Telling Time

In our three-dimensional world, measuring time remains one of the most perplexing pursuits. How humans measure time has changed dramatically through the ages.

How do we measure time? There are many answers. We can use the sun and the distant stars. We can use sand through a funnel. We can use atomic elements. We can use an expensive watch. Why do we measure time? That's a question for you to ponder yourself.

Time of Our Lives

Horology - The Index

U.S. Time Service Department

Daylight Savings Time

A Walk Through Time

Not all clocks go tick tock. Through the ages, the clock has evolved in many fascinating ways. Modern technology, of course, has truly changed the way clocks are made.

A History of Clocks

A Brief History of Clocks: From Thales to Ptolemy

Since the Sun stays still while the Earth rotates, the position of the Sun overhead reveals the passage of time. This basic concept makes the sundial work as a timepiece. Ancient sundials were quite simple, telling only the approximate time. Today, a modern sundial can tell time to the minute.

Sundials

A Modern Sundial

Sundial Links

Sundials on the Internet

Sundials on the Internet - The Equation of Time

Sundials on the Internet - Types of Sundials

Time Zone Page

Time Zone Converter

A Dictionary of Units

The natural world offers other constants that can measure time. Each of these timepieces relies upon a constant in nature, like the Earth's rotation or movement of water, to record and measure the passage of time.

Foucault Pendulum

Water Clocks - Bernard Gitton

Ball Clocks

The Astrolabe - An Instrument with a Past and a Future

Mystical WWW Time Grid

Spend some time on these games and activites.

Teaching Time

Time Estimation

Snapdragon-Tell the Time

Second Grader's Clock Quiz

Clocks…Teaching Time