Thermodynamics and Some Undecidable Physical Questions

It is shown that a number of questions, usually considered philosophical rather than scientific, can be reformulated to apply to a world of automata or “well-informed heat engines.” In some cases they admit of physical answers, but in many cases obtaining answers entails violation of the second law of thermodynamics. This is demonstrated explicitly for the problem of determinism and free will, for the discovery of the origin or ultimate fate of the universe, or for the discovery of causes or purposes in nature.