As the agricultural revolution was underway, humanity was also busy with other new endeavors. Here’s Marcelo Gleiser, writing for NPR’s Cosmos and Culture:
From what we thought we knew until very recently, apart from writing there was another key distinction between hunter-gatherers and the first civilizations: it was along the transition from one to the other that devices designed to measure the passage of time first appeared, primitive “clocks” able to follow certain periodic natural cycles. Stonehenge, of course, is the most famous example.
Experts suspected that before the transition, hunter-gatherers had a deep fascination with natural processes that evidenced the passage of time, but no tools to actually record it. Recently, though, a team of researchers led by Vincent Gaffney, professor of landscape archeology at Birmingham University, has proved that the Stone Age was much more sophisticated than we thought. They found a series of 12 large pits designed to mimic the various phases of the moon—arranged along a 164-foot arc—in Aberdeenshire, Scotland.
The pits aligned perfectly with the midwinter solstice of 10,000 years ago (the place where the sun would have risen then), so that the group could keep track of the passage of the seasons and the lunar cycle. The central stone, representing the full moon, measures about seven feet in diameter.
Amazingly, the way the pits were dug allowed for its “recalibration,” moving them year after year so as to keep pace with the solar year. For survival and cultural reasons, keeping track of time was essential to these societies, since their food supply depended on knowledge of migratory patterns for game and salmon along the Dee river.
Eight thousand years later, the world’s first computer also tracked the Moon’s subtle motions through the sky. Watch NOVA’s “Ancient Computer” streaming online: