I grew up on a coral island, and I was taught that it had been lifted out of the sea by "earth movements". Nobody ever told me what an earth movement was. The textbook did not say — and it could not, because it was printed in 1963, and the answer arrived in 1968.

This is the introduction to The Slow Machine: a nine-part series on how we found out that the continents move, and why almost every clue came from an instrument built for something else entirely.

In this episode — a volcano in St Vincent that three generations of my family have climbed, and that erupted again in 2021. A school geography textbook that was already out of date by the time I opened it. A geologist I met walking the hillsides near my house, who spent thirty years measuring one small island, and whose account of it was published eighteen years after he died.

And what Barbados actually turns out to be, which is not what I was taught, and is a great deal stranger.

It also explains why someone who is not a geologist is the one telling you this.

Next time: Episode 1, "Before the Question" — what people believed the Earth was before anyone measured it, and the afternoon in 1788 when a Scottish farmer looked at a cliff and saw the age of the world.

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The passage read in this episode is from "Geology and Geomorphology of Barbados" by Robert C. Speed (Geological Society of America Special Paper 491, 2012), pp. 3-4.

Written and narrated by Michael Goddard. Music composed with Suno. Sound effects from freesound.org, all Creative Commons 0. Every voice in this series is human.

Put an apple on a windowsill and leave it for a month. The inside shrinks, the skin does not, and it wrinkles. For about seventy years, that was the best available scientific explanation for the Himalayas.

Episode 2 of The Slow Machine is about a good theory — simple, mathematical, and wrong. A cooling, shrinking Earth with mountains for wrinkles. Lord Kelvin, the monarch of British physics, using it to put a clock on the age of the world, and Charles Darwin losing sleep over the answer. Eduard Suess in Vienna, who brought clean water to a city with cholera and then wrote the face of the whole Earth in four volumes. And the fossils that would not behave: a seed fern on four continents, and a freshwater reptile the size of a cat on both sides of the South Atlantic and nowhere else.

The Slow Machine is a nine-part series on how we found out that the continents move, and why almost every clue came from an instrument built for something else entirely.

Next time: Episode 3, "Two Facts That Cored the Apple" — how mountains turned out to be icebergs, and how the most certain number in nineteenth-century science was off by a factor of a hundred.

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Guest voices: Derek M (Lord Kelvin) and Alex John (Eduard Suess), both found on Fiverr. Every quotation is listed with its source on this episode's page at theslowmachine.com.

Written and narrated by Michael Goddard. Music composed with Suno. Sound effects from freesound.org, all Creative Commons 0. Every voice in this series is human.