The Science Pictures: Cycloid

A process that seems simple at first sight is hardly ever simple by nature. Think of a coin rolling off a table. It appears to be moving in a straight line, but in fact, it needs to constantly rotate to move at all. In this picture, two light bulbs attached to a rolling disk create two bright traces that reveal the unexpected complexity of how a familiar object moves. The light on the rim seems to be hopping: it hesitates at the bottom each time before soaring up again. The central line of light becomes its visual axis, maintaining the stable motion of the disk. Viewing this photograph reminds us that without ups and downs it is impossible to make one’s way forward.
– Sofia Lis ’20