SortStack #1525 — 2030-08-12

By size · Order from shortest to longest.

1. An acoustic guitar 99 cm

   The guitar's hollow body acts as an amplifier, resonating the strings' vibration into the air around it.

2. A concert grand piano 2.7 m

   A grand piano's strings pull with a combined tension of around 20 tonnes, held by a single cast-iron frame.

3. The Washington Monument 165 m

   Look closely and the stone changes shade partway up, marking where construction paused for over 20 years.

4. Aconcagua, Argentina 7 km

   The highest peak outside Asia, it can be hiked to the summit without ropes, yet thin air still kills climbers.

5. The Channel Tunnel 50.5 km

   Trains run through three parallel tubes beneath the seabed, with a smaller service tunnel between them for safety.

6. The Pan-American Highway (length) 30K km

   It runs almost pole to pole but for one gap: the roadless Darien jungle between Panama and Colombia.

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