[HN Gopher] I told a cat food company how much they'd save by us...
       ___________________________________________________________________
        
       I told a cat food company how much they'd save by using taller cans
       (2020)
        
       Author : Tomte
       Score  : 220 points
       Date   : 2021-02-06 13:49 UTC (9 hours ago)
        
 (HTM) web link (twitter.com)
 (TXT) w3m dump (twitter.com)
        
       | dekhn wrote:
       | another example of "why don't you just"- the tendancy of
       | technical people to tell other people technical people how to do
       | their job better, without the necessary context to understand why
       | it is a way (chesterton's fence).
        
         | LanceH wrote:
         | Your post is an example of attributing to technical people the
         | bad habits of all people. Much like, "engineers are bad at
         | business" -- people in general are bad at business.
         | 
         | Every person out there has a brilliant idea that just needs to
         | be implemented (by someone else), fitting nicely into the "why
         | don't they just".
         | 
         | Engineers are conspicuously good at _something_ and then it 's
         | fun to make fun of them, but I don't think their behavior in
         | this regard is any different than anyone else, except that they
         | may more frequently give thought to solving something.
        
         | 300bps wrote:
         | Agree absolutely. It also reminds me of, "For every complex
         | problem there is an answer that is clear, simple and wrong."
         | 
         | I don't know how people have the ego to think they're going to
         | study a problem for an hour or two and discover solutions that
         | have eluded competent people that have spent their careers
         | studying the problem.
        
           | toast0 wrote:
           | I've run into all sorts of things in my career where
           | competent people completely ignored parts of the problem.
           | Someone, qualified or not, spending two hours studying the
           | problems would apparently have been the first two hours
           | spent; and to good use.
           | 
           | Many times, I've stumbled across reports from other fields
           | about solving problems in ways well known for their field,
           | but unknown in mine that would apply well for some problems
           | in my field. A (kindly worded) suggestion and reference from
           | someone who thought to be helpful would be useful.
           | 
           | Of course, some fences are Chesterton's fences, and some are
           | just randomly placed fences in weird spots.
        
           | jiofih wrote:
           | It's much more complicated than that. Sometimes the people
           | who start from scratch actually lead to real innovation while
           | the scholars are stuck in their old world view. There is room
           | for both types of exploration.
        
             | koonsolo wrote:
             | I get your point. But that innovation comes from experts
             | too, not someone who watched 10 YouTube videos on the
             | subject.
             | 
             | I would say most novices soon find out why things are done
             | the way they are done. True innovation is really
             | exceptional.
        
         | rm445 wrote:
         | It's interesting to see this exchange, though, because it's
         | high-trust: I would bet the professor's initial letter was
         | courteously written, and asked if there were other factors
         | besides purely surface area to volume. The responder wrote a
         | clear technical letter without any marketing flim-flam. We are
         | in a golden age of communication in some sense, with blogs and
         | technical online communities. But I could hardly imagine
         | getting a letter from a corporation of this quality.
        
         | h_anna_h wrote:
         | > the tendancy of technical people to tell other people
         | technical people how to do their job better
         | 
         | "why don't you just" is a question, and if they had not asked
         | said question they (as well as the readers of their book) would
         | not know the (right) answer to it.
        
           | Closi wrote:
           | Why don't the IDIOTS at Heinz just make goddamn spherical
           | ketchup?! Everyone knows that a perfectly spherical ball
           | would reduce the amount of packing material per ml of ketchup
           | yet they are just closing their ears and not listening to the
           | maths.
           | 
           | And don't get me started on the cereal box people... THEY
           | SHOULD BE CUBES.
           | 
           | And I'm looking at you water bottles - if you were all cubes
           | too don't you realise how you could nest to avoid air during
           | shipping? They could have cut outs in the bases for lids...
           | Idiots everywhere!
           | 
           | I'm going back to my car. It runs on petrol because the
           | idiots in engineering haven't worked out it could just run on
           | hydrogen yet.
           | 
           |  _(All the above have reasons for being the way they are, and
           | I think it 's usually a good idea to understand why something
           | is the way it is before you try to change it)_
        
           | tshaddox wrote:
           | It's clearly phrased with the implication that the person has
           | never thought of doing it the way the speaker is suggesting.
        
         | grumple wrote:
         | Sometimes it's important to answer those questions: it spreads
         | knowledge and generates trust in the expertise of the person
         | being asked. Sometimes the suggestion might actually be a good
         | one, too.
        
         | kstenerud wrote:
         | Chesterson's Fence is the act of DECIDING without knowing.
         | There's nothing wrong with SUGGESTING without knowing. In fact,
         | that's a very desirable thing. Different disciplines bumping
         | into each other and making such suggestions is how great ideas
         | and great solutions are hatched.
        
           | Closi wrote:
           | I think there is another one to add to the list, which is
           | _assuming something is wrong_ without knowing enough about
           | the problem to know why something is the way it is right now.
           | 
           | E.g. Instead of telling a cat food company how much they
           | would save with a different size, you could ask a company why
           | they don't optimise for the lowest surface area, or if they
           | have considered it. The first assumes _you_ are right and
           | _they are wrong_ from the get go, while they are the domain
           | experts.
           | 
           | Really interesting dialogue though!
        
             | kstenerud wrote:
             | Assuming wouldn't be a problem either. Since the person
             | assuming is not in a position to decide policy, no harm can
             | come of it, and possibly a benefit could result if he
             | happens to be right.
        
