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 caves.
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 candles.
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:
Define the words below.
• caves • sailors
10 Language for success
Name all the kinds of lights that you use at home.
• electric • factories
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 out. 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 Davy invented the miner’s safety lamp for use in mines.
Thomas Drummond invented the limelight. It was used to light theaters.
Thomas Georges Claude Edison invented the invented the neon light. electric light bulb.
Garrett Morgan invented the electric traffic light.
Theodore Harold Maiman invented the laser for use in science and medicine.
Let’s think about it!!
Word Bank:
• invented • find out
Define the words below.
Make a time line of your life. List three or four important events in your life.
Academic Discussion
11
Unit 1
How You Use Light
How do you see?
You use your eyes to see.
Pupil
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 sends a message from the back of your eye down a path to your brain. When the message gets to your brain, you see.
The light hits the back of the eye.
Word Bank:
• pupil • lens • path
12 Language for success
Let’s think about it!!
Use the picture. Explain how you use your eyes to see.
Define the words below.
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
MEMO
14
Language for success