Timekeeping: Explore the History and Science of Telling Time with 15 Projects. Cet article n’est pas disponible.Timekeeping: Explore the History and Science of Telling Time with 15 Projects

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.

Linda Formichelli is a freelance writer whose articles have appeared in several youth and science publications including Ack!, Delta Education, Odyssey, Yes, and Zillions. She is the author of Becoming a Personal Trainer for Dummies, Renegade Writer, and a coauthor of Tools of Timekeeping. W. Eric Martin has written articles for more than 50 publications and has provided dictionary entries for Thomson Gale's World of Computer Science. He is a coauthor of Tools of Timekeeping. They both live in Blackstone, Massachusetts.

Sam Carbaugh is the illustrator of Amazing Math Projects You Can Build Yourself, Discover the Desert, Food: 25 Amazing Projects, George Washington: 25 Great Projects You Can Build Yourself, and Robotics." He lives in Grand Rapids, Michigan.