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[–] 160 points 2 years ago (6 children)

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

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  • [–] 85 points 2 years ago (1 child)

    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.

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  • [–] 31 points 2 years ago (1 child)

    Its decimal expansion is finite in the base pi.

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  • [–] 19 points 2 years ago (1 child)

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

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  • [–] 7 points 2 years 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.

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  • [–] 17 points 2 years ago (1 child)

    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

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    [–] 111 points 2 years ago (3 children)

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

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  • [–] 17 points 2 years ago (7 children)

    "exactly"

    uh huh. and how are you measuring that?

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    [–] 73 points 2 years ago (8 children)

    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.

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    [–] 71 points 2 years ago (1 child)

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

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  • [–] 7 points 2 years ago (2 children)
  • [–] 46 points 2 years ago (2 children)

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

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  • [–] 27 points 2 years ago* (last edited 2 years ago) (14 children)

    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?!]

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  • [–] 17 points 2 years 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)

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  • [–] 70 points 2 years ago (5 children)
  • [–] 16 points 2 years ago (5 children)

    Omfg why can’t I figure out why this does not work. Help me pls

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  • [–] 33 points 2 years ago* (last edited 2 years ago) (1 child)

    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

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  • [–] 24 points 2 years ago

    It's a fractal problem, even if you repeat the cutting until infinite, there are still a roughness with little triangles which you must add to Pi, there are no difference between image 4 and 5, the triangles are still there, smaller but more. But it's a nice illusion.

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    [–] 45 points 2 years ago (1 child)

    Let's say you got a circle with radius 1/π...

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    [–] 35 points 2 years ago (1 child)

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

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  • [–] 33 points 2 years ago (1 child)

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

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    [–] 24 points 2 years ago (4 children)

    Not if your diameter is d/pi. Then your circumference is d, where d > 0.

    Check mate atheists.

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    [–] 19 points 2 years 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.

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  • [–] 17 points 2 years ago*

    Joke's on them, tears are too salty to provide hydration.

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  • [–] 14 points 2 years ago

    The circumference of a circle with a diameter of 1 cm is exactly π cm. There you have it.

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  • [–] 11 points 2 years ago (1 child)
  • [–] 7 points 2 years ago

    Besides measuring it with a measuring tape.

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