Books on Amazon
Theoretical Entities/Unobservable/Mathematics/Physics/Field: are theoretical entities like electrons justified by the same methodology as mathematical entities (numbers, etc.)? - Quine-Putnam argument: many physical theories require fixation on numbers, but functions, etc. not on electrons. - Stronger: Electrons cannot be accepted without mathematics - N.B.: one could not say that the best explanations involving mathematical entities are weaker than those involving electrons, because the explanations would be the same.
Theoretical terms/TT/Observation/Observation rates/Ontology/Physics/Field: a theory which is assuming e.g. subatomic particles can be observing-wise equivalent to one which does not assume it. - That is, the theoretical entities can be eliminated for observation sets. Then the theory has less explanatory power. - Mathematical entities: are not so easy to eliminate.
Theoretical Entities/Physics/Unobservable/TT/Utility/Field: play a role in strong theories from which we can derive a large number of phenomena. - ((s) Phenomena, predictions, observations: are derivable from physical entities, not from mathematical entities).
A theory without e.g. subatomic particles: would not have simple principles. If a theory without theoretical entities produced the same consequences as one with theoretical entities, this theory could never be tested.
Theoretical Entities/Field: Theories about nobservable things are certainly not conservative. They lead to real new conclusions about observable things. - Unlike theories with mathematical entities. - Mathematical entities are true-maintaining within nominalistic inferences.
Realism, Mathematics and Modality Oxford New York 1989
Truth and the Absence of Fact Oxford New York 2001
Science without numbers Princeton New Jersey 1980