               | Closi wrote:
               | I just think it's just good practice to remain humble,
               | and consider that the people who own a giant tinned cat
               | food packaging line just _might_ know more about tinning
               | cat food than you do, with your degree in maths, and
               | frame the question as  'why do you not optimise to the
               | minimum packing material?' rather than 'you should
               | optimise to the minimum packing material'.
               | 
               | I personally find that approaching problems with an
               | attitude of "Why do you do it like that instead of like
               | this?", or even "have you considered this?", usually
               | provides more insight and a more collaborative discussion
               | than "You should do it like this".
        
               | rgoulter wrote:
               | "Ask vs Guess" is one difference between people.
               | 
               | Roughly, "it should always be okay to ask, since they can
               | always just say no" vs "saying no is a bit awkward, so
               | only ask for things if the answer is going to be yes".
               | 
               | In terms of the above:
               | 
               | Sure, the person doesn't have to apply the suggestions.
               | But the only reason you'd make a suggestion is if you
               | think something's wrong or could be improved. And
               | suggesting something is wrong if it isn't is awkward.
               | etc.
        
         | renewiltord wrote:
         | It's strange. Almost everyone I know in real life, when told
         | "Why don't you just do X instead of Y" treats it
         | enthusiastically as a chance to share some nuance about their
         | field.
         | 
         | Two instances recently come to mind, my asking my father (an
         | orthopaedic trauma surgeon) why we don't just make hips (in
         | total hip replacement) out of dead people's bone instead of out
         | of whatever material they do now, and my father's asking me
         | something about why blue LEDs are supposedly so hard (why don't
         | you just wrap them in blue film).
         | 
         | On the Internet, everyone is always like "you guys always think
         | you can do our job better!". In real life, everyone is always
         | like "hmm, that's interesting. Let me explain why". But perhaps
         | it's just everyone _I_ know.
         | 
         | I saw this the other day too in another HN comment0 where
         | people assume that "Why don't you just" and questions like that
         | are demeaning.
         | 
         | 0: https://news.ycombinator.com/item?id=25826835
        
           | zebnyc wrote:
           | I presume this has to do with how you frame the question and
           | the recipient perceives your intent.
        
             | renewiltord wrote:
             | I'm sure I agree, but surely there is something to how so
             | many commentators here clearly immediately assume that the
             | Prof's question must have been framed so that the best
             | interpretation is condescending.
        
           | PragmaticPulp wrote:
           | It's all about the context.
           | 
           | When you ask your father why something is done a certain way,
           | you're seeking information. You're not questioning the
           | competence of his field or implying that you have seen an
           | obvious solution that his entire field has simply missed.
           | 
           | However, when engineers say "This change will require 4-6
           | weeks" and their boss says "Can't you just add a form field
           | and run a database migration and ship it tonight?", the boss
           | is casting doubt on the team's assessment of the situation
           | and their competency in executing.
           | 
           | The demeaning nature varies with intent. If someone is asking
           | a simple question ("Why can't we just ship it tonight? Help
           | me understand") it's nowhere near as bad as a boss waiving
           | away objections with an over-simplified order ("Just change
           | the code and ship it tonight!")
        
             | kelnos wrote:
             | I don't think anyone would object that that kind of
             | negative reaction to a repeat offender (the hypothetical
             | manager) who has demonstrated through repeat behavior that
             | they have little respect for their employees' expertise.
             | 
             | What is a bit more pervasive, though, is a growing belief
             | that _any_ question of the form  "why can't you just...?"
             | is inherently condescending and rude.
             | 
             | Yes, I agree that a "help me understand"-style question is
             | the ideal way to ask, but I think people have definitely
             | become more (IMO unreasonably) sensitive against the "why
             | can't you just...?" form, when often it's asked innocently
             | and without a trace of disrespect.
             | 
             | Something I always try to remind myself: I can't control
             | other people's behavior, but I can control how I react to
             | it. We should try to gently correct truly bad behavior when
             | it is safe and constructive to do so, but it generally does
             | us no good to get all worked up about it in the first
             | place, especially if it's something as benign as a poorly-
             | worded question. And being impatient with these sorts of
             | things can be to our detriment; sometimes a fresh, layman's
             | perspective can provide an insight we hadn't considered.
        
           | tompccs wrote:
           | Absolutely - in fact in 2021 you might even be accused of
           | mansplaining, when actually the purpose of asking these
           | questions is to genuinely learn more about why the world
           | works the way it does! (And of course there are the
           | occasional examples of genuine insights gained from having a
           | fresh perspective - I remember reading about Alan Sugar
           | discovering that he could make satellite dishes for a tenth
           | of the cost by contracting the manufacture out to a bin lid
           | factory)
        
         | lallysingh wrote:
         | I ask that all the time, but start with "Pardon my ignorance"
         | or "I know you must have good reason, but..."
        
           | t0mas88 wrote:
           | That's also a useful managment tool. I often ask "Uninhibited
           | by any actual knowledge, I would think X is the easier
           | solution, what's the real story?" A competent team will
           | either explain why things are the way they are or give you an
           | improved version of X that may be faster than what they had
           | you if you're willing to accept the associated limitations.
           | Often that dialogue on limitations is valuable because the
           | client facing people may know some things about what
           | limitations can be accepted without client impact and are
           | thus good choices.
        
           | mark-r wrote:
           | I did that just yesterday with a comment here on HN:
           | https://news.ycombinator.com/item?id=26044548
        
       | Cogito wrote:
       | For those interested in the original source, one of the replies
       | [0] links to [1] which says that you can find the letter in
       | Applied Mathematics by Farlow & Hagggard (Pub. Random House,
       | 1988) p613.
       | 
       | > "There is a nice letter from the Carnation canning company
       | which is reproduced in Applied Mathematics by Farlow & Hagggard
       | (Pub. Random House, 1988) p613 on why cans do not adopt this
       | optimal shape."
       | 
       | 0: https://twitter.com/theohonohan/status/1235646988357701632
       | 
       | 1: https://plus.maths.org/content/comment/8352#comment-8352
        
         | wodenokoto wrote:
         | Does that mean the twitter account is either Farlow, Haggard,
         | or just somebody posting things as their own?
        
