Beyond the answers - interesting background to this quiz

When a single name becomes a whole industry

Thomas Edison is credited with the light bulb in 1879, but he was building on decades of work by other inventors. What set his version apart was not just the bulb itself but the system around it: a practical filament, vacuum technology and the ambition to power entire cities. His laboratory in Menlo Park, New Jersey, became famous as a place where invention was organised almost like a factory.

The mountain range at the centre of Asia

The Karakoram stretch across Pakistan, India and China, forming one of the highest and most dramatic landscapes on Earth. They are home to K2, the second-highest peak in the world, and to some of the largest glaciers outside the polar regions. Unlike the nearby Himalayas, which were formed by a different phase of mountain building, the Karakoram are still rising as the Indian and Eurasian plates continue to collide.

A novel that feels like a nightmare

Franz Kafka's The Trial tells the story of Josef K., who is arrested one morning without being told what he has done. The novel was never finished in Kafka's lifetime and was published after his death, against his own wishes. Its atmosphere of vague, inescapable bureaucracy gave us the word "Kafkaesque", now used for any situation that feels absurdly tangled in official rules.

The accidental discovery that saved millions

Alexander Fleming discovered penicillin in 1928 when he noticed that mould had contaminated one of his bacterial cultures and was killing the bacteria around it. It took more than a decade before scientists managed to purify it as a usable drug. By the later years of the Second World War, penicillin was being mass-produced and treating infections that had previously been fatal.