Weekly Online Lesson Online Lesson Archive Grade Level: 6-9 Subject: Physical Science

Electricity Shortage

For the eighth time in three weeks, an electrical state of emergency has been declared in California. On December 8th, officials briefly declared a first-ever Stage Three emergency, meaning that the state's power grid had been pushed dangerously close to its limit.

In response, the state had to temporarily shut down huge pumps that supply Southern California with water. It was the eighth time in three weeks an electrical state of emergency has been declared in California, and the fourth day in a row.

Three power plants that had been closed for maintenance will go back into full operation this week. This will ease the immediate problem, but officials say they expect more power shortages throughout the winter months.

It's easy to take electricity for granted until a blackout leaves homes and businesses without power. Then it's almost impossible to get anything done. Look around right now and count how many things around you are either turned on or plugged in. This week's online lesson is about the science of electricity and the different ways it can be generated.

Electricity and Magnetism

What exactly is electricity? You can see it when lightening strikes, or when you turn on a flashlight. Maybe you have felt electricity if you accidentally touched two live wires. But to understand what electricity is, you first have to know a little bit about how atoms work.

First stop this week is a fun interactive multimedia presentation from the Internet Plasma Physics Education eXperience site called Electricity and Magnetism. (You will need Shockwave to see it, but you can install the plug-in right from the site.) Click the arrow to begin the presentation, and to move from frame to frame. What is the definition of electricity? What is the difference between static electricity and moving electricity? How does resistance apply to electricity? What is a circuit?

For more about electricity visit Learning Power, from Southern Company, a power utility for the southeast United States. Click Watt's Electricity. Here you will learn about the history of the word electricity, how electricity is measured, and how power companies maintain the power grid. What is a volt? What is a kilowatt hour?

If you have some extra time, climb aboard the electricity Time Machine to learn about important years and important people in electricity history. Select a time period, and then drag the red triangle to a red mark on the timeline.

Generating Electricity

Producing electricity commercially requires a big operation. You can learn more about commercial power plants by visiting The Education Site's Electricity page. Click Generating to learn how electricity is produced at power stations. You will see huge generators turned by turbines which are, in most instances, powered by steam. Click Power Station to find a list of power stations in the U.K., and also a list of the types of power stations in use today. While Coal- and Oil-fired plants are the most common, other sources include Hydro, Wind, Nuclear, and others. Read about all of these types. Which do you think is the most cheapest? Which is the friendliest to the environment? Which do you think is the safest?

Now click Distribution to learn how power stations feed electricity into a network called the power grid. Perhaps you noticed that Great Britain uses 240 volts instead of 110, the standard in the U.S. What is a transformer? What is a power grid?

Theater of Electricity

If you visit Boston's Museum of Science online, you can check out the Theater of Electricity exhibit. Here you can learn a lot about electricity and lightning by learning about the museum's Van de Graaff generator. What's that? Think of it as a lightening machine. First, click History and learn about the origins of this odd scientific device. You can also click Construction to learn how it was built, and click Sparks to see the thing in action.

Ever wonder what would happen if you were in a car that got hit by lightning? Actually, nothing would happen. You'll find out why when you read Touching Lightning. And click Franklin's Kite to see how the museum uses the Van de Graaff generator to recreate the famous experiment of this inventor and statesman.

© Copyright 2002
Learners Online, Inc.