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March 15, 2000

What time is it? It depends on where you are. Time has been such an important question that as far back as the ancient Egyptians, people have devised ways to measure and keep track of it. Explore ancient and modern methods for timekeeping as well as such issues as time zones and time travel through the direct links on the Times Launch Point Web site:

Level 1

A History of Clocks: The word "clock" comes from the French word "cloche," which means bell. From sundials to modern timepieces, learn about methods for measuring time and the advantages and disadvantages of each.

Making a Sun Clock: Before there were clocks, people used the sun to tell time. Find out how to make a sundial and learn the difference between solar and standard time.

Water Clock: The ancient Egyptians, Greeks, Romans and Chinese developed various water clocks. Try making a water clock and discover how it can keep track of time even if the sun isn't shining.

Level 2

Daylight Saving Time: We know that Daylight Saving Time requires us to change our clocks on the first Sunday in April and on the last Sunday in October, but why do we do this? Learn about the history and rationale behind Daylight Saving Time as well as how railroad schedules helped speed the adoption of Standard Time in the 1880s.

Calendars Through The Ages: The concept of a day is based on the rotation of the Earth on its axis, while a year is based on the revolution of the Earth around the sun. Learn how astronomy is used to calculate various types of calendars and explore how cultures throughout history have developed tools and methods for measuring time.

Time Zone Converter: Find out what time it is all over the world through this collection of online time zone calculators.

Level 3

How Time Works: Why are there time zones? Where is the international date line, and what is the prime meridian? Learn how time is measured and view diagrams that show how atomic, pendulum, quartz and digital watches work.

A Walk Through Time: Learn about the history of tracking time and find out about the National Institute of Standards and Technology as it keeps the official U.S. time. View illustrations of ancient and modern timepieces and learn about world time zones.

Nova: Time Travel: Is time travel possible? Explore its possibilities through an interview with Carl Sagan, the written work of Clifford Picover and animations that demonstrate the theories of Albert Einstein.


The answer to this Internet quiz can be found in the sites at right.

What famous physicist explains that time travel is theoretically possible?

CLUE: See Nova, Time Travel

Find What You Need to Know: Have a project on California history? Need help doing a math problem? Launch Point now covers more than 100 topics for getting your schoolwork done. Go to for the full list of subjects and direct links to the best Internet sites.

Answer to last week's Quest: The water cycle consists of evaporation, condensation, precipitation, surface runoff, infiltration and transpiration.

Launch Point is produced by the UC Irvine department of education, which reviews each site for appropriateness and quality. Even so, parents should supervise their children's use of the Internet. This column was designed by Soo Lee, Lisa Ishimine, Wayne Rapp and Anna Manring.

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