section_path: Scientific approaches/Quantum physics
section_name: Quantum physics
paragraph_text: Quantum physics
  
  Early scientific thought often portrayed the universe as deterministic – for example in the thought of Democritus or the Cārvākans – and some thinkers claimed that the simple process of gathering sufficient information would allow them to predict future events with perfect accuracy. Modern science, on the other hand, is a mixture of deterministic and stochastic theories. Quantum mechanics predicts events only in terms of probabilities, casting doubt on whether the universe is deterministic at all, although evolution of the universal state vector is completely deterministic. Current physical theories cannot resolve the question of whether determinism is true of the world, being very far from a potential theory of everything, and open to many different interpretations.
  
  Assuming that an indeterministic interpretation of quantum mechanics is correct, one may still object that such indeterminism is for all practical purposes confined to microscopic phenomena. This is not always the case: many macroscopic phenomena are based on quantum effects. For instance, some hardware random number generators work by amplifying quantum effects into practically usable signals. A more significant question is whether the indeterminism of quantum mechanics allows for the traditional idea of free will (based on a perception of free will). If a person's action is, however, only a result of complete quantum randomness, mental processes as experienced have no influence on the probabilistic outcomes (such as volition). According to many interpretations, indeterminism enables free will to exist, while others assert the opposite (because the action was not controllable by the physical being who claims to possess the free will).