Too close to the sun

If you go to the Campo dei Fiori in Rome on 17 February every year, you’ll find yourself surrounded by an eclectic crowd of atheists, free-thinkers, Catholic reformers, anarchists, mystics, students, scientists and poets all jostling to lay tributes before the statue of the hooded Dominican friar whose shadowed face stares inscrutably towards the Vatican. His name is Giordano Bruno and his statue, erected by public subscription in the 19th century, commemorates the site where he was burned for heresy in 1600 at the hands of the Roman Inquisition.

In the four centuries since, the idea of martyrdom has attached to Bruno’s death, with various causes (including, recently, a member of the Russian protest group Pussy Riot) claiming him as a symbol of intellectual courage and free thought in the face of repressive authority. Because a number of the charges brought against him at his trials involved his repeated support for the heliocentrism of Copernicus and a belief in the possibility of an infinite universe, he has often been hailed — spuriously — as the first martyr for modern science. In 2014, the Fox TV series Cosmos: A Spacetime Odyssey dedicated much of its first episode to a simplified version of Bruno’s life, emphasising his cosmology; and in the same year Professor Brian Cox referred to Bruno’s ‘cinematic death’ in Human Universe — though he acknowledged that Bruno was ‘more belligerent free-thinker than proto-scientist’.

Though Bruno’s scientific ideas were sketchy at best, and he was as much interested in ancient magic and philosophy as he was in observational astronomy, his theories were picked up and developed by later thinkers, including Kepler and Galileo, and in many ways his reputation has been eclipsed by theirs. Now a new study by Alberto A.