Beyond the answers - interesting background to this quiz

Faraday, the bookbinder who rewired physics

Michael Faraday had almost no formal education. He learned science largely by attending public lectures and reading the books he bound as an apprentice bookbinder, and he later worked as an assistant to the chemist Humphry Davy at the Royal Institution in London. His experiments with magnets and coils showed that a changing magnetic field can produce an electric current, a discovery that underpins the electric generators and transformers we rely on today. He also introduced the concept of the field, which James Clerk Maxwell later expressed in mathematical form.

Picasso's long and restlessly changing career

Pablo Picasso was born in Malaga, Spain, in 1881, and he lived until 1973, so his career stretched across most of the 20th century. He moved through distinct phases, including the Blue and Rose periods, before co-founding Cubism with Georges Braque. His most famous anti-war painting, Guernica, was made in response to the bombing of a Basque town during the Spanish Civil War.

Why Mars is a carbon dioxide world

Mars has a very thin atmosphere, and roughly 95 percent of it is carbon dioxide, with small amounts of nitrogen and argon. Because the pressure is so low, liquid water cannot remain stable on the surface for long. The planet's polar caps contain water ice and frozen carbon dioxide, and the seasonal freezing and thawing of that CO2 helps drive Martian weather.

Cook's voyages and the Antarctic Circle

James Cook's ships crossed the Antarctic Circle in the 1770s during his second voyage, becoming the first recorded vessels to do so. Cook did not sight the Antarctic continent itself, but he sailed far enough south to show that any southern landmass would be cold and largely ice-bound. His voyages also produced detailed charts of the Pacific and helped establish practices that reduced scurvy among sailors.

Bratislava, a capital on the Danube

Bratislava sits on the Danube and borders both Austria and Hungary, making it one of the few capitals that touches two other countries. It became the capital of independent Slovakia in 1993, after the peaceful split of Czechoslovakia. Ljubljana is the capital of Slovenia, while Prague is the capital of the Czech Republic, so these three cities are easy to mix up.