Some watcher of the skies

We live in an age of astronomical marvels. Last year Europe’s Rosetta spacecraft made a daring rendezvous with the comet Churyumov-Gerasimenko, revealing a bizarre double-lobed mountain of ice and rock with landscapes of vertiginous crags and ashen scree slopes. In our image-saturated age it’s easy to forget that such views are only possible through the intermediary of sophisticated technology: cameras and computers and the spacecraft that carry them halfway across the solar system.

And yet this is nothing new. Ever since the Italian mathematician Galileo Galilei first turned his telescope to the heavens in the autumn of 1609, advances in technology and great strides in knowledge have gone hand in hand. Galileo’s Telescope is a new account of this turning point in the history of western civilisation, and its authors — three Italian history of science professors — give equal weight to the telescope’s scientific, cultural and political impacts. Translated into lucid English by Catherine Bolton, the book is full of entertaining insights and asides, but nevertheless retains a slightly academic tone, which is a pleasing contrast to the matey irreverence of much popular science and history writing today.

The customary version of Galileo’s story is familiar: his observations provided evidence in favour of the Copernican model of the solar system, displacing the Earth as the immovable centre of the cosmos and antagonising the Catholic church. He was tried for heresy, forced to recant publicly and spent his final years under house arrest. The tale has become shorthand for the subversive power of science, and Galileo’s apocryphal words, ‘And yet it moves!’ — supposedly muttered as he was led away by the Inquisition — symbolise defiance in the face of intellectual oppression.

Such popular accounts probably tell us as much about the obsessions of our own times as they do about Galileo himself.