SortStack #1350 — 2030-02-18

By size · Order from shortest to longest.

1. A classic incandescent light bulb 11 cm

   Its glowing filament reaches around 2,500 degrees Celsius, yet wastes most of its energy as heat, not light.

2. A ten-pin bowling pin 38 cm

   Pins are coated in tough plastic and weigh just enough to scatter dramatically yet stand back up reliably.

3. A skateboard 79 cm

   The kicktail that makes tricks possible was a 1970s accident that turned skating into an aerial sport.

4. 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.

5. A sperm whale 16 m

   Its head holds the largest brain of any animal that has ever lived, weighing about as much as a small person.

6. The Gateway Arch, St. Louis 195 m

   Its elegant curve is a catenary, the exact shape a hanging chain makes, flipped upside down for strength.

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