Predictability or otherwise of an event is a property not so much of the event, as of the theory that is used for prediction. Unpredictable events can be considered to be `predictable unpredictables' if there is a theory that predicts the probabilities of their occurrence. Everything else is an unpredictable unpredictable, and these are the most challenging for physics. Guided by an analogy with undecidability in mathematical theories, I consider what kind of physical theory might be required in order to predict those fundamental parameters that in current theories are unpredictable unpredictables.
Robert Wilson