Beyond the answers - interesting background to this quiz

The complicated question of Northern Ireland's capital

Belfast is the capital of Northern Ireland, but the city's story is bound up with the wider history of the island. It grew rapidly during the Industrial Revolution, becoming a major centre for linen, rope-making and shipbuilding - the Harland and Wolff yard famously built the Titanic. Since the partition of Ireland in the early 1920s, Belfast has served as the seat of government for Northern Ireland, while Dublin became the capital of the independent Irish state. The two cities sit roughly 160 kilometres apart, which is why the wrong answers in this quiz feel so plausible.

A country made of islands

The Comoros is an archipelago nation in the Indian Ocean, off the coast of East Africa, and its capital is Moroni, located on the island of Grande Comore. What makes the country unusual is that one of its islands, Mayotte, voted to remain under French administration rather than join the independent state. The Comoros also has a distinctive cultural mix, shaped by Arab, African and French influences - and it is one of the few countries in the world where a form of arranged marriage remains a widespread social institution.

Daguerre and the birth of practical photography

Louis Daguerre did not invent photography single-handedly, but his daguerreotype process, announced in 1839, was the first to be commercially successful. It produced sharp, one-of-a-kind images on silvered copper plates, and portraits quickly became popular in cities across Europe and the United States. One quirk of the process: each daguerreotype was unique, so copying an image meant photographing the photograph itself. Daguerre's name is one of the few from that era that is still widely recognised, even though later processes such as the wet collodion method soon overtook his.

The Southern Ocean and the Mariana Trench

Two questions in this quiz point to the world's oceans, and both answers are worth a second look. The Southern Ocean is the name given to the waters encircling Antarctica, a designation that many countries and scientific bodies now recognise as a distinct ocean. Meanwhile, the Mariana Trench lies in the western Pacific, near the Mariana Islands, and contains the deepest known point on Earth, Challenger Deep. The trench forms where one tectonic plate slides beneath another, a process that also helps generate the region's frequent earthquakes.