Was Lord Kelvin wrong? 3D-printed shape casts doubt on his 150-year-old theory

Isotropic helicoids are meant to rotate as they move through a fluid. Now physicists are not so sure.

Was Lord Kelvin wrong? 3D-printed shape casts doubt on his
150-year-old theory
Isotropic helicoids are meant to rotate as they move through a fluid. Now physicists are not so sure.