Ask HN: What weird or hard problems are you trying to solve? • Hacker News Board

Re: Ask HN: What weird or hard problems are you trying to solve?

#811

Post by alexyz12 » Wed, Jul 08, 2020, 3:23 AM UTC

mackie_roy wrote: post #795

alexyz12 wrote: post #392

I am building a database for human movement. Right now each exercise or pose or movement is indexed by its name - Downward dog, squat, handstand, etc. But this gets confusing when multiple names apply to the same movement. The true identifier is the motion of your limbs in space. I want to encode that motion/position so that if you try and upload L-sit handstand and also L-sit, it tells you that you are try to upload…

Is there a way to get updates with your project's progress? Human movement notation is also a hard problem for dance and choreography that needs solving. My partner has been talking about it for years, and there would definitely be interest from the dance world.

I don't have a GitHub repo or anything going yet. I can update this comment when I do. My email is in my profile if you want to stay in touch. In fact, I would really appreciate it. Dance and choreography would certainly be a big aspect.

Re: Ask HN: What weird or hard problems are you trying to solve?

#812

Post by dr_dshiv » Wed, Jul 08, 2020, 6:02 AM UTC

PaulDavisThe1st wrote: post #668

dr_dshiv wrote: post #468

Earlier quoted context omitted.

Silly indeed. The fact that integer relations are mathematical relations that bear so heavily on physical phenomena is precisely the point. That's what the ancients got so damned excited about. You may not find meaning in it, but it certainly drove the development of science and philosophy from Plato to Galileo to Kepler to Descartes to Newton, etc. Now, in recognizing that integer relationships are, in fact, an impe…

1) "Do not mistake your models for reality" (Lord Kelvin, sometime in the late 1800s) ... many of things that we describe with "small integers and ratios" are not in fact small integers and the ratios are rooted in our observations and thinking. The natural world is more fractal than integral, but the notion of "oh! that thing is a lot like two times that other thing" was a notion more accessible to natural philosoph…

* On Byzantine music (this discusses a paper discussing the octaves) https://spinstrangenesscharm.wordpress.com/2017/04/29/making...

* Your friend seems to be discussing the Pythagorean pure interval tuning system where, indeed, going up is different from going down --

* In my own empirical work, I've found that pure intervals are not preferred compared to slightly dissonant intervals (in 3 tone sawtooth chords). You can try it yourself -- perfect consonance sounds much worse! Understanding this conflict with mathematical intervals is part of trying to "solve" harmony

* I agree we should remain disinterested in our models, such that we are driven to improve them and not espouse them as reality.

* Yet, I think it is a mistake if we aren't inspired by simple models -- or at least take their hypotheses seriously enough to test empirically

* For instance, is cognitive dissonance involving actual dissonance of some kind? The brain is incredibly rhythmic and even has octaves in the coupling between brainwave bands. It would seem to be natural to test these theories that Plato laid out thousands of years ago -- for instance, that musical rhythm entrains neural rhythms through resonance effects. Maybe that sounds silly, but I'd argue that we are foolish to avoid gathering empirical evidence for these ideas!

* Similarly, harmony had a major effect on astronomy. It actually still does, at the level of the cosmic microwave background radiation, where the presence of perfect harmonic peaks in the signal were the conclusive proof that the universe is "flat"

* Using the concept of sympathetic resonance has been extremely generative in psychology (see Adam Smith's first book) as has harmony in economics. Expecting what is pervasive in physics to apply to these domains doesn't mean it should apply in exactly the same manner -- just that one should expect analogous effects -- at least to the extent that one is looking for explanatory theories to test! We are so far from understanding these domains that, if we don't at least consider these natural and ancient theories (because they seem silly), we are doing ourselves a disservice. Let us be inspired by the past and test, test, test!

Re: Ask HN: What weird or hard problems are you trying to solve?

#813

Post by hazeii » Wed, Jul 08, 2020, 9:29 AM UTC

ComputerGuru wrote: post #720

hazeii wrote: post #144

Earlier quoted context omitted.

Thanks for reply, and do you already work for us? :) We've burnt through a pile of MEMS devices, currently working with CRM100 gyro's. As far as I've got is we definitely need a non-contact solution, either optical or MEMS with a once-per-rev index pulse (which obv. needs to be within the same 0.05 degree requirement).

I’ve been tackling my own issues with ideas that are sound on paper for physically small products where I run into mechanical or industrial limitations/difficulties which I’m not (or at least certainly didn’t start out) well-versed in rather than any electronics or programming issues. I hit a brick wall years ago (asked here on HN in the distant past but didn’t get anywhere) and actually never progressed past that. I…

Good ideas though, we've come across the multiple MEMs approach (someone put I think 16 on a single PCB to get 4 times the resolution). The CRM100 [0] we're currently using is the best we've found so far for our application.

We're been using liquid-level inclinometers for calibration and lab testing, unfortunately they are too slow for use on the road.

LVDT's and similar would be great, however the engineering cost (at bicycle scale) puts them out of reach, which is the same for precision optics for IR solutions. Plenty of $1k+ encoders out there but way over budget for us!

Thanks for the ideas and feedback!

[0] https://www.siliconsensing.com/products/gyroscopes/crm-pinpo...

Re: Ask HN: What weird or hard problems are you trying to solve?

#814

Post by dredmorbius » Wed, Jul 08, 2020, 2:22 PM UTC

aerovistae wrote: post #810

dredmorbius wrote: post #797

Earlier quoted context omitted.

Yes, basically. The strace option should be doable. Terminal & timer a bit more work. So long as the print statements come between other blocks of code, though, I'd look at strace (or dtrace, gdb, etc.). Assuming Linux/Unix OS.

