A Walk Through Timeby NIST Physics Laboratory Ages: 12+We know little about the details of timekeeping in prehistoric eras, but wherever we turn up records and artifacts, we usually discover that in every culture, some people were preoccupied with measuring and recording the passage of time. Subjects: history, time, calendars, early clocks, sun, planets, reference
Analog Time Ages: 18+Free multi-time zone desktop clock. Analogtime Lite is totally free to use and comes free of Spyware. AnalogTime LITE includes small text ads from sponsors who help support development of Analogtime.Subjects: desktop, resource, time, analog
Telling Time and the Age of the Universeby David C. Black Ages: 14+The concept of time has always held a special fascination for humans. Even before Einstein provided us with Special Relativity and its notions of space-time, people mused on the possibility of knowing the future.Subjects: resource, history, time, radioactive decay, galaxy, universe, solar system
