Magnetic lodestone spoon and electric motor: what they have in common

1. Step 1. Magnetic lodestone spoon — is part of — South-pointing spoon (Chinese compass). A lodestone spoon that turns its handle to the south.
2. Step 2. South-pointing spoon (Chinese compass) — evolved into — Compass. A magnetic pointer.
3. Step 3. Compass — uses — Magnetism. The needle aligns with the Earth’s magnetic field.
4. Step 4. Magnetism — is used in — Hard disk drive. Magnetic recording.
5. Step 5. Hard disk drive — has part — Electric motor. A spindle motor.

Open Evothings