https://artwaste.land/strata/the-ring-that-forgets-its-sphere/
The Napkin Ring Problem — Why a Drilled Sphere's Leftover Volume Ignores Its Size
Drill a hole through a solid sphere and the leftover ring's volume is pi*h^3/6, where h is the ring's height. The sphere's radius never enters. A ring cut from...
napkin ring problemdrilledsphereleftovervolume