måndag 19 augusti 2013
Quantum Contradictions 11: Theory vs Computation vs Observation
Quantum mechanics is based on an unhapppy marriage between theory and observation/measurement, with the observer necessarily affecting the observed. The wave function describing e.g. (the statistics of) of the atomic world, is thus supposed to dwell in an enormous Hilbert space beyond any comprehension and deliver a real observable as an eigenvalue of a Hermitian operator by a "collapse of the wave function" upon observation, as if the observer decides life or death of the Schrödinger cat in its box by merely opening the box and looking at the cat.
But there is a form of observation which can be done without interference with what is observed, and that is computing solutions to the equations describing the physics and thereby gaining information about the physics without so to speak having to open the box and look at the cat. In this form of computational physics observation is not restricted to eigenvalues of Hermitian operators, but can give complete information about the state of a system at a later time given the state at an initial time.
The computer thus opens new possibilities of exploring physics which were not available when quantum mechanics was formed 100 years ago and forced physics into a dead-lock with the physicist facing himself instead of physics.