           | hombre_fatal wrote:
           | A cursory scan of their twitter account shows that it's the
           | latter.
        
             | dandanua wrote:
             | Also they reposted the story wrong, assuming cans were
             | short.
        
               | kemayo wrote:
               | The tweet-author being the original letter-recipient is
               | not necessarily inconsistent with them also having
               | forgotten exactly what they suggested 35 years ago and
               | just substituting in a general sense of what current cat
               | food cans are like. Particularly since they'd be, you
               | know, 84.
        
               | Zancarius wrote:
               | I feel kind of stupid reading this since I sometimes
               | (often?) forget the exact details of things I've written
               | just 3.5 days ago (!).
        
             | CrazyStat wrote:
             | What makes you say that? I skimmed through a couple pages
             | of tweets and it seems consistent with the twitter account
             | belonging to Farlow.
             | 
             | Somewhat surprising for an 84-year-old math professor to
             | have an active twitter account, but not out of the
             | question.
        
               | CrazyStat wrote:
               | Strong evidence that the account is indeed Farlow: the
               | profile links to a pinterest board [1] which is listed by
               | the NCTM [2] as being run by Farlow.
               | 
               | [1] pinterest.com/mathematicsprof
               | 
               | [2] https://www.nctm.org/tmf/library/view/75908.html
        
               | faeyanpiraat wrote:
               | It would be a strong evidence if the linking were the
               | opposite way.
               | 
               | If I link to the potus piterest page from my twitter
               | page, it would not mean anything.
        
               | CrazyStat wrote:
               | > if the linking were the opposite way.
               | 
               | the linking goes both ways: the pinterest page also
               | points to the @mathematicsprof twitter handle.
        
         | gostsamo wrote:
         | Thank you, I really hate when people post an image of text and
         | consider themselves smart for shortcutting normal posting.
        
       | dekhn wrote:
       | I don't want a tall cat food can. we feed the cat out of the can,
       | it can't reach the bottom of a tall can. Also, if you don't feed
       | out of the can, now you have to store half a can of wet food in
       | your fridge (ew).
        
         | jiofih wrote:
         | Poor cat. Must have hurt his tongue so many times and you won't
         | ever find out.
        
           | dekhn wrote:
           | I'm curious about this (since I don't want to hurt my cat).
           | Wouldn't he show pain or have a bleeding tongue?
        
         | tom_mellior wrote:
         | > we feed the cat out of the can
         | 
         | Don't you get problems with sharp edges that way? Also, even
         | short cans have a geometry that I would expect to be hard to
         | clean out completely with a cat's relatively short tongue.
         | Also, cans are very light, doesn't the cat move the can all
         | over the place compared to a heavier feeding dish? So many
         | questions...
         | 
         | > Also, if you don't feed out of the can, now you have to store
         | half a can of wet food in your fridge (ew).
         | 
         | Around here many people have reusable plastic lids to put on
         | open cans, those work well. The bigger problem is feeding
         | fridge-cold food to your cat, which is apparently not ideal.
         | When I had cats we mostly fed them with individual portion-
         | sized pouches. That generates a lot of non-recyclable waste
         | though.
        
           | dekhn wrote:
           | for the sharp edges, I haven't noticed a problem with that.
           | The cat sort of eats from the middle, not the sides. We put
           | the can in a larger plastic thing- which would normally hold
           | a cat food bowl (IE, it's the thing that holds the cat food
           | bowl in place) so it doesn't move around.
        
         | nether wrote:
         | Get a lid:
         | https://www.amazon.com/dp/B0746MLFB7/ref=cm_sw_r_cp_api_glt_...
        
       | mhb wrote:
       | A while ago, I noticed that the bread I eat sometimes had the
       | twist tie twisted clockwise and sometimes counter-clockwise
       | (annoying since that is the direction it should untie). I called
       | the company to ask why and they left a message with an
       | explanation. It wasn't a great explanation, but I was impressed
       | they responded. They said that the breads comes off the conveyor
       | belt and are routed two ways and the twisters are different.
        
         | JoeAltmaier wrote:
         | I grew up in a house with a left-handed dad and sister. Half
         | the time, the twistie was 'the wrong way' and in opening it,
         | I'd instead twist it into a hopeless knot.
         | 
         | Was a bachelor for 3 years on my own, and counted my blessings
         | every time I opened a loaf of bread. Then got married. To a
         | left-handed woman.
        
           | aaronbrethorst wrote:
           | Get some spring clips: https://www.amazon.com/dp/B07VJJWSL9/r
           | ef=cm_sw_r_cp_api_glt_...
        
             | Wistar wrote:
             | Nice find. Ordering now.
        
             | ReactiveJelly wrote:
             | I just fold the end of the bag over and use the weight of
             | the bread to weigh it down.
             | 
             | That way I also have an excuse to not eat the last slice.
             | 
             | Come to think of it, I haven't kept bread around for at
             | least a year.
        
           | usefulcat wrote:
           | Just use a clothes pin? It's faster too.
        
           | mhb wrote:
           | I wouldn't have expected that the CW to tighten things
           | convention was linked to right/lefthandedness. Especially
           | since many people seem to not have a notion about the
           | convention.
           | 
           | But maybe that's my right privilege talking.
        
