SortStack #209 — 2027-01-04

By size · Order from shortest to longest.

1. A tennis ball 6.7 cm

   Tennis balls are pressurised with gas and slowly go flat, which is why fresh cans hiss when opened.

2. A red kangaroo (standing) 1.5 m

   Kangaroos cannot walk backwards, a trait so iconic it earned them a spot on Australia's coat of arms.

3. A reticulated python 6.6 m

   The world's longest snake, it kills by constriction, tightening with every breath its prey exhales.

4. The Empire State Building 443 m

   It was built in just 410 days during the Great Depression, rising about a floor a day at peak speed.

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 River Rhine (length) 1.2K km

   It has been a vital trade highway since Roman times, still carrying more cargo than any other river in Europe.

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