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Time and Navigation

April 11, 2013

In the summer of 1838, one of the most audacious expeditions in American history set sail from Virginia - the United States South Seas Exploring Expedition. Over the next four years, its half-dozen ships would circle the world. The expedition confirmed the existence of the Antarctic continent, and its scientists collected thousands of birds, fish, insects, and cultural artifacts. The expedition also compiled some of the most detailed and accurate charts of the Pacific and Southern oceans to that date.

Safely plying the world’s oceans - and charting them with high precision - required two things: accurate clocks and a good knowledge of the sky. Navigators used the Sun and stars to plot their position north and south on the globe. But plotting their position east and west required not just the stars, but accurate timekeeping as well. Without it, the ships could have been miles off course, and the expedition’s charts would have been flawed.

The expedition is one of the topics in a new exhibit that opens tomorrow at the National Air & Space Museum in Washington. “Time and Navigation” explains the crucial role of accurate timekeeping in getting around our planet - from the first good mechanical clocks used by sailors in the 18th century, to the atomic clocks used by GPS satellites today.

When it comes to navigating around our planet, the clockwork precision of the stars is a big help - made even better with the precision of a good clock.


Script by Damond Benningfield, Copyright 2013

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