I'll research it, thank you. If I can't figure it out (I'm not great at systems-level programming), are you available for a small amount of contract work?

Email contact is in my description.

Let me know what OS / processes you're working with.

I'm much more a shell hacker than systems programmer but this smells doable.

Re: Ask HN: What weird or hard problems are you trying to solve?

#815

Post by infinitebit » Wed, Jul 08, 2020, 3:53 PM UTC

detecting the tempo of a rhythm a drummer is playing in real time (including tracking variations/drift in tempo) based on the time stamps of each drum hit (and starting at an assumed tempo). I've found in depth resource on problems that are similar, but not the same (wave form data rather than time stamps, all-at-once rather than real time, etc). I'm trying to keep myself open to the fact that the solution might be incredibly simple, and just unrelated to any path I've gone down, but it's led me down some interesting paths that I'm enjoying, so also just taking that for what it's worth

Re: Ask HN: What weird or hard problems are you trying to solve?

#816

Post by rxsel » Wed, Jul 08, 2020, 6:08 PM UTC

Sordelia wrote: post #453

Problems: - Of the countries in the world, none are really free, and generally have quite burdensome taxes relative to their benefits. - Representative democracy has not improved a whole lot from the v1.0 created a few hundred years ago. For example, voting is largely between "person I don't really like" and "person I hate," and you're just 1 vote in millions, meaning voting is irrational ( https://en.wikipedia.org/w…

Has this (Peacefully purchasing/acquiring land to establish a new state) ever been done in the past?

The capital to do it is certainly there.

Re: Ask HN: What weird or hard problems are you trying to solve?

#817

Post by rxsel » Wed, Jul 08, 2020, 6:21 PM UTC

master_yoda_1 wrote: post #237

“How to get 6 packs abs”, trying to solve this for at least last 10 years but it’s a really hard problem.

Science solved this problem way before the shake weight.

Understanding some basic concepts in nutrition/wellness, such as macros and micros, calories, how Energy Expenditure (keeping you alive, walks, lifting weights, etc) and Energy Storage (Fat, Muscle, etc) all ties in with your unique genetics, body composition and lifestyle goes a long way.

Quick and dirty trick: be at a low Body Fat Percentage and have abdominal muscles (which we all do ha).

Re: Ask HN: What weird or hard problems are you trying to solve?

#818

Post by koeng » Wed, Jul 08, 2020, 6:35 PM UTC

webmaven wrote: post #764

koeng wrote: post #701

Earlier quoted context omitted.

They won’t be. I definitely thought deeply about that aspect, but am choosing to not make them non-viable for the following reasons: 1. Payloads are in domesticated strains, which are less efficient than wild strains, which are already global 2. Exotic growth media requirements make the cells only for wealthy organizations, which is status quo and aren’t target audience Of course, if good reason comes to change that,…

Exotic in this case just means uncommon or rare in the wild, not expensive. Something like requiring both salt and aspartame would help prevent gene transfer in the wild (to related or unrelated strains) as well as making it unlikely to grow on its own.

I would love to have something like that, but unfortunately that’s a really hard problem in itself, so I’d likely only start working on it once the need arises

Re: Ask HN: What weird or hard problems are you trying to solve?

#819

Post by lambdatronics » Thu, Jul 09, 2020, 10:39 PM UTC

jamesrcole wrote: post #783

lambdatronics wrote: post #718

Earlier quoted context omitted.

We're in need of an information-theoretic definition of computation or information processing, in analogy to Shannon's definition of communication. I'm trying to work it out. It's clear that there is a relationship between computation and information via Landauer's principle. It's also clear that it's got to do with nonlinearity of dynamical systems: "The essence of computation is nonlinear logical operations." J. Ho…

> We're in need of an information-theoretic definition of computation or information processing Could you elaborate? It's not clear to me what you mean by that. > It's clear that there is a relationship between computation and information via Landauer's principle. Information, in the sense I'm concerned with, is an inherent part of computation. You can't have the latter without the former. > Semantics: in short, 'mea…

Shannon's theory of information doesn't offer a way to tell whether a channel is doing computation or merely transmitting the information -- the mutual information merely characterizes how much information goes across a channel, but is insensitive to any changes to the representation.

OTOH, the algorithmic complexity theory (a la Kolmogorov) doesn't really have the same generality as Shannon's theory. Flops is not a well-defined measure of information processing rate for the brain, for instance.

I got inspired by the "integrated information theory" folks -- they have this notion that combining information streams in a nontrivial* way is necessary and sufficient for consciousness. I disagree that it's sufficient for consciousness, but it might be sufficient for a definition of information processing or generalized computation.

> You can't have the latter without the former.

Agreed.

>That doesn't explain meaning in the case of imaginary or abstract details, or the system's conception of the meaning.

The mapping is in our heads. I don't know what you mean by "the system's conception of meaning" -- which system, and what is a conception of meaning?

Here's a link to the paper: https://www.pnas.org/content/pnas/79/8/2554.full.pdf

edit: *how to define 'nontrivial' is very much up for debate. edit2: formatting

Re: Ask HN: What weird or hard problems are you trying to solve?

#820

Post by webmaven » Fri, Jul 10, 2020, 1:51 AM UTC

koeng wrote: post #818

webmaven wrote: post #764

Earlier quoted context omitted.

Exotic in this case just means uncommon or rare in the wild, not expensive. Something like requiring both salt and aspartame would help prevent gene transfer in the wild (to related or unrelated strains) as well as making it unlikely to grow on its own.

I would love to have something like that, but unfortunately that’s a really hard problem in itself, so I’d likely only start working on it once the need arises

Presumably you're working on this as a technique for widespread use by other parties, which means you can't control what DNA is being transported. Minimizing the chances of escape seems only prudent.