             | leetcrew wrote:
             | I think it's more natural to twist things thumb-over-index.
             | index-over-thumb is a slightly awkward movement, at least
             | for me. this corresponds with the right-hand rule (relative
             | to your hand).
        
               | lallysingh wrote:
               | You get more power pushing with your thumb than pulling
               | with it. My thumb is stronger over one way over the
               | other.
        
               | leetcrew wrote:
               | sorry, confused myself with that bit about the "up"
               | direction of the bag. I think we agree.
        
             | GavinMcG wrote:
             | Righty tighty, lefty loosey, right? But I don't think there
             | _is_ a convention when it comes to twist ties, because a
             | twist tie isn 't something that gets tighter or looser.
             | It's more closely related to spinning.
             | 
             | I'd bet lefties spin tops counterclockwise, too, by and
             | large. Seems to me it comes down to external rotation of
             | the wrist being easier than internal.
        
               | kevincox wrote:
               | When I twist something I prefer to twist the top of my
               | hands out, so I would twist something different if I was
               | holding the tie with my left or right hand. So I
               | absolutely believe that the handedness affects this
               | because it will change which hand holds the bread and
               | which holds the twist tie. If I hold the bread in the
               | left (twist with my right) I would twist it clockwise
               | (righty tighty) and if I held the bread in my right I
               | would use my left and twist counter-clockwise.
        
               | snarfy wrote:
               | As a lefty I visualized myself spinning a top - it's
               | clockwise. That's because I'd use my right hand to spin a
               | top. Do righties not use their left hand to spin a top?
        
               | jstanley wrote:
               | > Righty tighty, lefty loosey, right?
               | 
               | This phrase always irked me, because when you're rotating
               | something, it's not moving either left or right. The top
               | of it moves right, the bottom moves left. Is it
               | tightening or loosening?
               | 
               | Further, the only time a phrase might be needed to work
               | out which way to tighten something is when it's
               | unusually-positioned, for example upside down or facing
               | away from you, and in those cases "righty tighty, lefty
               | loosey" gives exactly the wrong answer (to the extent
               | that it gives an answer at all, since "clockwise" and
               | "right" are not the same thing).
               | 
               | I prefer the phrase "clockwise moves the thing you're
               | turning away from you, anti-clockwise moves it towards
               | you", which I'm hoping will catch on.
        
               | lostlogin wrote:
               | > Righty tighty, lefty loosey
               | 
               | I remember an old mechanic sarcastically saying this when
               | I was a kid and as as he worked on an old car that had
               | wheel nuts that did up the other way on one side of the
               | car.
               | 
               | It really pissed him off.
               | 
               | A quick search seems to show that this was a thing.
               | https://www.quora.com/Why-did-the-old-Chrysler-cars-have-
               | lug...
        
               | kelnos wrote:
               | I read the first answer there, but it didn't answer the
               | related question: why don't _all_ cars have that weird
               | setup now? Is there a modern design feature that we have
               | nowadays that allows for normal threading on the left-
               | side wheels that keeps them from coming loose?
        
               | davchana wrote:
               | Think of the vantage point of observer standing (& his
               | land under his feet also rotating with circle causing him
               | to always rotate along the rotation.) at the center of
               | that circle. ACW will always be right moving to him, CW
               | will be left.
               | 
               | The other is, follow the fingers not thumb.
        
               | leetcrew wrote:
               | I feel like this is the sort of thing that actually makes
               | less sense when you develop explicit reasoning skills. as
               | a child, "righty tighty, lefty loosey" made perfect
               | sense. it never occurred to me that right/left could be
               | relative to the bottom (from my perspective) of a jar
               | lid. only when I started learning about math and
               | coordinate systems did I think "right/left relative to
               | what?".
        
               | tzs wrote:
               | I'd guess it is related to the conventional way steering
               | wheels work--turn clockwise to steer the vehicle right,
               | counterclockwise to steer it left. Hence, clockwise gets
               | associated with right and counterclockwise with left.
               | 
               | I have no idea why steering wheels work that way. If I
               | had to guess it would because most steering wheels are
               | below eye level so it makes sense that you move the top
               | of the wheel in the direction you want to go.
               | 
               | Note that if you are holding the top half of a steering
               | wheel that follows this convention, then when you turn
               | the vehicle the centriwhatever force on you will tend to
               | oppose the force you are using to turn the wheel. If the
               | steering while used the opposite convention, that force
               | would reinforce your force. That positive feedback would
               | make it a lot easier to lose control during the turn.
        
               | LiberatedLlama wrote:
               | Without power steering, holding the steering wheel at the
               | top gives you more leverage than holding it at the
               | bottom. When holding the wheel at the top, turning right
               | is a matter of moving your hands to the right.
        
               | gliptic wrote:
               | I prefer "clockwise lockwise".
        
               | tshaddox wrote:
               | The phrase is talking about the top surface of the circle
               | as the circle is facing you, since that's normally where
               | your vantage point is when you're turning something with
               | your hand. You have to think things through more
               | carefully if the circle is oriented differently (imagine
               | reaching through a broken window to turn a doorknob).
        
               | wl wrote:
               | I've adopted the right-hand rule: The screw goes the
               | direction my thumb points when my right hand closes. And
               | if it's something left-handed like a bike pedal, it's
               | easy to just use the other hand.
        
               | Dylan16807 wrote:
               | > This phrase always irked me, because when you're
               | rotating something, it's not moving either left or right.
               | The top of it moves right, the bottom moves left. Is it
               | tightening or loosening?
               | 
               | And the answer is "You look at the top, of course, why
               | would it mean the bottom?"
        
