What are these bumps on the top of a pull-tab can?

(old.reddit.com)

237 points | by mkmk 13 hours ago ago

35 comments

  • runlevel1 7 hours ago

    Reminds me of something from a few months ago:

    Someone on r/HomeNetworking cursed whoever invented the RJ45 connector, and in the comments, Richard Benett, vice-chair of the first IEEE 802.3 task group that wrote a standard around RJ-45-style connector, appears and offers to take the blame.

    That led to this short documentary: "TWISTED: The dramatic history of twisted-pair Ethernet" https://www.youtube.com/watch?v=f8PP5IHsL8Y

  • helsinkiandrew 11 hours ago

    Related: The Engineer Guy’s “The Ingenious Design of the Aluminum Beverage Can” on YouTube https://youtu.be/hUhisi2FBuw

    • boffinAudio 4 hours ago

      Whats crazy is that a significant portion of the aluminium minerals comes from a single source of bauxite in the world, near Pinjarra Western Australia .. something like 90% of the worlds aluminium is sourced from that one mine.

      • atombender 3 hours ago

        According this source [1], only about 35% of all bauxite is mined in Australia, so I don't think that's true.

        What's crazy is how modern shipping has made it economical to process this elsewhere, all over the globe. For example, from one of the biggest bauxite mines, in Pará, Brazil, the raw bauxite is shipped across the Atlantic to be processed by Hydro in Norway, which refines it into alumina powder, which is then shipped elsewhere to be refined into aluminum. You would think it would be more cost-effective and energy-efficient to centralize this, not to mention more environmentally friendly.

        [1] https://www.nsenergybusiness.com/news/profiling-the-top-five...

        • zdragnar 2 hours ago

          I took a small rabbit hole run into bauxite smelting when I found out a local place had their own power plant just for the process. It really does require that much energy.

          If the Brazil plant is putting out enough ore, I can definitely imagine it is cheaper to sell it internationally to someone with hydro power than to build and operate their own power plant.

        • cjs_ac 2 hours ago

          Extracting aluminium from bauxite is notoriously energy-intensive. During the nineteenth century, European aristocrats used aluminium tableware because it was more expensive than silverware. (They later switched back to silver when the novelty wore off and they realised aluminium was too light to feel right in the hand.)

        • boffinAudio 3 hours ago

          Yeah, I think this factoid has changed significantly in the decades since I learned it during a visit to Pinjarra. ;)

          Still, bauxite is pretty weird business.

    • larusso 11 hours ago

      Damn you beat me by a hair

  • imglorp 2 hours ago

    Further down, paraphrasing a thread,

        > why is the dot spacing different on the left vs right can?
    
        > When a product design like this gets licensed out to others in the same industry, they will often change the design slightly to make their version incompatible with other potential suppliers
    
       > why want incompatibility?
    
       > to enforce supplier loyalty
    
    Another kind of moat. Everyone is for a free market until they can use some form of lock-in to force a transaction.
  • dasil003 2 hours ago

    Remember when every other Quora answer felt like this? In retrospect maybe that was peak Web.

  • unwind 6 hours ago

    Very informative, like so many posts on the /r/whatisthisthing sub. It's awesome when random sources pop up, it's very rewarding!

    I had a similar moment once (I'm a regular reader of the sub) when someone asked about about a balise [1] when I was at one of the primary manufacturers and operators of them, doing work on software handling logs from passages. :)

    Also, of course whenever someone on here mentions Nagle's Algorithm [2] and gets fun feedback from a particular user, that's fun too! :)

    [1]: https://www.reddit.com/r/whatisthisthing/comments/yrijd9/wha...

    [2]: https://en.wikipedia.org/wiki/Nagle%27s_algorithm

  • larusso 11 hours ago

    Whenever it’s about cans I can only recommend this video from the engineer guy [1]. He makes no videos anymore sadly.

    https://youtu.be/hUhisi2FBuw

    • hobofan 8 hours ago

      > He makes no videos anymore sadly.

      Has he stated that anywhere? Because looking at the upload date (8 months) of the latest video and the gaps between previous uploads (sometimes multiple years), it doesn't look uncharacteristic for him.

    • vlachen 10 hours ago

      I can highly recommend his books, however.

      • larusso 9 hours ago

        I also think Technologie Connections filled his spot great. He started with sound and video topics but switched to household technologies.

  • a_shovel 12 hours ago

    xkcd "Work": https://xkcd.com/1741/

    "Sometimes I get overwhelmed thinking about the amount of work that went into the ordinary objects around me."

    • Larrikin 10 hours ago

      A former co-worker I knew said a technique he would use on a date that was going slow to try and make himself look smart and the date curious was to examine the design decisions of objects around them. The table, the paint used to make a painting, the shampoo that makes the dates hair smell so good, etc. Add in some history of the object and discuss until an interesting bit was found that could move the conversation else where. Seemed like it could work but I never needed to try it.

