Aug 12, 2025
This New Pyramid-Like Shape Always Lands With the Same Side Up
Wired
At first, it might seem obvious that this should work. “After all, this is how roly-poly toys work: Just put a heavy weight in the bottom,” said Dávid Papp of North Carolina State University. But “this only works with shapes that are smooth or round or both.” When it comes to polyhedra, with their sharp edges and flat faces, it’s not clear how to design something that will always flip to the same side.