             | issamehh wrote:
             | I'm right handed yet I generally use my left hand for twist
             | ties. I twist them counter-clockwise too. I never put any
             | thought into it beyond wanting bread.
        
           | siver_john wrote:
           | As the only left handed member in my family, I'm now curious
           | if I ever did that to my family. Though for tasks of that
           | nature I may actually use either hand, or maybe I just
           | started using the right hand because I was the weirdo (asking
           | my mother she said she never noticed but assumed I probably
           | just adapted and used my right hand).
           | 
           | As a bachelor I virtually make all my own bread so I don't
           | really notice, but I think I do take time to figure out which
           | way to twist before opening so maybe that is a thing.
           | 
           | This is just to say, the things you never think about, and I
           | enjoyed the irony of your situation from the reverse side.
        
             | samizdis wrote:
             | > As a bachelor I virtually make all my own bread
             | 
             | I so wish that the status of bachelor automatically
             | bestowed the gift of being a baker. Sadly, in my case, it
             | has not done so. I've tried to make all kinds of breads,
             | from flatbreads to sourdoughs to leavened and unleavened to
             | soda breads - all sorts. I would wish consumption of my
             | output on only my worst enemies.
             | 
             | Happily, though, I can buy packets of bread mix in the
             | supermarket and put them in a bread-making machine.
        
               | siver_john wrote:
               | I honestly only did it because I was cheap and I wanted
               | to remake a sandwich I had consumed before. I started
               | with a simple foccacia recipe and went from there. But I
               | started baking with my mother years earlier so I had some
               | experience.
               | 
               | I now for better or worse have the Toll House cookie
               | recipe memorized, but I'm terrible at making baked goods
               | look appealing.
        
               | teach wrote:
               | You should check out The Tassajara Bread Book by Edward
               | Espe Brown; it's a masterwork of clear technical writing.
               | The first basic recipe is expanded over 20+ pages,
               | explaining not only what to do but _why_.
        
               | samizdis wrote:
               | OK, I will do that, thank you. I'm a fan of Cooking for
               | Engineers, and particularly like the schematics. Scroll
               | to the bottom of this recipe to see what I mean:
               | 
               | http://www.cookingforengineers.com/recipe/36/Meat-Lasagna
        
               | Lukas_Skywalker wrote:
               | For an easy and delicious recipe, try Andy Jones'
               | "quarantine bread" [1]. I was rarely baking bread before,
               | but this recipe changed that completely. As he mentions,
               | it is really really hard to mess up. I once put it in the
               | oven without folding. Thought that this was
               | irrecoverable. It wasn't. Turned out great.
               | 
               | [1] https://andyljones.com/posts/bread.html
        
       | peter_l_downs wrote:
       | I am pretty sure this letter/meme has been around for years and
       | this twitter account isn't the original author, but it's a good
       | explanation of why cans are like they are, maybe, if anybody
       | involved in this story exists.
        
       | crazygringo wrote:
       | While this thing is ancient (it's dated 1987 after all), it's
       | funny that the Twitter caption gets it so wrong.
       | 
       | The Twitter caption is supposedly about making short cans taller,
       | while the letter is clearly a response to making tall cans
       | shorter (points 2, 4, 5).
       | 
       | If you're going to make a repost at least get it right ;)
        
         | dano wrote:
         | Ancient? I resemble that remark :-)
        
           | lostlogin wrote:
           | This is funny, but did you mean 'resent'?
        
             | adventured wrote:
             | It's a common joke to say that you resemble a remark when
             | it applies to you. Dano is joking that they too are ancient
             | like 1987 (you know, from the prior millennium).
        
       | fctorial wrote:
       | This letter argue that a tall-thin can is better, but most of the
       | cat food cans in market are short and wide. Only the first and
       | third point argue for short-wide cans (while promoting tall-thin
       | cans as well).
       | 
       | https://www.google.com/search?q=cat+food+can
        
         | nonick wrote:
         | "Most cans" you see there are the small ones. But as the
         | quantity grows, it is the height of the can that grows, and not
         | the diameter.
         | https://www.google.com/search?q=large+cat+food+can
        
         | kalleboo wrote:
         | The letter is from 34 years ago. What did most cat food cans
         | look like then?
        
         | Xylakant wrote:
         | There are obviously more concerns that are relevant. Most of
         | these containers contain single servings or maybe a few. Open
         | cans of cat food smell. Thin cans of single servings would be
         | narrow, getting the food out would be a pain.
        
           | JoeAltmaier wrote:
           | Exactly! Now explain 'tomato paste'. Comes in tall thin cans
           | like miniature tomato-juice cans, but just 1" wide.
           | Impossible to get all the paste out! Or even, any of it. Why?
           | Why? Why?
        
             | chipsa wrote:
             | Take off both ends. Slides right out.
        
             | leni536 wrote:
             | I always rinse out the remaining with a little bit of
             | water. The water will boil out anyway when I cook.
        
             | jimueller wrote:
             | I think the way to do it is to cut one end of, then the
             | other and use it to push the paste out through the can.
             | Doing that I've never had a problem.
        
               | alchemism wrote:
               | Thats also the trick for sliding out the cranberry jelly-
               | loaf things.
        
               | WWLink wrote:
               | Ocean Spray realized this and made the bottom of the can
               | un-openable. So now you either have to use a knife or
               | squeeze the can enough to loosen the cranberry jelly
               | loaf. I've found the same trick works on refried beans,
               | but it's not as amusing. lol.
        
             | trcollinson wrote:
             | They make lovely squeezable tubes. I would suggest giving
             | them a try! They are much better.
        
               | JoeAltmaier wrote:
               | I guess I'm reluctant to eat acidic stuff out of plastic.
               | But I suppose tin isn't much better.
               | 
               | I just reduce my own tomatoes if I need paste.
        
