As quantum theory celebrates its 100th birthday, spectacular successes are
mixed with outstanding puzzles and promises of new technologies. This
article reviews both the successes of quantum theory and the ongoing
debate about its consequences for issues ranging from quantum computation
to consciousness, parallel universes and the nature of physical reality.
We argue that modern experiments and the discovery of decoherence have
have shifted prevailing quantum inter- pretations away from wave function
collapse towards unitary physics, and discuss quantum processes in the
framework of a tripartite subject-object-environment decomposition. We
conclude with some speculations on the bigger picture and the search for a
uni_ed theory of quantum gravity.