A Portable Cosmos

Reviewed by: A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World by Alexander Jones Georgina Henderson (bio) A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World. By Alexander Jones. Oxford: Oxford University Press, 2017. Pp. 312. Hardcover $34.95. It's 1900 CE. You're sponge-diving off the small Greek island of Antikythera in the western Aegean Sea, and you see bronze fragments poking out of the seabed. You have found a Roman shipwreck of about 60 BCE, a merchant ship carrying amphorae, bronze and marble statues, and glassware. But the most exciting if not immediately obvious finds are the pieces of encrusted, corroded, and engraved bronze which were later identified as parts of the earliest mechanical computer, the machine now called the Antikythera Mechanism. "A Portable Cosmos" is a comprehensive examination of the Mechanism from its discovery to the present by an expert in the field. Dr. Alexander Jones is Professor of the History of the Exact Sciences in Antiquity at the Institute for the Study of the Ancient World, New York University, and a member of the Antikythera Mechanism Research Project (AMRP). Dr. Jones begins with the discovery of the shipwreck, the raising of its artifacts, and the analysis of the Mechanism, described as approximately the size of a shoebox. Initial investigations focused on the decipherment of the Greek letters engraved on the bronze plates, and conservation of the fragments. Scholarly theories about the Mechanism's function varied: was it an astrolabe? A planetarium? A computer? Researchers generally agreed that the device was connected with astronomy. Although its date and place of manufacture are unknown, Dr. Jones suggests that, based on festival and calendar inscriptions, it was made in Rhodes in the first half of the first century BCE and destined for Epirus, northwest Greece. Dr. Jones next discusses the techniques used to determine the form and functions of the Mechanism. In the early days researchers had to rely on photographs or firsthand viewing to study the device, but from the 1970s on, technological advances such as X-rays, gamma-ray radiography, linear and computed tomography (CT), and reflectance transformation imaging (RTI) permitted investigators to see inside the Mechanism. With the aid of these advances and in collaboration with the National Archaeological Museum in Athens, the AMRP began in 2005–6 to re-examine the Mechanism's eighty-two fragments and to work on various reconstructions. Scholarly and popular interest in the device soared after the AMRP published explanations of the gears and the decipherment of previously unreadable inscriptions in 2006. A detailed description of the fragments' back and front dials and inscriptions follows, augmented by line drawings and black-and-white photographs. Next come discussions of ancient astronomy; the Greek and [End Page 789] Egyptian calendars; Mesopotamian, Greek, and Roman astronomical records; literary references; and the Mechanism's roles in forecasting the cycles of the Panhellenic sacred games (a cultural rather than an astronomical function), planetary movements, and solar and lunar phases and eclipses. An engaging outline of ancient mechanical technology includes explanations of the workings of the Mechanism's gears and comparisons to those in Vitruvius's and Heron's odometers. Fundamental aspects of the Mechanism's manufacture are noted: the types of metals used; the possible production imperfections which would affect the accuracy of the device; and the extensive astronomical, mechanical, metallurgical, and mathematical knowledge that lay behind its design and construction. What, then, is the meaning of the Mechanism for the ancient and modern worlds? Dr. Jones says that, contrary to earlier opinion which held that this device was far too complicated for the science of its time, this machine is, in fact, based on contemporary Greek and Hellenistic knowledge and principles. The research it has sparked has led us to a reassessment and new appreciation of the depth and breadth of the science at that time. It was obviously too advanced a device to be without forerunners, none of which have survived. Early Mechanism investigators saw it as a navigational instrument or a tool for astrological guidance, but Dr. Jones suggests that it was suitable for basic astronomical instruction for philosophy students and educated

Ancient history · Archaeology · Art · Art history · Bronze · Decipherment · Wonder · Classics · Diverse Historical and Scientific Studies · Historical Astronomy and Related Studies · History · History of Science and Medicine · Philosophy