               | trcollinson wrote:
               | Oh! The tubes from Cento, which is a particular good
               | brand, are metal. I understand the acidic substance from
               | plastic concern. Though reducing your own is a good idea
               | as well. If you grow the tomatoes they will be
               | significantly better.
        
               | JoeAltmaier wrote:
               | They have that at WalMart! Sounds good, will give it a
               | try. The case-of-12 description is a little concerning.
               | Its apparently 'Adult Unisex'. Not sure what they think
               | I'm going to do with the paste...
        
               | riversflow wrote:
               | >I guess I'm reluctant to eat acidic stuff out of
               | plastic.
               | 
               | It might help to realize that plastics are extremely
               | resistant to acids. Hazardous Industrial acid products,
               | far stronger than anything a consumer can purchase, are
               | stored in Polypropylene barrels. Generally speaking
               | plastics are considerably more resistant to inorganic
               | chemicals than even specially formulated metal
               | alloys.[1](link even lists the resistant data for tomato
               | juice :)) Additionally, metal used for canning is
               | usually(always?) lined with plastic[2] to keep metals
               | from leaching. Ironically canned foods with bpa liners
               | are one of the biggest vectors of BPA intake we know
               | of.[3]
               | 
               | [1]https://www.usplastic.com/catalog/files/charts/LG%20CC
               | .pdf [2]https://www.ewg.org/research/bpa-canned-food [3]h
               | ttps://www.sciencedirect.com/science/article/abs/pii/S001
               | 39...
        
               | [deleted]
        
               | 4gotunameagain wrote:
               | All cans are lined with plastic, also a reason why you
               | shouldn't use metal utensils to scrape all the contents
               | out of the can
        
               | JoeAltmaier wrote:
               | Enamel, surely?
        
               | jiofih wrote:
               | They are all metal tubes, and I guess the lining, which
               | is plastic, is exactly the same as in the cans.
        
               | coryrc wrote:
               | Possibly ironically, the plastic lining cans is usually
               | toxic but regular tubes are made of polyethylene which is
               | safe!
        
         | Sharlin wrote:
         | At least here (Finland) the "standard" cat food can is taller
         | than it is wide [1]. Smaller, shorter containers are mostly
         | used by the more "premium" brands.
         | 
         | [1] https://www.puprise.com/whiskas-tuna-in-jelly-wet-cat-
         | food-c...
        
       | internet2000 wrote:
       | Classic example of a STEM person getting out of their lane and
       | thinking they know it all.
        
       | roel_v wrote:
       | LOL I can imagine how this went down when this letter came in at
       | this cat food factory.
       | 
       | Marketing: Hey you engineering nerds. We just got this letter
       | from an actual Professor, saying we can save money changing the
       | designs you made us use for the cans! Fix your mistakes or prove
       | why the way you made it is better!
       | 
       | Engineers: Hold my beer.
        
       | gambiting wrote:
       | The most shocking part of this to me is that someone had the time
       | and knowledge to reply to this. Is this common in any companies
       | anywhere still? In my experience customer support usually knows
       | nothing about the product, they are there to read off a script
       | and maybe authorize a repair/replacement. That you'd get a reply
       | from someone who understands thermal requirements for
       | sterilisation sounds almost surreal.
        
         | eterm wrote:
         | Yes, you could tell this letter was very dated and not just
         | from the type. I don't think you'd get a response like this at
         | all these days (if at all).
         | 
         | Maybe if the brand hooked into it as a marketing effort they
         | might publish a response all over their socials, but you'd
         | certainly not a private reply.
        
         | sonofhans wrote:
         | If you look at the end, you'll see the letter was signed by an
         | "Assistant Product Manager." In tech we might call that
         | position "Junior Product Owner" or "Technical Product Manager."
         | It's exactly the position I'd expect to either have the
         | answers, or have good enough relations with engineering to get
         | the answers.
         | 
         | My dad had various Plant Manager and Production Superintendent
         | roles at Goodyear for many years. He could tell you exactly how
         | each machine the factory operated, and why, and what the
         | functional tradeoffs were of different designs. He had a
         | Master's in engineering, which again is a common path to this
         | sort of role even in tech -- join as a capable engineer, learn
         | the product and industry, and somewhere along the way learn
         | that you have either talent or interest in management or
         | communication.
        
         | kalleboo wrote:
         | You might be able to get a response like this today if you
         | mention the brand on Twitter - that's usually a more marketing-
         | oriented support channel.
        
         | fctorial wrote:
         | Author sent the suggestion to the marketing, marketing
         | forwarded it to engineers and the engineers took that
         | personally. It was sort of like Torvalds C++ response.
        
           | LittlePeter wrote:
           | I had to Google, and I think this is what is meant with
           | "Torvald's C++ response":
           | http://harmful.cat-v.org/software/c++/linus
        
             | [deleted]
        
         | thenickdude wrote:
         | If you ask support questions of AWS, you often get connected
         | directly to the engineers responsible for the product, who are
         | able to hunt down the cause of quirks for you by direct
         | reference to their code.
         | 
         | What impresses me the most about this is the quality of triage
         | required to pass just the questions that really need it on to
         | the engineers to avoid oversaturating their bandwidth. I got
         | connected to them almost immediately.
        
           | gambiting wrote:
           | Well yes, maybe I worded my question incorrectly. I work at a
           | games studio and if we need to, we can get direct access to
           | the engineers working directly on the Xbox firmware and ask
           | them questions. It's possible.
           | 
           | But I'm also 100% certain that if someone sent a random
           | letter to Microsoft offering advice on the design of their
           | Xbox console, it wouldn't even make it to their engineers,
           | much less actually get a response from anyone within the
           | department.
        
