• lauha@lemmy.world
    link
    fedilink
    English
    arrow-up
    159
    arrow-down
    1
    ·
    3 days ago

    This is because fibonacci numbers approach golden ratio which is approximately 1,618033… and one mile is 1,609344 kilometres exactly.

  • gwl@lemmy.blahaj.zone
    link
    fedilink
    English
    arrow-up
    8
    arrow-down
    3
    ·
    edit-2
    2 days ago

    Ah yes, I always remember the Fibonacci sequence and totally wouldn’t find it harder to calculate than just doing the conversion the regular way

    /sarcasm

    • Dumhuvud@programming.dev
      link
      fedilink
      English
      arrow-up
      6
      arrow-down
      2
      ·
      2 days ago

      “Remember”? Do you also remember all the digits of π?

      It’s defined as F(0) = 0, F(1) = 1 and F(n) = F(n - 1) + F(n - 2). Which makes more sense than imperial units.

      • gwl@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        5
        arrow-down
        1
        ·
        edit-2
        2 days ago

        Or I could just do 1.6 km ≈ 1 mile whenever I need to convert from the standard that I use, Metric, to Imperial

        Far far far simpler

        Edit: I’m not American, I use sensible units, SI Metric

        • Dumhuvud@programming.dev
          link
          fedilink
          English
          arrow-up
          1
          ·
          3 hours ago

          Tbh, the last sentence was just a silly jab at the imperial units.

          I was mostly just making fun of the fact that you implied the Fibonacci sequence can be memorized, when it is infinite. I’m not saying that referring to it is simpler than dividing/multiplying by a constant, no.

      • UnderpantsWeevil@lemmy.world
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 day ago

        Which makes more sense than imperial units.

        But you’d only need to do the conversion if you started with imperial units.

    • atro_city@fedia.io
      link
      fedilink
      arrow-up
      41
      arrow-down
      2
      ·
      3 days ago

      Nah, that’s too difficult for USAians. They can memorize fibonacci numbers much more easily.

      • WALLACE@feddit.uk
        link
        fedilink
        English
        arrow-up
        17
        ·
        3 days ago

        Be like us Brits and measure short distances in metric, long distances in Imperial, yet struggle to convert between them.

        GPS navigation gets frustrating. It’s either metric “turn left in 4km” when all road signs and speeds are in miles, or imperial “turn in 200ft” when you have no idea how long 200ft is.

        • ITGuyLevi@programming.dev
          link
          fedilink
          English
          arrow-up
          6
          arrow-down
          1
          ·
          2 days ago

          I never understood the use of yards for exits over there, but the hardest part was figuring out what my GP meant when he said I needed to lose a couple ‘stones’… C’mon, you can’t expect me to learn imperial, metric, and whatever the hell that is.

          I’m already stuck having to be able to convert between elephants and F-250’s because my homeland REFUSES the metric system, now I have to study geology just to figure out how unhealthy I am (actually was, I’ve lost 40lbs since then).

        • Cethin@lemmy.zip
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          1
          ·
          edit-2
          2 days ago

          Yeah, people talk shit about Americans using Imperial, but Brits are so fucked up. At least we consistently use one shitty system. Brits are constantly switching between the two, and sometimes even using outdated systems no one else uses. Like, why the fuck do you use stones for body weight, but pounds, ounces, and grams for different measurements of weight? Be consistent at least.

      • Cethin@lemmy.zip
        link
        fedilink
        English
        arrow-up
        1
        ·
        2 days ago

        To be fair, kilometers make a lot more sense to me, as an American. However, everything is written in miles, and everyone speaks in miles. Estimating distance for me is easier in metric, but it isn’t really acceptable.

        (I play milsims, which is why I’m more used to it. Most Americans have almost zero experience with metric.)

      • fibojoly@sh.itjust.works
        link
        fedilink
        English
        arrow-up
        4
        ·
        edit-2
        2 days ago

        The idea the average Joe even knows of them… (edit: was thinking of Fibonacci, but even km are in doubt these days)

        • frunch@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          1
          ·
          2 days ago

          Well i was taught about kilometers in school, though i can’t speak to today’s curriculum…

    • Aeao@lemmy.world
      link
      fedilink
      English
      arrow-up
      13
      arrow-down
      1
      ·
      3 days ago

      Hey I’m going to have to ask you to censor that word. There’s American children on this ap! We can’t have them going to the playground and repeating that kind of language.

