Storia dell'astronomia: dalle origini al duemila e oltre

  • Giacomo Leopardi &
  • Margherita Hack
Edizioni dell'Altana: 2002. 646 pp. 37 euros. In Italian
Big future: improvements to telescopes since the eighteenth century led to astronomical advances.

In the introduction to his Why Read the Classics, Italo Calvino mentions only one Italian author, Giacomo Leopardi (1798–1837). Calvino does not praise Leopardi as the author of the Canti, which is one of the greatest poetic works of the nineteenth century, but instead refers to the unique education that the young genius received in his father's castle. Count Monaldo had a well-organized, 16,000-volume library in Recanati, a small town in central Italy, where young Giacomo used to sit and study in its central room, writing at a small table with his back to the east.

In 1811, while aged just 14 to 15, Leopardi wrote a 300-page history of astronomy, the Storia dell'astronomia. It contains more than 1,700 footnotes and references, and an organized bibliography of 300 works spanning two millennia and in many languages, both modern and ancient. He presumably had access to these in the astronomy corner of Monaldo's library. He refers to almost 2,000 astronomers, philosophers, poets and other authors, frequently in the original language. The new edition of his book, updated to the present day by the Italian astronomer Margherita Hack, includes translations of the Greek passages; young Leopardi assumed that his readers would not need them.

However, even at such a tender age, Leopardi was not merely trying to show off his immense erudition. His deep poetic and philosophical mind surfaces frequently in a sea of arid facts, dates and quotations. Consider, for example, his comment on the Latin translation of the Greek poem Phenomena by the little-known astronomer Aratus (circa 272 bc). The translation, they say, is by Cicero (yes, the illustrious one), and Leopardi goes off on a tangent on the poetic qualities of the great Roman. Along the way he entirely forgets the original subject — perhaps it was too boring.

Or take the story of the 'mechanical astronomical clock', sent in around ad 800 by the Arabic scientist al-Mansur to Charlemagne, and Gian Domenico Cassini's observations of Jupiter, showing the giant planet's fast rotation. Leopardi interprets these as implying that man learns to understand what is outside and far away better than what he is sitting on (namely, the copernican debate on the rotation of Earth) or what goes on inside his soul.

In the new, elegant edition of the book, Hack takes over where Leopardi ends. She had a daunting task because so much more has happened in astronomy in the past two centuries than in the previous two millennia. She does a splendid job of presenting an accurate and balanced account, even of today's accumulating, sometimes contradictory and always diverse discoveries. To keep the size of the book manageable, she had to keep within 200 pages, compared with the 300 of Leopardi. She spares us any debate on Cicero's poetics, but has an obvious soft spot for Sir Arthur Eddington, who added so much to our knowledge of the structure of stars, from whom we get ample quotes. However, in a philosophical vein akin to that of Leopardi, Hack ends her contribution with an enlightening reflection on the weak and strong anthropic principles. A difficult but important subject, this is where today's astronomy and philosophy converge to provide a coherent understanding of today's cosmology as it emerges from both ground- and space-based observations.

Hack was one of only a few women astronomers when she began her career, and she has campaigned hard for the place of women in science. The revered elder of Italian astronomy, she is now an important public and political figure, and celebrates her 80th birthday this week. Happy birthday, Margherita.