         | chiph wrote:
         | My UPS will occasionally go on battery because the incoming
         | line voltage crosses it's "too-high" threshold (127V). I sent
         | the power company a dump of the logs and requested they adjust
         | the tap on my house's transformer.
         | 
         | No response, and I'm pretty sure I'm on their "this guy is a
         | crank" list now.
        
       | NoOneNew wrote:
       | It's also cheaper to just buy a normal bag of ground coffee and
       | brew it in a french press/percolator/whatever than buy those
       | coffee pods which taste more like boiled cat shit than actual
       | coffee. Keurig would make the same letter to the same high horse
       | professor. Are you going to say Keurig is stupid for not selling
       | bags of coffee instead?
       | 
       | Doesn't matter how smart someone is, they always forget that
       | economics doesn't give two shits about their feelings or how
       | shiny their degrees are. Fancy little prefixes and suffixes to
       | your name doesn't help change reality.
       | 
       | People buy things for a multitude of reasons. Because people are
       | unique and allowed to do what they want for themselves, they tend
       | to like and value things different from _you_. Companies
       | capitalize on that.
       | 
       | Hell, want to get into some real nerdy math academics and
       | economics? What about that Japanese chalk so many of them love to
       | use? Something so exquisite and special to the professors of the
       | world for black board lectures. They went out of business. Why
       | couldn't your fancy letters and diplomas save that _important_
       | product? Where are the equations for that one?
        
         | robertlagrant wrote:
         | No, the response had good reasons, not like your "lol yeah but
         | people be crazy" stuff.
        
           | NoOneNew wrote:
           | Current cans of cat food are setup as either a single meal or
           | enough for 2 meals a day for a cat. Short to no time spent in
           | a fridge with a weak lid. People do not want to have an
           | opened can of cat food leeching stench into their fridge for
           | long periods of time. No "reusable" lid I ever found could
           | keep the smell out instead of ziplock bags, which get slimy
           | and nasty if your reuse them but then you're constantly
           | buying more bags.
           | 
           | A majority of the market won't buy bigger cans because they
           | prefer the convenience of one time, limited use to
           | potentially having your fridge smell like low quality fish
           | and chicken product gruel.
           | 
           | But that doesn't make for an interesting response to the
           | ravings of an uppity math professor. They didn't quite feel
           | like trying to explain the habits of normal, regular people
           | to a lunatic is worth their time. So they decided to have a
           | laugh in kind.
        
       | reaperducer wrote:
       | This is an example of the sort of foible of which people on HN
       | are constantly guilty.
       | 
       | Just because you're an expert at one thing does not make you an
       | expert at everything.
        
         | [deleted]
        
         | Tsiklon wrote:
         | This is true, though that said, on the flip side of things;
         | exchanges like the one between the letter's author and the cat
         | food company are exactly the sort of thing that helps expand
         | one's understanding outside of their own domain of knowledge.
         | 
         | Be it out of hubris or genuine interest, that the author of the
         | letter felt compelled to write to the company, they (and by
         | extension us) received an insight into the decision making
         | process behind one of the more mundane pieces of engineering we
         | see on a daily basis (I certainly did)
        
           | pp19dd wrote:
           | It was a good reminder that creation of many things takes
           | overlapping disciplines. It reminded me of a joke about a
           | mathematician optimizing a farmer's operation. He returns
           | after several months bursting with excitement, promises of
           | improved profits.
           | 
           | "First, we assume a perfectly spherical cow..."
        
       | MaxBarraclough wrote:
       | _More scrap metal is generated as the diameter is increased._
       | 
       | Can anyone comment on why that is?
        
         | lancebeet wrote:
         | If you imagine cutting out rectangles from sheet metal, you can
         | completely tile the plane. Punching out circles, you'll use a
         | maximum of roughly 91%. So I imagine the more of your material
         | you use for the sides, the less scraps you'll end up with. I'm
         | sure the problem is a lot more complicated than this though,
         | with deburring, corrugation and whatnot.
        
         | lmc wrote:
         | Edit: Disregard this. The other answers are better.
         | 
         | I guess it's because of the fat ends - if these have constant
         | thickness, the volume will only increase as diameter changes.
        
         | Cogito wrote:
         | My first thought was for the ends, and for a similar reason
         | that the smaller diameter cans pack more densely.
         | 
         | If you're punching circles out of sheet metal, you'll get more
         | waste with larger circles.
        
           | MaxBarraclough wrote:
           | > If you're punching circles out of sheet metal, you'll get
           | more waste with larger circles.
           | 
           | I don't think you would. The design can be scaled up or down
           | without impacting the proportion of the area which ends up
           | being 'useful'.
        
             | blt wrote:
             | The percentage waste per circle remains the same, but the
             | absolute amount of waste per can goes up.
        
         | johnp314 wrote:
         | One explanation could be the following based on the supposition
         | that one starts with rectangular pieces of metal. To minimize
         | waste for a circle one begins with a square piece and cuts out
         | the maximum circle contained therein. The waste is (area of
         | square) - (area of circle). If the circle was to be 4 inches in
         | diameter (2 inch radius) cut from a 4-by-4 square the waste is
         | 4^2 - Pi _2^2 = 3.43, whereas a 2 inch diameter circle cut from
         | a 2-by-2 square has waste of 2^2 - Pi_ 1^2 = 0.86. The
         | cylindrical side needed to achieve a given volume is
         | rectangular so has no waste in either case.
        
