SortStack #452 — 2027-09-04

By duration · Order from shortest to longest.

1. A Eurostar train journey from London to Paris 2.3 h

   Only about 20 minutes of the trip is actually under the sea — the Channel Tunnel remains the longest undersea rail tunnel in the world.

2. The Battle of Leipzig, Napoleon's 'Battle of the Nations' 4 days

   With around 600,000 soldiers from over a dozen nations, the 1813 clash was Europe's largest battle until the First World War.

3. A chicken egg's incubation, laying to hatching 21 days

   Chicks start cheeping to their mother through the shell a day or two before hatching — and she clucks back to encourage them out.

4. One year on Mercury (a full orbit of the Sun) 88 days

   Mercury's spin is so slow that a single sunrise-to-sunrise day there lasts about two of its years — you could outwalk its sunset.

5. The Holy Roman Empire, from Otto the Great to its dissolution 844 years

   Voltaire quipped it was 'neither holy, nor Roman, nor an empire' — yet it lasted 844 years before Napoleon finished it off in 1806.

6. 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.

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