Nerves & Senses

Fast wires and sensitive detectors

An interactive lesson with 8 steps, about 7 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Nerve pulses travel at about 1–100 m/s, much faster with myelin.
• Toe-to-brain signals take tens of milliseconds.
• Eyes and ears approach physical limits of sensitivity.
• Decibels are logarithmic: +10 dB means 10 times the intensity.

Steps

1. Electrical signals
2. Stubbing a toe
3. Catch the ruler
4. Why myelin helps
5. Extreme sensitivity
6. Decibels
7. Signal speed
8. A rock concert