HNHacker News
TopNewBestAskShowJobs

gattr

670 karma · joined December 6, 2017

I like graphics algorithms, astronomy, Rust and Linux.
submissionscomments
gattr··on A simple guide on words to avoid in government
On a similar note: bullshit detection script [1]. For some fun, try using it on some large well-known tech corp's homepage.

[1] https://mourner.github.io/bullshit.js/

gattr··on Peter Norvig critically reviews AlphaCode’s code quality
I see it differently; I'd be OK with an upload if the alternative is death, but only under strong protections: the digital version is legally treated as a human, I have full autonomy, the compute resources to run me (and the simulated environment of my choice) indefinitely are assured, and I can still interact with the real world. I'd just go on doing my usual stuff, like writing software for fun, enthusing over new discoveries in astronomy...

I can recommend Greg Egan's novels that touch on this:

1) Permutation City (mind uploading tech in its infancy)

2) Diaspora (mind uploading well established)

gattr··on Peter Norvig critically reviews AlphaCode’s code quality
Forgive my going off-topic, but what you wrote is basically my conclusion after reading the short story Lena [1] (mentioned some time ago on HN; strongly recommended). TL;DR: when mind uploading becomes possible, don't be an early adopter.

[1] https://qntm.org/mmacevedo

gattr··on Holodomor
I strongly recommend Timothy Snyder's lecture [1] on this topic (and the whole series in general).

[1] The Making of Modern Ukraine. Class 15. Ukrainization, Famine, Terror: 1920s-1930s https://www.youtube.com/watch?v=1dy7Mrqy1AY&t=1s

gattr··on The Peacekeeper missile’s navigation suite (2019)
Seconded.

Add to that the (insane?) early SIOP, a plan for an all-out attack on the USSR with waves of nuke-armed strategic bombers.

As for the Damascus accident, I'd love to watch a high-budget movie about it (preferably on the level of "Deepwater Horizon", with Mark Wahlberg to boot).

gattr··on Why some feces float and others sink
I was quite uncomfortable (but managed to get the business done) for the first week or so after arriving in the US (business trip) due to the inch-wide gaps around stall doors. When flying back, going to the toilet in the first European airport was very... moving.
gattr··on Rust and C++ Interoperability
I use GTK3 with Rust for my video acquisition tool [1] and it's been quite pleasant so far. However, from my testing GTK3 & 4 don't play nice with OpenGL drawing areas, so the next project I'm writing (also in Rust) using Dear ImGUI.

[1] https://github.com/GreatAttractor/vidoxide

gattr··on Some companies find only humans can do the job
Even if they make perfectly human-like, realistically acting sexbots with HW failsafes, there's the question of trusting the SW. It would be inadvisable to use such a black-box proprietary machine which is probably recording and sending detailed (and potentially embarrassing) telemetry. I'd expect a long wait for community-designed, open-source equivalents.
gattr··on Sound
That's not accurate. Only the inner core collapses (hence the "core-collapse supernova"; there are also other types), the rest rebounds, is heated up by core-produced neutrinos, and gets ejected. The Wikipedia article is a good start, also there are plenty of good papers on arxiv (e.g. on still-not-too-successful numerical modeling of the aforementioned "heating", without which the thing simply doesn't go bang).
gattr··on A study of lights at night suggests dictators lie about economic growth
Regarding China, the book "Guns, Germs and Steel" gives the following explanation: due to a lack of major geographic barriers, China became unified under a single rule early, and subsequent irrational decisions by despotic rulers brought stagnation. In contrast, it was impossible to unify Europe by force in pre-industrial age, hence the ongoing competition (and resulting development) between all the states.
gattr··on Rust 1.63
I wrote a video acquisition tool for astrophotography [1] (and I dogfood it). Uses GTK3 for GUI.

