• protist@mander.xyz
      link
      fedilink
      English
      arrow-up
      3
      arrow-down
      2
      ·
      1 year ago

      I summarized it above, there’s an extra rotation included when the outer circle moves along the inner circle, essentially falling a bit with every roll forward. If the outer circle rolled along a straight line of the same length as the circumference of the inner circle, it would only roll 3 times, but moving around the circle instead adds exactly one extra rotation. That other gent says this is used in calculating orbits too, where you’re also moving forward while constantly falling

      • SpaceNoodle@lemmy.world
        link
        fedilink
        arrow-up
        5
        arrow-down
        4
        ·
        1 year ago

        I read an article about it. Everybody is doing a shit job of describing what happens. The outer circle naturally makes a full rotation as it travels around the inner one, as the path it follows goes around a full 360°, so that counts as one of the rotations it ends up making, which is in addition to the 3 due to travel around the circumference.