Whenever I inform a fellow scientist that my PhD was in the Philosophy of Physics, the reaction often takes the following form:
What's that? I didn't know you could have a philosophy of physics!
To explain the distinction between physics and philosophy of physics, my pat response has typically been along the following lines:
Well, most physicists want to use physics as a calculational instrument to explain, predict and control the physical world, whereas the philosophy of physics aspires to understand what the physical world actually is.
On reflection, however, this is slightly misleading, because the default instrumentalistic philosophy used by physicists, is itself a tenable interpretational position in the philosophy of physics, and many physicists also aspire to understand what the physical world actually is. Nevertheless, as a crass simplification of a blurred distinction, it works quite well. In fact, I purchased a book this week which highlights the dichotomy. The Standard Model: A Primer, by Cliff Burgess and Guy Moore, is a fine book, but it has to be said that it is very much the anti-book to The Structure and Interpretation of the Standard Model. If the two books were ever allowed to come into contact, they would mutually annihilate, releasing a humungous amount of energy.
The synopsis of the latter asserts that "Rather than presenting the calculational recipes favored in most treatments of the standard model, this text focuses upon the elegant mathematical structures and the foundational concepts of the standard model." In contrast, the synopsis for Burgess and Moore's book states that "The book concentrates on getting students to the level of being able to use this theory by doing real calculations."
Moreover, Burgess and Moore fail to acknowledge any distinction between the first-quantized and the second-quantized Standard Model. This is partially because of their desire to merely equip the reader with a calculational competency, but is also a reflection of a general neglect of this distinction within the physics literature. This is a huge loss to the field, because the second-quantized theory is incapable of representing interacting fields with anything else other than a so-called perturbational approach, which treats interactions as brief collisions between particles which approach the state of free particles to the past/future of the interaction. In contrast, the first-quantized Standard Model provides a tractable representation of interacting fields (albeit not an empirically adequate one), and the structure thereof. Derdzinski's 1992 text, The Geometry of the Standard Model of Elementary Particles, emphasised this point, and The Structure and Interpretation of the Standard Model is, in part, an attempt to publicise Derdzinski's approach.
Alas, I suspect that the message will continue to fall not so much upon deaf ears, as outside the audible range of the physics community.