Moving in Elevated Circles Around the Celestial Equator, Lest We Forget Who Antonio Santucci’S Great Armillary Sphere Reveals How Patrons Sought Is Responsible

NATURE|Vol 466|1 July 2010 OPINION

correspondence, which was rescued from his description of the nexus of debts and rivalries moved to Florence in 1587 when Ferdinando flat and office by Hamilton. between these and others in the field reveals became Grand Duke of Tuscany, manufactur- Harman’s account is remarkable for that altruism was not always present in the ing this even larger sphere in 1588–93. interweaving Price’s life with the history of evo- actions of those working on it. The instrument is a sumptuous demonstra- lutionary theory, including the debates about Eponyms in science are becoming rare, tion piece rather than an observational tool. Its group selection and altruism in nature. Price but the Price equation is still with us. Evolu- lavish ornamentation reflects the power and had no inkling of how his work on altruism tionary biologists who use it have no excuse magnificence of the Medici family as well as the would later influence evolutionary theory. not to know what manner of man devised it, wonder of the heavenly array centred on God’s He had links to two men in particular who or how — at some point between the evening Earth. It is crowned by an orb and cross, a sym- provided the framework for the evolutionary of 5 January and the early morning of bol of divinely ordained rule and of Christ as biology of the 1960s and 1970s: R. A. Fisher 6 January 1975 — that man took a pair of scissors, saviour of the world. The disc below the orb and J. B. S. Haldane. Price formalized Fisher’s put them through his carotid artery and bled depicts God the Father, blessing the Universe fundamental theorem of natural selection and to death. ■ he has created. God is painted with great pro- shared connections with Haldane through W. F. Bynum is emeritus professor of the history fessional skill, possibly by the artist Ludovico University College London and his friends of medicine at University College London. Cigoli, author of a treatise on perspective and a Hamilton and Maynard Smith. Harman’s e-mail: [email protected] friend of Galileo Galilei. The discs marking the spring and autumn equinoxes are each adorned with two angels supporting the shield of the Medici and Christine of Lorraine, Ferdinando’s wife. Four more Medici shields are distributed moving in elevated circles around the celestial equator, lest we forget who Antonio Santucci’s great armillary sphere reveals how patrons sought is responsible. The Medici family had an impressive record immortality through science, explains Martin Kemp. of supporting astronomers. The stakes in astronomy were huge, both in practical terms Big science has always needed big patronage, Santucci was a little-known astronomer and in that it promised a kind of immortality. from rulers, rich aristocrats or state organiza- from Pomarance, a small town in the province Cosimo I, the first Grand Duke and father of tions. A striking example is the huge armillary of Pisa. Probably of humble origins, he excelled Ferdinando, brought the astronomer Ignazio sphere by the sixteenth-century astronomer in making magnificent instruments and rose Danti to Florence. But after Cosimo’s death Antonio Santucci. The sphere, now splen- to become professor of mathematics at the in 1574, Danti eventually moved to Rome didly restored, resides in the Museo Galileo — University of Pisa. and worked on the reform of the calendar formerly the Museo di Storia della Scienza — in Santucci flourished under the patron- that was eventually decreed by Pope Gregory Florence, where it forms the centrepiece of a age of Cardinal Ferdinando I de’ Medici in XIII. Had Cosimo lived longer, we might display of astronomical devices and globes. Rome, who sent another of Santucci’s armil- now have a Medicean calendar rather than a A mechanical representation of the scheme lary spheres to Philip II of Spain. It is now in Gregorian one. of the cosmos according to the Earth- the Escorial museum near Madrid. Santucci Santucci’s reputation, like those of other

E centred view of Ptolemy, the sphere Medicean and papal astronomers, nc E stands about 3 metres high. It is has been cast into the shade by

, flor , meticulously crafted from gilded the giant figure of Galileo. Galileo E

nc and painted metal and wood. The himself provided testimony of the E vertical and horizontal axes of the late conversion of Santucci to the outer celestial sphere support a Sun-centred view of the cosmos. nested series of seven inner spheres, In a letter to Christine of Lorraine

history of sci of history each of which traces the motion of in 1615, he reported that “the late E a planet. The large central Earth, mathematician of the University of with its tilted rotational pole, Pisa … undertook in his old age to m of th of m EU

s Equator and tropics, is marked look into the Copernican doctrine”. U with the continents and seas as they Santucci “found himself persuaded”, were then known. Particular care Galileo wrote, “and from an oppo- and m and E t has been lavished on the band on nent he became a very staunch U which the 12 signs of the zodiac are defender of it”. painted, reflecting astronomers’ duty It is poignant that the maker o – instit – o E to provide astrological charts. The of the grandest of Earth-centred ensemble stands on a sculpted base, armillary spheres changed his o galil o E

s perhaps a later replacement, of four mind shortly before he died. San- U m female sea creatures with bifurcated tucci’s immortality lay not in being serpentine tails. Their puffed-out right, but in being a great designer cheeks suggest that they signify and maker. ■ the four cardinal winds. A han- Martin Kemp is emeritus professor dle was provided to set the model in history of art at the University of in motion. Santucci’s gilded creation represents Ptolemy’s Earth-centred cosmos. Oxford, Oxford, UK.