      • jaybone@lemmy.zip
        link
        fedilink
        English
        arrow-up
        2
        arrow-down
        1
        ·
        2 days ago

        Are there children on this app though? Seems like they’d rather be on TikTok or whatever. Unless they are some edgy ML tankie contrarian maybe. In which case, expose to the metric system and nsfw content is the least of their problems.

        • Aeao@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          ·
          2 days ago

          Unfortunately the us system has the word “imperial” so tankies can’t stand it lol

      • Log in | Sign up@lemmy.world
        link
        fedilink
        English
        arrow-up
        1
        arrow-down
        1
        ·
        2 days ago

        They might realise that the metric system is much better than the stupid Imperial system, and this could make them fell guilty that their forefathers were ignorant bozos. Republicans hate it when children learn about the errors of their forefathers.

        • ricecake@sh.itjust.works
          link
          fedilink
          English
          arrow-up
          4
          ·
          2 days ago

          Their forefathers were actually in favor of the metric system. The US is an original signatory to the treaty of the meter, it’s the official unit of measure for the government and military, and we were on the brink of getting switched over when Republicans decided they didn’t want to spend money on the final conversion and education, despite it being a popular enough notion that it was used for advertising. (The two liter bottle became popular when they used the popularity of metric to sell plastic pop bottles).

          The fervent attachment to imperial is weirdly recent.

          • Aeao@lemmy.world
            link
            fedilink
            English
            arrow-up
            2
            ·
            2 days ago

            And are units are tied to metric system as well.

            1 inch is defined as exactly 2.54. That’s what an inch “is” in America.

            That’s why I liked my joke. We just hate the words themselves

    • PhAzE@lemmy.ca
      link
      fedilink
      English
      arrow-up
      13
      ·
      2 days ago

      Just gotta ask any of the 90% of the world who use it to find out. Americans hate this one simple trick!

      • gwl@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        4
        ·
        edit-2
        2 days ago

        Fun fact: there’s quite a lot of countries that use “mixed metrics”, with no real rhyme or reason for what uses old ancient imperial and what uses new shiny metric

        UK - Miles for long distances, switch to meters for distances less than a mile, always use km in air and sea. Milk in pints, petrol in liters, water in ml, beer in pints. Human heights in Feet Inches, building heights in Meters. Human weights in a unit even Americans don’t use anymore (Stone), animal weights in kg/g.

      • Yeather@lemmy.ca
        link
        fedilink
        English
        arrow-up
        4
        ·
        edit-2
        2 days ago

        Yeah, but does the kilometer have a cool origin like the mile? Checkmate math nerd.

        • PhAzE@lemmy.ca
          link
          fedilink
          English
          arrow-up
          12
          ·
          2 days ago

          I’d say it kind of does actually:

          The Kilometer is defined as one ten-millionth of the distance from the Earth’s North Pole to the equator along the meridian passing through Paris.

          Vs

          The mile originated with the Roman measurement of mille passus, meaning “one thousand paces,” with a pace being five Roman feet. The modern 5,280-foot statute mile evolved in England, where the 1592 parliamentary act defined the mile as eight furlongs (660 feet each) to standardize the distance.

          One is measured by earth, the other by stinky feet.

          • starman2112@sh.itjust.works
            link
            fedilink
            English
            arrow-up
            7
            ·
            edit-2
            2 days ago

            Yeah but earth is wobbly and imprecise so now we define the meter as “the distance light travels in a vacuum in 1/299,792,458th of a second”

            • angrystego@lemmy.world
              link
              fedilink
              English
              arrow-up
              2
              ·
              2 days ago

              That’a a cool definition. I wouldn’t call it an origin though, that would still be the Earth measurement through Paris, which is also cool.

