• ns1@feddit.uk
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    8 months ago

    More likely a mathematician would correct you instead of crying. Pi is not infinite, its decimal expansion is infinite!

    • zkfcfbzr@lemmy.world
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      8 months ago

      Plus even that isn’t enough: 10/3 has an infinite decimal expansion (in base 10 at least) too, but if π = 10/3, you’d be able to find exact circumferences. Its irrationality is what makes it relevant to this joke.

      A mathematician is also perfectly happy with answers like “4π” as exact.

      Plus what’s to stop you from having a rational circumference but irrational radius?

      Writing this, I feel like I might have accidentally proved your point.

      • danc4498@lemmy.world
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        8 months ago

        Mathematicians taking a physics class and being told they have to round things. That’s when the tears start flowing.

  • bstix@feddit.dk
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    8 months ago

    Easy. Take a wire that is exactly 1 meter long. Form a circle from the wire. The circumference of that circle is 1 meter.

  • janAkali@lemmy.one
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    8 months ago

    Who said Pi is infinite? If we take Pi as base unit, it is exactly 1. No fraction, perfectly round.

    Now everything else requires an infinite precision.

  • guywithoutaname@lemm.ee
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    8 months ago

    Not true. If you define the circumference in terms of pi, you can define the circumference exactly.

        • h3ndrik@feddit.de
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          8 months ago

          Was going to say the same. Also π isn’t infinite. Far from it. it’s not even bigger than 4. It’s representation in the decimal system is just so that it can’t be written there with a finite number of decimal places. But you could just write “π”. It’s short, concise and exact.

          And by that definition 0.1 is also infinite… My computer can’t write that with a finite amount of digits in base 2, which it uses internally.

          So… I’m crying salty tears, too.

          [Edit: And we don’t even need transcendental numbers or other number systems. A third also doesn’t have a representation. So again following the logic… you can divide a cake into 5 pieces, but never into 3?!]

          • lolcatnip@reddthat.com
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            8 months ago

            Not sure where you’re going with the decimal thing. Pi had infinite digits in any integer base because it’s irrational.

      • RandomStickman@kbin.run
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        8 months ago

        I think it’s because no matter how many corners you cut it’s still an approximation of the circumference area. There’s just an infinite amount of corners that sticks out

        • marcos@lemmy.world
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          8 months ago

          There’s just an infinite amount of corners that sticks out

          Yes. And that means that it is not an approximation of the circumference.

          But it approximates the area of the circle.

    • lolcatnip@reddthat.com
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      8 months ago

      That approach works for area but not for perimeter, because cutting off the corners gives you a shape whose area is closer to the circle’s, but it doesn’t change the perimeter at all.