what year was the light bulb invented

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					                                         How You Use Light
                                                                     Unit 1

Unit   1   How You Use Light

Light: Long Ago and Today

                            Long ago, people used fire to light their

                            In the past, sailors on ships used light
                            from the stars to help them find their way.

                                            In the 1870s, some people
                                            used light from gas lamps
                                            to light their homes. Other
                                            people used oil lamps or

                                                             Academic Discussion   9
        Unit 1              How You Use Light

                                                       Today, people use electric lights to light their
                                                       homes, stores, factories, offices, and many
                                                       other places.

                                                                         Let’s think about it!!
                      Word Bank:                                        Name all the kinds of lights
                      Define the words below.                           that you use at home.

                      • caves            • electric
                      • sailors          • factories

10   Language for success
                                                                       How You Use Light
                                                                                                   Unit 1

A Time Line of Lights

                                      Thomas Edison invented the electric light bulb in 1879.
                                      What lights were invented before the light bulb? What lights
                                      were invented after the light bulb? Look at the time line to find

                                      Use the time line to answer these questions.
                                      In what year was the electric traffic light invented?
                                      Which was invented first, the neon light or the limelight?
                                      Which was invented first, the miner’s safety lamp or the laser?
                                      What happened in the year 1879?

   1815              1816              1879            1910                1923                  1960

Sir Humphry      Thomas              Thomas         Georges Claude     Garrett Morgan       Theodore Harold
Davy invented    Drummond            Edison         invented the       invented the         Maiman invented
the miner’s      invented the        invented the neon light.          electric traffic     the laser for use
safety lamp      limelight. It was   electric light                    light.               in science and
for use in       used to light       bulb.                                                  medicine.
mines.           theaters.

                                                                      Let’s think about it!!
                Word Bank:                                           Make a time line of your life.
                Define the words below.                              List three or four important
                                                                     events in your life.
                • invented
                • find out

                                                                                           Academic Discussion   11
        Unit 1              How You Use Light

      How do you see?
      You use your eyes to see.

                                                               Light enters your eye through
                                                               a small opening. This opening
                                                               is called the pupil.

                                                        Lens              The light moves through
                                                                          the lens.

                      Optic nerve
                                                                          The light hits the back of
      The light sends a message                                           the eye.
      from the back of your eye
      down a path to your brain.
      When the message gets to
      your brain, you see.

                      Word Bank:                                Let’s think about it!!
                      Define the words below.
                                                                Use the picture. Explain
                                                                how you use your eyes to
                      • pupil                                   see.
                      • lens
                      • path

12   Language for success
                                                             How You Use Light
                                                                                         Unit 1

Write and discuss what you learned
1. What kinds of light do you use?

2. List two ways that light helps your community.

3. What did you learn about light that you didn’t know before?

4. Summarize the unit in one paragraph.

5. Choose two words from the Word Bank and write a sentence using each.

                                                                                 Academic Discussion   13
        Unit 2              Plant, Animal, and Climate


14   Language for success