gattr

You are mistaking two effects. Indeed, glass does not "flow" (it's not a "very, very viscous liquid"); but most assuredly it does sag under gravity - just as a heavy steel beam supported at the ends would.

This problem is much simpler to solve for mirrors than lenses, as mirrors can be supported under their entire surface (see [0] for how it's done in larger amateur telescopes), while lenses - only along the edge.

[0] https://www.cloudynights.com/topic/562906-18-point-flotation...

An interesting usage example for very black materials (which are required to be effective also at grazing incidence angles) is flocking the insides of amateur telescopes. Not that it's always necessary, but can help in some poor designs where the light beam might reflect off some optical tube elements etc. (which results in a decreased overall contrast).

One of the popular choices these days are adhesive sheets of black velour. Another option is thick dark paint mixed with sawdust.

Also the Fresnel reflection coefficient comes into play [0]: water surface has higher reflectivity at grazing-incidence angles than at those close to the surface normal.

[0] https://en.wikipedia.org/wiki/Fresnel_equations

To be precise: lifetimes are denoted by an apostrophe. (Backtick can be used in comments for Markdown formatting.)

Seems to work fine here (Firefox 68.0, Radeon R370, Fedora 5.2.7-100.fc29.x86_64, KDE/X-Window). That is, I can see the satellites and the rotating globe with strips of land gradually revealed.

So, to avoid people going insane, the code shall be put to refactoring. Each volunteer will only work on a single line of code [0]...

[0] https://en.wikipedia.org/wiki/The_Funniest_Joke_in_the_World

Banning open source software is probably not feasible (you can distribute the code as a printed book after all). They would have to:

- ban all Internet traffic that uses non-backdoored encryption (all ISPs would be required to report it)

- ban all amateur radio equipment, including all products one could use to build a satellite dish (like aluminium foil?..); keep a fleet of radio-direction-finding vans circling the streets

Eventually, maybe also ban general-purpose non-backdoored computers.

On a similar note: "How close would you have to be to a supernova to get a lethal dose of neutrino radiation?" [0].

BTW, this happens in the novel "Iron Sunrise" by Charles Stross, where people on an Earth-like planet suffer the misfortune of their star reaching (artificially) the supernova stage.

[0] https://what-if.xkcd.com/73/

Of course, my mistake.

I also updated the 1700X to 2700 this year, the "marginality problem" ([0]) affecting some of the early Ryzens (random segfaults after some minutes of heavily parallel workloads with lots of process creation - e.g. builds!) was getting more annoying when Rust needed to download and compile a bunch of crates. I'm very satisfied - more or less the same performance (3.2 vs 3.4 GHz), but 65 W instead of 95 W TDP.

[0] https://www.phoronix.com/scan.php?page=news_item&px=Ryzen-Se...

My tangentially related experience: when I switched (after 4 years) from a Core i5-3570K (4C/8T, 3.4 GHz nominal) to a Ryzen 7 1700X (8C/16T, 3.4 GHz nominal) last year, multi-threaded build time of a smallish C++ project I work on went down from 1 minute to 30 seconds.

I'd really like a comparable speed-up on my next HW upgrade; hoping for affordable 16-core CPUs 3-4 years from now.

Associated read: "Titan" by Stephen Baxter. Hard SF describing a manned mission to Titan using present-day level tech; great attention to detail, but be warned that the overall tone is rather depressing.

Myself, I'm absolutely fascinated by the confirmed hydrocarbon lakes and rivers on Titan and can't wait to see actual optical images from up close (so far we only got synthetic-aperture radar images [0]).

[0] https://en.wikipedia.org/wiki/Titan_(moon)#Lakes

Interesting point. I can add that it ran smoothly with full-size view on an IBM PS/2 70/80 laptop with a 386SX 20 MHz.

I got a RPi 3B+ to build and test some open-source amateur astronomy tools I contribute to - everything has been working quite nicely so far (I use Fedora on my computers and it also works fine on the Pi). I'm eyeing the RPi 4 with interest.

