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Ask HN: What's the hardest problem you've ever solved?

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Re: Ask HN: What's the hardest problem you've ever solved?

#351

Post by ph0rque »

brianpgordon wrote: post #262
ph0rque wrote: post #102

Earlier quoted context omitted.

Thanks for the idea! I found a variety of altimeter apps for the phone; I'll have to try just walking around my yard with one (or several), then see if it's possible to get elevation data on a map from such an app.

I'd suggest getting an app like Sensors Multitool for Android which gives you the raw output of your phone's sensors. I tried one of the altimeter apps a few years ago to see how tall a big hill was, and the value that the app reported turned out to be far off the actual value. There are various techniques for mixing and cleaning data from the GPS and barometric pressure sensors and a premade altimeter app (if it's n…

Thanks for the tips! I don't need accurate readings, just precise ones (so the map can be internally consistent; here's what I drew manually for my property: https://i.imgur.com/2ZGmB1M.png). I'll keep in mind what you suggest when I am ready to develop that part of the app.

Re: Ask HN: What's the hardest problem you've ever solved?

#352

Post by unimpressive »

yholio wrote: post #90

I somehow decided I needed to cheat to pass a certain exam because I was basically crap at memorizing stuff. So I used an analogue wireless headphone, an induction loop around my neck and a mobile phone. Since I lacked an accomplice to dictate, I read aloud the hundreds of pages and recorded myself, careful to preserve and properly serialize things like complex formulas. This was before the era of iPods and SDCard pl…

Amazing as this tale is, folks for anyone else who is sure that memorization is too hard don't do this. The real tip is:

Spaced repetition. Load up Anki or Mnemosyne and stick the info in there.

"Craig prepared for Jeopardy! by studying the online archive of past questions maintained on the J! Archive website. Using data-mining and text-clustering, he identified the topics most likely to occur in game questions,[9] then used the spaced repetition program Anki for memorization and tested himself using his own program.[10][11][12][13][14]

Craig played quiz bowl as a student at both Virginia Tech and the University of Delaware.[15] Before his Jeopardy appearances, he played numerous Jeopardy scrimmage matches against his friends with quiz bowl experience.[14]"

https://en.wikipedia.org/wiki/Roger_Craig_(Jeopardy!_contest...

Re: Ask HN: What's the hardest problem you've ever solved?

#354

Post by steelframe »

grenoire wrote: post #91
yholio wrote: post #90

I somehow decided I needed to cheat to pass a certain exam because I was basically crap at memorizing stuff. So I used an analogue wireless headphone, an induction loop around my neck and a mobile phone. Since I lacked an accomplice to dictate, I read aloud the hundreds of pages and recorded myself, careful to preserve and properly serialize things like complex formulas. This was before the era of iPods and SDCard pl…

Damn, man. You're hired.

In the workplace, no amount of technical ability can compensate for a lack of ethics.

Re: Ask HN: What's the hardest problem you've ever solved?

#355

Post by astrostl »

Hardest, IDK. Most clever, the first that springs to mind is a power supply unit (PSU) replacement on an old HP server. It went down over the weekend, and HAD to be back up. It also had a proprietary pin setup with more than the standard ATX plugs. I popped in an ATX replacement, and it wouldn't go.

If you've never seen a PSU plug, it just has a bunch of cables placed into a plastic block for socket standardization - you're plugging in a chunk of plastic, which is physically assuring that each cable will go in place. Since I had little to lose, I severed the plastic block on the OEM PSU as to create two plugs: one ATX/standard, one proprietary. I then tried firing up the system with a standard ATX PSU in the ATX sockets, and the proprietary plugs (connected to a dead and not even power-connected) into the proprietary sockets. And it worked! I let the system run like this with a dead OEM PSU plugged into it with an open case as I waited for a proper part replacement.

I'm still not sure what those cables actually did. I posted about this on Usenet, and got 1-2 emails over the years about how it had saved someone else's bacon. Sadly, I can't even find it after the Deja News -> Google Groups -> offline transition of Usenet search.

Re: Ask HN: What's the hardest problem you've ever solved?

