Sources of Quantum Mechanics

It's no wonder some might feel frustrated or discouraged reading the papers in this collection. Even though those papers were written several decades ago, they had been all forefront research papers then. Some papers should be difficult even for a physics major if one is not in the specific field; some are difficult because of the usage of "old-style" notations such as writing matrix equations in a certain way; still you may find a couple papers very much readable even with a minimal amount of training in mathematical skills.

...you're probably out of luck, because no seems to really understand Quantum Mechanics! However, understanding how these very strange concepts arose while physics was "under construction" in the early 20th Century is probably the best way to come to terms with it. This book seems to be the best thing to a "blow by blow" account of how different ideas emerged, were discussed, and were modified or rejected. It contains translations of many of the original (mostly German) key papers, along with a prefatory essay that places them in context. Reading these papers is much preferable to reading the typical brief history of QM presented in most text books: you can see what the pioneers were really thinking about, in their own words, as opposed to a retrospective point of view that ignores the ambiguities they actually faced. It begins with Einstein's derivation of the Planck spectral distribution law; includes Ehrenfest's discussion of adiabatic invariants; Bohr's final presentation of the old Quantum Theory; several papers on the theory of dispersion; and on to the development of matrix mechanics by Heisenberg, Born and Jordan; and Dirac's reformulation. It does not cover Schroedinger's development of wave mechanics, nor the derivation of the Dirac equation for the relativistic electron, nor quantum field theory. However, the period covered was the most paradigm-shattering part of the development of QM. Perhaps unfortunately, it is unlikely that the typical student of Physics will have the time to study this book. However, for those who really love Physics and want to understand it, this book is essential. With 17 major papers, it has enough material to occupy months of personal study.