Colgate Professor Anthony Aveni Shows How Modern Astronomy Built Upon Works of Hesiod

Anthony Aveni, the Russell B. Colgate Professor of Astronomy and Anthropology at Colgate University, opened the Winslow lecture to a standing-room only crowd at the Kennedy Auditorium with a quote from the 2002 blockbuster, My Big Fat Greek Wedding. "Everything is Greek," he said, quoting the father character Gus Portokalos, whom Aveni jokingly referred to as a renowned Greek philosopher. What Aveni meant, he soon revealed, was that modern astronomy is built upon the works of the Greek astronomer, Hesiod. 

The earliest astronomers concerned themselves with mapping and recording the cycles of the moon. For farmers and hunter-gatherers, the consistent 29½-day cycles of the moon's phases were the easiest ways to record the times of the year. Ancient civilizations assigned practical names to the months of the year: In Winter Month, it would be cold. In Planting Month, it was the ideal time to plant crops before the heat of the summer came. 

Over time, methods of reading and recording time through celestial bodies became both more complex and more accurate. Although the cycles of the moon could be useful in keeping track of how much time had passed during any given period, they could not be counted on to precisely predict the present time of year. Months of 29½ days did not fit seamlessly into the calendar year of 365 days, so a 12-month year measured by the phases of the moon was not a viable means of calculating years, Aveni explained. Civilizations, instead, began to map and chart the position of the sun on the horizon as it fluctuated to the north and south during different seasons. When the sun falls at night into the valley, explains one map, it is time for harvesting the grain. But the foremost advancements in astronomy and its implications in agricultural life were made by the Greeks. 

One of the crowning achievements of the Greek empire was its complex knowledge of astronomy, and one of the pioneers of Greek astronomy was the philosopher and poet, Hesiod. Hesiod used a combination of the sun, stars, and the moon to mark certain times in the year. His thousand-line poem, Works and Days, charts the activities of the heavens and provides guidelines for planting and harvesting. In wine-making, Hesiod offers detailed instructions for planting, pruning, and picking grapes. He says, "when Orion and Sirius come in the middle of heaven and Arcturus confronts the rosy-colored dawn," the time is right for picking. There was one night a year when the star Arcturus stayed out to see the light of day, and this was the ideal day for harvesting grapes. 

Centuries later, during the time of the Romans, the detailed, 12-month calendar that we still use today emerged as a standard across Southern and Eastern Europe. With the knowledge at hand of the 365-day calendar year, astronomers were able to map far into the future, and farmers were able to plan by dates rather than by what they saw in the sky. Aveni emphasized that as astronomical techonology advanced, the practice became less animistic and less embedded in social and religious affairs. But, Aveni made sure to mention, as technology continues to make astronomy more precise, he never ceases to amaze his students when he shows them what can be done with just a stick and a string. 

-- by Patrick Dunn '12