Description
An awardwinning science writer examines the ways humans have measured time throughout history and discusses the various units that are used to keep track of it. By the author of Waves: The Electromagnetic Universe.
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A fascinating tour of time measurement through the ages. Children discover how humans learned to recognize time and began to measure it in smaller and smaller units from the precisely placed boulders at Stonehenge, which marked the equinoxes; to Egyptian obelisks, which measured the hours; to modern-day atomic clocks, which subdivide seconds.
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