Timekeeping: Explore the History and Science of Telling Time travels through the past and into the future to explore how humans have measured the passage of time. From ancient civilization's earliest calendars and shadow clocks to GPS and the atomic clocks of today, kids will track the evolution of timekeeping devices, meet the inventors of calendars and clocks, and learn interesting facts and trivia. Hands-on projects and activities include making a shadow clock, using a protractor to create a sundial, measuring time using water, and creating your own calendar. Kids will understand how civilization's vague abilities to track days and months has transformed over the centuries into a sophisticated ability to keep time to the millionth of a second.