Time, Einstein And The Coolest Stuff In The Universe

At the turn of the 20th century Einstein changed the way we think about time. By the beginning of the 21st his thinking is now shaping one of the key scientific and technological wonders of contemporary life: atomic clocks, the best timekeepers ever made. Nobel Prize winning physicist William Phillips explains how these ultra accurate clocks are still being improved with super cooled atoms - better to than a second in 100 million years.