Information can be sent from place to place using patterns. Long ago, people used drums, smoke signals and flags. Morse code uses short and long signals, dots and dashes, for each letter: S is dot-dot-dot and O is dash-dash-dash, so SOS is a famous call for help. A pattern can be sent with light, sound or electricity.
Today phones and computers send information as patterns of on and off signals, called digital codes, through wires, radio waves and light in fibre-optic cables. A good code is simple, clear and agreed by both sender and receiver. Engineers compare codes to see which sends a message fastest with the fewest mistakes.
Worked example
In a class code, one beep means 'A' and two beeps mean 'B'. What does beep, beep-beep, beep spell?
- One beep = A.
- Two beeps = B.
Answer:The message is A, B, A: 'ABA'.
Key words
- code
- a set of agreed signals that stand for information
- Morse code
- letters made of dots and dashes
- digital
- sent as on/off patterns
- receiver
- the person or device that gets the message
New questions every time.
NGSS-referenced: 4-PS4-3