Source: Cyberchase: "Clock Like an Egyptian"
Funding for the VITAL/Ready to Teach collection was secured through the United States Department of Education under the Ready to Teach Program.
An Egyptian Clock
(Video)
In this video segment from Cyberchase, Harry discusses the importance of telling time and describes the ways that people are able to keep track of time. He describes a variety of different timekeepers, such as clocks, watches, and hourglasses. He also discusses the difference between digital and analog clocks.
Download and ShareHere are some Frame, Focus and Follow-up suggestions for using this video in a math lesson.
What is Frame, Focus and Follow-up?
Frame: Sometimes when a person doesn’t have a watch they will try to keep track of time by saying something like, “One Mississippi, Two Mississippi, Three Mississippi, …” How does that help a person keep track of time? What do they have to do when they are doing this to make sure it is fairly accurate?
Focus: As you watch this video segment, take note of the different types of timekeeping devices you see. Watch to find out how these different devices are able to keep track of time.
Follow Up: How does a grandfather clock work? Is the pendulum important? Since a pendulum would be too large for a wristwatch, what acts as the replacement for a pendulum in a watch? What is the difference between an analog clock and a digital one?
WOMAN: Excuse me, do you have the time?
HARRY: I have all the time in the world. Greenwich Mean Time? Eastern, Pacific, Mountain and Central, what's your pleasure?
WOMAN: I just want to know what time it is now.
HARRY: Now ? Where? Tokyo or London ?
WOMAN: Here and now.
HARRY: Oh, 10:40:03, :04, :05, :06, :07, :08.
WOMAN: Thanks.
HARRY: I love time. It's so timely. You got a sec? Let me tell you something about time. Time has always been with us since the beginning of time. Time may seem like it's moving slowly when we're waiting on line, or time may seem like it's flying when we’re having fun, but that's only the way we feel. A watch or a clock is the machine that counts the number of beats that happen during a certain interval. Watches and clocks are “time-keepers”. They count those beats second by second. There are lots of different kinds of watches. This is an analog watch. It has a little hand and a big hand. This is a digital watch. It displays the time using a numerical readout instead of pointing to numbers on a face. This is a broken watch. It never moves from 4:12. But it shows the correct time twice a day. I once tried to become a human clock by counting 1 Mississippi, 2 Mississippi. It took me exactly 1 second to say 1 Mississippi, but my human clock began to slow down when I got to 367 Mississippi. This is watch I invented. It measures in 3 minute intervals, only I can't figure out how to keep a tally and my arm gets really tired after about 12 minutes. This is a wrist sundial. I don’t know what I was thinking on that one. This is one I’m really proud of. I call it a “pulsometer”. It uses my pulse like a pendulum, only it gains 5 minutes every time I run up a flight a stairs, so that's no good. If you have the time I can show you some really interesting things. This is a grandfather clock. There are grandmother clocks, too. That pendulum, that swings back and forth, is creating a regular beat. Most of the rest of the clock works together to regulate and record the number of beats and move the hand. Every clock or watch has something inside to create a beat. You can't put a pendulum in your pocket. You could, but it would be very uncomfortable. The balance wheel, which maintains a regular beat just like a pendulum, made watches and clocks portable. Mr. Kantrowitz, why are balance wheels important?
MR. KANTROWITZ: So people can tell time without looking at the grandfather clock or the church steeple.
HARRY: What would we do without clocks? You'd never know when the train would leave, but you could never be late. There would be no good times, but no bad times either. People want to know the time all the time. Maybe it's to see if they have the time for whatever they want to do. If there were no way to measure time, no one could say "Time for dinner" or "Time to go to bed" or "Time for me to leave!"
Loading Standards
Teaching Tips
Print Teaching Tips
