Philippa Gander is a world-renowned sleep researcher. Now professor emeritus at Massey University, she has produced a nifty guide to chronobiology, the study of biological rhythms. Humans (and all living, she delves into many aspects of sleep, such as why vehicle crashes occur most commonly at 6am and 4pm, the role of sleep loss in the Challenger tragedy, and the question of whether earlier humans had split sleeps. Much of our physiology, behaviour and health, including gene expression, also show seasonal patterns, she says, on which modern life – and lighting – often has a deleterious effect.
