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skytreader

778 karma · joined April 4, 2017

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skytreader··on Ask HN: Did preparing for LeetCode type of interviews improve your skills?
> It ("getting to world finals") is exponentially harder since due to how ICPC works the rules make it a piece of cake if you are from an unnamed college in norther America but much harder if you are from an established IIT

Rephrased as I understood it in context, it says: "unnamed colleges in northern America has better chances at getting to WF than India, Belarus, or China".

Which is a surprising statement to me. At my time (2008-2012, followed it a few more years thereafter), the heavy hitters were from Belarus/Russia, China, and India to a smaller extent. I remember getting news that Shanghai Jiao Tong really dedicates time to training, almost like a sport. Petr Mitrichev is Russian and tourist (forgot his real name) is AFAIK Belarusian. At least Mitrichev coached in grassroots programs for IOI which then translated to ICPC performance. Maybe India wasn't as dominant but I believe they were at least a considerable contingent in the Asia-regional levels.

So it seemed to me the competition format favored these countries over US universities, which focused on research. Not to mention China and Russia loved hosting big ICPC events, if not the World Finals itself.

Do elaborate on your statement please. I am curious why you'd make that claim.

skytreader··on HashCow, BTC.TOP have halted China operations after Beijing crackdown on Bitcoin
> At its peak, NANO might consume about as much as energy as a single shopping mall.

That's not a comforting analogy. A shopping mall processes payments that confirm almost instantly too, even on exchange, on top of running lights, security, maybe a movie theater, some music over PA, running escalators, cooking food, etc.

And that's just energy consumption. NANO also has hardware costs that scale linearly with the size of a network.

> XMR is about 60 Gwh...at least until more cryptographers work on XMR to figure out how we can increase efficiency.

Educate me if there's an approach I'm missing here but computing experience so far suggests that there will be little improvement in these figures for a damn long time. As it seems to me, P will have to equal NP before significant strides are made in this domain, at which point of course we've opened a Pandora's box that renders most crypto (not just -currency) insecure.

> There are trivial things that consume far more energy than crypto

Of secondary importance to me but I'm really curious what you think these things are.

> Why do you keep saying the technology hasn’t matured after 11 years?

For the record, you are the first person in our exchange to suggest that this tech is still in its infancy. To quote your previous reply:

> Again, this is a technology in its infancy. [https://news.ycombinator.com/item?id=27262914]

Actually, in your very post that I am replying to, you say that,

> These are early stage projects.

My point is, they may be massive improvements, generational strides from BTC, but if after 11 years there are still roadblocks to wider rollout (like, as you concede, efficiency), it's just rational to second-guess the approach.

(Footnote: I feel like the purpose of my ACID DB analogy flew over your head. The whole point of it is not to impress but rather to show why raw throughput without specifying the hardware offers little insight. But that's a moot point here.)

skytreader··on HashCow, BTC.TOP have halted China operations after Beijing crackdown on Bitcoin
> NANO transactions confirm instantly.

> XMR transactions confirm in <2 minutes.

> ETH2 with Optimistic Rollups can scale to 100,000 TPS.

Do you have figures for how much compute power they need for those too?

I could write an ACID-compliant DB that could do 1M TPS but if to achieve that I had to buy a gaming rig or two, run it at basically full capacity, then it all sounds less impressive.

> Again, this is a technology in its infancy.

But when will it stop being in its infancy? At what point do we cut our losses and say this approach isn't working (if I may add, a question every scientific experiment should reckon with)?

> I do not understand the disappointment - Rome wasn’t built in a day.

But we move at a faster pace than the Romans now and if a technology hasn't matured after 11 years, then that's reasonable grounds for disappointment don't you think?

skytreader··on HashCow, BTC.TOP have halted China operations after Beijing crackdown on Bitcoin
> Drug/Darknet markets, for one. Ransomware for another. These are stress-tests for any currency and prove that crypto can work to exchange value in a real market setting.

Those aren't real market environments by a long shot and far from stress tests. These markets have transactions that are low-volume but high-value. Me, what I'm looking for is something along the lines of "How many grocery transactions globally can crypto do per second?", i.e., high-volume, low-value. Now _that's_ a stress test.

Quick Google survey tells me that BTC can do 10 transactions per second _tops_. That's far from a workable state of affairs. It's not even "promising tech".

skytreader··on Nvidia cripples cryptocurrency mining on RTX 3080 and 3070 cards
Total hardware noob here. How do they do it? Is there a particular instruction that ETH needs to be "efficient" but games can live with throttled? Or perhaps a sequence of instructions that's signature to ETH?
skytreader··on Movies every physics lover should watch (2020)
> It's actually a pretty decent movie, but it's a drama, not sci-fi. It uses "science" purely as an aesthetic device without actually exploring any scientific effects.

