Safety boundary
Use simulations, printed optics, and eye-safe light only. Do not direct lasers or intense light at people.
Explicit physics instruction
Analog signals vary continuously, while digital systems encode information in discrete states or symbols.
Noise can distort both, but digital receivers can often regenerate states when distortion remains within decision thresholds.
Error rates, bandwidth, sampling, and redundancy affect communication quality; digital is not magically noise-free.
Vocabulary: digital signal; analog signal; noise; threshold; error rate.
Worked example
If a receiver interprets voltages above 2.5 V as 1 and below 2.5 V as 0, moderate noise may change measured voltage without changing decoded bit state.
Guided question
Why can a digital signal survive some distortion that would visibly alter an analog waveform?
Independent work
- Classify sample signals as analog or digital.
- Calculate an error rate from supplied bit counts.
- Explain one tradeoff between redundancy and bandwidth.
Misconception check
Digital transmission does not eliminate noise; it can make correct state recovery more robust.
Formative check
What metric directly measures incorrect received symbols?
Reveal response
Error rate.
Mentor evidence conference
Ask Archaemenes to audit wave variables, encoding assumptions, metrics, and model limits.
Teacher guidance
Foundation: Use binary-state examples.
Core: Analyze error-rate data.
Extended: Evaluate encoding/redundancy tradeoffs.