Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Aug 23, 2012
Dr. Steve Jefferts of the National Institute of Standards and Technology in Boulder, Colorado is an expert on how we measure time. In fact, he co-developed one of the world's most accurate atomic clocks. But why do we need such accuracy? Learn why atomic clocks are so important in our everyday lives.