Fair assessment, but I beg to differ on your definition of "sci-fi"; I find it quite restrictive. You can say the same for Bradbury's "The Martian Chronicles". Mars might as well be Narnia as he just uses the notion of it being an alien planet to set-up tension and make a point about human behavior. It's more philosophical/psychological than scientific but I'd still call it sci-fi.

I guess you are entitled to expect a harder integration of science from a 2011 sci-fi film but I think "Another Earth" definitely takes from established, if outdated, cues in the genre.

But potaytos and potahtos. We can differ in opinion.

skytreader··on Movies every physics lover should watch (2020)
Love "Arrival" but I won't nominate it for this list. It's for "physics lovers" and "Arrival" is more for linguistics nerds; the central plot of the film hinges on the Sapir-Whorf Hypothesis, after all.

In the same note of "sci-fi but not exclusively physics", I want to recommend "Another Earth"---very indie production, for better and for worse. Also, if you are a physics nerd, a certain plot point might irritate you. But, on behalf of the film, I ask you to grant it a bit more patience and suspension of disbelief. For me it hits the same dramatic notes as "Interstellar". Good quality intellectual entertainment.

skytreader··on Sony discontinues its last DSLRs
> Sony appears to have quietly stopped selling its A-mount DSLR cameras

I just hate that Sony can't be bothered to give an explicit send-off to the A-mount line. Coupled with their abysmal customer service reputation, this really makes Sony my textbook example of a faceless, uncaring $BIGCORP. (Oh should I call them $ONY now?) It's really such a shame since I like their products, otherwise.

I've owned an SLT-A35 since 2011. Being the first interchangeable lens camera I bought, this purchase was a declaration of investment in Sony's ecosystem. Four or five years later, the A-mount line grew stale in favor of the mirrorless line. 2015-2016 was confusing because Sony won't just admit their roadmap for the A-mount. I remember they did release a few more A-mounts but it was either at the very high end or was Japan-only.

FWIW, at least I scored one great deal because camera shops started to practically give away their A-mount inventory. And I got a mount adapter that I now use with an a6K. ¯\_(ツ)_/¯

skytreader··on .org doesn't mean credible
I also didn't realize the carousel of screenshots has a caption specifying the site name. Which I thought was an odd oversight.

Then I realized the site name is in a thin red font on a dark background.

skytreader··on Elevator Sabbath service mode (SHO)
I'm not a religious scholar but these interpretations:

- "do not fix things on the Sabbath" ban[s] completing circuits

- "do not break things on the Sabbath" covers breaking a circuit

sound extremely convoluted to me. A switch's express purpose is to break and complete circuits to direct current. It is part of the object's usage, part of the creator's intent on the object's utility. It has modes of operation where the circuit is broken and complete by design. The saner interpretation of this law IMO would be along the lines of "if a switch got stuck on a Sabbath, good luck on the energy bill, mate".

I have one of those trash cans with a pedal that opens the lid. It is a switch but none of it is electronic. Are Jews not allowed to operate these contraptions on a Sabbath too? It arguably introduces a break in the object, namely the opening for the trash can. Heck, does Jewish law even allow opening trash cans on a Sabbath, at all? By such broad applicability, the only difference between any lidded trash can (a closed object most of the time) and an electric circuit is the presence/absence of current. Can a Jew unlock padlocks on a Sabbath? What about opening doors?

(FINAL NOTE: HN mostly has charged---pun intended---discussions over things we deem ridiculous. Such discussion is NOT my intent here. I know J. Random Netizen like me isn't going to change Jewish culture in two paragraphs. I just wanted to waste actuations of my mechanical keyboard to register my astonishment and confusion over this interpretation.)

skytreader··on Is Werewolf Killing the Conference Hackfest? (2007)
My experience is different. One thing I looooovvvveeeee (I can't emphasize that enough) about Werewolf games is that it enables emergent narratives. The story writes itself, even in the one-night variant. Narrators, just write down the proper order of role callout each night. Waking one group up before another is what can spoil a game/round.

I even used to not like being the narrator because I'm not in on the thrill. But knowing exactly what's happening and seeing people blunder, or take advantage of confusion, or whip up an alibi out of nowhere, is just as much a roller-coaster!

There was even one time as a narrator, had one of the players been capable of reading micro-expressions, they would've had a huge leg-up from seeing my reaction to an in-game "day" event.

