Hacker News: sjburt

New comment by sjburt in "Postmortem: Our first VLEO satellite mission (with imagery and flight data)"

sjburt — Sat, 24 Jan 2026 20:42:13 +0000

The diffraction limit (under 1.22 h* lambda/d) of a 1m optic at 250km in visible light is about 17cm. How can you achieve 10cm resolution?

New comment by sjburt in "Jane Goodall has died"

sjburt — Wed, 01 Oct 2025 19:52:34 +0000

On the Jane Goodall page: https://en.wikipedia.org/wiki/Jane_Goodall#Gary_Larson_carto...

New comment by sjburt in "Computational Complexity of Air Travel Planning [pdf] (2003)"

sjburt — Sun, 20 Apr 2025 07:30:39 +0000

At least a few years ago (~2014), the fare search was actually nearly instant, but all major airfare search sites added a delay because customers had the impression they were getting a better deal when they had to wait. It seems like the delay has been dialed back lately.

New comment by sjburt in "The belay test and the modern American climbing gym"

sjburt — Mon, 24 Mar 2025 03:32:58 +0000

I’m not sure why people are making a big deal of it. At my gym it took maybe 3 minutes. You tie a knot and show you know how to take up slack. And it only needs to be done once.

There is a second test for lead but most people take a class and get the lead card during the class.

New comment by sjburt in "Zig; what I think after months of using it"

sjburt — Wed, 05 Feb 2025 05:16:40 +0000

When you are modifying a long closure and don’t notice that you are shadowing a variable that is used later.

I know “use shorter functions” but tell that to my coworkers.

New comment by sjburt in "No Calls"

sjburt — Fri, 17 Jan 2025 04:34:28 +0000

The worst part is that the sales person has to go back and pitch their team on whether it’s worth their time to get back to you.

New comment by sjburt in "'I'm running a Mud so I can learn C programming ' (1993)"

sjburt — Tue, 03 Dec 2024 18:29:34 +0000

Really curious about this:

> If you have access to a program named 'Purify' ... learn how to use it.

Anyone know what this was or use it?

New comment by sjburt in "Company claims 1k% price hike drove it from VMware to open source rival"

sjburt — Tue, 03 Dec 2024 14:18:59 +0000

“10x price hike” would have been totally clear. “Factor of 10 price hike” would probably be a formal way to say it.

New comment by sjburt in "The Raspberry Pi CM5 Is Weeks Away?"

sjburt — Tue, 26 Nov 2024 02:36:38 +0000

The Debian images (https://raspi.debian.net/) haven't been updated recently and don't support the Pi 5 at all. And support for other hardware is inconsistent.

New comment by sjburt in "The English Paradox: Four decades of life and language in Japan"

sjburt — Thu, 07 Nov 2024 18:44:43 +0000

How is this any different from going into a Panda Express and trying to order in Mandarin?

New comment by sjburt in "Bop Spotter"

sjburt — Tue, 01 Oct 2024 15:28:23 +0000

https://x.com/fulligin/status/1841022534848036949/photo/1

> As of 12:30am PST I have located the Box and successfully executed a Rickroll Injection Attack on the target system. Out of respect for the artist I will not be revealing the Box's location, but for any veteran Mission resident only a couple obvious locations exist.

New comment by sjburt in "James Earl Jones has died"

sjburt — Tue, 10 Sep 2024 02:33:59 +0000

I think it helps that the technical concept that drove the main plot was a very real and still-present risk to public key encryption systems.

New comment by sjburt in "Zen 5's 2-ahead branch predictor: how a 30 year old idea allows for new tricks"

sjburt — Sat, 27 Jul 2024 03:58:10 +0000

In benchmarks, branch predictors guess correctly 90-95% of the time.

New comment by sjburt in "At the Mountains of Madness"

sjburt — Wed, 10 Jul 2024 17:27:04 +0000

It seems like every article about nix goes on and on about DLL hell. I've been using Debian/Ubuntu for 15+ years and never really experienced dependency hell. I guess maybe this is thanks to hard work by Debian maintainers and rarely needing to run a bleeding edge library, but also, why do we need to run bleeding edge versions of everything and then invent an incredibly complicated scheme to keep multiple copies of each library, most of which are completely compatible with each other?

And then when there's a security problem, who goes and checks that every version of every dependency of every application has actually been patched and updated? Why would I want to roll a system back to an (definitely insecure) state of a few months ago?

What problem does Nix solve that SO numbers (properly used) doesn't?

I have many of the same questions about Snap and even Docker.

New comment by sjburt in "Astronauts take shelter in Starliner, other spacecraft after satellite breakup"

sjburt — Thu, 27 Jun 2024 20:21:39 +0000

Note that his tweets indicate that he does not believe it to be an ASAT test.

https://x.com/planet4589/status/1806333953617334688

New comment by sjburt in "I kind of like rebasing"

sjburt — Fri, 21 Jun 2024 22:27:10 +0000

I think the problem is that often the order you want it in a clean history is not exactly the chronological order it was developed. Eg you may build out a feature vertically, tweaking the interfaces between the components as you go along. But a clean, atomic git history would probably introduce each component in a finished state in separate commits.

New comment by sjburt in "I kind of like rebasing"

sjburt — Fri, 21 Jun 2024 21:49:24 +0000

The main issue is that on a longer branch, you have to fix all the rebase conflicts on the oldest commit. Then, if you changed something in the conflict zone, you fix it again on the next commit, because the next commit used to be based on something else. Sometimes git rerere can help with this, but I find it fairly unreliable (could be user error!) If you do a merge, you only need to resolve it all once.

Otherwise I tend to prefer rebase.

New comment by sjburt in "The Moon brings a wild but precarious fish orgy to California's beaches"

sjburt — Tue, 23 Apr 2024 14:11:18 +0000

Moon phase is caused by moon position.

New comment by sjburt in "Git Bisect-Find"

sjburt — Sat, 20 Apr 2024 06:52:35 +0000

if you don't know what commit is good, just go way way way back. Go back 10,000 commits instead of 1,000. The magic of bisection search is that opening your search window by 10x only adds 3 (well, 3.332) extra bisections.

New comment by sjburt in "RocketStar tests fusion-enhanced in-space propulsion process"

sjburt — Mon, 15 Apr 2024 04:46:14 +0000

Fuel mass is very much the limiting factor. "Electric" or "ion" propulsion of this general type are used on satellites for things like orbit raising or orbit maintenance. They don't provide very much thrust, but they provide a very high ISP (often 10x what would be possible for a chemical reaction propellant), which typically translates to a longer lifespan for a vehicle or the ability to carry less reaction mass and more payload.