No windows. No watches. No TV. When humans were sealed underground for weeks at a time without clocks, their biology kept time anyway. This episode explores the bunker experiments that revealed the brain’s internal clock — and why it’s so stubborn.

Teething hurts, but it is not a disease. From hare-brained remedies to modern misunderstandings, this episode explains why the correct treatment for teething is palliative — and why that’s less alarming than it sounds.

From Magellan’s three-year voyage to the invention of the International Date Line, this episode explores how humans resolved the problem of lost and gained days on paper — but not in human physiology.

From stroke wards to boxing rings — and even airport “suspicious behaviour” lists — yawning appears at curious moments. This episode explores what it really signals, and why fatigue and boredom are the least interesting explanations.

Julius Caesar hid his baldness with a comb-over. Not even a dictator can dictate his own hairline.

In this episode, I explore the strange hormonal paradox behind male pattern baldness — why the same androgens that thicken your beard can shrink the follicles on your scalp. From ancient observations to twentieth-century hormone experiments, this is the biology of balding.

Bad breath has existed forever. The disease halitosis, however, is newer.

From Joseph Lister’s antiseptic surgery to Listerine — once sold as a floor cleaner and a treatment for gonorrhoea — this episode explores how bad breath became a disease, and what’s actually happening inside your mouth when it smells.