This game is so much fun!

skytreader··on You might as well timestamp it
My goodness. I remember having to explain this to my manager. They really wanted recording + playback in our platform. For as many browsers as possible. Even mobile (iOS, I'm looking daggers at you). In 2015.

AFAIR I just said fuck it and made playback as permissive as possible (i.e., only prevent media playback if canPlayType returned ""). I don't know how advisable that is but the bug got off my back anyway.

I dunno what makes this so difficult, why we can't get at least a definite "yes" even in 2021.

skytreader··on Old Book Illustrations
So I think the one thing that will resonate with the HN crowd is the fact that Stan Prokopenko, one of the hosts, is also some sort of small-time tech entrepreneur. This comes up throughout the episodes but two that really focus on his efforts are:

https://www.youtube.com/watch?v=OtApUuFLeGA&list=PLVeITADsnv...

https://www.youtube.com/watch?v=qtpRGxe5_H8&list=PLVeITADsnv...

If you take programming/hacking as an art and hold fierce ideals over it, some of their other episodes might also benefit you, either personally or professionally:

Reinventing yourself: https://www.youtube.com/watch?v=Y2gp5_F7-9U&list=PLVeITADsnv...

On the Gaming Industry: https://www.youtube.com/watch?v=eBkbFBl05-s&list=PLVeITADsnv...

Becoming more creative https://www.youtube.com/watch?v=DX9e5WAOoQ8&list=PLVeITADsnv...

I just want to say, whatever your feelings about programming as an art there are still definitely differences between the two industries. I might just be biased because if I didn't love my paycheck too much, I'd probably be making indie comics.

skytreader··on The Cursed Computer Iceberg Meme
I really didn't get this and Google search comes up with nichts. Maybe cause I'm in Germany so it doesn't ring a special bell to Google. Explainer someone?
skytreader··on Old Book Illustrations
Cool! I've been listening a lot to the Draftsmen podcast lately and one thing that they keep mentioning is "studying the (old) Masters". I'm not sure if these qualify as "Masterworks" per their definition but it's from the same era, i.e., when drawings/engravings/art had to be planned and executed carefully because a mistake is not as cheap as a CTRL + Z.

Another thing Draftsmen made me realize is the actual art (or at least craftsmanship) of comics. They may be mass entertainment (i.e., we're talking mainstream here, not your charming indie series) but even in their early incarnations comic art was still grounded in solid art principles. A lot of the works here exhibit that thesis:

- Prints like https://www.oldbookillustrations.com/illustrations/dreams-lu... remind me of Marc Hempel's work on The Kindly Ones arc of Gaiman's Sandman.

- Kind of a cheap shot to mention Charles Vess but look at prints like https://www.oldbookillustrations.com/illustrations/many-beat... and you really see the movements that influenced him.

- The range of https://www.oldbookillustrations.com/illustrations/woman-par... might as well be 80s-90s pop art, if not for the finer details in the shadows.

- Like Vess, Frazetta might be too easy an example but I fancy he took his technique of theatrical lighting and exaggerated dynamic ranges from old black and white engravings.

skytreader··on Have I Been Facebooked?
> Your phone number has not been found in the leak. This is good, but you should be worried anyway.

I, too, am wary of Facebook but to other people, without reasoning provided, this sounds like FUD. Maybe at least link to an article explaining why they should be concerned anyway.

skytreader··on Sick of these startup executives, painting a rosy picture for employees
Am I the only one who doesn't see a rosy picture in the Twitter thread? The tone is definitely positive compared to huyenchip but it isn't idealized to the point of being disingenuous. I'd say it even paints an accurate depiction of a start-up's struggles.

Her first point is even "Play the long game". It's not an overnight success. "Wealth creation doesn't happen in one go, make it a long game, with regular payouts, that then get invested in some form again & grow more & more".

The Twitter thread and the blog post aren't contrasting experiences. Yes you had to do lots of something you didn't want to do but that something was you, an engineer, had to do market studies for a feature you would later build. Yes most startups won't offer a clear career trajectory because, quoting the thread, "Will you be a brilliant full stack engineer or do you have potential to start as a good one but can pickup quickly & grow into a data engineering role".

Yeah start-ups could overhype the experience the way they oversell their product. But I don't see the that in the thread.

skytreader··on Security Breach at US Universities
Foreigner's two cents: it's not that they don't care---the abysmal availability of Google Street View attests to that among others---but rather a combination of (a) masses (and hence bureaucrats) not having as comprehensive a definition of "personal-data invasive" as those that work in tech and (b) this German trust in any document that can be ratified/made into a legal proclamation.