As for interesting consequences of a vastly different planetary age: in one SF novel (could be Peter F. Hamilton's, I can't remember right now) humans colonized an Earth-like planet only some 2 billion years old or so. Its uranium ores had so high U235 content (as opposed to Earth's 0.72%, which requires costly enrichment), that you could simply smelt it and put straight in a reactor (cheap nuclear-powered locomotives anyone?).

I absolutely recommend all of these. And of course Reynolds's "House of Suns", which sort of takes the "lighthugger" concept up to eleven.

I've been fully on Linux since 2015. For C, C++ and Rust: Visual Studio Code with appropriate plugins (previously, until ca. 3 years ago - Eclipse). At work we have CLion. For quick editing I'm content with Kate, the text editor bundled with KDE.

Actually, you could "mouse look" in the original game, sort of - in addition to looking left/right, moving the mouse up/down would also move the character forwards/backwards.

Not much to see here, in Polish all the forms (for plural and singular) are just:

pies, psa, psu, psem, psie, psy, psów, psom, psami, psach

Agreed on the subjectivity. At home (on a 24" 4K monitor) I use Consolas (18 points), at work (on 24" FullHD) I like Ubuntu Mono.

For building my (rather small) projects for Windows I use MSYS2 [0]; it uses pacman for package management and has quite a big library of ready binaries.

[0] http://www.msys2.org/

Impressive, to be sure, especially the technical side of things.

However I really dislike greenhouses like these for the huge amount of light pollution they cause (speaking as an amateur astronomer). Sure, it probably doesn't matter much in a densely populated area like the Netherlands, but they start to also pop up here in Eastern Europe, in (previously-) dark-sky locations.

Is it publicly visible? At the moment in your profile I can only see "about", submissions, comments, favorites.

I still have the code (old and ugly, so not on GitHub; but it still builds and works) and examples. Let me know where I should send it.

I agree it's a great exercise. Years ago I added a very simple stack-based VM to my raytracer to allow procedural textures & normal maps. The scene script would e.g. contain a material description like this:

  material {
      diffuse rgb = [0, 0, 1] * (1-(0.5+0.5*noise(x*0.000002, y*0.000002, z*0.000002, 0.66, 2))) + [1, 1, 1] * (0.5+0.5*noise(x*0.000002, y*0.000002, z*0.000002, 0.66, 2));
  }

i.e. an expression with 3-vectors and scalars and a few basic functions (noise, sin/cos, etc.). This can be easily "compiled" (during script parsing) for execution on the VM. Then the overhead during actual raytracing was quite small.

Ah, one of my favorite astronomy-related trivia.

It also shows how a supernova can (briefly) shine as brightly as its whole host galaxy (i.e. some 10-11 orders of magnitude stronger than an average dwarf star - like you wrote, those basically "smoulder").

And in Dukaj's "Perfect Imperfection" [1] occasionally multiples of Planck time are used (with metric prefixes), as the post-humans and "out-of-space computers" can operate on very small time scales.

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

I remember reading an analysis saying it's the "persistence" features in games that have the strongest potential for addition. E.g. you could play Counter-Strike all night, but the only thing you bring out is your improved skills. Unlike MMORPGs and similar where you "develop the character" and "accumulate equipment" (these days, also for real money).

I'm into computer graphics, so for me it's raytracing. The principle is simple, so one can quickly code some "shiny spheres" example, but then there's a lot of interesting connected stuff to learn: linear algebra, spatial data structures, Monte Carlo extensions, ...

It's interesting to note that, regardless of actual origin of life, a significant exchange might have been occurring (or is still occurring) between Solar System bodies (judging by how we found a number of Martian meteorites on Earth). So if we find life elsewhere in the Solar System, it might be quite compatible.

The idea is mentioned in Kim Stanley Robinson's "2312", where simple organisms exist in Enceladus's ocean, and some people inject them for fun (with neutral or mildly beneficial effects).

Motorized sex-androids also come to mind (remember the articles about the existing ultra-realistic doll makers? the "UI skin" part is already there).