Two researchers in India who wondered why students kept leaving their shoes outside hostel rooms ended up shining ultraviolet light into athletes' sweaty sneakers. Within a few minutes, the rotten smell was gone. Leave the lamp on too long, though, and the shoes heated up and gave off a strong burnt-rubber odor.
The work, by Vikash Kumar, an assistant professor of design at Shiv Nadar University near Delhi, and his former student Sarthak Mittal, won the 2025 Ig Nobel Prize in Engineering Design. The official citation honored them for analyzing, from an engineering design perspective, how foul-smelling shoes affect the experience of using a shoe rack. The prize was presented on September 18, 2025, at Boston University.
