Platinum-iridium cylinder and turbojet engine: what they have in common
- Step 1. Platinum-iridium cylinder — is part of — Standard kilogram. A 39 × 39 mm cylinder.
- Step 2. Standard kilogram — is made of — Platinum. A platinum–iridium alloy.
- Step 3. Platinum — is material for — Cochlear implant. The electrodes are platinum.
- Step 4. Cochlear implant — is made of — Titanium. The case is titanium.
- Step 5. Titanium — is material for — Turbojet engine. Compressor blades.