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@divbyzero@mathstodon.xyz

Post #676531

2026-02-28 04:43 UTC

Another 3D-printing suggestion from Colm Mulcahy: Archimedes proved that if you slice a sphere of radius r with two planes a distance h apart, the surface area is 2πrh—the same as a cylinder of the same radius and height. So, it doesn't depend on where the slicing occurs. 1/2

Replies (2)

  • @divbyzero@mathstodon.xyz 2026-02-28 04:43

    Idea: Produce 3D-printed slices of a (hollow) sphere, all of the same height. Print with 100% fill. They should all weigh the same. Bam!

    Open ##2712449

  • @rreusser@mathstodon.xyz 2026-02-28 05:29

    @divbyzero@mathstodon.xyz reminds me of the Martin Gardner problem where you drill though a sphere. If the length of the hole ends up at six inches, what is the volume of the remaining material? I won’t spoil it, but I always found the simplest way to the solution pretty enjoyable.

    Open ##2712474