Researchers have developed a method to construct solid objects that roll down pre-determined paths, which they reckon could have applications in quantum mechanics and medicine. To get a ball of malleable clay to roll down a simple path, you can force it down a specific path once, squashing it as you go. Take it to the top again, restart it from the initial starting point on the ball's surface, and it will roll down the same path. The researchers took this principle to develop an algorithm that could produce a shape capable of following almost any pre-determined path, even making the weird-shaped solids out of 3D-printed plastic and solid ball-bearings (for weight) to prove the point. Elisabetta Matsumoto, assistant professor in the School of Physics, co-wrote an accompanying article to the study saying "future work developing for more precise mathematical understanding of the issue would help to connect this work to applications, as well as to open up more purely mathematical veins of research."