Sunday, November 13, 2011

The Antikythera Mechanism at HSS 2011

Posted by Darin Hayton on 11/13 at 11:01 PM

The Antikythera Mechanism continues to attack considerable attention, both scholarly and popular. The Antikythera Mechanism Research Project continues apace. There is a website devoted to the mechanism, The Antikythera Mechanism. It has been the subject or a recent, popular book: Decoding the Heavens. And perhaps the best evidence that the mechanism has become part of popular culture is the LEGO reconstruction—see Reconstructing the History of Science, in LEGOs and its link to the details at Andrew Carol’s site and the very nice Nature video. So it is no surprise to find a panel dedicated to the mechanism as this year’s History of Science Society Annual Conference: “New Views of the Antikythera Mechanism: A Geared Astronomical Computing Machine from the Second Century BCE.”

Alexander Jones offered a general history of scholarship on the mechanism, reviewing the three main efforts to understand the mechanism: Derek de Solla Price, Michael Wright, and the Antikythera Mechanism Research Project. He the turned his attention to a German classicist Albert Rehm who seems to present something of a puzzle. Rehm published next to nothing on the mechanism but was cited by de Solla Price as having made significant contributions to its study. Rehm, it turns out, had initially studied classical literary treatments of constellations before moving on to the study of calendars and early clocks. He published an early study of the anaphoric clock in Salzburg. He wrote a monograph on Greek theories of weather that included a section on the Antikythera mechanism. He concluded that the mechanism was used to predict weather. In response to a contest in the early 1900s he wrote a monograph-length study of the mechanism in which he tried to decode the inscriptions and reconstruct the mechanisms use. This manuscript was never published but survives in Munich. Jones suggested that de Solla Price was referring to this manuscript when he praised Rehm’s insights.

Alexander Jones speaking about research on the Antikythera Mechanism at HSS 2011(Source: Author’s photo)

Following Jones’s introduction, John Morgan launched into a detailed analysis of ancient Greek calendrical practices in his paper: “Ancient Greek Luni-Solar Calendars.”

John Morgan explaining one of his transparencies (Source: Author’s photo)

Morgan explained the various ancient efforts to correlate the solar and lunar cycles leading up to the most accurate, Metonic Cycle. He then posed the question: Can we tell if the Athenians were using the Metonic Cycle to regulate their civil calendar? His detailed analysis of calendars, archon lists, and related sources convincingly showed that the Athenians were, in fact, using the Metonic Cycle. During the question period the real payoff for this research became clear: previously scholars had assumed that ancient astronomers had had little influence on the civil authorities. This research indicates that cities were using the best astronomical knowledge to construct their calendars. In other words, astronomers did have a considerable influence on civil authorities.

In his paper “A Clockwork Bronze: The Calendar and ‘Olympiad Dial’ on the Antikythera Mechanism,” Paul Iversen examined the inscriptions on the mechanism and compared them to inscriptions found throughout the Greek world in order to identify the probable origins of the Antikythera Mechanism. Based on epigraphic and orthographic evidence, he was able to identify cities that were related, most tracing back to Corinth. This information seemed to rule out Syracuse as the place of origin. Further support for his conclusion was found on the Olympiad Dial, which lists various games that occurred at regular intervals.

Paul Iversen explaining an inscription on the Olympiad Dial (Source: Author’s photo)

While the precise origin of the mechanism may never be known, Iversen’s research seems to have narrowed down the possible places by excluding Syracuse and by arguing for Corinth or one of its colonies.

Niels Bos’s “The Planetary Extension for the Antikythera Mechanism: Statistics, Analysis and Reconstruction” was a detailed effort to determine whether or not the mechanism could have represented planetary motion and how. Beginning from the models for planetary orbits, Bos tried to translate those models into gear trains. He and his colleagues found that the remaining fragments allowed them to represent planetary orbital periods and in the process they found a use for a previously “63-tooth unused gear.”

Niels Bos showing how he got from the fragments to his model of planetary motion (Source: Author’s photo)

Finally, James Evans suggested that the theory of the solar motion on the mechanism might, in fact, be Babylonian and not Greek: “Greek or Babylonian Solar Theory on the Antikythera Mechanism?” His careful analysis showed how technical, precise measurements—in this case absolute angular measurements of the scales on the mechanism—can help us understand the conceptual work that undergirds the mechanism. He showed that the solar anomaly was represented on the mechanism by a non-uniform zodiac scale set against a uniform calendrical scale. He argued that the most probable model for the non-uniform solar motion was a Babylonian linear theory.

James Evans explaining the differences between the calendrical and zodiac scales (Source: Author’s photo)

What was amazing about this panel was the degree of technical detail and the shared body of knowledge. Except for Jones’s paper, all the other papers were grounded in technical details—analysis of Metonic Cylces and compiling tables of data; sophisticated epigraphy and textual reconstruction; statistical models and theoretical reconstructions; Babylonian solar theories. And audience members and speakers seemed to share a nearly coterminous body of knowledge such that they could engage effortlessly in detailed discussions about particular historical points, e.g., at one point when somebody noted “surely the 307/306 anomaly was a result of the aftermath of the revolution,” a number of people chimed in with names of people, battles, and other significant civil events. Unlike other panels, where people often ask questions about their own, tangentially related research, in these panels the questions seemed almost to dwell on minutia. Nobody asked unrelated questions.

It was an interesting if at times dauntingly technical panel. As an interloper, I would have liked a little more context and a little more effort to connect these erudite papers to broader issues in ancient astronomy or science. Other than some pathological curiosity, why should anybody care about these chunks of corroded bronze and what they might represent? That broader question seemed to go unasked.

Tags: alexander jones, antikythera mechanism, hss 2011, james evans, john morgan, niels bos, paul iversen