Artificial satellite and sickle: what they have in common
- Step 1. Artificial satellite — has part — Solar panel. Powering satellites.
- Step 2. Solar panel — is part of — Electronic calculator. Many run on a solar cell.
- Step 3. Electronic calculator — evolved from — Arithmometer. Electronics replaced mechanics.
- Step 4. Arithmometer — has part — Crank. The handle for adding and subtracting.
- Step 5. Crank — is part of — Reaper. A crank moves the knife.
- Step 6. Reaper — evolved from — Sickle. Mechanical reaping.