           | nonick wrote:
           | From a 4-by-4 inch square you can make 4 2-by-2 inch squares,
           | therefore the loss from 4 small squares would be 0.86x4=3.44,
           | same as one large square.
        
         | nabilhat wrote:
         | One factor missed in other answers, mentioned in the letter, is
         | that the ends are made from thicker stock than the cylinder,
         | and increase in thickness as diameter increases. The scrap
         | ratio of the ends doesn't change in area, but the volume of
         | scrap per can does.
         | 
         | What's interesting is how the letter's scrap argument has aged
         | - take a look at cans in common household sizes today. Most are
         | only capped on one end. The cylinder and opposite end are a
         | single deep drawn [0] unit. That can body will consume a round
         | portion of material and _definitely_ increases overall scrap
         | ratio over old double-capped cans.
         | 
         | [0] https://en.wikipedia.org/wiki/Deep_drawing
        
           | Tsiklon wrote:
           | I note that here in the UK, cans of soda tend to be deep
           | drawn, capped at the top, and that most food/soup cans are of
           | the traditional double capped variety. I wonder does this
           | come down to the pressures of the contents or is there
           | another reason involved.
        
             | nabilhat wrote:
             | I do a lot of manufacturing adjacent and overlapping work.
             | The primary justification for cans (by a long shot) is
             | going to be process steps and cycle time. Very roughly
             | counting manufacturing operations, while surely overlooking
             | tons of other handling and preparation common to either
             | method:
             | 
             | A double capped can has 7 specific manufacturing tasks: 3
             | cutting steps (2 ends, 1 center), 1 roll forming step, 1
             | weld step to close the cylinder, and 2 end capping steps.
             | Forming ribs into the cylinder and can should happen
             | simultaneously when the cylinder is roll formed and when
             | the ends are punched from sheet stock.
             | 
             | A single capped can has 4 specific manufacturing tasks: 2
             | cutting steps (1 blank for the can, 1 lid), 1 draw form
             | step, and capping the end. Trimming the edges of the draw
             | formed can should be combined with the forming operation.
             | 
             | Draw forming tools are expensive, the world is still full
             | of cheap, perfectly functional, secondhand canning
             | equipment. Either way, cans sell for cheap and at low
             | margins. Takes a lot of volume to make ROI. _Or_...
             | Aluminum! Aluminum is far more expensive than steel and is
             | finicky to weld reliably. Draw forming soda cans eliminates
             | any need for welding and allows manufacturing of thinner
             | can walls, which reduces material consumption, and the
             | bottom can be shaped to hold pressure with less material.
        
               | Tsiklon wrote:
               | Thanks for sharing! I assume it's the dome shape on the
               | bottom of a soda can that's specifically there for
               | holding pressure in that case (a balance of accommodating
               | the greatest strength per unit surface area measured
               | against the cost of the forming process)
        
       | CamelCaseName wrote:
       | The title doesn't mention the interesting part -- the company
       | responds with reasons why they made their cans a certain size.
       | Definitely worth clicking through.
       | 
       | I'm not sure about 1987, but today, Carnation is a lot more than
       | "a cat food company".
        
         | kps wrote:
         | It's Nestles all the way down.
        
       | plasticchris wrote:
       | I did something similar once, mailing v8 about how they could
       | make their cans squatter. I even wrote a script to find the
       | optimal shape. I think it went straight into their crank file.
        
       | Ma8ee wrote:
       | What is left out from the letter is that the marketing department
       | probably have a say in the design too. Nowadays they probably
       | have tested which geometries that sell best to different target
       | groups.
       | 
       | And then we also have the user perspective. A short wide can is
       | easier to scoop from.
        
         | mentos wrote:
         | Yea I was expecting an argument that their cans stand out on
         | the shelves and lead to higher sales.
        
       | throw982739182 wrote:
       | Okay but what really bothers me are square powdered juice
       | packets. This is the only way powdered juice comes in my country
       | and we're all poor and re-fill soda bottles, so WHY the hell are
       | they square? Powder spills everywhere. Why are they not tube
       | shaped. And why aren't there ones for small water bottles for on
       | the go? One of these days I will write to the companies...
        
         | ChickeNES wrote:
         | This is so odd to read, as in the US there are certainly tube-
         | shaped single serving drink mixes (indeed, I have one sitting
         | on my desk right now). For example:
         | https://www.powdermixdirect.com/Gatorade-Sqwincher-Single-Se...
        
       | [deleted]
        
       | dmitrygr wrote:
       | This reinforces the old saying. "Don't take down the fence until
       | you know why it was put up." I wish more computer science
       | programs taught this as an important principle. Too many people
       | today assume that if something is newer, it is necessarily
       | better, and rush to rewrite or replace things that had been
       | working well, and would continue to do so, with new and untested
       | and unproven replacements.
        
       | adav wrote:
       | I wonder if the customer service department at a large FMCG
       | company would be so empowered as to send such a detailed response
       | these days. I'd expect either no response or a generic answer
       | with goodwill a voucher.
        
         | jolmg wrote:
         | I was impressed they'd send such a letter at all. On seeing
         | your comment, I now notice that the letter was written in 1987.
        
       | [deleted]
        
       | vanderZwan wrote:
       | Highly recommended related YT video:
       | 
       |  _The Engineering Guy: The Ingenious Design of the Aluminum
       | Beverage Can_
       | 
       | https://www.youtube.com/watch?v=hUhisi2FBuw
        
         | Hamuko wrote:
         | I know for a fact that I've watched this before but still I
         | just had to rewatch it.
        
       | GekkePrutser wrote:
       | Well, besides the reasons given I'd say they probably buy these
       | cans ready made so custom cans would cost a lot more due to
       | economies of scale.
        
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