Bioluminescence was earlier viewed as a fascinating feature of the living world, but one whose study seemed unlikely to contribute in any practical way. Today, bioluminescence is no longer an esoteric area of research. Applications are numerous, ranging from the rapid detection of microbial contamination in beef and water, to finding the location of cancer cells, to working out circuitry in the brain. Prof. J “Woody” Woodland Hastings is a leader in the field of photobiology, especially bioluminescence, and is one of the founders of the field of circadian biology (the study of circadian rhythms, or the sleep-wake cycle). He is the Paul C. Mangelsdorf Professor of Natural Sciences and Professor of Molecular and Cellular Biology at Harvard University. Program co-presented by Chicago Council on Science and Technology and the Harvard Club of Chicago.