      • NikkiA 6 hours ago

        The fact that he got to try this routine multiple times tells me it probably didn't work.

        He also sounds unbearable.

      • daseiner1 9 hours ago

        I've never had a date going slow that also included me being able to smell her hair.

      • HPsquared 2 hours ago

        Then it's a jumping off point to talk about economics, perfect date material.

      • gardenhedge an hour ago

        It's probably fine for conversation but writing it down and using it as a tatic definitely makes it strange

    • HPsquared 4 hours ago
    • noneeeed 7 hours ago

      I love this comic.

      There's an idea in psychology called the illusion of explanitory depth. It's the idea that everyone has much more confidence in their understanding of how things work, even the most mundane and apparantly simple things, than is warranted. In turn we tend to hugely underestimate the difficulty, complexity and skill in jobs we have never done.

      The world is absolutely full of utterly prosaic objects that are far more sophisticated that we imagine, either in their function and design or in their manufacture.

      Most people overestimate how well they would cope in some post-apocalyptic world. But I think even many people who regard themselves as prepared, underestimate how much skill and sheer effort is involved in making really simple things like rope. To do more than just scrape by you would need to reconstruct a society of specialists, it won't be the rugged individualists.

      • potato3732842 4 hours ago

        I hate this take (and every other take wherein one basically looks down their nose at the rest of the population and claims they all have a bad take on something).

        Most things are pretty simply and someone with a basic understanding could get them mostly right or at least right enough to work. The complexity comes from the many layers of refinement over the years. No, your clay molded toilet won't flush like a modern one but if you understand the basics of how a toilet works it'll probably flush.

        • noneeeed an hour ago

          This absolutely isn't looking down on people. I didn't say that people couldn't do these things. I am absolutely ignorant of how the vast majority of the world actually works. I would never look down on someone because they don't know something. I get very annoyed with my fellow techies and the way they seem to assume that non-technical people are stupid for not understanding things that they themselves see as simple and obvious.

          Of course people can learn anything. It's that we tend to not realise that we don't know this stuff, and so we underestimate the difficulty/complexity of them. This often leads to people actually looking down dismissively on other people's jobs, as they assume they must be simple or easy, because they have never done them. You get endless political commentry on how people doing certain jobs don't deserve to be paid well because what they do appears "simple". Train drivers are a classic example. It's a job that is a lot harder and more involved than it appears at first.

          For a while I worked in the rail industry. That was full of things that were way more complex and involved than I had ever realised. Things that seemed simple on the surface had decades of refinement and subtlety to them born of experience.

          Your example is a great one. The principals of the flushing toilet with a siphon flush, ballcock and an S-bend outflow are not complex, but a lot of people have no idea what pressing a flush down actually does to get the water into the bowl, how it refills or what the S-bend is actually for (it's more than just the smell, sewer gas is explosive). It's the reason that a lot of people don't tackle more DIY jobs, they suddenly realise they don't understand it. But it's also why YouTube is so great, because these things are all learnable.

          In the event of a societal collapse, I sometimes think that preserving all the instructional YouTube videos would be our best hope for rebuilding :D

        • infecto 2 hours ago

          I believe you are overestimating the percentage of the population that understand the basics of how a toilet works. Not looking down on those folks but in my experience, there are folks that think about how things work or have some practical experience, the rest don't ever think about it and so most likely do not even understand the basics. Nothing wrong with it but its fairly apparent.

          Inversely, those folks that think about how things work tend to be fairly overconfident in their ability to recreate/repair/innovate. In reality there are often fine details that you miss.

        • smitelli 2 hours ago

          Is this hypothetical person going to build a municipal water and sewer system for their toilet too? Or will they just dig a well, which requires no skills or effort at all? /s

  • amyames 8 hours ago

    the pull tab on the right has a divot in it where it makes contact with the can, and it concentrates more pressure at the point of contact to pop the seal.

    That’s an attempt to mitigate cans where you’d pull the tab and the tab would just break off without opening the can. So the person who answered it’s usually because of the seal is right.

    other half’s dad [retired from] Campbell in Ohio and isn’t an internet let alone a Reddit person, you’d never guess how much trivia there is about their #2 can. I’d have commented but a brand new account will probably be buried as spam … and the second answer is correct anyway.

    • juancb 8 hours ago

      I hope to someday be too good for Reddit. For now I tend to use it or at least click on links to it like I do for Twitter.

  • johtso an hour ago

    It's the pig's eyes of course!

  • dartos 12 hours ago

    Old Reddit vibes

    • whamlastxmas 6 hours ago

      Yeah I started reading it prepared for it to be fake LLM slop