Mosi-oa-Tunya – the Smoke that Thunders, also known as the Victoria Falls – straddles the border between Zambia and Zimbabwe. From its broad, smooth-flowing course across a flat basalt plain the Zambezi river suddenly plummets down a fissure in the rock, foaming and churning into the narrow gorge over a hundred metres below. I remember visiting in my childhood: the roar of water, the arc of rainbows in the drenching spray, the smell of wet vegetation, the unprotected edge.

…the forces
that divergent guide my life
are like two teams of horses
straining at my heart.
Yet I contain no vacuum –
and am slowly torn apart.

This snippet of a poem, written when I was seventeen, expresses the conflict I felt between my passion for the arts and for the sciences, specifically between poetry and applied mathematics. To my teenage self, the two seemed inherently incompatible. Mathematics, as I understood it at the time, was logical and disciplined, whereas poetry required what Keats described as ‘Negative Capability, that is when a man is capable of being in uncertainties, Mysteries, doubts, without any irritable reaching after fact & reason’ (Keats, 1817).

Was it like that for you as well, when you were at school? Words lived. They had histories, back-trails to ancient Greek rhetoric or Roman sensibility, to mediaeval French farms, soggy lowland water-meadows, absurd colonial rituals. They sang, they danced, with their own characteristic rhythm and energy. You could play with words, write stories, compose poems, tell jokes, formulate riddles, act them out, set them to music. And you could read them, voraciously.