An incompleteness theorem for physics

We show how Gödel's incompleteness theorems have an analog in quantum theory. Gödel's theorems imply endless opportunities for appending axioms to arithmetic, implicitly showing a role for an entity that writes axioms as logically undetermined strings of symbols. There is an analog of these theorems in physics, to do with the set of explanations of given evidence. We prove that the set of explanations of given evidence is uncountably infinite, thereby showing how contact between theory and experiment depends on activity beyond computation and measurement---a physical activity of logically undetermined symbol handling.