Axle and radar: what they have in common

1. Step 1. Axle — is part of — Armillary sphere. The celestial axis.
2. Step 2. Armillary sphere — uses — Euclidean geometry. The rings model the celestial circles.
3. Step 3. Euclidean geometry — is used in — Shukhov Tower. The hyperboloid is assembled from straight bars.
4. Step 4. Shukhov Tower — has part — Antenna. A radio tower.
5. Step 5. Antenna — is part of — Radar. An antenna emits and receives.

Open Evothings