[1] https://github.com/GreatAttractor/vidoxide

gattr··on Please put units in names
I myself can't remember seeing Gy in astronomical papers, but I've seen Ga (gigaannum).

https://en.wikipedia.org/wiki/Year#SI_prefix_multipliers

gattr··on Photo captures space station crossing the moon
In a similar vein, a high-res ISS image by Alessandro Bianconi showing a damaged radiator:

https://www.astrobin.com/375799/?nc=all

(Taken with a 14" telescope. Good "astronomical seeing" conditions and necessary post-processing notwithstanding, the smallest resolvable details depend linearly on telescope's aperture (i.e., the primary optical element's diameter).)

EDIT: I also like this animation a lot, ISS crossing the sky (9.25" telescope):

https://astropolis.pl/topic/79691-przelot-iss-z-ogniskowej-2...

gattr··on Learning Standard C++ as a New Language (1999)
Somewhat related: [1]. A bit provocative title, but it's actually about "teaching (the newcomers) C++ constructs first before going through C-era ones".

[1] CppCon 2015: Kate Gregory “Stop Teaching C" (https://www.youtube.com/watch?v=YnWhqhNdYyk)

gattr··on IBM open sources fully-functional Lego microscope design (2020)
On a related note, if one's willing to forego proper mechanics and lighting, for imaging small stuff you only need a digital video camera and a microscope objective lens (or just a photographic lens with some macro rings). I got good results [1] with a machine vision camera from PGR (comparable to RPi camera module) on a tripod pointed at a slide held in a "third hand", with desk lamp shining from behind ("oblique illumination"). Yes, one can easily move it sideways and focus by hand.

[1] https://vimeo.com/user12237688 (technical details in the description)

gattr··on A new wave of Linux applications
FWIW, my smallish project [1] (Rust + GTK3) builds and works on Windows out of the box. I use the MSYS2 build environment.

[1] https://github.com/GreatAttractor/vidoxide

gattr··on Rnote – A note-taking application for drawing tablets, written in Rust and GTK4
In my small project ([1], Rust + GTK3) I pass the program state wrapped in Rc<RefCell> to my update functions (closures-as-event-handlers) and so far it's been OK (after all they're executed sequentially from the main thread only). One just needs to remember not to hold the borrow when displaying a message box (as in GTK it enters a new message loop recursively).

[1] https://github.com/GreatAttractor/vidoxide

gattr··on The mystery of social behavior in octopuses
There is a subplot about intelligence-enhanced cephalopods in Stephen Baxter's SF novel "Manifold: Time".
gattr··on Ask HN: How are your interviewers being rude to you?
Interesting. I haven't seen it here in Europe, but there is such a jar in Mrs. Nguyen's nail salon in the TV series "Better Call Saul" [1]. (Well, I'm not sure about the rose petals.)

https://www.youtube.com/watch?v=OIg9WdWJoME

gattr··on A submarine's weakness: its software?
But if the torpedo has pinged, the sub knows something's afoot, and it could quickly scan in that direction with its own active sonar (giving up your position be damned, we're under attack already) to guide its interceptors. Plus, the attack torpedo is now rushing ahead - and loud.

Sword and shield indeed; it seems the submarine tactics people must have a lot of fun playing with these scenarios.

gattr··on A submarine's weakness: its software?
Sure, but here I imagined you could just home on the attacker's active sonar.
gattr··on A submarine's weakness: its software?
Ah, good point about the structural issue. But as for giving your position away, I meant it to be the last resort, when you're detected and under attack already.
gattr··on A submarine's weakness: its software?
A bit off-topic, but maybe some experts could answer a question?

I've recently re-read Clancy's "Red Storm Rising", the sections on submarine (and anti-) warfare are really interesting (I understand some of it may be simplified/fictional). E.g., how the Mark 48 torpedo can be set to and launched in "hunting mode", where it circles at a slow, undetectable speed, and only after acquiring a target it suddenly accelerates for a kill.

