The Long Trajectory of Rubber Physics: 3500+ Years and Counting

Natural rubber has followed an extraordinary trajectory from an indigenous Mesoamerican technology to an industrially essential material. This selective history begins with processing Castilla elastica latex more than three and a half millennia ago to produce durable ceremonial and practical objects. Its unusual elasticity generated European excitement and scientific curiosity, but rubber remained technologically limited until nineteenth‐century sulfur vulcanization by Goodyear and Hancock enabled commercially viable products and supported the growth of the tire and automobile industries. Scientific understanding developed more slowly. Gough and Joule established rubber's unusual thermoelastic behavior, while early twentieth‐century studies revealed strain‐induced crystallization and yielded fundamental data on crystallization and the glass transition. Rubber was central to Staudinger's macromolecular hypothesis and to later statistical theories of chain molecules, cross‐linked networks, and entropy‐driven elasticity, which became foundations of modern polymer physics. Its strategic importance accelerated development of synthetic elastomers in Germany and the USSR and, during World War II, in the United States. The same Gough‐Joule response that helped establish rubber and macromolecular physics now motivates elastocaloric cooling. Novel solid‐state refrigeration concepts based on rubber show substantial cooling power, although significant challenges remain before commercialization.