• @ns1@feddit.uk
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    1618 months ago

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

    • zkfcfbzr
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      868 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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        138 months ago

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

    • @chillhelm@lemmy.world
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      198 months ago

      This is the correct answer. Pi is known. What it’s decimal expansion looks like is irrelevant. It’s 1 in base Pi.

      • @cogman@lemmy.world
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        78 months ago

        Yup, similar to the square root of two and Euler’s number.

        These are numbers defined by their properties and not their exact values. In fact, we have imaginary numbers that don’t have values and yet are still extremely useful because of their defined properties.

    • @Carnelian@lemmy.world
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      178 months ago

      The actual punchline here should have been “there is no known equation to calculate the exact perimeter of an ellipse”, then sucking tears from an astrophysicist

    • LanternEverywhere
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      58 months ago

      Exactly, a fraction is completely as valid of a way to express a number as using a decimal.

      1/2 = 0.5

      They’re both fully valid ways to write the exact same quantity

  • @bstix@feddit.dk
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    1118 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
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    738 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.

      • @otp@sh.itjust.works
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        38 months ago

        I’m pretty sure a base-Pi counting system would mean that Pi is π, not 1.

        You’d count π, 2π, 3π, 4π, and so on. It doesn’t change reality, just the way you count and represent numbers.

        I might be off, but it’s definitely not π = 1.

      • janAkali
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        8 months ago

        You still think in 1-based system, Pi unit * Pi unit is Pi of Pi units or 3.14159… Pi units. Also, Pi unit / Pi unit is 1/Pi Pi units or 0.318309886183790… Pi units…

      • @nul9o9@lemmy.world
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        88 months ago

        6π is an acceptable answer for finding the circumference of a circle with a radius of 3 units of something.

      • janAkali
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        78 months ago

        1 is also a number, a number we chose by convention to be a base unit for all numbers. You can break down every number down to this unit.

        20 is 20 1s. 1.5 is 1 and a half 1.

        If we have Pi as a unit, circumference of a circle would be radius*2 of Pi units. But everything that doesn’t involve Pi would be a fraction of Pi, e.g. a normal 1 is roughly 1/3 of Pi units, 314 is roughly 100 Pi units, etc. etc.

      • Gnome Kat
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        458 months ago

        Putting things in base 10 is also a definition. Digits aren’t special.

        • @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?!]

      • @HopFlop@discuss.tchncs.de
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        178 months ago

        That doesnt make a difference. You can find the exact circumference of a circle, you just cant express it in the decimal system as a number (thats why we have a symbol for it so you can still express the exact value)

  • Dippy
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    358 months ago

    Nasa uses 15 digits of pi for solar system travel. And 42 digits is enough to calculate the entire universe to atomic accuracy

    • Malgas
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      178 months ago

      And 65 digits is sufficient to calculate the circumference of the visible universe to within a Planck length.

  • amio
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    338 months ago

    Yeah, calling pi infinite makes me wanna cry, too.

    • @Artyom@lemm.ee
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      8 months ago

      If only mathematicians had a number for that. Ya know, the people famous for making names for things on average once per published paper, most of them completely useless.

  • @UsernameIsTooLon@lemmy.world
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    198 months ago

    Technically you can’t measure anything accurately because there’s an infinite amount of numbers between 1 and 0. Whose to say it’s exactly 1? It could be off by an infinite amount of 0s and 1.

    Achilles and the Tortoise paradox.

  • JoYo
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    98 months ago

    Besides measuring it with a measuring tape.