“ Schrödinger and Heisenberg independently uncovered dual descriptions of particles and atoms. Later, the theories proved equivalent. Then in 1926 Heisenberg’s previous advisor, Max Born, discovered why no one had found a physical interpretation for Schrödinger’s wave function. They are not physical waves at all; rather the wave function includes all the possible states of a system. Before a measurement those states exist in superposition, wherein every possible outcome is described at the same time. Superposition is one of the defining qualities of quantum mechanics and implies that individual events cannot be predicted; only the probability of an experimental outcome can be derived.
— The Reality Tests [an article on the implications of quantum fysics] http://www.seedmagazine.com/news/2008/06/the_reality_tests_1.php?page=3
