Alidade sighting rule and data centre: what they have in common

1. Step 1. Alidade sighting rule — is part of — Astrolabe. A sighting rule.
2. Step 2. Astrolabe — works like — Antikythera mechanism. Both are analogue astronomical calculators.
3. Step 3. Antikythera mechanism — works like — Orrery. Mechanical models of celestial motions.
4. Step 4. Orrery — evolved into — Planetarium. Models of the sky.
5. Step 5. Planetarium — is made of — Concrete. Zeiss’s first dome was thin concrete.
6. Step 6. Concrete — is material for — Data centre. The building is concrete.

Open Evothings