Wall Street Journal
January 3, 2017
Isn’t measuring time a fairly simple matter? It seems complicated only because of the mechanical clock’s intricate assemblage of clicking gears or the atomic clock’s reliance on oscillating atomic energy states. But imagine a world in which time’s passing is measured by the sun or stars. Could anything be more elementary? The world is itself a clock: Look closely, and you can take time’s measure.
But visit the Institute for the Study of the Ancient World at New York University to see its remarkable exhibition, “Time and Cosmos in Greco-Roman Antiquity,” and that notion will quickly disappear. Many artifacts in these two modest galleries are large irregular stone fragments of strange shapes, with curved sides and carved lines. They are almost all ruins of calendars and sundials going back to the late fourth century B.C., when time really was measured by the sun and stars. And their cryptic markings, we learn, incorporate complex conceptions of the ancient cosmos.
It took five years to arrange the loans of these objects from museums all over the world. From Salzburg, Austria, is a fragment of a bronze disc with engraved images; watch a short animation and we see that in the first or second century, it was part of a Roman waterclock used at the frontier of the Empire—one of the few surviving relics of such fragile timepieces.