(a) isn't really uniquely German, of course. Most people not in tech, though privacy-conscious, won't really bat an eyelid on Windows 10 telemetry, Instagram's excess of data gathered, etc.

With (b), I bet the Universities are satisfied that Microsoft has all clearances/certifications to be GDPR-compatible or whatever else. That pacifies their cynicism. If shit hits the fan, the courts can worry about it. The important thing is they checked all the boxes in the paperwork with sufficient diligence.

Again, just my two cents. I'm not even European but it seems to me Switzerland in real-life is what Germany is in most people's imaginations. But again, that's just more of my opinions.

skytreader··on Arabian Nights
Cooool! Exactly what I'm looking for. Actually think I've heard of this before (I follow one of the GH contributors) but realized, just now, it's the mirror I am looking for. Thanks!
skytreader··on Arabian Nights
Technically, Project Gutenberg blocks Germany. Anyway this also surprised me last year! Protip: Main PG is blocking DE IPs but mirrors aren't. Unfortunately, [mirrors](https://www.reddit.com/r/books/comments/81t0ad/project_guten...) don't have the convenient search infra, just the texts. If you can get the ID somehow, then you can navigate to the text in question.

Maybe I missed a more convenient mirror. In which case I'd be really glad for links to convenient mirrors.

skytreader··on All my servers have an 8 GB empty file on disk
Oh man, reminds me of a Game Dev war story I read years ago. This purportedly happened in those console days with very limited memory capabilities.

In some game studio, as a project neared its release, the team was still struggling with memory issues. No matter what they did, they had a surplus of just about 2MB. The artists have reduced their polygon counts drastically, the programmers have checked every possible leak, have optimized algorithms and buffers the best they could but the 2MB surplus just kept haunting them.

That's when the VP of Engineering stepped-in. Calling the TL of the project into a closed-doors optimization code-review, they had the source code on a large screen and the TL talked the VP through everything the team has done so far to stay within the memory budget.

As the TL finished the walkthrough, the VP opens some mother-of-all files and deletes a cryptic variable declaration to the effect of:

  int toLiveBuffer[2000000];
The VP then explains that he hid this declaration in their codebase after a project that had to optimize drastically late into the development cycle. But first he wanted to make sure that the team did their homework.

And poof. They emerge from the closed-doors meeting jubilant and victorious. The game is ready for prime time!

skytreader··on We found and fixed a rare race condition in our session handling
> On March 2, 2021, we received a report via our support team from a user who, while using GitHub.com logged in as their own user, was suddenly authenticated as another user.

Sobering thought for me is how probable it is that a similar issue might be present in other platforms. The title calls it "rare" but given (a) the number of complex-enough web/app platforms in use today, (b) just the endless number of ways/infra permutations for "doing x", and (c) the size of a typical company's codebase and dependencies, could it be a more common occurrence than we think?

Total anecdote, up for you to believe: Back in April 2016, one of my then-housemates bought a brand-new Macbook Air. A week into his ownership, he exclaims surprise that he is logged-in to another Facebook account, someone we are totally not acquainted with. I borrow his MBA and try to investigate but, alas, I lack expertise for it. The only relevant thing I can eke out is that they both went to the same event a week or so ago and probably shared a Wifi AP, where a "leak" could've happened. Or maybe a hash collision in FB's side?

I would've reported it to FB but then I don't have enough details; with the two conjectures I have, I'm basically holding water with a sieve. But now the thought that someone I totally don't know might end up logged-in in my FB account is a possibility that bothers me. And I have no idea how to prevent it other than minimizing what could be compromised (and no, "Get off FB!" just isn't in the cards, I'm sorry).

Kudos for Github for investigating and fixing this issue. Another thought that occurred to me while writing this is how many users of other platforms might be filing issues like this but can't provide enough detail and so their reports are eventually marked as "Could Not Reproduce". Not exactly leaky sessions but just general security mishaps that they would struggle to describe to support.

skytreader··on GitHub, fuck your name change
The current problem surrounding using AI/ML in this area is that it can't distinguish between Jean Pierre and John Paul, Luc and Luke and authorities rely on it with no nuance or discernment.

You worry about artificial neutrality creeping in to the algorithms, but the algorithms already reflect human bias. We can't even reliably tell where someone is from yet we expect our AI to do it close to flawlessly.

