SortStack #2055 — 2032-01-24
By duration · Order from shortest to longest.
- An average human yawn 6 sec
Yawns are so contagious they jump species: dogs catch yawns from their owners, and even reading the word can trigger one. You're welcome.
- A frilled shark's pregnancy 3.5 years
At an estimated three and a half years, it's the longest known gestation of any vertebrate — embryos grow just over a centimetre a month.
- A periodical cicada's life cycle, egg to final emergence 17 years
They spend 17 years underground and mere weeks in the sun — the prime-numbered cycle may have evolved to dodge predators' breeding rhythms.
- The construction of the Great Pyramid of Giza 20 years
Herodotus and modern estimates agree on roughly two decades — meaning workers placed a multi-tonne block about every five minutes of daylight.
- The Ottoman Empire 622.7 years
Founded before the printing press, it ended after the airplane — the empire spanned 623 years and three continents at its height.
- How long the Hagia Sophia has been standing 1.5K years
Built in just five years under Justinian, it has since served as cathedral, mosque, museum, and mosque again across nearly 1,500 years.