• polonius-rex@kbin.run
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    2 months ago

    the point isn’t to prove that the triangle is a triangle it’s to prove that the system of mathematics you made up actually works

    • weker01@feddit.de
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      2 months ago

      Until you prove that you can’t prove that the system you made up works.

      • Kogasa@programming.dev
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        2 months ago

        Nobody is practically concerned with the “incompleteness” aspect of Gödel’s theorems. The unprovable statements are so pathological/contrived that it doesn’t appear to suggest any practical statement might be unprovable. Consistency is obviously more important. Sufficiently weak systems may also not be limited by the incompleteness theorems, i.e. they can be proved both complete and consistent.

        • weker01@feddit.de
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          2 months ago

          I think the statement “this system is consistent” is a practical statement that is unprovable in a sufficiently powerful consistent system.

          Can you help me understand the tone of your text? To me it sounds kinda hostile as if what you said is some kind of gotcha.

          • Kogasa@programming.dev
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            2 months ago

            Just explaining that the limitations of Gödel’s theorems are mostly formal in nature. If they are applicable, the more likely case of incompleteness (as opposed to inconsistency) is not really a problem.

        • bitfucker@programming.dev
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          2 months ago

          Oh, what if the Riemann hypothesis is such a statement then? Or any other mathematical statement. We may not have any use for them now, but as with all things math, they are sometimes useful somewhere unexpected.

          • Kogasa@programming.dev
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            2 months ago

            It’s extremely unlikely given the pathological nature of all known unprovable statements. And those are useless, even to mathematicians.

            • bitfucker@programming.dev
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              2 months ago

              Math is also used to make a statement/model our universe. And we are still trying to find the theory to unify quantum mechanics and gravity. What if our math is simply inconsistent hence the theory of everything is not possible within the current mathematical framework?

              Sure when you are solving the problems it is useless to ponder about it, but it serves as a reminder to also search for other ideas and not outright dismiss any strange new concept for a mathematical system. Or more generally, any logical system that follows a set of axioms. Just look at the history of mathematics itself. How many years before people start to accept that yes imaginary numbers are a thing.

              • Kogasa@programming.dev
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                2 months ago

                Dunno what you’re trying to say. Yes, if ZFC is inconsistent it would be an issue, but in the unlikely event this is discovered, it would be overwhelmingly probable that a similar set of axioms could be used in a way which is transparent to the vast majority of mathematics. Incompleteness is more likely and less of an issue.

        • weker01@feddit.de
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          2 months ago

          It’s very counter intuitive. As the other commenter suggested I was referring to Gödel and his incompleteness theorem.

          Actually if the system you made up doesn’t work it would be possible to prove that it does inside that system as you can prove anything inside a system that doesn’t work.

          That is why my comment is not entirely accurate it should actually be: Until you prove that if the system works you can’t prove that the system works.

          Can you spot the difference in the logic here?

    • Fushuan [he/him]@lemm.ee
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      2 months ago

      You just reminded me of having to prove that math signs work and do what they do from basic axioms to integers and rational numbers using logical proofs… Damn that was interesting but SO tedious…

    • Cethin@lemmy.zip
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      2 months ago

      Well, at that level I think it’s more to show you know how to prove it. You’re working under the assumption the axioms of the system you’ve been told work.

  • PunnyName@lemmy.world
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    2 months ago

    I nearly failed geometry because I didn’t understand what my instructor wanted from me.

  • MuchPineapples@lemmy.world
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    2 months ago

    Yes but what if one side is so slightly curved that it’s invisible to the naked eye? Then your total angles would be 179.99 degrees and it’s not a triangle.

  • Brickardo@feddit.nl
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    2 months ago

    Even philosophy 101 can give you a ton of reasons why looking at it just isn’t enough

  • sundray@lemmus.org
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    2 months ago

    “If we can’t prove these two triangles are similar while not being congruent, the world is doomed.”

    “Oh my god. We need a 10th grader with at least a B-average, stat!”

  • Semi-Hemi-Lemmygod@lemmy.world
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    2 months ago

    I loved geometry. It made algebra make sense. Plus I had a really awesome geometry teacher. He looked like Shel Silverstein and was super pumped every day to teach math.

    • Cethin@lemmy.zip
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      2 months ago

      I loved geometry. It’s the class where I first got experience programming. I just sat in class programming stuff on my calculator not really paying attention. I did fine in the class luckily.

      Totally unrelated, but I (30 yo) recently realized I’m almost certainly ADHD. There definitely weren’t any identifiable signs before that people should have noticed…

  • Sotuanduso@lemm.ee
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    2 months ago

    In one of my last CS classes, we did proofs and would use “by observation” for this kind of thing.

  • NutWrench@lemmy.world
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    2 months ago

    Equilateral triangle. All three sides are equal length and it has three interior angles that add up to exactly 180 degrees.

  • pseudo@jlai.lu
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    2 months ago

    Are you telling me that “you can see this is a triangle” ??! You can see ?? How dear you say that!