It’s an age old question. If it were possible to go back in time, where, and why, would you choose to go?
Throughout the ages the possibility of time travel has haunted people’s imagination. The idea recurs in literature, film scenarios and, today, it permeates BBC television’s highly successful series Doctor Who – the longest running science fiction show in the world according to The Guinness Book of Records.
Travelling forward in time is a theme of ancient folk tales and myths. The Mahabharata of ancient India tells the story of the King Revaita, who goes to heaven to meet the creator Brahma and discovers that many ages have passed when he returns to Earth.
The 8th century Japanese legend of Urashima Tarō recounts the tale of a young fisherman who rescues a turtle and is rewarded with a visit to the undersea palace of the Dragon God. He stays there for three days but, after returning to his village, finds himself 300 years in the future.
Washington Irving’s famous children’s story “Rip Van Winkle” (1819) is about a man who wanders into the mountains, drinks a potion and wakes up 20 years later. Some people think it’s a futuristic allegory of late-night abuse of Facebook.
Then there is backward time travel. In 1836 Alexander Veltman, one of the most successful Russian writers of his period and a pioneer of science fiction, published The Forebears of Kalimeros: Alexander Filipovich Macedon. Its narrator bizarrely rides to ancient Greece on a hippogriff, meets Aristotle, and goes on a voyage with Alexander the Great before returning to the 19th century.
Charles Dickens’ A Christmas Carol (1843) is thought to be one of the earliest depictions of time travel, as the main character, Ebenezer Scrooge, is transported to Christmas past, present, and yet to come. However, they are more visions than actual visits, since Scrooge only observes each episode and is forbidden to intervene.
Mark Twain’s A Connecticut Yankee in King Arthur’s Court (1889) is the tale of Hank Morgan, who sustains a head injury and wakes up under an oak tree near Camelot where a knight takes him to the nearby castle. Recognizing that he has travelled back to the 6th century, Hank realizes that his superior knowledge should enable him to take charge of the place.
In 1999 J. K. Rowling used time travel in Harry Potter and the Prisoner of Azkaban, when Harry and Hermione go back three hours into the past to save the life of his godfather, Sirius Black, as well as that of Buckbeak, yet another hippogriff.
Fiction has it easy. In the opinion of American physicist Michio Kaku, writing in Scientific American (24 November 2003):
“It would take a civilization far more advanced than ours, unbelievably advanced, to begin to manipulate negative energy to create gateways to the past. But if you could obtain large quantities of negative energy – and that’s a big ‘if’ – then you could create a time machine that apparently obeys Einstein’s equation and perhaps the laws of quantum theory.”
Of course, physicists are, by nature, optimistic. The improbability of time travel ever becoming a realistic proposition finds its antidote in the limitless bounds of human imagination. Where would you like to go?