Historical geography: borders that used to exist
Every border on the current map is younger than it looks, and a good number are younger than the people living on them. These are the ones where the change is recent enough to still be in living memory.
How long did the Anglo-Zanzibar War of 1896 last?
About 38 minutes
Widely recorded as the shortest war in history, lasting between 38 and 45 minutes from the first shell to surrender.
Which country switched from driving on the left to the right overnight in 1967?
Sweden
Dagen H, 3 September 1967. Sweden's neighbours drove on the right and most Swedish cars were already left-hand drive. Accidents actually fell at first, as everyone drove nervously.
Source: Swedish Transport Administration archives
In 2011 Samoa skipped a day entirely. Which one?
30 December
Samoa moved west of the international date line to align its working week with Australia and New Zealand, so 29 December was followed directly by 31 December.
Source: Samoan government proclamation, 2011
What was unusual about the shape of the Berlin Wall?
It enclosed West Berlin
West Berlin was an island inside East Germany, so the wall ran right around it, about 155 km in total, of which only about 43 km faced East Berlin.
Source: Berlin Wall Foundation
Which is the world's newest widely recognised sovereign state?
South Sudan, from 2011
South Sudan gained independence in July 2011 after a referendum, becoming the 193rd UN member state. Kosovo declared in 2008 but is not universally recognised.
Source: UN member state admissions
Roughly how much distance does the Suez Canal save on a London to Mumbai voyage?
About 7,000 km
Without Suez, ships round the Cape of Good Hope. The canal cuts the London to Mumbai route from roughly 19,000 km to about 11,500.
Source: Suez Canal Authority distance tables
Travelling through the Panama Canal from the Atlantic to the Pacific, which way do you go?
South-east
The isthmus curves, so the canal runs north-west to south-east. The Pacific entrance at Panama City is about 40 km east of the Atlantic entrance at Colon.
Source: Panama Canal Authority charts
Why does the prime meridian pass through Greenwich?
An 1884 conference chose it
The International Meridian Conference in Washington picked Greenwich because about two-thirds of the world's shipping tonnage already used charts based on it. France abstained and kept Paris time for decades.
The United States bought Alaska from Russia in 1867 for roughly how much per acre?
About two cents
7.2 million dollars for about 375 million acres works out near two cents an acre. It was mocked at the time as Seward's Folly, until gold and oil were found.
Source: Treaty with Russia, 1867; US National Archives
Which country's borders have changed least in the past 500 years?
Portugal
Portugal's mainland borders have been essentially fixed since 1297, making them among the oldest stable frontiers in Europe. Its overseas empire changed enormously; the metropolitan shape did not.
Source: Treaty of Alcanices, 1297; European boundary histories
Before radio, how did ships work out their longitude?
By carrying an accurate clock
Comparing local noon with the time at a reference meridian gives longitude. John Harrison's marine chronometers solved a problem that had cost thousands of lives.
Source: Board of Longitude records; Royal Museums Greenwich