Thousands of calls Cs be carried at the same time by a beam of laser light. Many stores are using lasers in checkout lines. A Universal Produce Code is printed on each product. A laser beam is bounced off the bands of the code and a computer identifies the code. The computer figures the bill and keeps a record of what was sold.
Holograms are three-dimensional photographs produced by lasers.
We are finding more and more uses for light each year. Have students work in small groups of 4 to 8. Give each group a candle and have them light it. Place a kerosene lamp on a table. Have a student remove the chimney and light the wick.