Andy Murrayâ€™s unexpectedly strong start against Roger Federer in the Wimbledon 2012 final put the Daily Telegraph columnist Matthew Norman in a science-fiction mood. â€˜It seemed weâ€™d been transported to one of those parallel universes into which Doctor Who likes to slip with insouciant ease,â€™ he commented. A year later, that alternative world became reality, as Murray took the title, leaving journalists to apply the same familiar image to others. Contrasting Murray with the doubles champion Jonny Marray â€” who still rents a flat and drives a Ford Fiesta, despite holding a Grand Slam title â€” the Daily Mail opined: â€˜The stark reality is that the two champions, who share a passion for tennis, live and work in a parallel universe.â€™
Where did this idea of parallel universes come from? Science fiction is an obvious source: in the 1960s, Captain Kirk met his â€˜other selfâ€™ in a Star Trek episode called â€˜Mirror, Mirrorâ€™, while Philip K Dickâ€™s novel The Man in the High Castle (1963) imagined an alternate world in which the US was a Nazi puppet state. Since then, the idea has become mainstream, providing the image of forking paths in the romantic comedy Sliding Doors (1998), and the spine-chilling â€˜What if?â€™ in Philip Rothâ€™s novel The Plot Against America (2004), which envisaged the anti-Semitic aviator Charles Lindbergh defeating Roosevelt in 1940. But thereâ€™s also science fact. In 1935, Erwin SchrÃ¶dinger proposed his famous thought experiment involving a cat in a box whose life or death is connected to a quantum event, and in 1957 the American physicist Hugh Everett developed his â€˜many worldsâ€™ theory, which proposed that the act of opening SchrÃ¶dingerâ€™s box entailed a splitting of universes: one where the cat is alive, and another where it is dead.