Communicating with Light: People

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SWBAT explain devices that people use light to communicate.

Big Idea

Who uses light to communicate? Go from sea to shining sea as we visit a lighthouse, board a Navy ship, and take a stroll on the red carpet!

Instructional Notes

The culminating task for this unit is engineering a device that will allow communication over a distance.  The essential question guiding the light portion of this unit is, "How can we communicate with light?"  Today we will build students' background knowledge of communication devices using light.

The essential question incorporates two NGSS standards as we investigate the properties of light and also move towards the culminating engineering design product.

  • 1-PS4-3. Plan and conduct an investigation to determine the effect of placing objects made with different materials in the path of a beam of light.
  • 1-PS4-4. Use tools and materials to design and build a device that uses light or sound to solve the problem of communicating over a distance.

This unit is broken down into two main parts: sound and light.   Throughout this unit, I use a KLEWS anchor chart to record our new learning.  This is a science-specific type of KWL chart designed with primary students in mind!  Check out this video I like to call KLEWS chart 101:



5 minutes

First, students reread the essential question with me, "How can we communicate with light?"  Today is all about building background knowledge, so first I hold a class discussion to see what ideas students bring.  I ask questions like:

  • Who communicates with light?
  • What kind of lights can we use to communicate? (traffic signals, blinkers, flashing neon lights...)
  • Do we ever communicate with light in school? (some teachers flash or turn off lights to signal quiet)

I record the question under the "K" (what we know) portion of the KLEWS chart, and underneath, I write student responses.  This year, my students came with little to no understanding of ways to communicate with light.  Once I suggested a traffic light, they were able to state what message the colors communicate (red means stop).  Their lack of ideas really helped affirm for me how crucial this lesson is because it builds background.

For the opening, I set the purpose for learning by reading the objective.

Friends, today we will be investigating different ways of communicating with light.  At the end of the lesson, you will draw a diagram showing one of the devices we study today.  Be thinking about which one you would like to record. 

Exploration ~ the wave crest

20 minutes

During this lesson, students will investigate 3 ways to communicate with light: lighthouses, Morse code, and spotlights.  If your students are quite familiar with one of these examples, I'd put that one first to build confidence.

As we explore the devices, I often take notes on a web.  The center of the web reads, "How can we communicate with light?"  Depending on your class's abilities, students can take notes in journals as you take notes together.  This year, my students asked if they could take notes.  I played a transition song while students got their journals.  My students each have a marbled composition notebook as a dedicated science journal.  Rather than recording on a web, I paused the videos to monitor comprehension but did not record as shared writing on the easel.

Most of my students took notes independently.  Here is some sample student work with notes from each videostudent work #2, and student notes with questions.  By allowing students the ability to take notes independently, their responses are personal to what they individually were most interested in.  Without modeling note-taking in language arts over the last few months, though, this would have been successful only as a shared writing experience.  


Most children have heard of lighthouses in my area, although few have been to see one.  I send home a list of local lighthouses via email to my classroom parents, because they can make a quick day or weekend trip to see one!  I ask, "Who do lighthouses communicate with?  Why do they use light?"  Next, I show a short video clip or slightly longer video clip about lighthouses.

Morse code

I introduce this method of communication before showing the video clip.

Friends, in the military, ships often had to communicate with each other.  But, captains couldn't yell from ship to ship.  Instead, they developed a code called Morse code with short and long blips.  Check out this clip that the Navy might use to help train their cadets today!


I introduce this method as well.  

Spotlights are ways to communicate that something special is happening.  They get your attention with light!  Celebrities might have spotlights on them at the red carpet, or at the opening of a new store.  Check out how people in Philadelphia are using a special of spotlights to communicate!


5 minutes

At the end of our investigation, I want students to evaluate the different types of communication using lights.  We sit on the perimeter of the rug so that students are facing each other, which helps get conversation going!  I facilitate a discussion with questions like these:

  • Which of these communication devices is most helpful?
  • Which one is most important?
  • Which one would you most like to try?

If students provide short answers, I follow-up with questions like these:

  • Why do you think that?
  • Who agrees or disagrees with this idea?
  • Who has different thinking to share?

Finally, students will draw and record at least one type of light communication in their journals.  My classroom atmosphere is pretty student-centered, so my students are comfortable laying on the rug near the web if they need help spelling.  You can also provide a list for students to glue into their journals, which will aid them with any writing tasks.  I have a list here for you, and the extra bullets are for your class to write other ideas you generated!

Note: This year, because my children chose to take notes during the videos, I actually gave them the list ahead of time to glue in.  This then became a spelling aid.