During the Activity
Activity Sequence in Brief
Students examine a light bulb on the overhead projector and discuss its historical context. Students draw a light bulb.
Teacher and students discuss the light bulb parts. Students label a world map with raw materials.
Students reflect on the global resources needed to make a light bulb.
Students write a paragraph discussing the statement: Modern technologies encourage global relationships.
Engage (15 minutes)
- Place a sample clear light bulb on the overhead projector. Focus the projector until the insides of the bulb can easily be seen.
- Ask students, What human need is met by a light bulb? Accept all reasonable answers. Then ask, "What did people do for light before the discovery of electricity and the invention of the light bulb?" (People used kerosene lanterns, candles, torches, oil lamps, fire, sunlight, etc.)
- Tell students that the light bulb on the overhead projector is called an incandescent light bulb. Every incandescent light bulb has a filament, bulb, and base. Point out that fluorescent lights contain mercury vapor instead of a filament.
OPTION 1: If students did not read the Extension Student Reader Article, "How are New Technologies Developed?" for Activity 2.2, Choosing Research Topics then:
Ask students if they remember who invented the light bulb? (Thomas Edison) Tell students that the light bulb was invented in 1870 and that the original light bulb used a filament made from plant fibers. Explain that, although the materials in today's light bulbs are different, the basic design is the same.
OPTION 2: If students did read the Extension Student Reader Article, "How are New Technologies Developed?" for Activity 2.2, Choosing Research Topics then:
Ask students what they remember about the invention of the light bulb from reading the Student Reader Article, "How are New Technologies Developed?" (assigned for Activity 2.2, Choosing Research Topics.) Who invented the light bulb? (Thomas Edison) When was the light bulb invented? (1870) What was the original light bulb filament made from? (Plant fibers) Explain that, although the materials in today's light bulbs are different, the basic design is the same.
- Divide students into teams of two to three students each. Distribute a copy of the Dissecting Technologies Student Activity Sheet to each student and one clear light bulb in a sealed, clear plastic bag to each student team.
- Ask students to be very careful in handling the light bulbs so that they do not break.
- Tell students to begin the activity by drawing the light bulb on the backside of their activity sheet, labeling as many parts as they can. Let them know that it's okay if they don't know many of the parts. Allow approximately 5 minutes for this. Remind students to handle the light bulbs carefully.
- Circulate and assist as needed.
Explore (20 minutes)
- Display the transparency: Light Bulb.
- Begin probing for the names of common parts of the light bulb and ask students to speculate on what the parts might be made of. Students should easily recognize glass, copper, and perhaps tungsten or aluminum. Point out that glass is often made from several different substances. You might also ask if students know what alloys are. (Two or more different metals combined.) Explain that one common alloy is brass, which is made of zinc and copper. Write the correct answers on the overhead transparency. (See the Light Bulb Teacher Answer Key.) Tell students to correct their own drawings as needed.
- Have students complete Step 2 on their student activity sheets: Match the different parts of the light bulb to the resource table at the bottom of their activity sheets and record these in the column labeled "Light bulb part."
- When they are finished with Step 2, have them move on to Step 3 of their activity sheets, identifying and labeling which resources are found in a particular country. Display the image: Labeled World Map for students to refer to while they work.
Explain (15 minutes)
- Bring the teams together as a class. Ask students if they see a relationship between raw materials, global locations, and the manufacture of light bulbs. Probe for comments that point to the fact that the light bulb is made up of materials that potentially are imported from all over the world.
- In addition to the raw materials to construct light bulbs, ask students if they can think of other things that are also required to make a light bulb work. Probe for answers that include electricity generated by solar cells, dams, and generators.
- If time permits, ask students the following reflective questions:
- What light bulb materials are imported by the United States? (All of the materials except argon, coal, nitrogen, silica, and trona.)
- Could light bulbs be constructed only from materials found in the United States? (No.)
- What materials might be in short supply? (Manganese and tungsten.)
- What might happen in the United States if we no longer had good trade relations with one of the countries supplying an important material? (Possible answers include: fewer light bulbs might be available; light bulb costs might increase; changes in light bulb design or technology might be necessary; more recycled materials would be used, a different light bulb might be designed and used.)
- Remind the students to meet in the computer lab for the next class (for Day One of Activity 4.2, Project Research: Materials).
EXTENSION: Depending upon the number and variety of items collected for Activity 1.2, Defining Technology, you may want to let your students "dissect" telephones, digital clocks, radios and other complex, modern technology items. Prior to dissecting these items, set up boxes or bags with labels to assist students in sorting components into different material categories. Some recommended categories are: glass, metal - copper, metal - other, wood, and plastic. Safety is an important issue. Dissecting technology items to their basic components can be difficult and pieces may fly off as students struggle to get things apart. This procedure can present obvious eye and face hazards. Provide some basic tools, such as pliers, screwdrivers, and hammers, as well as eye protection for each student.
- As homework, ask each student to write a paragraph that discusses the following statement: Modern technologies encourage global relationships. Collect the paragraphs at the beginning of the next class.