Why Sailors Needed a Clock to Find Their Way

A compass could tell sailors which way they were heading. But it couldn't tell them how far east or west they had sailed. For that, they needed something surprisingly ordinary: a clock. This animated history-of-science story follows John Harrison's decades-long effort to build a timekeeper that could survive life at sea. Discover how comparing two times can reveal longitude, why a clock that works on land can fail aboard a ship, and how the remarkable H4 was tested across the Atlantic. From a simple idea to years of failed experiments, this is the story of turning time into a way home. Subscribe for more stories about the ideas and inventions that changed how we understand the world.