American biologist Robert B. Sothern has spent forty-five years seeing if he encounters a similar effect as he ages. Five times a day he records his temperature, blood pressure, heart rate and estimation of the passing of a minute. He never misses a day, even when he’s on holiday. His main research interest is in whether the timing of medical treatments can affect their efficacy, a theory about which most researchers remain sceptical, but his diligent self-study does tell us something extraordinary about time perception. As he has become older his time estimation has become less accurate and time seems to be gradually speeding up.