#356

Post by dennis_jeeves »

yholio wrote: post #261
yesenadam wrote: post #252

Earlier quoted context omitted.

You rejected ethical behaviour 'on principle', you even seem proud of that. Have you kept doing that in life? Do you feel like an impostor, presumably with your degree that you didn't think you could acquire without cheating, or couldn't be bothered? A surprising number of the replies to your comment also seem to think cheating like that at university is perfectly fine.

Ethics is not something that gets decided by the Dean and laid down in a code of academic ethics. The University is just a part of society and it has it's own perverse and quite unethical practices; for example, the tendency to grab one's money and time and not provide any substantial education in return. Furthermore, the university might be perfectly aware that it provides crap services and that fraud is rampant, ye…

Hey Yholio, don't even bother to explain to the nuts here, who are questioning your 'ethics'. They do not have a nuanced view of ethics. For them the rules, as laid out by the authorities (in your case the university) is the template of what is 'ethical', they are incapable of thinking beyond that. The frightening thing is that they unfortunately represents the vast majority of people.

Re: Ask HN: What's the hardest problem you've ever solved?

#357

Post by collyw »

simonbarker87 wrote: post #53

Fixing a SRAM 11 speed GX rear shifter on my mountain bike. I was on a downhill MTB holiday and fell off, snapping the thumb trigger on my rear gear shifter. Replacing the shifter is usually like a £30 part, but I was in an alpine resort in summer so the shops that stocked them were charging nearly £100! I had my tools and some super glue so sat down to repair it. The snapped part fixed in two minutes but getting tha…

Curious if your hourly rate at work works out at more than £28.5 per hour, as that's what your time would have cost. Saying that I imagine the satisfaction was worth it. (I do a lot of my own bike repairs and a 5 minute youtube video usually works out as closer to an hour or two when I try.)

Re: Ask HN: What's the hardest problem you've ever solved?

#358

Post by max76 »

slededit wrote: post #346
max76 wrote: post #155

Earlier quoted context omitted.

Some classes are on the critical path to graduation. I wouldn't suggest delaying an entire degree because one or two classes have bad exams. Cheating to avoid memorization is childish, but let's not forget that students are usually children, or still in the process of maturing into adults.

University students are legally adults and we’re considered so until recently. I don’t thin infantalizing young adults is healthy.

In the US the legal age of adulthood is 18. This is very far from the actual maturity point. It's not infantalizing to be accepting and unsuprised when a 18-22 year old does something childish.

Edit: Being a child, and acting childish is an important part of the life cycle that allows development. We seem to be bumping into some biological limits on how late we can extend it, but if it were possible I would.

Re: Ask HN: What's the hardest problem you've ever solved?

#359

Post by stefs »

yread wrote: post #348
ak39 wrote: post #260

Earlier quoted context omitted.

I was going to say the same thing. We really need a HN hall of fame for many of these types of comments. Pure gold. Made my Sunday.

I've made htts://www.reddit.com/r/HNDepthHub to share interesting comments, feel free to add some

that comment would be a better fit for hnbestof

Re: Ask HN: What's the hardest problem you've ever solved?

#360

Post by effie »

1000units wrote: post #230
max76 wrote: post #155

Earlier quoted context omitted.

Some classes are on the critical path to graduation. I wouldn't suggest delaying an entire degree because one or two classes have bad exams. Cheating to avoid memorization is childish, but let's not forget that students are usually children, or still in the process of maturing into adults.

It's already terrible enough the extent to which higher education has become an infantilizing scam in the US. Failing to learn critical coursework should delay graduation, and cheating should result in expulsion. These are good things.

In a perfect university teaching environment, yes. However, in real life sometimes cheating is necessary. Real university environments are flawed, rules and requirements often stacked against the student. They have to pay up, get a massive loan, endure narcis/dumb teachers and stupid administratory requirements, and educate themselves despite that environment. After a lot of invested time and money donated by state/parents, if faced with particularly nasty course exam they are unable to pass in a legal way, it would be crazy to fold and waste all that investment.
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