Let's consider this excerpt from [1]:

Terminal Homing is the final stage of the torpedo attack. (...) Terminal homing is an active sonar ping that retransmits on reception becoming more rapid as the range to target closes at maximum speed. (...) The target is alerted to the attack, but there is nothing it can do to defeat the weapon at this point. The weapon is too close and moving too fast to allow time for a countermeasure to be effective.

Now, I might have read too much David Weber ([2]), but wouldn't a small, cheap-ish counter-torpedo suffice? Put 10-20 of them in small automated launchers all around the hull, and let them crash head-on with the (now perfectly detectable) approaching boat-killer, still at a safe distance (which is.. I don't know, 100-200 m?)

[1] https://www.thedrive.com/the-war-zone/33018/modern-submarine...

[2] https://en.wikipedia.org/wiki/Honorverse

gattr··on Hubble finds evidence of persistent water vapor in one hemisphere of Europa
It gets better; one of JWST's uses will be whole-planet monitoring of Mars (which can't be conveniently done by Mars orbiters):

https://www.nasa.gov/feature/how-the-webb-telescope-will-exp...

gattr··on A Closer Look: How I Created a 248MP Photo of the Sun
Ignoring the (rather slow) orbital motion of the Moon, consider: the sky (and the Moon) appears to rotate 360°/24 h. This amounts to 360/(24*3600) = 0.004167 °/s. The apparent size of the lunar disc is about 0.5°, so it takes about 120 s for the Moon to move by its own diameter in the sky. Plenty of time.
gattr··on A Closer Look: How I Created a 248MP Photo of the Sun
In that link it is due to the wavelength used (extreme UV, which shows only active regions as bright, and the prominence layer surrounding the limb.)

However, in many amateur pictures taken in the H-alpha wavelength (like in TFA), the artistic choices come into play, as you said. In the Simon's first image the prominence layer (just outside the limb) is shown as-is (positive), while the disc interior is shown inverted (a negative; note e.g. how the sunspots became white). This is done to get a somewhat more "3D look". In a normal, non-inverted image, the mottles and filaments show up as dark features on a bright background, while inverting may make them look more "natural" (to some) - sometimes downright "casting shadows" (a solar filament often has a brightening around its base - which becomes dark after inversion).

Source: I'm the ImPPG's author (and enjoy solar astrophotography myself).

gattr··on Ask HN: What are some tools / libraries you built yourself?
Back in 2015 I needed a convenient & fast post-processing and image alignment tool for (mainly) astrophotography time lapses, that's how ImPPG was born [1, 2]. (If GIMP had had high-bit-depth support back then, I'd probably try to write a plugin instead.) I still use it, and make small additions every now and then. It's seen some use in the community (probably mainly for solar imaging); GitHub reports a couple thousand downloads for the release that's been up the longest.

[1] https://greatattractor.github.io/imppg/

[2] https://github.com/GreatAttractor/imppg

gattr··on OpenAstroTracker: 3D printed, open source star tracker
A few fellow astrophotographers have built and used them successfully (forum link in Polish):

https://astropolis.pl/topic/71039-monta%C5%BC-wirus-2020/

gattr··on The Ponzi Career
I'll mention the SF novel "Black oceans" [1] again. It describes a scheme where someone extremely driven and confident of success, but utterly poor, can make a deal with certain shady organizations, which - in case you don't make it and repay them in agreed time - will simply harvest you for (very valuable) organs.

[1] https://en.wikipedia.org/wiki/Charne_oceany

gattr··on The Expansion of the Universe
If anyone begins to feel trapped in a cage, please don't just yet. For instance, astronomers currently estimate on the order of 10¹² planets in Milky Way alone, of which up to 11 billion could be Earth-sized and orbiting Sun-like stars [1]. So there's still plenty to explore/colonize, especially if you include the few tens of neighboring galaxies.

[1] https://en.wikipedia.org/wiki/Milky_Way#Contents

← PreviousPage 6 of 9Next →