SortStack #2745 — 2033-12-14

By speed · Order from slowest to fastest.

1. The growth of human hair 175.3 mm/year

   Scalp hair grows roughly 1.25 centimetres a month, so a single strand reaching your shoulders is years old.

2. A king penguin waddling on land 2.8 km/h

   A penguin's waddle is surprisingly efficient, storing and releasing energy with each side-to-side rock.

3. A galloping zebra 66 km/h

   No two zebras have the same stripe pattern, which may help them recognise each other and confuse biting flies.

4. A car cruising the German autobahn 200 km/h

   Parts of Germany's autobahn have no speed limit, where ordinary sedans legally travel faster than racetracks allow elsewhere.

5. 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.

6. NASA's Parker Solar Probe 692K km/h

   The fastest human-made object ever, it slingshots around the Sun, dipping into the star's blazing outer atmosphere.

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