The submarine, designated O-12 in U.S. Naval lingo, measured in at 175 feet long. She was, even by the standards of the early 1930’s, not a particularly impressive sight, with a brief career spent meandering about the then-quiet Panama Canal Zone. Decommissioned on 17 June 1924, she was consigned to the Philadelphia Navy Yard to await scrapping. It was an unremarkable fate for a relatively unremarkable vessel, and were events indeed to play out in this particular fashion, it is doubtful the memory of O-12 would live on past some musty Naval archive. This early and rickety contraption for sailing beneath the waves was, however, destined for greater things, as she became the first machine to take humans past—or rather, beneath—one the last great unexplored frontiers the Earth has to offer.
The boat in question was a near-antique. Predating the American entry into World War I, she had been built in 1916 by the Lake Torpedo Boat Company of Bridgeport, Connecticut, designated with the hull number SS-73. Unexpectedly, her ultimate fate in the hands of Philadelphia’s scrappers was sidelined by an eccentric Australian gentleman, though it is safe to assume that no tears were shed in the U.S. Naval headquarters when he offered to take her off the Navy’s hands. O-12 was given a new, though ultimately brief, lease on life, in a journey that was to span the breadth of the Atlantic Ocean and past the rim of the Arctic Circle. It was an expedition that in the literal sense would go where no man had gone before, furthering the frontiers of science…while simultaneously threatening everyone involved with watery graves and financial ruin.
Before London taxi drivers are allowed to convey paying customers in their renowned black cabs, they must be ‘of good character’, in a reasonable state of physical health, and have spent, on average, about three years studying for a gruelling examination that tests their spatial awareness of all the city’s streets, shortcuts, and famous and not-so-famous landmarks and locations. This process extends well beyond remembering the basic street layout; candidates must be able to determine the shortest route between any two locations in the city, and may be asked to pinpoint one of around 25,000 different points of interest, or ‘points’, pieced together in a jigsaw-like series of 320 set routes, or ‘runs’, that crisscross the ancient capital. This body of learning is known as “The Knowledge of London”, or simply “The Knowledge”. Of those starting to learn the Knowledge, only 30% will eventually succeed in gaining It and passing the examination to become bona fide London cabbies.
Inevitably, the existence of over 20,000 heads so thoroughly stuffed with such a distinct pattern of learning proved irresistible to neuroscientists. In 2011, they used MRI imaging to inspect the brains of trainee London taxi drivers before and after Knowledge acquisition. They showed that one particular structure, the hippocampus— which is concerned with spatial memory and navigational ability— became measurably larger in individuals who had successfully attained the Knowledge and gained cabbie status. For many years, scientists believed such changes were impossible in adults, and that only foetuses and children could manage such brain-changing feats.