In the 1920s, a Russian biologist observed that onion root cells emitted light. This discovery, known as the "onion root experiment," led to the identification of "biophotons." Research into biophotons expanded from onions to other organisms, including bacteria, frog embryos, and humans. Scientist Nirosha Murugan is currently investigating this phenomenon. Her research aims to understand the source of biophotons and their potential connection to life, disease, and death. The episode features a "Life Flash" video that visually demonstrates enhanced zinc sparks with fluorescent dye. It also references articles about the onion root experiment and the scientist Fritz Albert Popp. Further reading is provided on "zinc sparks" at fertilization and "death flashes" reported by caregivers. Murugan's lab is researching photon emissions in relation to brain activity and cancer diagnosis. The text also includes calls to action for listeners to support the show and subscribe to its newsletter. Leadership support for Radiolab's science programming comes from the Simons Foundation and the John Templeton Foundation.