Modern Physics

How do we define "Modern Physics"? Can something that has its origins in the 19th century really be considered "modern"?  For our purposes, we are going to consider Modern Physics to be topics where the laws of Classical Physics are stretched to their breaking points.  On these pages, we will give a brief overview of Quantum Mechanics (the study of the behavior of the electron) and Nuclear Physics (the study of the behavior of just the nucleus of the atom.)  These are topics that continue to evolve as we learn more about our world and the fundamental particles and forces that make up everything.