Coin-operated vending machines, automatic temple doors, a programmable self-driving cart and the first recorded steam engine all existed in first-century Roman Egypt, built by one man. This episode explores the life and work of Hero of Alexandria, a teacher at the Mouseion whose personal history is almost entirely unknown, but whose date was pinned down in the 1930s when Otto Neugebauer matched a lunar eclipse described in his surveying manual Dioptra to the year 62 AD.

We walk through the mechanics of his inventions: a ten-minute automated play driven by falling weights and knotted ropes, temple doors opened by heated air and a water bucket, a cart programmed by string wound around its axle, the aeolipile steam sphere, a wind-powered organ, an odometer that dropped pebbles every Roman mile, and a holy-water dispenser triggered by the weight of a coin. We also cover his mathematics, including Heron’s formula, Heron’s method for square roots and Hero’s principle of light, and ask why a slave-based Roman economy never turned his steam engine into an industrial revolution.

• How forensic astronomy narrowed a 400-year window for Hero’s birth to the first century
• Why the temple doors and the steam engine were separate mechanisms, despite a common myth
• The seesaw lever that made the ancient vending machine shut off automatically
• How Byzantine and Arabic scholars preserved his surviving texts like Metrica and Pneumatica
• Why later works were falsely attributed to him as his name became a brand for genius