1ST GRADE SCIENCE • WAVES: LIGHT AND SOUND

How Can We Send a Message?

Let's explore how people use light and sound to talk to each other, even when they are far away!

What's Happening?

🔍 LOOK AT THIS!

You try to shout, but your friend cannot hear you. The playground is too loud! How can you send your message?

Your friend can't hear you!
💭 THINK ABOUT IT
  • What could you do to get your friend's attention?
  • Could you use light or sound to help?

Big Ideas About Sending Messages

Sometimes it is hard to talk to someone. They might be too far away. Or it might be too noisy. This is called a communication problem. That means you have trouble getting your message to someone.

But guess what? We can use light and sound to help! Let's learn how.

1

Sound Can Send Messages

Sound is what we hear. A bell, a horn, or a whistle makes sound. We can use loud sounds to send a message to someone far away. A fire truck siren tells people to move out of the way!
2

Light Can Send Messages

Light is what we see. A flashlight, a blinking light, or a bright color can get someone's attention. A lighthouse uses a big bright light to warn ships at night!
KEY TAKEAWAY
KEY TAKEAWAY

Let's Try It!

🔬 LET'S INVESTIGATE

Let's think like scientists! Scientists ask questions and design solutions. That means they think of a problem and then try to solve it!

Here's What You Can Try:

  • Stand across the room from a friend or family member.
  • Try to tell them "come here" WITHOUT talking. You can use a flashlight, wave your hands, clap, ring a bell, or stomp your feet!
  • Ask your friend: Did they understand your message? What worked best?

What you might need: a flashlight, a bell, your hands, and a friend!

Ways to Send a Message

What We Discovered

When we tried different ways to send a message, we learned something important. Light works great when someone can see you. Sound works great when someone can hear you.

But here is the tricky part. Sometimes one way works better than the other!

If it is very dark outside, waving your hands will not help. Your friend cannot see you! But a bright flashlight might work because the light stands out in the dark.

If it is very noisy, a quiet whisper will not help. Your friend cannot hear you! But a very loud horn might work because it is louder than the noise around you.

When Does Each One Work Best?
KEY TAKEAWAY
KEY TAKEAWAY

Do You See the Pattern?

Scientists look for patterns. A pattern is when something happens in the same way again and again. Let's look for a pattern!

Every time people have a communication problem, they think: "What tool can help me send my message?"

THE PROBLEMTHE SOLUTIONLIGHT OR SOUND?
🌙 It is dark at seaA lighthouse shines a bright lightLight ☀️
🚗 Cars need to stopA traffic light turns redLight ☀️
🏫 Time to come insideA school bell ringsSound 🔊
🚒 Fire truck coming!A loud siren wailsSound 🔊
🚲 Bike coming behind youA bike bell ringsSound 🔊
KEY TAKEAWAY
DO YOU SEE THE PATTERN?

Light and Sound in the Real World

People use science to solve problems! Engineers are people who design things to solve problems. That means they think of a problem and build something to fix it.

Here are some amazing things engineers made using light and sound:

1

🚦 Traffic Lights

Cars and people need to know when to stop and go. Engineers made traffic lights with colored lights. Red means stop. Green means go. The light sends a message everyone can see!
2

🚨 Fire Alarms

When there is a fire, people need to get out fast. Engineers made fire alarms that make a very loud beeping sound AND flash a bright light. They use BOTH light and sound!
🛠️ DESIGN CHALLENGE — CAN YOU HELP?

Words to Know

📖 KEY VOCABULARY
  • Communication — sending a message to someone. When you talk, wave, or write, you are communicating.
  • Communication problem — when it is hard to send a message. Maybe it is too noisy or too dark.
  • Light — something we can see. It comes from the sun, flashlights, and lamps. We can use light to send messages.
  • Sound — something we can hear. It comes from bells, voices, and instruments. We can use sound to send messages.
  • Solution — a way to fix a problem. Using a flashlight in the dark is a solution!

Show What You Know!

1
A crossing guard needs to tell drivers to stop so children can cross the street safely. Which device would best help the crossing guard communicate this message?
2
A soccer coach is on the other side of a noisy field. The players cannot hear the coach's voice. What is the best way to solve this communication problem?
3
A family is camping at night. It is very dark and they need to find the path back to their tent. What is the problem, and which device uses light to help solve it?
4
A lifeguard at a swimming pool needs to warn swimmers that the pool is closing. The swimmers are splashing and playing loudly in the water. Which solution uses BOTH light and sound to communicate the message?

What's Next?

🔮 WHAT'S NEXT?
Varsity Tutors • 1st Grade Science (NGSS) • Waves: Light and Sound — Communication with Light and Sound