Bag and laser: what they have in common
- Step 1. Bag — has part — Zip. A zip.
- Step 2. Zip — is part of — Wetsuit. A zip on the back.
- Step 3. Wetsuit — uses — Thermal insulation. Insulation.
- Step 4. Thermal insulation — is used in — Vacuum flask. Insulation.
- Step 5. Vacuum flask — has part — Mirror. The silvering reflects heat radiation.
- Step 6. Mirror — is part of — Laser. A resonator made of mirrors.