xkcd: Coordinate Precision but pi (π)?

I tried looking for some answer but found mostly

  • People reciting pi
  • People teaching how to memorize pi
  • How to calculate pi using different formula
  • How many digits NASA uses

Update question to be more specific

In case someone see this later, what is the most advanced object you can build or perform its task, with different length of pi?

0, 3 => you can’t make a full circle

1, 3.1 => very wobbly circle

2, 3.14 => perfect hole on a beach

3, 3.142 => ??

4, 3.1416 => ??

5, 3.14159 => ??

Old question below

In practice, the majority of people will never require any extra digit past 3.14. Some engineering may go to 3.1416. And unless you are doing space stuff 3.14159 is probably more than sufficient.

But at which point do a situation require extra digit?
From 3 to 3.1 to 3.14 and so on.

My non-existing rubber duck told me I can just plug these into a graphing calculator. facepalm

y=(2πx−(2·3.14x))

y=abs(2πx−(2·3.142x))

y=abs(2πx−(2·3.1416x))

y=(2πx−(2·3.14159x))

Got adequate answer from @dual_sport_dork and @howrar
Any extra example of big object and its minimum pi approximation still welcome.

  • dual_sport_dork 🐧🗡️@lemmy.world
    701·
    11 months ago

    On the NASA front, I believe I read somewhere that NASA determined that only 40 decimal places of pi are required to define a sphere the size of the observable universe to the accuracy of +/- the width of one hydrogen atom. It seems like you could file that under “close enough.”

    Just using 3 is certainly too low of a precision – unless you’re writing a major work of religious literature, of course. 3.1 is likewise unlikely to result in acceptable accuracy on a terrestrial scale. I’ve always used 3.14159 which is conveniently exactly what I can remember without looking it up and it’s always been good enough for me. I don’t think I’ve ever in my life needed to scribe a circle much larger than a couple of feet across at any rate.

    You may be interested in reading this: https://blogs.scientificamerican.com/observations/how-much-pi-do-you-need/

    • AmidFuror@kbin.social
      51·
      11 months ago

      Upvoted for religious text reference. Another way to put it would be if you are OK with being off by 33% for insect leg count, you can use 3 for pi.

    • g6d3np81@kbin.socialOP
      3·
      11 months ago

      Thank you, I already skimmed through that article before posting. Maybe I failed to put my question into words properly.

      I want examples similar to pool/fence circumference in the article. Along the line of “We’re building x, and this is the worst rounding we can go, one fewer digit and it will be off by y”