Time's Mysteries Part I: Marking Time

Sunday, December 27, 2009 - 16:00

ENCORE Time's a mystery, yet we've invented clever ways to capture it. From sundials to atomic clocks, trace the history of time-keeping. Also, discover the surprising accuracy of nature's dating schemes - from the decay of carbon to laying down tree rings.

Plus, why the "New York minute" stretches to hours in Rio de Janeiro: cultural differences in the perception of time.