So its my fault you don't show enough understanding to be worth explaining high level topics to? Its my fault you appear to have no interest in honest back and fore discussions? Rpenner made a comment earlier in the thread about you not engaging in actual discussion and I agree with him. Attempts to engage in discussion of the details ends up with you saying something wrong, someone correcting you, you complaining and then the thread never recovers because you have to have the point reiterated 10 times, from multiple people. Okay, if you want an actual discussion lets first gauge the appropriate level of any answer. Do you know what a Hamiltonian is? A Lagrangian? Can you go between them? Do you know how they relate to things like the Dirac equation or the Einstein field equations? Are you able to do variational methods (actually do, not quote the Wiki definition)? Are you familiar with functional analysis in any way? To what level of linear algebra are you comfortable with? To what level of calculus are you comfortable with? When answering "to what level" please give examples of things you are comfortable with. Once we nail down what you do and don't know we can start filling in the gaps of what you don't know. If you are honest and forthcoming then I'm willing to be pleasant and jolly. Start bullshitting then don't expect a hug from me.