time measurements

Provides information and anecdotes about the history of time, examining the planetary basis of Earth's days and how it relates to the development of clocks; and looks at ideas about the past--and the nature of time itself--that people have come up with throughout the ages.

A collection of simple ways to measure time and ideas for related experiments that could be used for a Science Fair project.

Looks at some of the many different methods people have used to tell time throughout history, and discusses the standardization of time around the world. Includes a glossary.

Examines how humans have measured the passage of time, from calendars and shadow clocks to GPS and modern atomic clocks.

Cartoon illustrations and text provide information about time, discussing how to measure time, how to see things that happened in the past, ways people in the past tried to see the future, the connection between space and time, black holes, and how to build a time machine.

Simple text and activities explain the nature of time, its importance, and its measurement, exploring days of the week, seasons, months of the year, the concepts of past, present, and future, and more.

Explains how the earth's movements around the sun and the resulting movement of shadows have been used to tell time. Includes illustrations that pop up or fold out to demonstrate how sundials work.

Explores the concept of time, detailing scientists' efforts to study and measure it. Details the relationship between time and travel at near-relativistic speeds and features full-color photographs throughout.

Describes the role of the seasons in timekeeping, the ways ancient peoples kept time, the calendars of different religions and cultures, and early and modern clocks, as well as geologic time, and discusses space-time and the fourth dimension.