pretty decent interface, the search function is very good, and the (anti)features mentioned in the footnote are incredibly easy to not use, as the creators seem to understand that many of their users have a very strong preference to avoid AI bloat.

New comment by jdranczewski in "Discord will require a face scan or ID for full access next month"

jdranczewski — Mon, 09 Feb 2026 21:39:23 +0000

For large communities, the very granular role-based permission system of Discord can be put to some good use, I don't think Slack has a trivially equivalent feature.

New comment by jdranczewski in "Data centers in space makes no sense"

jdranczewski — Wed, 04 Feb 2026 09:54:25 +0000

You can, but the heat needs to go somewhere, and now you're back to square one, with "how do I get rid of all this heat". Earth refrigerators have a large heat exchanger on the back for this purpose. In fact now you need to get rid of both of the heat your compute generates and the energy your refrigerator pump uses - an example people often give is that a fridge with an open door actually heats the room, as it spends energy on moving heat around pointlessly.

New comment by jdranczewski in "Prism"

jdranczewski — Tue, 27 Jan 2026 22:39:55 +0000

To add to the points raised by others, "just install LaTeX" is not imo a very strong argument. I prefer working in a local environment, but many of my colleagues much prefer a web app that "just works" to figuring out what MiKTeX is.

New comment by jdranczewski in "UK company sends factory with 1,000C furnace into space"

jdranczewski — Sat, 03 Jan 2026 17:08:01 +0000

If you've managed to find more details about what process exactly they're implementing I'd be glad to see it - I assumed plasma-based growth, since the BBC article mentions that it's a plasma that is at 1000C here (making heat dissipation less of a problem too), but if they're growing ingots that would usually be done from liquid silicon, which sounds like a mess in space. So are they doing plasma-growth of ingots (which I haven't heard of, but I haven't heard of many things), or are they bringing wafers up and growing ultra-pure layers on top... The website is not super clear on this from what I've seen.

New comment by jdranczewski in "OpenSCAD is kinda neat"

jdranczewski — Sun, 21 Dec 2025 09:31:18 +0000

An interesting use case of OpenSCAD is open source hardware with many contributors - the reasoning being that we only have mature version control tooling for text-based files (say git), and so your CAD design should be text-based. I was introduced to this idea by https://openflexure.org/projects/microscope/ - they managed to build a fairly complex 3D printed microscope project on this principle.

I'm aware of Onshape having a git-like workflow as well, wonder how the two compare! A fully cloud-based suite would probably not work well for an open source project.

New comment by jdranczewski in "Children with cancer scammed out of millions fundraised for their treatment"

jdranczewski — Tue, 16 Dec 2025 08:10:01 +0000

The article says they visited both the US and Israel registration addresses and didn't find the organisation's offices. I was impressed by the amount of "on the ground digging" by the journalists here!

New comment by jdranczewski in "Programmers and software developers lost the plot on naming their tools"

jdranczewski — Fri, 12 Dec 2025 10:57:46 +0000

Following on on the DoD example, the field of astronomy is infamous for its terrible acronyms: https://lweb.cfa.harvard.edu/~gpetitpas/Links/Astroacro.html

New comment by jdranczewski in "Pebble Index 01 – External memory for your brain"

jdranczewski — Tue, 09 Dec 2025 20:28:11 +0000

Yes! The ring reminded me of the Core too. Perhaps with voice processing and the infrastructure around MCP (which I haven't used myself, but Eric brings up in the blog) a fully headless, voice-based device like this is more feasible now than in those days

New comment by jdranczewski in "Await Is Not a Context Switch: Understanding Python's Coroutines vs. Tasks"

jdranczewski — Wed, 26 Nov 2025 11:43:34 +0000

I may be misunderstanding it, but the examples shown don't seem to be illustrative? It seems reasonably obvious that the prints will happen in this order in any language, because in example 1 we are explicitly (a)waiting for the child to finish, and in example 2 both of the parent prints are above the await. So I don't feel like either of these makes the point the author is trying to get across?

New comment by jdranczewski in "New Glenn Update"

jdranczewski — Fri, 21 Nov 2025 15:17:56 +0000

I think in your first point the difference is between "calculation" and "conversion". For calculations, it's generally accepted that arbitrary numbers are possible and a calculator may have to come out. For conversions, it's nice to be able to say that 1250m is 1.250km - I bump into conversions much more commonly than having to do calculations, and it's nice to be able to do them in my head.

I don't think the second point is particularly valid. The SI unit is a kg - which is weird, but always consistent. All Physics units in metric involve kilograms. I will grant that it's unusual that it has a prefix, but still - if you know the 7 base SI units (including the kg), the rest follows reasonably, and conversions are trivial compared to Imperial (orders of magnitude vs arbitrary multipliers).

Fundamentally yeah, what one's familiar with is the system that feels most intuitive, but I don't think these specific arguments against metric work super well

New comment by jdranczewski in "New Glenn Update"

jdranczewski — Fri, 21 Nov 2025 09:06:17 +0000

I've always found the weather argument somewhat unconvincing, because 0°C being the freezing point of water is very much a useful point of reference in weather contexts - it's roughly where one may expect iced-over pavements and rain to turn to snow! And then the higher temperatures are a question of getting used to it - 40°C instead of 100°F is very very warm, 30 is pretty hot, 20 is reasonably warm, etc.

But then I grew up with Celsius, so no wonder I'm used to it!

New comment by jdranczewski in "Uv is the best thing to happen to the Python ecosystem in a decade"

jdranczewski — Thu, 30 Oct 2025 08:30:27 +0000

I agree that having a reliable main environment for quick experiments is great! On Windows I just use the main Python installation as a global environment, since no system stuff depends on it, on Linux I tend to create a "main" environment in the home directory. Then I can still have per-project environments as needed (say with uv), for example for stuff that I need to deploy to the VPS.

Note that I'm mostly in the research/hobby environments - I think this approach (and Python in general, re: some other discussions here about the language) works really well, especially for the latter, but the closer you get to "serious" work, the more sense the project environment approach makes of course

New comment by jdranczewski in "Why did Crunchyroll's subtitles just get worse?"

jdranczewski — Tue, 07 Oct 2025 08:09:43 +0000

https://caption.plus/ does excellent work for a couple YouTube/Nebula channels - not as exciting as the above, but they do coloured speakers, positioning to avoid in-video text, and an occasional animation to punch up a joke! I'm most familiar with their work for Tom Scott (+ the Technical Difficulties) and Jet Lag: The Game.

New comment by jdranczewski in "Scream cipher"

jdranczewski — Sat, 20 Sep 2025 20:28:16 +0000

Ah, my bad! I did not know these were a thing, but that makes more sense! Teaches me a thing about only quickly trying things in an online REPL on mobile and jumping to conclusions - I forgot curly braces were also a way to denote a set

New comment by jdranczewski in "Scream cipher"

jdranczewski — Sat, 20 Sep 2025 19:16:56 +0000

I was rather confused by the dictionary comprehension syntax used there, because I wasn't aware that you could write one without the ":" to delineate the key: value pair. Turns out you can, but it just creates a dict with no values stored, just the keys! This works here because the returned dict is an iterable that returns the keys on iteration, and "update" accepts an iterable of (key, value) tuples - and the keys are just that in this case. So the effect is the same as if it was a list comprehension! Just slightly more confusing