section_path: Physics and determinacy
section_name: Physics and determinacy
paragraph_text: Physics and determinacy
  
  The existence of information about a closed system is a major concept in both classical physics and quantum mechanics, encompassing the ability, real or theoretical, of an agent to predict the future state of a system based on knowledge gathered during its past and present. Determinism is a philosophical theory holding that causal determination can predict all future events, positing a fully predictable universe described by classical physicist Pierre-Simon Laplace as " the effect of its past and the cause of its future ".
  
  Quantum physics instead encodes information as a wave function, which prevents observers from directly identifying all of its possible measurements. Prior to the publication of Bell's theorem, determinists reconciled with this behavior using hidden variable theories, which argued that the information necessary to predict the future of a function must exist, even if it is not accessible for humans; A view surmised by Albert Einstein with the assertion that " God does not play dice ".
  
  Modern astronomy cites the mechanical sense of information in the black hole information paradox, positing that, because the complete evaporation of a black hole into Hawking radiation leaves nothing except an expanding cloud of homogeneous particles, this results in the irrecoverability of any information about the matter to have originally crossed the event horizon, violating both classical and quantum assertions against the ability to destroy information.