SortStack #64 — 2026-08-12

By speed · Order from slowest to fastest.

1. A gray squirrel 19.5 km/h

   Squirrels plant thousands of trees by accident, forgetting where they buried many of the nuts they hid.

2. A racing greyhound 76 km/h

   Greyhounds reach their top speed in just a few strides and spend much of a sprint completely airborne.

3. A volcanic pyroclastic flow 700 km/h

   A pyroclastic flow is a searing avalanche of gas and ash that buried Pompeii's residents almost instantly.

4. A bullet from a .357 Magnum 1.5K km/h

   A supersonic bullet creates a tiny sonic boom, which is part of the sharp crack you hear from a gunshot.

5. A tank's sabot round 5.8K km/h

   A sabot round sheds a casing in flight, leaving a slim dart of dense metal that punches through armour.

6. NASA's X-43 scramjet 11.9K km/h

   The X-43 set an air-breathing speed record by burning fuel in a stream of air rushing through it many times faster than sound.

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