3 ms·

Unraveling the physics of knitting

76 points by gmays 2y ago

rkangel 2y ago
I recommend knitting as a hobby for engineers. It has a lot in common with a processor running code: a few simple primitives, run repeatedly, combined to produce a complex result. it's also satisfying, produces useful results, not too expensive to get into, and can be done from the comfort of your sofa. If you're looking to learn, I recommend verypinkknits on YouTube (https://www.youtube.com/@verypinkknits https://www.youtube.com/@verypinkknits)
- 082349872349872 2y ago
  > ...can be done from the comfort of your sofa. It can also be done during the sorts of meetings which should've been emails.
  - phatskat 2y ago
    It honestly makes me much more ok to see a day of meetings on my calendar. Sure I’m going to listen to other people go back and forth on component padding for way too long, but I’m also going to get a chunk of a sweater done, all while being paid.
- klyrs 2y ago
  Sadly there's something else that engineers and knitters have in common that limits my cross-participation: repetitive stress injuries
  - soperj 2y ago
    what do you do for injury prevention?
    - michaelrpeskin 2y ago
      a bit off topic, but I've spent a LONG time in front of a computer (going on 41 years of programming) and my wife is a compulsive knitter... I'm not sure that we know the full story on RSI. It think that repetitive motion is necessary but not sufficient. I don't know enough to speak authoritatively on it, but here's my anecdote: I've been compulsively in front of a computer since I was 6 writing code. I still write a lot of code, but also do a lot of analysis work and R&D designing algorithms, so if I'm not writing code, I'm still doing tons of modelling and other "computer work." I don't have any ergonomic setup or anything fancy. I generally just work directly on my laptop sitting on a crash pad couch (https://www.metoliusclimbing.com/crash-pad-couch.html https://www.metoliusclimbing.com/crash-pad-couch.html). Basically, if anyone who studies ergonomics would look at how I work and probably have a heart attack. My wife took up knitting as a stress reliever in grad school, and 25 years later if she's not working (on a computer), she's knitting (I have SO many hats!). Neither of us have any symptoms or signs of even starting to get any RSI. I spend a bunch of time rock climbing (hence the crash pad couch) and lifting weights, maybe that counter acts it? We have a very low inflammatory diet (I've seen about inflammation kicking off RSI and then it getting aggravated from there). I don't know. I have no real idea, but give our lifestyles we should have some form of RSI if you listen to the prevailing theories. But we don't. Not trying to suggest anything in particular as a reason, but just wanted to point out that RSI is not a given.
      - throwup238 2y ago
        > I spend a bunch of time rock climbing (hence the crash pad couch) and lifting weights, maybe that counter acts it? One more anecdata to add in support of lifting weights: I started experiencing the early symptoms of wrist RSI and went to a physical therapist who showed me some wrist strengthening exercises with free weights. Within weeks the pain disappeared and hasn't come back in years despite no other ergonomic changes (I still lift weights). PT also recommended rockclimbing or pretty much any exercise that strengthens the forearm muscles as an alternative.
      - j33zusjuice 2y ago
