From Sundials to the Atomic Second
Short articles about several different methods of timekeeping,
This site shows a "current" view of a topographically
correct, but flat, Earth, with areas of night and day in their
appropriate locations. Zooming as well as other variables are
An amazing Java-based site that not only shows current areas of
light and darkness on the earth (in both map and globe formats),
this site also provides animations of diurnal and seasonal
Another great page from Marshall Brain, providing a brief overview
of clocks, measuring time, time zones, and more. Be sure to read
though the fun pull-out on the right side of the page!
Essays from Carl Sagan and Clifford Pickover along with activities
and a glossary about time travel from NOVA.
A brief history of the measurement of time.