Is it possible to design a shape to roll along any fixed path?

In a study ‘motivated largely by fundamental curiosity’, a team of scientists in South Korea and Switzerland set out to see if they could design shapes to roll along any desired path on a flat surface. This entertaining video from Nature chronicles the team’s research, documenting how, using a combination of simple and sophisticated techniques – as well as a bit of tweaking once the 3D-printed objects got rolling – they were able to create shapes to travel along nearly any possible path. The result is a fascinating glimpse into what happens when the conditions of computation enter the real world, as well as how a bit of curiosity can have potentially significant consequences – in this case, in the realm of quantum and classical optics.