        I think RSIs come from muscular imbalances, and tightness. It’s not just repeating the same motion, but that motion being almost uniquely how those muscles engage. You climb, so your forearm muscles are exercised on both sides. I’m guessing you also stretch a lot. But imagine you didn’t use the posterior muscles in your forearm, only the anterior. Eventually, the posterior muscles sort of seize in a tightened state because they can no longer counterbalance the anterior forearm muscles. Eventually, this could lead to nerve impingement, which creates the RSI. Tangentially, I know a lot of people who get pain between their shoulder blades from craning at the computer. What fixes that pain almost 100% of the time? Stretching your chest and anterior shoulders. It’s definitely possible that you have something else going on, but it’s insanely common for a person’s shoulders to roll forward, which puts immense stress on your back. Easy test: stand with your arms at your side, and your palms should be roughly parallel to your outer quad. If they’re turning in and pointing toward your knees (gorilla like), you need to stretch. In my opinion, there is a major gap in understanding of the muscular system in medicine. MDs don’t know how to approach pain except to numb it, or cut it out. Idk why, I just know that I’ve not personally seen useful results from MDs. PTs, ime, are usually excellent. But you schedule appointments with your MD, PTs only come in after an MD recommends it (at least in the US), which leads to the wrong solutions being tried a lot.
    - klyrs 2y ago
      I don't take on hobbies that aggravate my pre-existing condition.
- palata 2y ago
  Do you have a similar channel for crochet?
emj 2y ago
It is physical and satisfying to work with fabric, I have met a lot of nice people while learning hand weaving. I have not tried stitching but my experience mirrors that of the article, just "the simple things" with twill or satin can be a rabbit hole you need to limit yourself to understand them. There is a lack of easy to access models of how different thread interact with each other, just creating a simple pattern is more of an art form or knowledge which thread works best. If you talk with the people who works with it it becomes apparent why, there is a myriad of edge cases. There are some really cool physical 3D models, at least on in C/Python on github. It is easy to see why it is expensive to do fully automated, one computer controlled actuator per pixel adds up in complexity and costs if you want to do 3d thread work.
eitally 2y ago
/u/rkangel recommends knitting as a hobby for engineers. I put quilting into the same category for the same reasons. Here's some inspiration for mathematical quilting: https://mathematicalquilts.com/Home_Page.html https://mathematicalquilts.com/Home_Page.html (you can find plenty more with simple searches)
bregma 2y ago
Anyone who knits knows the textile, stitch, and tension all contribute different properties to the finished fabric and can be used to various effects even in the same garment. For example, a rib stitch done on a smaller needle size (which affects tension) is usually used for cuffs so they don't flop all over like the stitch and tension used for the main body of work would. What's interesting is these folks have engaged in a systematic engineering study to document these different choices and their effects on the properties of the fabric. Interesting because knitting has been around for thousands of years and everyone knows this stuff, but it's generally considered a women's craft in Western society and so has little value. Times are changing.
- KineticLensman 2y ago
  > and so has little value The knitted ROM in the Apollo Guidance Computer [0] had a lot of value, and a stunning memory density of 72 kilobytes per cubic foot. Little Old Lady memory, indeed. [0] https://en.wikipedia.org/wiki/Core_rope_memory https://en.wikipedia.org/wiki/Core_rope_memory

