I recently realized how odd it is that studying physics has never been able to hold my interest despite how interesting I find physics. I came to the conclusion that it is because I've always felt lost while studying physics. There are so many theories and it is hard to figure out how they all relate to each other. For example, it is rarely clear to me which theories describe high-level phenomena (e.g., thermodynamics) and which are currently considered fundamental (I don't know an example). Also, I am rarely sure of the context in which a theory holds.

I would love a resource that gives the important equations in physics in some logical order with a focus on the model in which the equation operates. It should describe the aspects of the real world that the model is capable of representing and those that it cannot. It should describe the mapping between the model and the real world. It should describe which models subsume other models and which equations derive from more fundamental equations. In the end, I would like to understand (or at least have some insight into):

  • which models and equations are currently accepted as the most fundamental,
  • the current state of the problem of finding a unifying theory, and
  • which real-world phenomena have yet to be captured by any model/equation.

So, I'm basically looking for a mathematical road map of physics so that I can orient myself before learning more in depth about specific topics. Does such a resource exist?

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    $\begingroup$ There are no "equations of physics". The order in which one would say things are more "fundamental" and more "derived" is not the order in which one should learn them, and often the more "fundamental" things are not needed at all for the "coarser" stuff. It is also heavily opinion-based what "most fundamental" even means. Do you think that if there were such a resource as you describe, there would still be hundreds upon hundreds of books on tiny subsets of physics? $\endgroup$ – ACuriousMind Nov 13 '14 at 17:31
  • $\begingroup$ @ACuriousMind: I'm looking for a map of the subsets of physics, not a map of THE physics. $\endgroup$ – Bryan Nov 13 '14 at 18:05
  • $\begingroup$ @KyleKanos: I'm hoping for a specific technical resource to be used as a reference. If someone asked for a map of the world, you wouldn't hand them a geography textbook. $\endgroup$ – Bryan Nov 13 '14 at 18:11
  • $\begingroup$ @Bryan: But if someone weren't asking for simply a map, but information on the demographics and resources of the nations in the world, a geography textbook would be the best gesture. Here, you are not simply asking for a map of physics, you are asking for a detailed layout of the differing subsets of physics. Therefore, a textbook is your best bet. $\endgroup$ – Kyle Kanos Nov 13 '14 at 18:13
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    $\begingroup$ Your request is unreasonable, it's as simple as that. Your map analogy fails miserably because maps are not complicated to the point where you'd have to study 10+ years to understand what even ONE of the countries really looks like (on the map). Do you understand what we're getting at? $\endgroup$ – Danu Nov 13 '14 at 18:15