Comment on Let π = 5

• PM_Your_Nudes_Please@lemmy.world ⁨6⁩ ⁨months⁩ ago

  In astronomy, pi=10. Because when you’re trying to estimate distances measured in millions of light years, the difference between 3 and 10 is just one or two orders of magnitude on a small number. It’s pretty common for astronomers to do napkin math by rounding every single number to the nearest zero. 91k becomes 100k for instance. Because the napkin math estimations are just trying to gauge whether some celestial event or object is a thousand light years away, ten thousand, a hundred thousand, etc… And pi becomes 10, because that’s the nearest round number.

  source

  • LazerFX@sh.itjust.works ⁨6⁩ ⁨months⁩ ago

    Fermi Estimation. Where you’re dealing with something so big, you’re just interested in the magnitude.

    source
• Agent641@lemmy.world ⁨6⁩ ⁨months⁩ ago

  “About yay big.”

  source
• maniclucky@lemmy.world ⁨6⁩ ⁨months⁩ ago

  Excuse me what? I’ve been an engineer for a decade and have never met anyone that would do that. We have calculators.

  source

  • assassin_aragorn@lemmy.world ⁨6⁩ ⁨months⁩ ago

    I think they mean napkin math. Like you’re in a meeting and they ask for a general idea if something will work or not

    source

    • Jimbo@yiffit.net ⁨6⁩ ⁨months⁩ ago

      We all have phones with calculators, don’t really need to do napkin math anymore

      source

      • assassin_aragorn@lemmy.world ⁨6⁩ ⁨months⁩ ago

        Depends on the level of precision you need. If I want the volume in a 500 foot long, 3 inch pipe to roughly estimate how much supply I need to order, I wouldn’t need a calculator. It would very roughly be 90-95 ft3. (Divide 500 by 4 two times and multiple by 3)

        Then I would spend 5 minutes double checking myself haha.

        source
    • maniclucky@lemmy.world ⁨6⁩ ⁨months⁩ ago

      I suppose. I’m still internally outraged and haven’t run into such a situation before, but I accept this.

      source

      • assassin_aragorn@lemmy.world ⁨6⁩ ⁨months⁩ ago

        To be fair most of the situations where I’ve run into this have never involved pi, and sometimes it’s just qualitative.

        source

        • -> View More Comments
• ColeSloth@discuss.tchncs.de ⁨6⁩ ⁨months⁩ ago

  I feel like a proper engineer would call only going two places past the decimal “rounding pie”.

  source