          • groet@feddit.org
            link
            fedilink
            English
            arrow-up
            2
            ·
            2 days ago

            one ten-millionth of the distance from the Earth’s North Pole to the equator

            On ten-thousandth. The circumference through the poles is ~40,000km

  • ExperimentalGuy@programming.dev
    link
    fedilink
    English
    arrow-up
    20
    ·
    2 days ago

    This is such a cool example of how some recursive algorithms have a closed form. We all know that there’s a simple equation to plug miles into to get kilometers, but we don’t talk about how the Fibonacci sequence has a closed form. This is so cool.

      • WolfLink@sh.itjust.works
        link
        fedilink
        English
        arrow-up
        5
        ·
        edit-2
        2 days ago

        Closed form means it can be written out as a specific, finite set of instructions that work the same regardless of what the input to your function is.

        For Fibonacci, it is most commonly defined in its recursive form:

        f(0) = 0
        f(1) = 1
        f(x) = f(x-1) + f(x-2) for integer x > 1
        

        But using this form, computing a very large Fibonacci number requires computing all the numbers before it, so it’s not the same finite set of instructions for every number, it takes more computation to generate larger numbers.

        However, there is a closed form formula for generating Fibonacci numbers. Using this formula, you can directly compute any large Fibonacci number without having to compute all those intermediate steps. It takes the same amount of work to compute any Fibonacci number.

        f(x) = (a^x - b^x)/√5
        a = (1+√5)/2
        b = (1-√5)/2
        

        (Note that a and b here are constants; I only wrote them separately to avoid a mess of nested parenthesis)

        For an example of something that doesn’t have a closed form, we do not know of a closed form for generating prime numbers. There are several known algorithms for generating the nth prime number, but they all depend on computing all the previous prime numbers, making it very difficult to compute very large prime numbers (in fact, how generating large primes is actually done is by making an educated guess and then checking that it’s actually prime). Discovering a closed form formula for prime numbers would have a huge impact on mathematics and cryptography.

      • gwl@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        3
        ·
        edit-2
        2 days ago

        It’s rough estimation, a deviation of anything less than 50% is accurate enough for that

        Edit: Ooh I thought you were trying to “um actually, it’s 1.66”, but I just realised they put 0.6 instead of 1.6

    • Routhinator@startrek.website
      link
      fedilink
      English
      arrow-up
      2
      arrow-down
      2
      ·
      1 day ago

      US and Israel are the only places that still use Imperial. While older generations in Canada and UK will speak about weight in Imperial, the official unit system is Metric.

      • UnderpantsWeevil@lemmy.world
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 day ago

        US and Israel are the only places that still use Imperial.

        But the US has a global business empire. So you’ll see the Imperial/Metric conversions all over the planet.

  • ramble81@lemmy.zip
    link
    fedilink
    English
    arrow-up
    12
    ·
    2 days ago

    To go from km to mi I always leaned “multiply by 6 and move the decimal one to the left”. So 6km is ~3.6mi. Or 10km is just about 6mi.

    • BeardedGingerWonder@feddit.uk
      link
      fedilink
      English
      arrow-up
      1
      ·
      1 day ago

      Honestly divide by 5 and multiply by 8 usually isn’t too difficult and just gives you the right answer.

      I remember it by 200mph is 320kph.

    • Pup Biru@aussie.zone
      link
      fedilink
      English
      arrow-up
      2
      ·
      edit-2
      2 days ago

      or add half and then 10% (because it’s 1.6km to the mile): easier than multiplying decimals or large numbers by 6, and the inverse is 0.6mi=1km so easy to remember both ways (same thing but don’t “add” just start from 0)

    • untorquer@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      ·
      2 days ago

      I used to remember because space (Karman line) is 100km or 62mi up. I guess it helps to be a space nerd for that one. Kind of just figure 1.6 going the other way.

  • melsaskca@lemmy.ca
    link
    fedilink
    English
    arrow-up
    4
    ·
    2 days ago

    Cool! I wish I would have known this in the 70’s when Canada changed over from British Imperial units to the Metric system. Maybe this is the incentive needed to push the usa into the rest of the metric system world!

    • Mycatiskai@lemmy.ca
      link
      fedilink
      English
      arrow-up
      9
      ·
      2 days ago

      If every measurement being a factor of ten of a smaller or bigger unit isn’t going to convince Americans of the ease of metric then the Fibonacci sequence isn’t going to convince them.