3 ms·

Unless by plane they mean airplane, since in curved 3d surface this is not automatically given to be true.

• layer8 11mo ago
  Even if it was talking about airplanes, it doesn’t mention “surface”. So it would still hold, given that airplane parts aren’t infinitely thin.
  • MarkusQ 11mo ago
    Though if you fly economy it seems like they're bent on approaching it as a limit.
    • layer8 11mo ago
      As long as they don’t actually reach the limit, the proof still holds.
• IAmBroom 11mo ago
  Topologically, an airplane is identical to a universe of curvature=+1. Since the size of the grid versus the airplane/universe is not given, I will assume there are infinitely many grid points.