Comment on How do people calculate pi to the hundredth+ decimal place?

• rmuk@feddit.uk ⁨1⁩ ⁨day⁩ ago

  It’s true! I just drew a circle and measured it. Turns out π≈5.

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  • qt0x40490FDB@lemmy.ml ⁨1⁩ ⁨day⁩ ago

    From your measurement of pi, we can deduce that you live in an anti-de Sitter space, so all the string theorists will now be sending you emails to test out their theories.

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• qt0x40490FDB@lemmy.ml ⁨1⁩ ⁨day⁩ ago

  Overly snarky response: Uhhhm. Have you been asleep since, what, 1915 or something? We have extraordinary evidence, and everyone has accepted it, in so far as I know.

  Less snarky response: the path on which light moves is the universes instantiation of a straight line. It is “the (locally) shortest path between two points”, the same definition you learned in geometry class. Yet in our universe, two straight lines can intersect each other twice. This is because our universe has at least some local curvature, meaning it is non locally non Euclidean. In order to have a mathematically perfect circle you would need to live in a universe without any matter or energy, and with certain other properties.

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  • bjoern_tantau@swg-empire.de ⁨1⁩ ⁨day⁩ ago

    Meh, spacetime curvature has so little effect that it actually does come down to measurement accuracy. And if you go to the scale of the whole universe it is flat as far as we currently know.

    Now I wonder how LISA will handle curvature changes due to sun, earth and moon moving around, or if they won’t make enough of a difference.

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    • qt0x40490FDB@lemmy.ml ⁨1⁩ ⁨day⁩ ago

      I mean, Geodetic interferometers already exist and can measure very small deviations. Give them arms the length of the observable universe and they will increase in accuracy, not decrease in accuracy.

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    • qt0x40490FDB@lemmy.ml ⁨1⁩ ⁨day⁩ ago

      If you constructed a circle with the radius of the universe, then measured its circumference and radius measurement accuracy would easily be able to tell the difference between a real circle and a mathematical circle. That is because neither the circumference of the circle will nor the diameter of the circle will be moving through empty space. They will be near enough to matter to measure detectable deflections.

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