THE BUTTERFLY
Evan Treborn can travel in time. Specifically he can travel back in time when he reads from the journal he kept in his childhood. This puts him right back in the specific moment again. But: whenever he varies his behaviour »the second time around«, no matter how slightly, the effects on his current present are far reaching. Evan will suddenly re-emerge not at college but in prison for murder or find that both his hands have been amputated. This, in short, is what the 2004 film »The Butterfly Effect« starring Ashton Kutcher and Amy Smart is about. It explores the eponymous concept from chaos theory, a field of study on the intersection of mathematics and physics in which outcomes in dynamical systems cannot be determined despite the fact that their behaviour can be predicted. The Butterfly Effect describes a tiny change within a system which can lead to a surprising and completely unexpected outcome. This is best illustrated by the question that gave the effect its popular name:
»Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?« – The title of a lecture Edward Norton Lorenz gave to the American Association For The Advancement Of Science in 1972. Lorenz had studied mathematics and then served as a meteorologist for the United States Army Air Corps during World War II. Upon his return he decided to study meteorology and later held a professorship in the field at the renowned MIT in Cambridge, Massachusetts. In the 1960s he pioneered computer simulation in meteorology so as to better be able to predict certain weather phenomena. One day Lorenz performed a calculation involving the value 0.506127. When he set up a second round of computations he – trying to save time as well as then very expensive processing power on the calculator – entered 0.506 as the base value instead. Despite the seemingly minor change in value created by the omission of a few decimal places the calculation yielded vastly different results. It led Lorenz to the (correct) conclusion that the weather beco-
Issue 18 | April 2015
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