jeffparsons (u/jeffparsons)

jeffparsons commented on Making Minecraft Spherical bowerbyte.com/posts/block... · Posted by u/iamwil

jeffparsons · a day ago

I took a swing at something vaguely similar a long time ago now: https://github.com/jeffparsons/planetkit

My approach was to build a hex grid on a geodesic sphere. It's a very different trade-off.

jeffparsons commented on The Block Stacking Problem sites.pitt.edu/~jdnorton/... · Posted by u/lisper

dooglius · 13 days ago

I don't see how. Consider the block of minimum altitude, what's stopping it from falling?

jeffparsons · 11 days ago

I didn't specify the challenge clearly. I meant to allow blocks in any orientation, as long as they would be stable.

So you can, for example, have blocks sloping down from the edge of the table by sandwiching one end of them between two other blocks with enough vertical distance between them, and enough weight on top.

jeffparsons commented on Leaving Gmail for Mailbox.org giuliomagnifico.blog/post... · Posted by u/giuliomagnifico

onlyhumans · 11 days ago

Fastmail is kind of a weird service. If you stop paying they release your email for someone else to take over. Pretty unacceptable this day and age.

jeffparsons · 11 days ago

This would be easily solved for customers who care about it by allowing you to pay a one-off fee to reserve the name for ~100 years.

Or they could just absorb that.

Any idea why it works that way? Have they offered an explanation?

I'm a Fastmail customer but I've never noticed this because I use my own domain.

jeffparsons commented on The Block Stacking Problem sites.pitt.edu/~jdnorton/... · Posted by u/lisper

cousin_it · 14 days ago

If the blocks are thin enough, I think it's possible. Stack three blocks. Position the left edge of the stack on the edge of the table, so it's hanging downward at a slight angle, and stack enough blocks on top that it holds. Now slide the middle block 2/3 of the way out. The friction should still hold.

I think it's also possible for other shapes, all the way up to square blocks. But you need to build a bunch of nested "clamp" arrangements, instead of just one.

jeffparsons · 13 days ago

That's basically the direction I was going in my head. I just remembered we have a bunch of Kapla blocks in the house, so I may be able to do this "IRL"!

jeffparsons commented on The Block Stacking Problem sites.pitt.edu/~jdnorton/... · Posted by u/lisper

jeffparsons · 14 days ago

> My goal here is to develop an intuitive sense of comfort with the behaviors of these stacks. If I succeed, you will not just understand that the physics allows the stacks to be stable, but you will feel that it is proper and just.

I love this kind of writing. It feels like the author is excited to bring me along on a journey — not to show off how smart they are. In this way it reminds me of Turing's original paper that introduced his "computing machine". It presents a fantastically deep topic in a way that is not just remarkably accessible but also conversational and _friendly_.

I wonder why so little modern academic writing is like this. Maybe people are afraid it won't seem adequately professional unless their writing is sterile?

jeffparsons commented on The Block Stacking Problem sites.pitt.edu/~jdnorton/... · Posted by u/lisper

jeffparsons · 14 days ago

How about this one:

Assume an arbitrarily high coefficient of friction between all surfaces. Can you stack the blocks on the table such that at least one block is wholly below the top of the table?

I think I have an answer to this, but I've only worked it through in my head, so there's a good chance I'm wrong!

jeffparsons commented on There is no memory safety without thread safety ralfj.de/blog/2025/07/24/... · Posted by u/tavianator

devnullbrain · a month ago

Rust checks overflow by default in debug builds

jeffparsons · a month ago

I've often thought that I'd prefer it to check by default in release builds, too, but I understand that comes with a performance penalty that a lot of folks aren't happy with.

I assume this implies that common processor architectures (x86_64, aarch64) lack trap-on-overflow variants of their integer arithmetic instructions? If the explanation really is that simple, it's pretty disappointing.

jeffparsons commented on I watched Gemini CLI hallucinate and delete my files anuraag2601.github.io/gem... · Posted by u/anuraag2601

AgentME · a month ago

I think Rust is a bad example, but I think the general idea that the design of a programming language can help with the weaknesses of LLMs makes sense. Languages with easy sandboxing (like Deno where workers can be instantiated with their own permissions) or capability-based security could limit the blast radius of LLM mistakes or insecure library choices made by LLMs, while also giving similar benefits to human programmers and code reviewers.

jeffparsons · a month ago

Why is Rust a bad example? Of the code bases I've tried Claude on so far, it's done the best job with the Rust ones. I guess having all the type signatures there and meaningful feedback from the compiler help to steer it in the right direction.

Has your experience been different?

jeffparsons commented on I wrote my PhD Thesis in Typst fransskarman.com/phd_thes... · Posted by u/todsacerdoti

berti · 2 months ago

I’ve run into this exact issue several times with group projects at university in the 2010s, and each time recovery was copying chunks of plain text from backup copies into new documents as you say. Luckily by the time we got to the final year capstone project the whole group was happy to go with LaTeX. Not sure if these Word issues have even been fixed since.

jeffparsons · 2 months ago

I don't have a source for this, so take it with a huge grain of salt... but for some reason I have a memory of someone telling me that the older versions of Word saved and loaded documents by writing the bytes of in-memory data structures directly to files on disk, with not much in the way of marshalling or validation in the middle. Because it was fast, or something. You can imagine the kind of edge cases and oopsies that might result.

The new versions at least serialise to some kind of monstrous XML representation of Word's internal state, so while it's not going to win any awards for world's most elegant document format, it should be slightly harder to corrupt in subtle ways.

jeffparsons commented on I wrote my PhD Thesis in Typst fransskarman.com/phd_thes... · Posted by u/todsacerdoti

shermantanktop · 2 months ago

Why do CS doctoral candidates have such a fascination with typesetting? I mean, be into whatever you’re into, I guess.

But as soon as someone starts talking about LaTEX and how they spent months on their macros, I think “another hapless victim has fallen into LaTEX’s trap.” It’s like an ant lion that feeds on procrastinating students.

jeffparsons · 2 months ago

Another reason to use LaTeX for papers back in the day was that Microsoft Word would routinely corrupt large documents in terrifying ways. Sometimes the root of the corruption existed in the document somehow long before any of it was visible, so even recovering from an old backup would just lead to the problem repeating. I recall the only way to properly "recover" an old backup was to copy it all via plain text (e.g. Notepad), and then back into a brand new Word document.

This is all to say, if you're working on a theis or even a moderately large assignment, working in Word was not good for the nerves.

Looking back, I probably should have just worked in plain text and then worried about formatting only at the very end, but ummm, yes, I guess another hapless victim did indeed fall into LaTeX's trap. :)