Common sense tells us that two identical situations are going to have identical consequences for all eons. But it turns out that if we insignificantly modify one of them, over time the differences become very noticeable. This was proven by American meteorologist Edward Norton Lorenz in 1973 by omitting a few thousandths in a computer-simulated climate calculation; comparing those results against those of the real value he discovered that the model had changed markedly in a projection of only two months. He presented the calculations in a lecture entitled "Predictability, Can The Flutter of a Butterfly in Brazil Make a Tornado Appear in Texas?" , surely inspired by the Chinese proverb "The slight flutter of a butterfly's wings can be felt on the other side of the world". Or perhaps in Ray Bradbury's short story "The Sound as a Thunder," where a character travels back in time and accidentally kills a butterfly, to return to the present and find a totally changed world. Since then it has been called the "butterfly effect" to every small change that according to the chaos theory could bring enormous consequences in the future.