76 points by gmays 2y ago

I recommend knitting as a hobby for engineers. It has a lot in common with a processor running code: a few simple primitives, run repeatedly, combined to produce a complex result. it's also satisfying, produces useful results, not too expensive to get into, and can be done from the comfort of your sofa. If you're looking to learn, I recommend verypinkknits on YouTube (https://www.youtube.com/@verypinkknits https://www.youtube.com/@verypinkknits)

082349872349872 2y ago
> ...can be done from the comfort of your sofa. It can also be done during the sorts of meetings which should've been emails.
- phatskat 2y ago
  It honestly makes me much more ok to see a day of meetings on my calendar. Sure I’m going to listen to other people go back and forth on component padding for way too long, but I’m also going to get a chunk of a sweater done, all while being paid.
klyrs 2y ago
Sadly there's something else that engineers and knitters have in common that limits my cross-participation: repetitive stress injuries
- soperj 2y ago
  what do you do for injury prevention?
  - michaelrpeskin 2y ago
    a bit off topic, but I've spent a LONG time in front of a computer (going on 41 years of programming) and my wife is a compulsive knitter... I'm not sure that we know the full story on RSI. It think that repetitive motion is necessary but not sufficient. I don't know enough to speak authoritatively on it, but here's my anecdote: I've been compulsively in front of a computer since I was 6 writing code. I still write a lot of code, but also do a lot of analysis work and R&D designing algorithms, so if I'm not writing code, I'm still doing tons of modelling and other "computer work." I don't have any ergonomic setup or anything fancy. I generally just work directly on my laptop sitting on a crash pad couch (https://www.metoliusclimbing.com/crash-pad-couch.html https://www.metoliusclimbing.com/crash-pad-couch.html). Basically, if anyone who studies ergonomics would look at how I work and probably have a heart attack. My wife took up knitting as a stress reliever in grad school, and 25 years later if she's not working (on a computer), she's knitting (I have SO many hats!). Neither of us have any symptoms or signs of even starting to get any RSI. I spend a bunch of time rock climbing (hence the crash pad couch) and lifting weights, maybe that counter acts it? We have a very low inflammatory diet (I've seen about inflammation kicking off RSI and then it getting aggravated from there). I don't know. I have no real idea, but give our lifestyles we should have some form of RSI if you listen to the prevailing theories. But we don't. Not trying to suggest anything in particular as a reason, but just wanted to point out that RSI is not a given.
    - throwup238 2y ago
      > I spend a bunch of time rock climbing (hence the crash pad couch) and lifting weights, maybe that counter acts it? One more anecdata to add in support of lifting weights: I started experiencing the early symptoms of wrist RSI and went to a physical therapist who showed me some wrist strengthening exercises with free weights. Within weeks the pain disappeared and hasn't come back in years despite no other ergonomic changes (I still lift weights). PT also recommended rockclimbing or pretty much any exercise that strengthens the forearm muscles as an alternative.
    - j33zusjuice 2y ago
      I think RSIs come from muscular imbalances, and tightness. It’s not just repeating the same motion, but that motion being almost uniquely how those muscles engage. You climb, so your forearm muscles are exercised on both sides. I’m guessing you also stretch a lot. But imagine you didn’t use the posterior muscles in your forearm, only the anterior. Eventually, the posterior muscles sort of seize in a tightened state because they can no longer counterbalance the anterior forearm muscles. Eventually, this could lead to nerve impingement, which creates the RSI. Tangentially, I know a lot of people who get pain between their shoulder blades from craning at the computer. What fixes that pain almost 100% of the time? Stretching your chest and anterior shoulders. It’s definitely possible that you have something else going on, but it’s insanely common for a person’s shoulders to roll forward, which puts immense stress on your back. Easy test: stand with your arms at your side, and your palms should be roughly parallel to your outer quad. If they’re turning in and pointing toward your knees (gorilla like), you need to stretch. In my opinion, there is a major gap in understanding of the muscular system in medicine. MDs don’t know how to approach pain except to numb it, or cut it out. Idk why, I just know that I’ve not personally seen useful results from MDs. PTs, ime, are usually excellent. But you schedule appointments with your MD, PTs only come in after an MD recommends it (at least in the US), which leads to the wrong solutions being tried a lot.
  - klyrs 2y ago
    I don't take on hobbies that aggravate my pre-existing condition.
palata 2y ago
Do you have a similar channel for crochet?

emj 2y ago

It is physical and satisfying to work with fabric, I have met a lot of nice people while learning hand weaving. I have not tried stitching but my experience mirrors that of the article, just "the simple things" with twill or satin can be a rabbit hole you need to limit yourself to understand them. There is a lack of easy to access models of how different thread interact with each other, just creating a simple pattern is more of an art form or knowledge which thread works best. If you talk with the people who works with it it becomes apparent why, there is a myriad of edge cases. There are some really cool physical 3D models, at least on in C/Python on github. It is easy to see why it is expensive to do fully automated, one computer controlled actuator per pixel adds up in complexity and costs if you want to do 3d thread work.

eitally 2y ago

/u/rkangel recommends knitting as a hobby for engineers. I put quilting into the same category for the same reasons. Here's some inspiration for mathematical quilting: https://mathematicalquilts.com/Home_Page.html https://mathematicalquilts.com/Home_Page.html (you can find plenty more with simple searches)

bregma 2y ago

Anyone who knits knows the textile, stitch, and tension all contribute different properties to the finished fabric and can be used to various effects even in the same garment. For example, a rib stitch done on a smaller needle size (which affects tension) is usually used for cuffs so they don't flop all over like the stitch and tension used for the main body of work would. What's interesting is these folks have engaged in a systematic engineering study to document these different choices and their effects on the properties of the fabric. Interesting because knitting has been around for thousands of years and everyone knows this stuff, but it's generally considered a women's craft in Western society and so has little value. Times are changing.

KineticLensman 2y ago
> and so has little value The knitted ROM in the Apollo Guidance Computer [0] had a lot of value, and a stunning memory density of 72 kilobytes per cubic foot. Little Old Lady memory, indeed. [0] https://en.wikipedia.org/wiki/Core_rope_memory https://en.wikipedia.org/wiki/Core_rope_memory