If you want to know where you are, you need a good clock. For centuries sailors have used clocks to locate where they are out at sea. Today we use synchronized clocks and orbiting satellites for location. In this episode of STEM in 30, we take a look at the challenges of navigating at sea, in the sky, and even in space.

This program is made possible through the generous support of Boeing.

See more STEM in 30: http://airandspace.si.edu/stemin30