4TH GRADE SCIENCE • WAVES AND THEIR APPLICATIONS

Patterns That Talk: How Patterns Represent Information

Discover how people use repeating patterns — from drumbeats to digital codes — to send messages across distances.

The Phenomenon: Drums That Send Messages

🔍 ANCHORING PHENOMENON

The drummer doesn't just bang randomly. Each message has a specific pattern — a certain combination of high and low sounds, played in a certain order. When the pattern changes, the message changes. People who know the system can "read" the drumbeats like you read a sentence in a book.

Illustration of talking drums sending a message between two villages through sound wave patterns
💭 Thinking Questions
  • How can sounds carry a message if they are not words?
  • What makes one drum pattern different from another, and why does that matter?
  • Where else have you seen patterns used to share information?

What Scientists Know: Patterns and Information

When scientists study how people share information, they notice something important: patterns are everywhere. A pattern is an arrangement of things — sounds, lights, symbols, or movements — that repeats or follows a rule. When people agree on what a pattern means, that pattern can carry information — facts, messages, or instructions that someone else can understand.

This is the key idea: patterns of signals can represent information. The signals themselves (a sound, a flash of light, a mark on paper) might seem simple on their own. But when they are arranged in a specific pattern, they become a code that stores and sends information.

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Patterns Are Everywhere

A pattern is any arrangement that follows a rule or repeats in a predictable way. The letters in a word follow a pattern that gives the word its meaning. Musical notes follow a pattern that creates a melody. Even the colors of a traffic light follow a pattern: red, yellow, green.
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Signals Carry Patterns

A signal is something that can be detected — a sound, a light, a vibration, or a mark. Signals can be arranged into patterns. For example, a flashlight can blink on-off-on-off in a pattern, and each different pattern can mean a different thing.
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Patterns Represent Information

When the sender and the receiver both understand the code, a pattern becomes information. Morse code uses patterns of short and long signals (dots and dashes) to represent every letter of the alphabet. The pattern IS the message.
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Digital Information Uses Simple Patterns

Computers store all information — text, photos, music, videos — using just two signals: 0 and 1. These are called binary digits (bits). Different patterns of 0s and 1s represent different pieces of information, from a single letter to an entire movie.
KEY TAKEAWAY
KEY TAKEAWAY

Let's Investigate: Building a Flashlight Code

🔬 INVESTIGATION SPOTLIGHT

Design and Test a Light-Signal Code

What scientists and engineers do: Scientists look for patterns in data to understand how information is transferred. Engineers design systems that use patterns to send information reliably. In this investigation, you will act like an engineer and develop a model — a simple code — that uses patterns of light to send messages.

Question: Can you create a code that uses only short and long flashes of light to send a three-letter message across a room?

Materials you would need:

  • A flashlight or small lamp
  • Paper and pencil (to design your code)
  • A partner (the receiver)
  • A timer or watch

Procedure:

  • Design a code chart that assigns a unique pattern of short flashes (●) and long flashes (▬) to each letter you need.
  • Practice sending each letter pattern with your flashlight. A short flash = light on for about 1 second. A long flash = light on for about 3 seconds.
  • Without telling your partner which word you chose, send your three-letter message using only light patterns.
  • Have your partner use the code chart to decode each letter and write down the message.
  • Compare the sent message with the decoded message. Did the information transfer correctly?

What you would observe: When the code is followed correctly, the receiver can figure out the exact message — even without hearing any words. The pattern of light signals represents the information. If you change the pattern, the message changes.

A flashlight code chart showing how patterns of short and long light flashes represent different letters

What We Discovered: How Patterns Encode Information

When you design a code (like the flashlight code above), you are doing exactly what engineers and scientists do: you are creating a system where specific patterns represent specific pieces of information. The investigation showed us several important things about how this works.

First, you need a set of basic signals. In the flashlight code, there were only two signals: a short flash and a long flash. That's it — just two types of signal. But by arranging those two signals in different patterns, you can represent every letter of the alphabet. Each letter has its own unique pattern, and no two letters have the same pattern. This is what makes the code work: the pattern is what carries the meaning.

Second, both the sender and the receiver need to know the code. If your partner did not have the code chart, they would see the flashes but not understand the message. The light signals would still travel through the air, but the information would be lost because the receiver could not decode the pattern.

