Beyond the answers - interesting background to this quiz

One small step, watched by millions

The first crewed Moon landing took place in 1969, when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin walked on the lunar surface while Michael Collins orbited above. Armstrong's first step was broadcast live to an estimated audience of hundreds of millions. The 20th century also saw the first human spaceflights, making it the only century so far in which people have both left Earth's atmosphere and stood on another world.

The wit behind Dorian Gray

Oscar Wilde published The Picture of Dorian Gray in 1890, and it remains his only novel. A Faustian story about a portrait that ages while its subject stays young, it caused a scandal in Victorian Britain for its hints of decadence and hidden vice. Wilde was better known in his own time as a playwright and wit, with stage hits such as The Importance of Being Earnest.

Why tungsten hides behind a W

Tungsten's chemical symbol is W, from wolfram, the name it carries in German and several other languages. The element has the highest melting point of any metal, around 3,400 degrees Celsius, which is why it was long used for light bulb filaments. Its Swedish name, tung sten, means "heavy stone", a nod to its unusual density.

Balance lives in the inner ear

The sense of balance comes from the vestibular system in the inner ear, where fluid-filled canals detect head movement and position. This information travels to the brain, which combines it with vision and body feedback to keep us upright. The cerebellum helps fine-tune movement and coordination, but the sensors themselves sit in the ear.