I'm from East Asia and I think I can distinguish an East Asian's country of origin maybe 70% of the time. But 70% is nowhere near good enough if a person's life literally depends on the decision. And I bet you'd be hard-pressed to find someone even in around 90% accuracy. Migration and shared culture, among other things, make this difficult.

skytreader··on How a game about making zines helped me recapture my creativity in lockdown
I only came across the concept of zines the past year, while in lockdown. That coupled with the growing nostalgia for "the old web" gave me the idea to create a Neocities account for "creative idea brain dumping". The intent is for it to hold the creative work (e.g., photography, fiction, or just plain web/coding experiments) that I have not deemed good enough for my usual self-promotion channels (like DeviantArt and FB for my photography, GitHub for coding). I've never experienced zines but I feel like this captures their spirit; publications that can't get any more amateur if they tried.

Alas, I got caught up in the project planning tendencies I've acquired from work. I got to design homepages for two projects/e-zines but that's pretty much all I've finished. Nested in my project directories are markdown files of stories in various stages of completion, a portfolio of digital paintings that have lost stylistic cohesion, CSS and JS files for half-baked "cool ideas". In my Trello boards are concepts and character backstories though, right now, there's only one card in-progress and null finished.

But I'm not disappointed with it! I definitely learned a lot in this ultra-unfinished project. It gave me the impetus to finally learn CSS and JS properly (as opposed to copy-pasting SO snippets to meet deadlines). And I bought a Wacom tablet and learned digital painting which is a really cool hobby to wait lockdowns out.

It is exhausting trying to do everything as a one-man team but the act of brainstorming itself is creativity-refreshing. I'd still like a finished work to point to but, with all I've already done, I have found internal satisfaction.

skytreader··on In the 90s part of Germany's air traffic control software ran on Emacs
I liked the account but to be honest this line about Herr Doktor and Moses really flew over my head. It's just a bunch of cultural allusions but I don't see how they connect.

- Herr Doktor is a traditional German title, roughly equivalent to the more-known "Doctor of Medicine (MD)" or "Juris Doctor (JD)".

- Is the allusion to Moses due to this story being post-war/unification and Moses is a Jewish figure? (There might be technicalities between "Jew", "Israelite", and "Abrahamic" but I'm even more ignorant here than I am of German customs.)

- Is "space on the stone tablets", "11th Commandment" an allusion to the (in)famous German noun-phrases? Like "Wohnungsgeberbestatigung" which is actually three words (trans: "apartment-provider's confirmation"/"landlord's confirmation").

So...explainer from anyone who got this line?

skytreader··on Changes to LastPass Free
Sorry if I'm asking an obvious question but how is this more convenient than pure-desktop Lastpass? If I'm inconvenienced by Lastpass' change of terms this is hardly a solution isn't it?
skytreader··on Ask HN: Indepth Introduction to RDBMS (Or Postgres) Internals
For Postgres specifically: http://www.interdb.jp/pg/
skytreader··on Ask HN: Show me your half baked project
Erdem (https://github.com/skytreader/erdem) is a small "media-center" webapp that I've been building. I'm also using this as an opportunity to learn React.

Over the years I've amassed a collection of video files with filenames similar but not exactly like, "Lionel Messi vs Miroslav Klose".

The actual data set is dirtier, can't be regexed, etc. A key property of my data set is that a name features in the filename of different files.

I made this to easily answer the question "Hey, I want to watch a video about Messi. I wonder what I have?"

So, being the computer scientist I am, I thought it'd be interesting to index the filenames. Hence, the indexer whose code I experiment with a lot; dirtier than usual, very "academic" style.

Then I realized all I need is a search function (which I have implemented already!). Life works. Maybe I'll keep with the indexer idea but just for something to play with.

P.S., I have words to say about React but this isn't the thread for it I guess. Been a frustrating experience so far. But well, that's why I used it in such a rough hack in the first place.

skytreader··on Wikipedia frequently-encountered sources, color-coded by perceived reliability
Curious and funny: The Onion is slightly more reliable than some non-satire websites.

For Wikipedia's purposes, I would think Onion would be an outright "Do not use".

I wonder what cites The Onion? The only reason I can think of would be for meta-Onion entries, e.g., Wiki entry on The Onion itself, perhaps their management board, etc.

skytreader··on Assembly language, arcade games, YouTube: former Microsoft engineer Dave Plummer
https://www.youtube.com/watch?v=Ig_5syuWUh0

Is the story straight out of the horse's mouth. What you miss from reading transcripts of interviews/reddit comments is that this guy has got a great sense of humor. He obviously reads from cues on his Mac (oh the irony, winkwink) but the storytelling/delivery is not far from stand-up comedy.

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