Type of SignalBasic Signals UsedWhat the Pattern RepresentsExample
Talking drum beatsHigh tone, low toneWords and phrasesHIGH-LOW-LOW = "come"
Morse code (light/sound)Short signal (dot), long signal (dash)Letters and numbers● ● ● = S
Computer data (binary)0 and 1Text, images, sound, video01000001 = A
BrailleRaised dot, flat spotLetters and numbers⠁ = A

Notice something interesting in the table: every single coding system uses a small number of basic signals — sometimes just two! The power is not in the signals themselves, but in the patterns they form. A computer uses only 0 and 1, but with long enough patterns of those two digits, it can store an entire movie. The pattern is the information.

Diagram showing how the word CAT is encoded in binary using patterns of 0s and 1s

The diagram above shows how a computer stores the word "CAT." Each letter is represented by a unique pattern of eight 0s and 1s. Change even one digit, and you get a completely different letter. The pattern is what determines which piece of information is being stored or sent.

Patterns and Connections: Seeing Patterns Across Science

One of the most powerful ideas in science is that patterns show up everywhere — not just in codes and communication, but across all areas of science. Scientists look for patterns in data to help them explain and predict what will happen. Recognizing a pattern often leads to an important discovery.

In this lesson, we have focused on how patterns represent information in signals and codes. But let's look at how patterns carry important information in other areas of science too.

Area of ScienceThe PatternThe Information It Represents
Waves & CommunicationShort and long light flashes, or 0s and 1sLetters, numbers, images, music — any message
Earth Science — WeatherTemperature, air pressure, and cloud type readings over many daysScientists use these patterns to predict tomorrow's weather
Life Science — Animal BehaviorFireflies blinking their lights in a specific on-off patternDifferent flash patterns tell other fireflies what species they are
Life Science — DNAThe order of four chemical "letters" (A, T, C, G) in DNAInstructions for building every part of a living thing
Earth Science — Rock LayersRepeating layers of different rock typesInformation about what the environment was like millions of years ago

Do you see the connection? In every case, information is stored or communicated through a pattern. The pattern might be made of sounds, lights, chemical molecules, or layers of rock — but the underlying idea is the same. When something follows a recognizable pattern, it can carry meaning.

KEY TAKEAWAY
KEY TAKEAWAY

Real-World Connections: Patterns in Action

The idea that patterns can represent information is not just a classroom concept — it is the foundation of nearly every communication technology you use every day. Engineers design devices that convert information into patterns of signals and then convert those patterns back into information at the other end.

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📱 Smartphones and Texting

When you send a text message, your phone converts each letter into a pattern of electrical signals (based on binary — 0s and 1s). Those signals travel as radio waves to a cell tower, then to your friend's phone, which decodes the pattern back into letters. The message travels as a pattern of waves, not as actual letters floating through the air.
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🎵 Digital Music

A song stored on a computer or streaming service is really just a long sequence of 0s and 1s. Those binary numbers represent tiny samples of the sound wave — the loudness and pitch at each moment. When your speaker reads the pattern, it turns those numbers back into vibrations you can hear as music.
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📊 QR Codes and Barcodes

The barcode on a cereal box uses a pattern of thick and thin lines to represent a product number. A QR code uses a pattern of black and white squares. A scanner reads the pattern and instantly knows what product it is or what website to open. The pattern IS the information.
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🚦 Traffic Signals

Traffic lights use a simple pattern of colors — red, yellow, green — to communicate information to drivers. Everyone understands the code: red means stop, green means go. The pattern repeats in a predictable way, and changing the pattern (for example, a flashing yellow) changes the message.
🛠️ ENGINEERING DESIGN CHALLENGE

Think about: How will you make sure each message has a unique pattern? How will you make the code easy to remember? What if two messages look too similar — how would you fix that? Test your code with a partner and improve it based on what works and what causes confusion.

Key Vocabulary Review

  • Pattern — An arrangement of things (sounds, symbols, numbers, colors) that follows a rule or repeats in a predictable way.
  • Signal — Something that can be detected and used to send information, such as a sound, a flash of light, or an electrical pulse.
  • Information — Facts, messages, or instructions that can be understood by someone who knows how to decode them.
  • Code — A system of rules that assigns specific patterns to specific meanings, so information can be sent and received.
  • Binary — A system that uses only two signals (0 and 1) to represent all information. Computers use binary code.
  • Encode — To convert information into a pattern of signals using a code.
  • Decode — To convert a pattern of signals back into information using a code.
  • Morse Code — A coding system that uses patterns of short signals (dots) and long signals (dashes) to represent letters and numbers.

Practice: Test Your Understanding

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What's Next?

🔮 WHAT'S NEXT?
Varsity Tutors • 4th Grade Science (NGSS) • Patterns That Represent Information